WO2005074662A2

WO2005074662A2 - A centrifuge apparatus and system, and method for operating the same

Info

Publication number: WO2005074662A2
Application number: PCT/US2005/004847
Authority: WO
Inventors: Gabor Lederer
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-01-30
Filing date: 2005-01-31
Publication date: 2005-08-18
Anticipated expiration: 2006-07-30
Also published as: WO2005074662A3

Abstract

A centrifuge system (100) includes a drive motor (5, 150) mounted independently relative to a sample carrier (10, 202) to eliminate detrimental forces born by a motor drive shaft. The sample carrier includes a rotating center operably connected to the drive motor. The drive motor cooperates with a resilient mounting system (4, 259) enabling self-centering, force and vibration compensation, and improving motor life. In a selected embodiment, the sample carrier and a tube member (203) provide respective operably cooperable contoured surfaces enabling relative smooth pivoting motion during use, minimizing sample vibration, and improving a desired sample separation while minimizing sample remixing. In other selected embodiments an air management system (300) enables motor cooling and minimizes specimen heating.

Description

A CENTRIFUGE APPARATUS AND SYSTEM, AND METHOD FOR OPERATING THE SAME

PRIOR RELATED APPLICATIONS

This application claims priory from provisional patent application US Ser. No. 60/540,550 filed January 30, 2004, and incorporates the provisional patent application in its entirety by reference thereto.

BACKGROUND OF THE INVENTION

1. Field of the Invention methods for using the same. More particularly, this invention relates to centrifuges useful for separating or treating chemical, biological, or biomedical materials. More particularly, this invention relates to apparatuses and methods for breaking up or subdividing flowable materials into two or more components by utilizing a rotatable carrier and subjecting the material to forces.

2. Description of the Related Art

Centrifuges are versatile and relatively lightweight machines, which can be used for routine bench-top separation work, particularly in laboratories or physicians' offices In general, centrifuges provide fast separation and high process rates for materials of different densities like blood or urine by using relatively high rotational speeds and a rotatable carrier that holds sample tubes at a fixed angle (generally 45 degrees) during rotation. Often an electro/mechanical escapement timer is provided for a simple shutdown after a set run-time. As noted, a common application for bench-top centrifuges is to separate blood components for various lab tests. Centrifuges have been used in the medical and pharmaceutical industries for quite some time to separate materials of different specific weights. In many cases, barrier gels are used to maintain the separation of the separated materials or sometimes only their specific weight differences maintain separation in a sample tube. Conventional centrifuges usually have common structural features. In general, laboratory or bench centrifuges are mounted so that the vertically disposal drive spindle supports a rotatable assembly carrying the sample tubes. At high rpm, the spindle would be subject to vibration and flexure, with concomitant adverse resultant forces applied to the flowable sample material. Such vibration and flexure causes damage or distortion in and to the drive spindle and motor. Typically the electric motor drive has a drive shaft or spindle that is hard mounted to an angular cone or fork-shaped rotating carrier tray that holds several sample holders. Examples of conventional bench-top centrifuges are the CFVI line of centrifuges manufactured by Cygnus, Inc. Each CFVI centrifuge comprises a high strength, flame-retardant molded ABS plastic housing, which rests on four non-suction thermoplastic rubber feet. A shaded pole, thermally protected motor is mounted to the housing with steel reinforced braces, which provides a low and stable center of gravity for the centrifuge. A rotor head is provided that is made of high-impact ABS and is attached to the motor shaft be a spline and retaining screw. The rotor head is adapted to hold up to six tubes. The rotor head is angled, sealed, low noise, and has low air-resistance. A high-impact polycarbonate, clear cover encloses the sealed rotor head. The centrifuge comprises a safety interlock that allows rotation of the rotor head only when the cover is closed and latched. An electronic timer linked to a motor control circuit provides timed spin cycles. A similar related art bench top centrifuge is the Becton Dictson ADAMS® Compact II Centrifuge that incorporates a fully adjustable hand timer and cover with operations at relatively high speeds up to 3400 rpm. This design includes an angled rotor design holding tubes at 37 degrees off the vertical. A further related art bench top centrifuge is the Horizon Mini E® model, which includes a hand timer and holds sample tubes at a 45 degree angle. It is also common in related art centrifuges to cause the sample tube with flowable material (e.g. blood) to pivot upwardly with increasing rpm and comconmitant centrifugal force. Conventional pivoting mechanism often gripped only the top portion of a sample tube and do not prevent lateral jiggling. The pivot mechanism or structure often imported ragged and jerky movements to the tube resulting in undesirable remixing and less than desired control ofthe material flow in the tube undergoing centrifugal forces. hi one example of a centrifuge tube assembly (US 6,835,353), the contents of which are fully incorporated by reference, a tube assembly includes an elongated or sloped tube bottom and a cap having a pair of ports for communication with an interior of the tube. One of the ports is centered over the elongated tube bottom allowing sampling at the center-bottom of the sample tube post-centrifuging. This design attempts to compensate for sample remixing by allowing ready access to the likely least disturbed sample contents. As a consequence, an unanswered need exists to minimize remixing after centrifugation to increase specimen yield. In a patent related to one operable use of a centrifuge, (US 6,368,298), the contents of which are fully incorporated by reference, a centrifuge is employed in a process for concentrating blood plasma for the subsequent preparation of a autologous fibrin glue. As discussed in this related reference, a method for forming fibrin glue broadly includes the steps of separating plasma from a blood specimen, contacting the plasma with an activator and related coagulating substance, and centrifuging the plasma to form a fibrin-web. As discussed, a fibrin web is assistive in regenerating body tissue in a hving organism and is commonly produced in a clot small film having the diameter of the bottom of a common test tube. As disclosed, it is important to minimize shaking or other forces effective to cause intermixing between phases separated during centrifugation. Intermixing phases reduces the effectiveness of the system. Unfortunately, this disclosure fails to provide a supportive disclosure for minimizing intermixing. The disclosure also fails to provide a system for easily increasing a size of the fibrin membrane to a beneficial size or adaptive geometry, and similarly fails in providing a system for manufacturing custom shaped fibrin based membranes. Additionally noted in Grippi et al. (US 2004/0071786 Al), the contents of which are fully incorporated by reference, a method for preparing a solid-fibrin web includes a centrifuging step wherein concentric cylinders are employed to vary g-forces during operation. As required, a concentric container is centrifuged forming a generally uniform thickness fibrin film about an circumferential inner surface. The method disclosed requires separately removing the film (formed as a cylinder) by laterally slicing and pulling the formed material from the concentric container and then laying and sfretching the film on a flat surface. Unfortunately, this method involves applying thinning and stretching forces to the film that prove a detriment to process control. Thus, an unanswered need exists for providing a system that produces a readily accessible fibrin film as close to final-use form as possible to minimize product quality control concerns. As discussed in US 2004/0071786, a hydrophobic membrane is employed to substantially prevent an aqueous liquid, such as platelet-rich plasma, from flowing through its pores until a set hydrostatic pressure is reached. Examples of hydrophobic membranes may include, but should not be limited to, polypropylene, polycarbonate, cellulose, polyethylene, TEFLON® of Dupont and combinations thereof. Other examples of hydrophobic membranes include Millipore®. membranes and screens manufactured by Millipore, or Nucleopore®. membranes and screens manufactured by Nucleopore®. Alternatively, a plastic diaphragm having precision holes drilled therein with a laser could also be used. When using a hydrophobic membrane, blood may be introduced into a cell-separation chamber, but will not fall into a densification chamber defined via the membrane. A proper hydrostatic pressure must be achieved by first separating the red blood cells from the plasma at a low rpm. Subsequently, the rate of centrifugation is increased to achieve the desired pressure to overcome the surface energy/surface tension constraints that define the flow pressure. In other words, the gravitational force will increase with the rate of centrifugation, which will result in the platelet-rich plasma flowing through the hydrophobic membrane, but not the red blood cells. The membrane will substantially block the red blood cells. Another modification to the above systems includes changing the configuration of a secondary or modified densification chamber as disclosed. As required in the disclosure, the modified densification chambers may be used in systems, wherein the primary and secondary chambers have the same or different radii, wherein the chambers are concentric, and/or wherein a separating medium or hydrophobic membrane is used. The densification chambers may have different interior walls that facilitate the removal of the membrane, and ensure the greatest recovery of the membrane, but all are cylindrical in nature. For instance, as disclosed a densification chamber may contain a woven biodegradable fabric (such as Goretex®, manufactured by Goretex) that improves the tear strength of the membrane for initial placement in the body, and that will later dissolve. The outer wall ofthe cylindrical chamber may also contain molded bumps or grooves that support the fabric away from the cylindrical wall at a uniform length to achieve a fibrin and platelet thickness of desired dimension on both sides ofthe fabric. As also discussed, typical g forces used to effect plasma cell separation may range from 200 to 15,000g, and more commonly in the 1,000 to 10,000g range, depending upon the geometry of the centrifuge employed, for a predetermined time, typically greater than 5 to 15 minutes. These forces are necessary to force separation for fibrin production. Unfortunately, this reference fails to aid the production of fibrin products by either increasing volume, or decreasing processing time and limiting damaging operable vibrations. This disclosure also fails to increase production in convenient shapes and sizes for use, without employing complicated post centrifuge separation and unrolling processing steps. Thus, a need exists for an improved fibrin product manufacturing system, at reduced times and in increased volumes without reducing quality. Advances in the Human Genome Project have demanded innovative solutions to sample preparation in the ever changing landscape of molecular labeling and manipulation, gene mapping, gene expression, amplification, DNA sequencing and proteomics. Sample preparation has often been a bottleneck to the analysis of complex biological materials, especially in high throughput automated applications employing multiple sample sets such as genotyping and DNA sequencing. In view of the above difficulties in the conventional arts; solutions are needed in the centrifuge and biomedical centrifuge arts that avoid, minimize, or eliminate at least one of the aforesaid concerns problems attendant conventional vertically designated drive spindle supported sample tube carriers. It is also desirable to provide a centrifuge having simpler controlled tube pivot and resultant centrifugal lines particularly at high speeds. It is further desirable to provide a self-containing and self-calibrating centrifuge. It is still firrther desired to provide a centrifuge with improved airflow characteristics. Finally, it is still further desired to provide a centrifuge that was particularly suited to treat or form alternative biological or biomedical materials.

OBJECTS AND SUMMARY OF THE INVENTION

Noting the detriments of previously known constructions, it is therefore a principal desire of the present invention to provide an improved centrifuge addressing at least one ofthe listed detriments and concerns. In servicing the need and desire for an improved centrifuge, it is another alternative and optional desire of the present invention to provide a centrifuge with an improved drive and mounting system, which minimizes the adverse drive spindle characteristics noted above. It is another alternative desire of the present invention to provide a centrifuge that aids self-centering in both vertical and horizontal perturbations. It is another alternative desire of the present invention to provide a centrifuge that lowers a center of rotational gravity to improve safety and reduce vibration. It is another alternative desire of the present invention to provide a centrifuge with improved drive characteristics. It is another alternative desire of the present inventions to provide a centrifuge that is. easily programmable, may be reprogrammed in situ, and is self- calibrating. It is another alternative desire of the present invention to provide a centrifuge with improved airflow characteristics and a thermal management system to minimize thermal detriment to the motor and specimens. It is another alternative desire ofthe present volume to minimize specimen warming during use, or by introduction into an atmosphere warmed by previous repeated use. It is another alternative desire of the present invention to provide a centrifuge system wherein a pivoting motion of a sample holder is consistently smooth and uniform. It is another alternative desire of the present invention to provide a specialized housing for a sample holder. It is another alternative desire of the present invention to provide a centrifuge that is readily adapted for diverse centrifuge methods of treatments, convenient formation of biological or biomedical materials at improved volumes, and adaptation to a variety of adaptive uses. It is another alternative desire of the present invention to enable a production system for manufacturing biological products, including optional near- net shapes and increased sizes, while minimizing post forming production steps. It is another alternative desire of the present invention to provide a centrifuge system that has an improved design and a comprehensive electronic operation system while providing increased safety and ready adaptation across a diverse range of operational use. The present invention relates to a centrifuge system including a drive motor mounted independently relative to a sample carrier that minimizes detrimental forces born by a motor drive shaft. The sample carrier includes a rotating center operably connected to the drive motor. The drive motor cooperates with a resilient mounting system aiding self-centering, force and vibration compensation, and improving motor life. In a selected embodiment, the sample carrier and a tube member provide respective operably cooperable contoured surfaces enabling relative smooth pivoting motion during use, minimizing sample vibration, and improving a desired sample separation while minimizing sample remixing. In another selected embodiment, a thermal management and air flow system minimize thermal damage and thermal gradients during operation. According to an embodiment of the present invention there is provided a centrifuge assembly, comprising: a vertically mounted motor assembly; means for mounting said motor assembly on a first mounting assembly proximate a first distance from a support surface; a rotatable carrier assembly; means for rotatably mounting said rotatable carrier assembly on a second mounting assembly proximate a second distance from said support surface; said first distance being larger than said second distance, and means for operably connecting said motor assembly to said rotatable carrier assembly enabling a driving rotation during a use, whereby said motor assembly and said rotatable carrier are independently mounted and operably connected. The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conduction with the accompanying drawings, in which like reference numerals designate the same elements. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a front open perspective view of one embodiment ofthe present invention. Fig. 1 A is a front closed perspective view ofthe embodiment of Fig. 1. Fig. IB is a bottom view ofthe embodiment shown in Fig. 1. Fig. IC is a rear view ofthe embodiment shown in Fig. 1. Fig. ID is a partial side sectional view of a centrifuge assembly according to another embodiment ofthe present invention. Fig. 2 is a side sectional view of the embodiment shown in Fig. ID with an alternative housing assembly. Fig. 3 is a first embodiment of a locking mechanism for a cover lid according to the present invention. Fig. 4 is a cross sectional view ofthe embodiment o the present invention shown in Fig. 1 depicting at least a partial air flow path during operation. Fig. 5 is a perspective view of a sample carrier and mount noting specimen holder rotation during use according to one embodiment ofthe present invention. Fig. 5A is a top perspective view of a sample carrier or sample tray according to one embodiment ofthe present invention. Fig. 5B is a bottom view of Fig. 5 A. Fig. 5C is atop view of Fig. 5 A. Fig. 5D is a cross-sectional view along line 5D-5D in Fig. 5C. Fig. 5E is a perspective view of a motor housing and sample support member according to one embodiment ofthe present invention. Fig. 5F is a top view of Fig. 5E. Fig. 5G is a cross-sectional view along line 5G-5G in Fig. 5F. Fig. 6A is a perspective view of an arrangement of a sample carrier or tray on a sample support according to one embodiment ofthe present invention. Fig. 6B is another adaptive embodiment of a sample carrier or support arrangement according to another embodiment ofthe present invention. Fig. 6C is another adaptive embodiment of a sample carrier or support arrangement enabling film formation within a sample holder or within a removable carrier apparatus, according to another embodiment of the present invention. Fig. 6D is another adaptive embodiment of the present invention combining a film formation capacity with an alternative sample support capacity. Fig. 6E is another adaptive embodiment ofthe present invention providing a pivoting sample capacity for centrifuging a plurality of individual pipette-type samples maintained with contained and optionally removable multiple-sample housing members while rm^'nimizing sample remixing. Fig. 7 is a cross sectional view of a motor assembly with an adaptive drive shaft assembly and motion compensation assembly according to one embodiment ofthe present invention. Fig. 7A is an expanded view of a drive shaft-housing interface, as shown in Fig. 7. Fig. 7B is an expanded view of a motor mount assembly enabling lateral and vertical compensation, as shown in Fig. 7. Fig. 8A is a bottom perspective view of a motor assembly according to one embodiment ofthe present invention. Fig. 8B is a top perspective view ofthe motor assembly shown in Fig. 8 A. Fig. 9A is a top perspective view of an air rotor and support according to one embodiment ofthe present invention. Fig. 9B is a bottom view of Fig. 9A depicting one embodiment of a rotational marking display. Fig. 10 is an exploded assembly of one embodiment of the present invention including a motor cover, motor assembly and sample support. Fig. 11 is a perspective view of an alternative electromechanical lid lock assembly according to one embodiment ofthe present invention. Fig. 12 is a top perspective view of a sample holder according to one embodiment ofthe present invention. Fig. 12A is a cross-sectional view along line 12A-12A in Fig. 12 inclosing an additional sample tube and cap. Fig. 12B is a cross-sectional view of an alternative embodiment of a sample holder providing a flat bottom for adaptive centrifugation. Fig. 13 is an illustrative power supply layout according to one suggested and alternative embodiment ofthe present invention linking a lid lock circuit, a motor control circuit, and an initial power supply circuit. Fig. 14 is an illustrative assembly of various control circuits for an input/display/control assembly according to an alternative embodiment of the present invention, wherein the assembly depicts illustrative assemblies of various microprocessor controls, their circuits, and displays.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are to be understood as being in simplified form and are not to a precise scale or perspective. For purposes of convenience and clarity only, directional terms, such as top, bottom, up, down, over, above, and below may be used with respect to the drawings. Similarly, directional markings including arrows or dashed alternative position lines may depict motion or action. These and similar directional terms and indicators should not be construed to limit the scope of the invention in any manner. The words "connect," "couple," "support," and similar terms with their inflectional morphemes do not necessarily denote direct and immediate connections, but also include connections through mediate elements or devices. Regarding one embodiment of the present invention, a brief summary provides a centrifuge system having a motor that is independently mounted from the rotatable carrier or assembly or motor cover. The rotating motor cover includes its own independent rotating center, and its own bearing independent from the motors and separates the motor from a surrounding chamber. The motion or drive shaft or spindle does not bear the weight ofthe rotatable assembly and functions to substantially lower a center of gravity. The rotatable assembly comprises its own independent rotating center, preferably with a ball bearing assembly. The rotatable assembly is connected to the motor by a flexible coupling assembly, which allows easy changes between a wide variety of motor selections and sample holders for the different centrifugation tasks without necessitating a change in other parts ofthe device. The flexible coupling assembly also extends the lifetime of the motor and its bearings and enables a reduction in standard motor size for a speed due to the weight-bearing reduction. The motor is positioned on a pedestal assembly or motor holding assembly, which includes a wave spring which bears the weight of the drive motor while allowing adaptive flexibility during use, as will be discussed. The pedestal assembly or motor holding assembly serves several functions, including; supporting the motor, providing a rotational center (i.e., a ball bearing) to carry an independent rotatable carrier assembly, and integrate an impeller mechanism for providing a beneficial airflow to cool the motor and enhance a thermal management system capable of transporting warmed air away from the motor and specimens to minimize thermal impact. The centrifuge motor is mounted on the pedestal assembly in a way that allows the motor assembly to self-align so the independent motor cover bearing and the motor shaft align themselves during use. As noted, an additional benefit to the present invention is a substantially lowered center of gravity, i conventional designs, sample trays or holders were positioned at the top of a drive motor. In the present design, the rotatable carrier assembly ensures that specimen holding units are substantially below the top of the drive motor, often at a bottom one-third of the drive motor. As a consequence, the present invention provides a substantially lowered center of gravity and, in turn, this increases safety, minimizes vibration, and reduces motor stress. Aspects of the present invention also provide an adaptive housing assembly that enhances many functions, including: providing a cover for the rotatable carrier assembly to control or minimize undesirable air resistance and improve thermal management while simultaneously improving operator safety. Referring now to Figs. 1, 1A, IB, IC, and 4, in one embodiment of the present invention a centrifuge assembly 100 combines a plurality of sub- assemblies including at least a housing assembly 101, a motor assembly 150, a rotatable carrier assembly 200, and an electronics assembly 250. Electronics assembly 250 has no particular design or casing and is visually represented by reference numerals 250 in Fig. 1, but may be positioned anywhere within centrifuge assembly 100 according to a manufacturer's design and component requirements. The electronics assembly 250 is equipped with electronics that provide digital readout, time setting, rpm indication and others. The electronics assembly 250 is also equipped with electronic rpm control for AC and DC type motors, an unbalance indication, an emergency stop circuit, a total cycle count indicator, and a self-calibrating feature. Housing assembly 101 includes a lid or cover assembly 102 pivotably joined to a base assembly 103 spaced from a supporting surface (not shown) by a plurality of supporting leg members 104. Housing assembly 101 serves to operably contain, and support the entire centrifuge assembly 100, as will be described. Base assembly 103 includes a front portion 105 with a display unit 106 operating as one of an analog and a digital display unit. In preferred embodiments, display unit 106 may be a digital LCD (Liquid Crystal Display) or LED (Light Emitting Diode)display, or a combination of both depending upon a manufacturer's preference. Digital displays are preferred with the present embodiment of electronics assembly 250 as being easily interfaced with the incorporated electronic assembly 250, but nothing herein shall prevent the use of analog displays in concert with controlling electronics. Those skilled in the art of circuit and electronic equipment design will recognize that additional display areas may be provided on base assembly 103, and even on cover assembly 102, depending upon a manufacturer's desire without departing from the scope ofthe present discussion. Process control input regions 107 allow an easy touch-interface with electronics assembly 250 contained within housing assembly 101, as will be described. As shown, input regions 107 allow operation of preferably a speed/time increase, a speed/time decrease, on/off, timer set, lock and unlock functions, and many others as may be suggested by a manufacturer. Housing assembly 101 includes an optional cover locking and release assembly 108 including electromechanical locking and release mechanisms 20A (Fig. 3), 20B (Fig. 11), cover latch mechanism 108A, and hinge assembly 108B. As will be described below, cover locking and release assembly 108 includes a cover-position sensor (not shown), enabling electronics assembly 250 to determine whether or not cover assembly 102 is secured to base assembly 103. As will also be described, cover locking and release assembly 108 includes a capacity to securely lock cover 102 to base assembly 103 during use for increased safety, and to prevent opening while motor assembly 150 is spinning. Cover assembly 102 and base assembly 103 of housing assembly 101 may be constructed from any suitable material including metals and plastics or combinations ofthe same. In one preferred embodiment, cover assembly 102 and base assembly 103 are constructed from high strength non-metals including plastic, nylon, acrylic or other materials useful in forming a strong, tough, and reasonably light body. Since centrifuge assembly 100 operates at high speeds, RPM's as high as 3700, housing assembly 101 should be constructed to contain debris during equipment breakdowns and protect operators. A bottom base plate 1, 109 is provided for supporting housing assembly 101, and is typically constructed from metal for rigidity, strength, and disability. Base plates 1, 109, while preferably constructed from metal may alternatively be constructed from any suitable material. Base plates 1, 109 are securely joined with base assembly 103 and serve to contain the internal assemblies during use and transport. Base plates 1, 109 may include vent openings 110 to ensure electronics assembly 250 and the other assemblies are able to remain cool during operation. Optionally, a vent fan (not shown), may pierce housing assembly 101 to flush warm air during repeated use to improve quality control by keeping electronics assembly 250 cool, mirώnize thermal variability, and n inimize thermal strain on all the internal components. In another embodiment, base plates 1, 109 may be pressure-sealed with housing assembly 101, enabling the use of a selected partial pressure atmosphere (Ag, N2, etc.) within centrifuge assembly 100 to support selected experimental uses. As will be discussed more fully below, the present embodiment provides a hollow tube with a ventilation aperture 1A that pierces base plates 1, 109 proximate a center of centrifuge assembly 100. A speed or rotation sensor 111 is positioned in base plates 1, 109 proximate a pattern or image 112 display (see Fig. 9B) to enable rpm sensing during use, as will be described. Housing assembly 101 and centrifuge assembly 100 also contain a thermal management and air moving system, shown generally at 300 for cooling motor assembly 150 during use, and limiting sample thermal buildup during operation, as will be described. Thermal management system 300 includes a chamber member 301 defining a bounded region within housing assembly 101 for separating motor assembly 150 and rotatable carrier assembly 200 from the remaining interior area of housing assembly 101, as shown best in Fig. 4. As best seen in Figs. 1 and 4, an air shield 302 covers a top portion of chamber member 301, is in a closely spaced position with an outer surface of a portion of rotatable carrier assembly 200, and functions to operably separate chamber member 301 from an external atmosphere during operation. Air shield 302 is removable for easy replacement and simple access to chamber member 301. During operation, when lid or cover assembly 102 is closed, a sealing lip 303 contacts portions of air shield 302 and serves to minimize air disturbance of rotatable carrier assembly 200 during use while aiding air and thermal management system 300. As shown, one or more cover stabilizers and air sealers 102A serve to stabilize cover assembly 102 in a lid-closed position. Select ones of cover stabilizers and air stabilizers 102A are positioned proximate hinge assembly 108 and aid-cooling airflow, as will be described. During operation, thermal management system 300 enables air flow represented by Arrows Y in Fig. 4, to develop as air is drawn in through ventilation aperture 1A, passed through motor assembly 150 (as will be described) and through a plurality of air movement channels and openings 151 formed in an inner region of lid 102 proximate sealing lip 303. Air movement channels and openings 151 are in open communication with a plurality of rear air openings 304, formed in a rear portion of cover assembly 102 and in select rear ones of the plurality of cover stabilizers and air stabilizers 102 A. In this manner, air flow Arrows Y develop from bottom ventilation aperture 1A, serve to cool motor assembly 150 (as will be discussed), and ultimately exit the rear of housing assembly 101 via air openings 304 without detrimentally interfering with specimen holders, as will be described. One particular benefit of the present design is that thermal management system 300, in concert with air chamber member 301, air shield 302, and cover assembly 102, and other elements noted herein, serves to continuously introduce and distribute new cooling air via ventilation aperture 1A and evacuate warmed air at a rear of the unit. This system enables convenient thermal maintenance of motor assembly 150 while substantially minimizing interfering air currents under cover assembly 102 during use. By both minimizing perturbing air currents and providing simple thermal maintenance, the operable life of centrifuge assembly 100 is greatly improved, less strain is placed on motor assembly 150, and unit vibration is minimized improving sample quality and sample separation. One additional benefit provided by the present design, and the use of thermal management system 300 is that centrifugation specimens are subject to a lower thermal gradient. Thermal management system 300, and air shield 302 serve to substantially thermally separate a bottom (specimen region) of a sample tube (shown later) from a top portion of the sample tube/tube holder retained within rotatable carrier assembly 200. As will be understood by those skilled in the art, most specimens undergoing centrifugation are at a bottom of a specimen tube (to be introduced) and positioned within air chamber member 301 (below air shield 302), while the tops of the specimen tubes are retained below cover assembly 102 proximate air shield 302 (best sheen in Fig. 4) within the path ofthe now warmed air flow from motor assembly 150. As a consequence, the actual specimens are consistently maintained in a cooler operating region. Those skilled in the art will understand that the present design for thermal management system 300 separates the now-warmed-cooling air (after cooling motor assembly 150) from the atmosphere surrounding the ends of the specimen tubes/tube holder within air chamber 301. As a further consequence of the present design, each specimen is exposed to a substantially reduced thermal gradient, enabling an increased quality control and minimizing sample variation between individual runs. As a result, the present design manages air movement and provides a thermal management system to minimize detrimental thermal variability. It should be understood, that at high rpm, the un-shielded air within conventional centrifuges frequently cavitates and causes substantial vibration. With the present air management system 300 and structural design in mind, those skilled in the art will recognize that the air within chamber 301 (a defined air spinning chamber) shown by Arrows Z is perturbed only by the specimen holders/sample tubes (described later), and not by external airflow or cross currents. This allows the ready development of a senn-laminar or a laminar airflow within chamber 301 during use; further minimizing specimen exposure to vibration and thermal gradient It should be additionally understood, that additional air maintenance systems may be employed in combination with the present invention. These additional systems optionally include an air-pressure reduction system to reduce the atmospheric pressure within chamber 301 or under cover assembly 102 via an evacuation or vacuum system. The present invention may also be adapted to include an air maintenance system that also includes the use of cooled air transferred under pressure through ventilation aperture 1A to increase a cooling effect. These additional systems may also be adapted to supply a selected gas or gas combination to chamber member 301 during use to preserve a desired specimen atmosphere. Referring additionally to Figs. ID, 2, and 3, there is shown one alternative motor and rotatable carrier assembly according to one aspect of the present invention. In this embodiment, an alternative centrifuge assembly 100 A includes a drive motor assembly 5 disposed on a pedestal assembly comprising base plate

1, and is spaced apart from a motor plate 3 by a vertically-extending shaft member 2. Between motor assembly 5 and motor plate 3 is a vertically extending shift-able/flexible mounting element 4. A lid 14 covers centrifuge housing 14 and covers motor housing 7 and chamber member 301. Motor assembly 5 is seated directly on flexible mounting element 4. As noted above, ventilation aperture la is defined through base plate 1, shaft member

2, motor plate 3, and flexible mounting element 4. As described in further detail below, motor assembly 5 is constructed so that cooling air may enter through vents in its underside, driven by a supporting impeller mechanism 12A and exit through vents in its topside. Motor assembly 5 include may be any suitable motor. Preferably, for rotational speeds less than about 3500 to 3800 ipm, motor 5 is an A/C motor. Suitable A/C motors include asynchronous motors, synchronous motors, and shaded-pole motors. Alternatively, for rotational speeds more than about 3500 to 3800 rpm, motor 5 is preferably a D/C/ motor, which can be traditional or brushless. A motor shaft 5 a holds a flexible driving element 6, which is preferably a hexagonally-shaped block or nut. The flexible driving element 6 is connected to a rotatable carrier assembly, which comprises a motor housing 7 and a replaceable sample tray 10. Motor assembly 5, motor shaft 5 a, and flexible driving element 6 are disposed within housing 7. Space is provided between an inner surface of housing 7 and an outer surface of a motor to allow for airflow, as described in greater detail herein below. As illustrated in Fig. ID, housing 7 comprises an upper portion having an opening 7a adapted to receive flexible driving element 6. In addition, flexible driving element 6 preferably comprises a shoulder 6a that is wider than opening 7a so that flexible driving element 6 is prevented from passing completely through opening 7a. hi other words, housing 7 rests on the upper surface of shoulder 6a. To prevent motor 5 from rising off flexible mounting element 4 during operation, motor shaft 5a comprises a ledge 5b that abuts the lower surface of shoulder 6a. The weight of motor housing 7 is thusly transferred through shoulder 6a onto ledge 5b. Significantly, using the arrangement shown in Fig. ID, motor 5 is held in place during operation between flexible mounting element 4 and flexible driving element 6 without any additional mounting provision, such as screws, nuts, etc. Moreover, flexible mounting element 4 and flexible driving element 6 effectively suspended motor 5 so that vibrations created by motor 5 during its operation are not transmitted to motor housing 7. This improves motor life and specimen quality control. In this alternative embodiment, flexible mounting element 4 and flexible driving element 6 are preferably made of a flexible material (e.g., rubber), which can be natural or synthetic. Preferably, the flexible rubber used to make flexible mounting element 4 and flexible driving element 6 has a hardness of about 70 to about 80 shore. As noted, motor cover or housing 7 may be made of any suitable material by any suitable method. One preferred material for housing 7 is ABS plastic. A preferred method for making housing 7 is injection molding. In another embodiment, housing 7 may be formed from a metal. Motor cover assembly or motor cover housing 7 includes a lower portion, the inner surface of which is connected to an inwardly-extending air connecting plate 9. A connecting plate 9 comprises an inner edge that is supported on a rotatable bearing assembly 8, which is preferably a ball bearing. Rotatable bearing assembly 8 surrounds shaft 2. Thus, the lower portion of housing 7 is supported by rotatable bearing assembly 8, and motor 7 is substantially completely enclosed within removable housing 7. The size (i.e., the diameter) of bearing assembly 8 is determined by the size of shaft 2, which is primarily determined by a desired airflow required by motor 5. To maximize the potential airflow to motor 5, bearing assembly 8 is preferably a high-strength, large diameter ball bearing, even though housing 7 is relatively lightweight. Airflow within housing assembly or motor cover 7 is required to cool motor 5 during operation ofthe centrifuge. The inner surface ofthe upper portion of housing 7 is provided with a plurality of fixed vanes 7b, which create airflow wit in housing 7 when housing 7 is rotated by motor 5. Preferably, housing 7 comprises six vanes 7b, but any number of vanes may be provided on housing 7 or along the surfaces of housing 7. Upon rotation of housing 7, air initially within housing 7 is forced by vanes 7b through the space between housing 7 and motor 5. The flowing air passes out of housing 7 through vents provided in connecting plate 9. Concurrently, fresh air is pulled into motor 5 through shaft 2. Therefore, rotation of housing 7 provides an airflow that comes up into shaft 2, up through motor 5, down between housing 7 and motor 5, and finally out through connecting plate 9. In addition, to further enhance air flow within housing 7, flexible mounting element 4 may comprise a plurality of substantially vertical ribs 4a of impeller mechanism 12A adapted to create a laminar flow of air that encourages air to exit housing 7. The amount of airflow required by motor 5 depends on factors well known to those skilled in the art, such as the type and size of the motor, the required rotational speed, and the weight ofthe rotational carrier. In the present embodiment, a carrier tray assembly 10 is removably attached to motor housing cover 7 at its inner portion 10c to a medial shoulder portion 7c of housing 7. Tray 10 is adapted to receive a plurality of sample holders 11 having optional caps 12. Tray 10 comprises a plurality of hollowed or downwardly radially rounded receptacles 10a adapted to hold a respective number of elongated sample tube holders 11. A sample tube holder 11 adapted for use with tray 10 comprises a flared neck portion 11a having an outwardly rounded shape matching the downwardly rounded shape of rounded receptacles 10a. Thusfy, a sample tube holder 11 may freely pivot (cooperatively pivot) within tray 10, such that sample tube holder 11 will be substantially vertical before and after rotational operation of the centrifuge and substantially horizontal during rotation operation of the centrifuge, with smoothly pivoting operation there between. This present design may be referred to as a system or mechanism for cooperatively pivoting or smoothly pivoting a sample tube or sample tube holder relative to a sample holding tray. Preferably, each sample tube holder 11 comprises a flat bottom surface so as to be able to stand on its own, and protective cap 12 prevents air exposure of the sample if the sample tube therein is broken or if the specimen somehow climes the walls ofthe tube during centrifugation. As noted, cooperatively rounded receptacles 10a and sample tube holders

11 may be color coded for ease of use. For example, in order to facilitate quick and proper balancing of the centrifuge, opposing pairs of receptacles may be coded with the same color (or other indicia, not shown) so that a user can easily identify each opposing pair of receptacles. Accordingly, the user will not have to count the number of receptacles and or calculate which are the opposing receptacles. The user would simply place a sample tube holder in each of the same-colored (same indicia) receptacles, knowing that same-colored receptacles are opposing receptacles. This technique speeds operation and minimizes human enor. As noted above, in the present embodiment centrifuge assembly 100A includes centrifuge housing 13, which allows the rotatable carrier to rotate with a minimum of air friction. Housing 13 has a lid 14 adapted to provide access to the centrifuge assembly, while also preventing additional air entry to the chamber during rotational operation ofthe device. Recognizing that human error exists, and that centrifugation forces are substantial, lid 14 preferably engages an electromechanical locking mechanism 20A to secure lid 14 during the centrifugation process. A prefened locking mechanism for use in the present invention comprises two pins 15, each having a recess or groove 19. The respective grooves 19 of the respective pins 15 receive respective tines of a locking fork 16 when lid 14 is in a closed position. Preferably, pins 15 are mounted in housing 13, and locking fork 16 is mounted in lid 14. A spring 18 resiliently urges locking fork 16 into the grooves 19. When the centrifuge process is completed a solenoid 17 pulls locking fork 16 from grooves 19, thereby releasing lid 14. Those skilled in the art should recognized that solenoid 17 may be substituted with a manual releasing knob (not shown), either one being optionally interfaced with a variety of automatic motor breaking systems upon electronic notice of a lid-open condition, to minimize operator injury. The present system includes an electronic breaking system, not shown, capable of stopping rotating motion within approximately 20 seconds for improved user safety. Referring now to Figs. 5 through 5G, and Figs. 12A to 12C, rotatable carrier assembly 200 includes a motor cover or motor housing cover 201 (covering motor assembly 150), and a sample holding unit 202 of interchangeable design. As shown, sample holding unit 202 includes a plurality of openings 210 for pivotably receiving respective sample tube holders 203 having removable caps 204 for holding a sample tube 206 (shown in Fig. 12 A) having a replaceable and removable cap 204A opposite an external flat bottom support surface 205. As noted, flat bottom surface 205 allows sample tube holders 203 to stand upright on a surface for easy use and transport. When a sample tube 206 includes a rounded bottom, sample tube holder 203 may have a conesponding rounded bottom to distribute force equally during centrifugation. In optional embodiments, sample tube holders 203 may themselves be employed to hold specimens, as noted in Fig. 12B. hi this embodiment, an inner bottom surface of sample tube holder 203 is also flat or perpendicular to the long axis ofthe sample tube holder. As a consequence, small volumes of material may be centrifuged allowing segregation by mass with no remixing as will be discussed. Since the flat bottom provides a uniform support surface, small samples experience uniform separation. Since sample tube holder 203 has a flat bottom and stands upright, no separate support is needed, and a user may pipette a small sample from a bottom ofthe tube without remixing concern. Sample holding unit 202 rests on a lower portion 209 of motor cover or motor housing cover 201, and is easily and removably joined to the same via a plurality of joining threaded receptacles 211 by respective bolts (not shown). Threaded receptacles 211 formed in lower portion 209 are interspaced with openings 212 for removably fixing rotatable carrier assembly 200 to a bearing assembly as will be described (shown later). Sample holding unit 202 includes openings 211A conesponding to threaded receptacles 211. An upper portion 219 of motor cover or motor housing cover 210 protects and covers motor assembly 150 while enabling a smooth air-cooling path during operation, as will be described. Motor cover or motor housing cover 201 includes a plurality of venting openings 213 for removing warmed thermal air from an inside of motor housing cover 201 proximate motor assembly 150. Sample holding unit 202 includes a plurality of openings 214 for receiving respective sample tube holders 203, as shown. An outer perimeter 202A, of sample holding unit 202, is cylindraceous and is in close position with an inner edge surface of air shield 302 as shown in Fig. 1. Outer perimeter 202A has a greater thickness than an inner perimeter 202B of sample holding unit. Openings 214 provide geometries denoting respective first vertical axis

215 openings coincident with a vertical axis of respective sample tube holder 203 vertically positioned within openings 214 in a stopped condition. Openings 214 have a second horizontal axis 216 opening coincident the axis of sample tube holder 203 in a horizontal position in a run position. During operation, sample tube holders 203 operably pivot from the vertical position to the horizontal position through an arc 217, as shown under the centrifugal forces apphed by motor assembly 150. Openings 214 include a continuous smooth pivoting transition surface 218 between each axis 215, 216 position. The radius of opening 214, perpendicular to either axis 215, 216, is the proximate diameter of sample tube holder 203 to prevent tube holder 203 from passing through opening 214 and away from the rotational center. Transition surface 218 has a centrally located continuous radius region 218A defining a first cooperative surface region along a portion of a partially spherical-arc surface (e.g., along the transition between the vertical and horizontal positions). Obviously, those skilled in the art will recognize, that since sample tube holder 203 is cylindraceous, it can rotate about either axis in either position and throughout arc 217. It is therefore suggested; that the present design provides a mechanism or a system for providing cooperatively contoured surfaces allowing smooth pivoting motion throughout a centrifugal cycle without unintended specimen remixing while also limiting tube rattling. A waist region 207, of cylindraceous sample tubes 203, includes an arcuate transition surface 208 forming a second continuously cooperative surface portion matching the first cooperative surface portion along continuous region 218 A. As a consequence, the cooperative surfaces (first and second) nest smoothly together and allow a smooth cooperative sliding motion during use. As a consequence of the present design, both sample holding unit 202 and sample tube holder 203 are refened to as including continuously cooperative surfaces that enable a smooth transition (without jarring) pivoting between axial positions 215, 216. As earlier noted, a common problem in centrifugation is the positioning of sample tubes in non-symmetrical positions. This problem was particularly acute where there were no markings, or where the markings were only alphanumeric. The present invention cures this problem by providing sample holding unit 202 with clear visual indicators or indicia (not shown) along transition surfaces 28 proximate each respective biaxial opening 214. These indicia are similar on opposing sides of a central axis of holding unit 202, and are commonly a visual pattern (check, dotted, striped, etc.), but may also be a color (blue, red, etc.), or combination of both allowing a rapid user-determination of opposite openings 214. As an additional feature of the present invention, each opening 214 of sample holding unit 202 includes a smooth back radius portion 221 matching an external diameter of sample tube holder 203. Each opening 214 also includes a smooth front radius portion 222 matching the external diameter of sample tube holder 203. This construction allows openings 214 to securely contact sample tube holder 203 about an actuate region and a portion of it's cylindrical body wall, thereby preventing sample holder units twisting or rattling and non-radial movement relative to a sample holding unit center. fn view of the above description, those skilled in the art should recognize that openings 214 having transition surfaces 218 with the additional cooperative elements discussed, thereby forming a system for ensuring specimen radial alignment, preventing sample specimen rattling during use, and during any necessary unit 100 transport or sample holder unit 202 transport. As a consequence, the present invention substantially minimizes unintended specimen rattling throughout a use-cycle, and the resultant undesirable sample remixing. As a result, the present invention enables centrifugation of much smaller specimen volumes than previously achievable by drastically reducing remixing and preserving a centrifuged specimen. As shown, sample holding unit 202 may alternatively be refened to as a sample holding tray, and may be readily adapted for the separation of particles or items either by weight or within a gel or both. Referring now to Figs. 6A and 6B, rotatable carrier assembly 200 includes motor cover or motor housing cover 201 in combination with a removable sample holding unit 223 (or sample tray 223) having a plurality of sample slots 228 enabling a sample tube holder 203 (or sample holder). Sample holding unit 223, similar to sample holder unit 202, is removably secured to lower portion 209 of motor cover or motor housing cover 201. Each sample slot 228 includes a first horizontal radiused surface 229 conesponding to the radiused cylindrical walls of sample tube holder 203, and preventing unintended lateral or non-radial movement of sample tube holder 203 to minimize sample rattling and jarring. Each slot 228 also includes a cooperative surface 230 that smoothly contacts cooperative surface 208 on each respective sample tube holder 203 and prevents sample tube holders 203 from sliding radially away from motor cover 201 during use, while allowing a smooth non- jarring pivot in an optional construction, discussed below. In one optional construction for sample holder unit 223, a second radiused surface 231 is set at a pre-selected angle, between 75 and 10 degrees below first horizontal radiused surface 229. Second radiused surface 231 is formed similarly to first radiused surface 229 and conespondingly minimizes non-radial movement of sample tube holder 203. fn this assembly, contrary to that described above, a specimen within sample tube holder 203 is preferably separated by gel that will resist remixing (induced by the gravitational field) upon the termination of centrifugation. Second radiused surface 231 allows a user to securely position a gel-based specimen within a sample tube holder 203, allowing the angled slope to prevent the slow movement of the gel while the remaining sample slots 228 are filled. During use, sample tube holders 203 resting within second radiused surface 231 pivot about the cooperative surfaces along arc 233 to assume a horizontal position allowing the gel separation to advance. Where sample holding unit 223 is not provided with second radiused surfaces 231, sample tube holders 203 remain in the horizontal position throughout the cycle. Obviously, while a capped fluid specimen may be centrifuged in this assembly, upon termination of centrifugation the separated fluid specimen would remix degrading specimen quality substantially. The principal benefit of the present sample holding unit design is the low physical profile and easy access. Also show are stack support surfaces 232 on gel separation sample holding unit 223 proximate motor cover or motor housing 201. As will be obvious to those skilled in the art, where two sample holding units 223 are stacked (Fig. 6B) forming a combined multi-stack sample holding unit 224, support surfaces 232 support each respective layer. As will be obvious to those skilled in the art, adaptive multi-stack sample holding unit constructions may be provided without departing from the scope and spirit of the present invention. Referring now to Fig. 6C, rotatable carrier assembly 200 includes motor cover or motor housing cover 201 and a film separation sample holding unit 225 removably secured to lower portion 209 of motor cover 201. This special arrangement enables ready separation via a gel or film forming process wherein the desired part will settle on vertical walls 234 of respective sample chambers 235 during centrifugation. Optionally, a removable insert or other sealed sample cartridge or holder (not shown) may be securely positioned within a sample chamber 235 for centrifugation. Each sample chamber 235 is supported by a tray support 236 projecting outwardly and laterally away from motor cover or motor housing cover 201. Vertical walls 234 are generally parallel to the axis of rotation for motor cover 201. A plurality of strengthening and alignment slots 237 project radially from motor cover 201. Slots 237 serve to stiffen the generally planar construction of tray support 236 and minimize harmonic wobbling created by air resistance, slight variations in sample weight, or other factors. In some embodiments, a single sample holding unit 235 may include four, six, eight or more sample chambers 235 balanced about an outer periphery of tray support 236. In still a further alternative embodiment, alignment slots 237 are provided with matching recess (not shown) on a bottom surface of each tray support 236. hi this embodiment, multiple tray supports 236 may be positioned on each other, allowing an engagement between the recesses (not shown), and respective alignment slots 237. This recess/slot engagement mechanism engagement prevents multiple tray supports 236 from rotating relative to each other and eases ready stacking to improve sample volume. As a present example, two sample holding units (as shown in Fig. 6C), may be positioned at right angles to each other and enjoy the recess/slot engagement mechanism to prevent respective rotation while doubling the specimen volume during each centrifugation. In a further alternative embodiment, sample chambers 235 may be provided in an interchangeable manner with tray support 236, allowing ready separation from support 236 (and later reengagement) for further processing and/or pre-staging of multiple sample chambers 235 prior to additional centrifugation. In this embodiment, a user may acquire a single tray support with a plurality of differently shaped and sized sample chambers 235, allowing ready interchangeabiUty and adaptation to a desire sample size or text matrix. Such a kit may also include additional matching weights, thereby allowing a first sample chamber 235 to be inserted on tray support 236 at a first position, and a differently weighted sample chamber 235 to be inserted on tray support at a second position, the difference in weight being employed to satisfy the need for a matched weight during centrifugation. Each sample chamber 235 includes back wall 234 formed as optionally a planar flat wall (truly flat), or as a slightly arcuate shape (as shown) aligned with a circumference defined by the swing of tray support 236 during operation. Both operations provide advantages to a film separation process. Where the back wall is planar the centrifugal forces vary slightly across its surface (since only the centerline of the back wall circumscribes the true diameter). Thus, a planar back wall may experience slight non-perpendicular force vectors during use, allowing non-exact radial particle separation. Where this concern is minor, for example in gross sample preparation, this type of sample chamber may be used. The benefit is that, being formed in a planar condition, the resultant product will not have to be further flattened upon withdrawal from the sample chamber. Where the back wall is arcuate (as shown) the gel separation process will experience substantially uniform centrifugation forces across the entire wall face minimizing specimen variation. The detriment to an arcuate back wall is that the resultant product will need to be further flattened upon withdrawal from the sample chamber. In either circumstance, the present alternative embodiments discussed above, allow the ready separation of particles in a gel specimen and easy adaptation to a wide variety alternative combinations, assemblies, stacks, and adaptations responsive to expectant customer needs. fn yet another alternative embodiment, a sample-holding unit 225 may be provided with a modified continuous sample chamber (not shown) completing the entire available circumference within the centrifuge (for example 25 centimeters in diameter). Such a sample chamber would be joined at a top and a bottom section by a support to prevent non-circumferential operation while allowing easy separation of a continuous film the length of the entire centrifuge diameter. This construction may also be modified to provide a U-shaped radial cross-section for the sample chamber allowing, again, a continuous film formation. Referring now to Fig. 6D, rotatable carrier assembly 200 includes motor cover or motor housing 201 and a sample holding unit 226 combining both the sample chamber 235 design discussed above in Fig. 6C, and the gel separation designs noted in Figs 6 A and 6B. Those skilled in the art will also recognize that the present combination may be additionally modified to include or integrate the sample holder unit design 202 noted in Fig. 5, as long as the principal guiding balanced mass distribution (symmetry) is maintained to minimize undesirable vibration during operation. As shown in Fig. 6D, both assemblies involve gel-based type separation system sample holders, and as a consequence, sample holding unit 236 may be prefened by certain users conducting solely gel-based centrifugation. As should also be recognized, two or more sample holding units 226 may be stacked, resting on respective stack support surfaces 232 and a balanced position minimizing rotational vibration. As an example, two sample holding units 226 may be position generally perpendicularly on motor cover or motor housing cover 201, thereby distributing their mass in a balanced manner about the central axis of motor cover 201 and minimizing rotational vibration and eccentric tendencies. Referring now to Fig. 6E, in this embodiment rotatable carrier assembly

200 includes motor cover or motor housing 201 and a sample holding unit 227, as shown. Sample holding unit 227 includes tray support member 236, formed as previously discussed and stiffened by strengthening alignment slots 227 to diminish flexing at high rotation while enabling multi-stacking. In considering this embodiment, the present disclosure again intends to incorporate by reference the disclosures in US 2004/0071786 or US 6,368,298 regarding sample analysis and use in the formation of biological materials to reduce healing time and minimize healing discomfort. As shown, two pivot assemblies 238 extend at opposite sides of tray support 236. As will be understood from the above discussions, additional pivot assemblies 238 (in balanced sets) may be additionally positioned about the outer perimeter region of fray support 236. As will be additionally understood from the above discussion, alternative embodiments may provide multiple sample holding units 227, stacked in layers, allowing complementary alignment slots 227 to intermesh and prevent relative rotation during use. When multiple sample holding units 227 are stacked, they are positioned in a balanced manner minimizing vibration during rotation. Each pivot assembly 238 includes a receiving support (not shown) for removably receiving and supporting a multi-sample holder 239. The receiving support is pivotally suspended within frame set 241, as will be described. Multi- sample holders 239 are commonly used during laboratory analysis where many small specimens need to be transfened via pipette for later analyzed or where analysis is conducted in concert with an automated testing device capable of being "mapped" to sample and test individual sample openings 240 anayed across the scope of multi-sample holder 239. For example, multi-sample holders 239 are commonly used during pipette- sample transfers, mass spectrometry, immunoassays, investigation of enzymes or micro-organisms, and for testing blood and other biological fluid components in small volumes, or for forming small volumes of biological material (including fibrin components or others) for later testing. Multi-sample holders 239, commonly used in pipette-based analysis, are provided in a wide variety of designs with differing numbers and sizes for sample tubes 240. In the past, it had been extremely difficult, if not impossible, to apply centrifugation to these types of multi-sample holders 239 as an entire block. One substantial detriment to any effort to centrifuge a multi-sample holder 239 is the requirement that the separating force be provided generally along the length of each individual sample tube 240 throughout the complete centrifugation process (start to stop) to both achieve the desired separation result and prevent disastrous remixing. Since each sample tube 240 is very small, often including only a few milliliters or grams of sample material, any unintended remixing usually voids the analysis, requiring costly retesting. According to the present invention, pivoting assemblies 238 provide an operable mechanism for both centrifugation, and in situ pivoting to minimize or eliminate remixing throughout the centrifugation process. Those of skill in the art will recognize that the present design may be modified without departing from the present spirit and scope. In one adaptive embodiment, multi-sample holder 239 may be fixed in respective pivot assemblies 298, to act as receiving support for a disposable and insertable multi sample holder known in the art (not shown), wherein each individual tube (joined along a common interface, slips within conesponding individual sample tubes 240 for support and retention during centrifugation. As noted above, each pivot assembly 238 is rotatably supported within frame set 241 along a pivot axis T by pivot pins 242 rotatably positioned within respective pivot holes 243. Pivot pins 242 allow pivot assembly 238 to rotate through arc S during use, between a first position R and a second position Q (shown in dashed outline) throughout the centrifugation process. This pivot mechanism enables the separating force to be aligned generally along the length of each individual sample tube 240 while also enabling a smooth transfer along arc S to substantially eliminate remixing biological specimens. While not shown, a spring assembly or member (not shown) functionally joins pivot assembly 238 to frame assembly 241. The spring assembly (not shown) provides a variable spring rate throughout a centrifugation cycle and enabies a mechanism for pivoting pivot assembly 238 to continuously reposition multi-sample holder 239 in respect to the centrifugation force, even under heavy electronic breaking. The spring assembly allows the present invention to rapidly adapt to variable centrifugation forces, and rapid changes in force, while minimizing remixing and preserving sample integrity. In the embodiment shown, frame assembly 241 optionally includes pivot- guiding slots 244 for slidably guiding slip pins 245 joined to each side of pivot multi-sample holder 239. In combination, pivot guiding slots 244 and slip pins 245 provide a rotating guidance throughout pivot arc S between position R and position Q, and mimmizing misalignment as a further quality improvement provided by the present invention. While pivot assembly 238 is discussed in combination with multi-sample holder 239, the present invention also discloses alternative adaptive embodiments wherein a replacement sample holder (not shown), allows the use of a flat film- forming specimen support (for example during the formation of an antilogous fibrin maternal as discussed above in a process similar to those noted in US 2004/0071786 or US 6,368,298. In this manner, the embodiments noted may be used for direct film formation in a flat shape eliminating the need for shtting a film formed in a cylindraceous centrifugation manner. For example, the present invention again incorporates by reference the disclosures in US 2004/0071786 or US 6,368,298, and discusses a method for preparing a solid-fibrin web; wherein the method may include steps of drawing blood from a patient, separating plasma from the blood according to one embodiment of the present invention contacting the plasma with a coagulation activator and concurrently coagulating and centrifuging (see above and employing a selected sample holding unit noted in Figs 6A through 6E), the plasma to form a solid-fibrin web suitable for supporting and ideally regenerating body tissue in a Uving organism. As earlier noted, advances in the Human Genome Project have demanded innovative solutions to sample preparation in the ever changing landscape of molecular labeling and manipulation, gene mapping, gene expression, amplification, DNA sequencing and proteomics. Sample preparation has often been a bottleneck to the analysis of complex biological materials, especially in high throughput automated applications employing multiple sample sets such as genotyping and DNA sequencing. While the general analysis of specimens, fluid and gel, and the formation of fibrin glue have been discussed; the present invention may also include a process for platelet separation within the scope of its biological sample handling capacity. Substantial wound healing features have been achieved employing platelet Rich Plasma, presumably by the release of platelet-derived growth factor (PDGE) and transforming growth factor beta (TGF-B), as well as a fibrin-rich base that provides early tissue revascularization and a framework for epithelial migration. In sum, the present invention provides a substantial improvement in sample preparation capacity to research and generate therapeutic solutions to medical needs. The present invention also provides improved creation of near net shape biological tissues (for example, replacement cartilage and specially formed tissue replacements), by eliminate the prior art unrolling step, and allow large film forming shapes at electronically controllable centrifugation forces. In one aspect of near net shape formation, the present invention may include specially formed frays having a mold shaped for a particular body part, for example the skin on an eyelid. Employing the present sample preparation process, autologous fibrin glue may be formed as a two dimensional near net shape film for easy replacement by a surgeon, without the damaging effects and risks of cutting a preformed rectilinear sheet to a desired form. In a second example, a three dimensional form (for example an ear or nose) by be positioned

(with a duplicate for balance) on a flat surface rotatably supported in respective pivot assembly 238. Employing centrifugal force, a biological film (for example a fibrin glue) may be formed on the three-dimensional form, allowing simplified transplant to a patient. In sum, the use of non-human and hetrologous cells and tissue transplants increase patient risk of allergic reaction and of blood born diseases. Therapies aimed at the reduction of healing time and addressing these issues require support from improved sample preparation and film formation techniques. The present invention provides solutions to these needs. In each combination and alternative embodiment noted above, each sample holding unit or alternative design or combination may be sold separately (in kit form) from motor cover 201, allowing ready adaptation to a diverse customer base along differing marketing lines. Referring now to Figs. 7 through 11, motor assembly 150 is covered by motor cover or motor housing cover 201 including a plurality of vent openings 213 along an upper portion 219 thereof. Motor assembly 150 is positioned on a pedestal assembly 251, flexibly linking a base plate 109 to a motor base plate assembly 252 along a vertically- extending mounting element 253 bounding ventilation aperture 1 A. A motor 254 is cylindraceous and includes an outer surface member including one or more ventilation openings allowing warm air to escape motor 254. Motor 254 has a first outer diameter that is less than an inner diameter of motor cover 201 allowing air flows 255 to pass from pedestal assembly 251 upwardly between motor 254 and the inner diameter of motor cover 201 and pull warm air outward through vent openings 213 and into air management system 300 for later exit through air openings 304. In this way, air management system 300 enables centrifuge assembly 100 to cool motor 254 principally, and also cool specimen holders and the specimens themselves as discussed earlier. Pedestal assembly 251 includes a top support plate 256A and a bottom support plate 256B. Bottom support plate 256B includes a ventilation aperture 256C and is firmly fixed to, and spaced from, top support plate 256A by a plurality of studs 257 forming an opening G between each plate for cooling airflow. Vertically extending mounting element 253 projects from base plate 109 and is firmly fixed by slip ring 258 retained within a groove 260, and prevented from upward motion thereby. A first fixing washer 259 surrounds vertical element 253 on base plate 109 and prevents unintended separation between base plate 109 and vertical element 253, as shown. As a consequence, vertically projecting mounting element 253 is firmly fixed to base plate 109 and housing assembly 101. Vertically projecting mounting element 253 supports both rotatable carrier assembly 200 and motor assembly 150, and due to the high speeds involved must be firmly secured to the inflexible base plate 109. Other methods for joining mounting element 253 may be employed without departing from the spirit and scope ofthe present invention. A first wave washer 261 and a sliding washer 262 are positioned about vertical mounting element 253 at a bottom portion, as shown best in Fig. 7B. An inner diameter of wave washer 261 and sliding washer 262 is slightly larger than the outer diameter of mounting element 253 providing a slight movement gap 263 for lateral adjustment and compensation as will be described. A strong bearing assembly 264 has an inner race 264A and an outer race

264B that support a plurality of ball bearings 264C. Preferably, bearing assembly 264 is selected to enable rotational speeds well in excess of any predicted rpm design range. An impeller and support assembly 265 includes an upper support member 266, extending from an inner diameter region and covering a portion of bearing assembly 264, outwardly to an outer impeller aπay 267. Impeller array 267 includes a plurality of impeller blades 267A positioned within a plurality of conesponding openings 267B, as shown. Impeller blades 267A may be shaped in any convenient manner to promote air flow, but as shown are slanted off the vertical and are curved about an arc to "scoop" air upwardly and impart a vertical motion to the air to draw air from ventilation aperture 1A, air chamber 301, and elsewhere to aid motor cooling and support air management system 300. A separable bottom member 267C defines an inner bounding region (shown but not numbered) proximate mounting element for receiving and securing strong bearing assembly 264 within impeller assembly 265, as shown.

As shown best in Fig. 7B, bottom member 267 contacts a bottom of outer race 264B and secures the same to upper support member 266, thereby integrating bearing assembly 264 with impeller and support assembly 265. Motor cover or motor housing cover 201 is secured to an outer perimeter of impeller assembly 265 via openings 212 (noted above) and conesponding threaded receptacles 212A by threaded bolts (not shown). In this manner, motor cover 212 is removably secured to impeller assembly 265. While the present assembly suggests one prefened embodiment, those skilled in the art may reposition elements and achieve the same function without departing from the spirit and scope ofthe present invention. Bearing assembly 264 and impeller assembly 265 are assembled as shown, and positioned firmly about mounting element 253 where inner race wall 264A aligns with and contacts the outer perimeter of mounting element 253. As a consequence of this assembly, the entire weight of impeller and support assembly 265 is born by strong bearing assembly 264 that, in turn, is firmly supported by sliding washer 262 and wave washer 261. The firm contact between inner race wall 264A and mounting element 253 provides firm alignment between impeller assembly and support base 109, and prevents inner race wall 264A from rotating relative to mounting element 253. A washer 268 is positioned on a top portion of inner race wall 264A and includes a slightly larger inner diameter than the outer diameter of mounting element 253 allowing slight relative movement thereto. Washer 268 includes an outer lip portion 268 A projecting upwardly to contain a washer 269 tightly sealed to the outer diameter of mounting element 253, as shown to additionally secure impeller assembly 265 and bearing assembly 264 firmly to mounting element 253. In view of the above assembly, it should be obvious to those skilled in the art that any sample weight transmitted to impeller and support assembly 265 via motor cover or motor cover housing 201 is transfened to mounting element 253 through strong bearing assembly 264. It should also be apparent to those skilled in the art, that the present assembly enables motor cover housing 201, impeller support assembly 265, and bearing to flex only slightly vertically by compressing wave washer 259. It is also noted, that the present assembly spaces impeller assembly 265 a vertical distance L from base plate 109 to accommodate this very slight flexing. As designed, wave washer 259 has a substantially strong bending moment and is compressed by press-fit installation of strong bearing assembly 264. Since wave washer 259 provides strong elastic urging between fixed base plate 109, and pressure fit inner race wall 264, no real lateral movement is allowed and only slight vertical movement is allowable or expected, but the assembly serves to further dampen vibration and flex within distance L. As will be later described, pedestal assembly 251 additionally serves to pre-stress bearing assembly 264 to increase bearing life and improve smooth running. A wave washer 270 is positioned on fixing washer 269 to support a bottom portion of bottom support plate 256B. Wave washer 270 spaces bottom support plate 256B of pedestal assembly 251 a vertical distance M from the top of upper support member 266, as shown. It should be noted, that upper support element 266 of impeller assembly 265 is recessed a slight distance (distance M) from the top surface of impeller aπay 267. As a consequence, it should be noted, that upon full compression of wave washer 270, bottom support plate 256B will enter the recess to aid the self-centering and compensating mechanisms of the present invention, as will be discussed. It is also noted, that vent aperture 256C of bottom support plate 256B is larger than an outer diameter of mounting element 253 by a lateral distance N on each side. A second slip ring 271 is received within a retaining groove about a top diameter of mounting element 253, and secures the bottom support plate 256B on top of wave washer 270, flexibly joining pedestal assembly 251 (and motor 254) to mounting element. As discussed above, second wave washer 270 has a very high spring rate and substantially resists compression, but remains sufficiently flexible to enable the lateral sliding and self-centering and compensating mechanisms ofthe present invention. Motor 254 includes a drive shaft 272 projecting upwardly through an opening 281 into a receiving cavity 273 within the top portion of motor cover 201. A slight gap O is provided between the outer diameter of drive shaft 272 and the inner diameter of opening 281. Receiving cavity 273 includes a step 274 forming a key retaining area 275 for receiving a key 276. A flat surface 277B on drive shaft 272 engages a conesponding flat surface on an inner opening in key 276 to prevent relative rotation there between. While not required, in one alternative embodiment, a slight lateral distance P exists between an external diameter of drive shaft 272 and a part of the inner opening in key 276. In this alternative embodiment, flat surface 277B continues to engage key 276 to prevent relative rotation, but slight lateral movement is allowed via distance P to compensate for vibration, eccentric motion, and specimen weight differences. A slip ring 277 within a groove 278 covers receiving key 276 and prevents unintended separation between receiving key 276 and drive shaft 272. A firm spring 279 is compressed within receiving cavity 273 between a floor of receiving cavity 273, and receiving key 276. Firm spring 279, and the anangement provided, enables substantial benefits to the present invention. Initially, firm spring 279 keeps key 276 firmly engaged with portions of drive shaft 272 preventing separation and relative rotation. Additionally, spring 279 provides an urging force on drive shaft 272 keeping internal motor bearings (not shown) in motor 254 from spinning freely and damaging the motor. For optimal function, bearings should be kept under slight compression. Still further, spring 279 may place slight tension on strong bearing assembly 264 and similarly prevent free rotation for optimal bearing performance. Finally, spring 279 enables a slight shifting between drive shaft 272 to facilitate the alignment and eccentric compensation mechanisms noted herein. During operation, it should be understood, that weight from specimens, and rotatable carrier assembly 200 (including all weight from sample holding units), is born by a strong rotating bearing assembly 264 via support and impeller assembly 265, and not by rotational shaft 272. Rotational shaft or motor shaft 272 serves only to impart rotational force to rotatable carrier assembly 200 for centrifugation of specimens. As a result, the present invention provides a mechanism or system to eliminate sample-bearing weight on a centrifuge motor drive shaft while substantially reducing a center of gravity. It will be understood, that larger motors have larger internal bearing assemblies, but in general no small-sized centrifuge motor includes internal bearings of the size and strength of strong bearing assembly 264. Thus, as a consequence, of the present designs, where the rotating sample carriers are not fixed or directly attached to the drive shaft, there is a substantial increase in both motor life, and sample weight capacity beyond the designs previously provided. This may be refened to broadly as a mechanism for conecting misalignment/realignment of the motor assembly and motor cover housing assembly. As noted above in reference to Fig. 3, Fig. 11 provides an alternative construction to an electromagnetic cover locking mechanism 20B including a horizontally moving locking bracket 25 joined to a solenoid 29 within a cover edge member 28 for engaging cover assembly 102 and locking it firmly to base assembly 103. Springs 27 enable a rapid release/engagement of locking bracket 25 depending upon solenoid movement. One benefit of the present design is that it is completely retained within cover edge member 28 and electrically joined to electronics assembly 250. This operable connection to electronics assembly 250 enables a substantial safety improvement by preventing unintended lid opening during rotation or excessive vibration. Locking mechanism 20B may also be programmed to lock at a beginning of a programmed operation and open at the end, providing convenient safety. While additional elements are noteable within locking mechanism 20B, including security mechanism 20C, it is important to understand that in one prefened embodiment, locking mechanism 20B is integrated with electronics assembly 250. As discussed earlier, conventional centrifugal devices are also incapable of self-centering in situ (during operation) adjustment. According to one aspect of the present invention, when motor assembly 150 is not centered relative to rotatable carrier assembly, pedestal assembly 251, wave washer 270, and the other mechanisms for self-centering noted early allow motor assembly 150 so shift slightly along the surface of wave washer 270 using distance N to compensate and achieve a proper center condition. As a further measure of the adaptive self-centering capacity and suspension benefits of the present invention, motor assembly 150 may also shift using distance M to compensate and achieve a centered orientation. Due to the substantial forces exerted by even slight differences in sample weight, and the conesponding damage created by the resultant vibration, the present invention has a substantial beneficial impact on centrifuge life. To understand this condition, we may consider first a conventional centrifuge with a rotatable sample tray fixed to a drive shaft of a vertically positioned motor. In this conventional centrifuge, the outermost edge of the sample fray operates as the furthest lever-point, and the rigid junction between the drive shaft and the sample tray acts as the lever's fulcrum. As a consequence, a slight change in mass, or variation in mass about the outermost edge of a conventional sample fray has a magnified impact on the drive shaft and imparts a substantial bending moment upon the rigid junction. These substantial forces must be absorbed by the motor's internal shaft bearings and frequently cause premature failure and excessive heating. In contrast to conventional designs, we may consider the entire rotatable carrier assembly 200 as a moment arm, with the outermost position of a respective sample holding unit acting as the furthest lever-point, and the interconnection at drive shaft 272 as a possible fulcrum. Since the present invention provides a complete independent suspension for carrier assembly 200, meaning that all weight is born directly by strong bearing assembly 264, no weight or bending moment is transfeπed to drive shaft 272 and no true fulcrum can exist. Drive shaft 227 only functions to impart rotational energy to rotatable carrier assembly 200, and does not carry any weight. As a consequence, motor 254 enjoys increased operation life and cooler running conditions. The present invention also compensates for any unbalanced force or vibration that may act upon drive shaft 272 and motor 254 by first elastically separating drive shaft 272 from the top of motor cover 201 through the use of spring 279 and thereafter allowing a slight realignment via optional space O, and in rare eases space P, and second by elastically allowing pedestal assembly to shift using distances M and N to absorb any eccentricities and off-center alignments. Thus, the motor is weight-supported by the wave spring allowing lateral movement by sliding along the wave spring while retaining vertical integrity to recenter and compensate for specimen variation and eccentric movement.

Furthermore, spring 279 in a slight way applies a pressure on bearing race 264 further preventing free non-contacting rotation and reducing bearing wears. Finally, it should be noted, that in one embodiment rotatable carrier assembly 200 can itself shift slightly along direction L relative to mounting element 253 to absorb substantial eccentricity and vibration. Since manufacturers may select variable spring rates for respective wave washers, the present system may be readily adopted to systems typically handling hght or heavy loads without departing from the basic scope and spirit ofthe present invention. In addressing the needs noted above, the present invention provides variable embodiments, wherein the motor axis and shaft do not bear pivoting weight and receive no bending moment, the motor is positioned "within" a rotatable carrier assembly providing a reduced profile, an independent suspension is provided for the sample holder and cover units, a simple vibration absorption, realignment, and reentering system readily adapted to a wide verity of analytical situations with varying weights, and an air and temperature management system increases cooling, reduces air interference.

It is understood, that the above description and drawings are only exemplary of the present invention and that changes in circuitry, components and configuration is possible without departing from the scope of the present invention as defined in the following claims. With the above discussion in mind, we can now discuss several of the optional and unique electronic and system confrol features of the present invention provided within electronics assembly system 250 not easily depicted a physical-system based manor (as above). While several of these items/systems/functions/circuits have been previously infroduced, suggested or discussed, others are introduced here for the first time. These features are newly provided in a bench-type centrifugation system. In alternative embodiments of the present invention a theory of operation, particularly for elecfronics assembly 250, is provided below including many specific and alternative features, but not limited to a microprocessor controlled centrifuge system with: 1. Programmable run-time and speed-set/rpm-set circuits with motor control functions are provided. These circuits are electronically adjustable via the confrol surfaces or buttons noted above, and enable both a continuous run- length and speed (rpm) adjustment in situ (while running). This system enables simple and prompt conection to preserve the integrity of a sample run, or modify a run to conect an initially inconect time or speed input. This in situ conection capability provides convenient timesavings while preserving sample validity during scientific tests (prevents re-running samples and running samples for variable lengths of time). a. In one embodiment, these circuits also enable simple elecfronic calibration and optionally a cycle counter. b. In another system embodiment, a secure password entry is required to operate the system. c. In yet another alternative embodiment, the circuits may include a warning notice (LCD display) area with a cut-off to require and provide notice of scheduled maintenance while initiating a motor cut-off to prevent operation after a scheduled maintenance date cut-off. 2. A digital display, in one case a four digit LED or LCD display, or several disparate visual displays, provide a visual operator/user feedback of various selected capacities, including time-set, time remaining, speed set, speed variation, repair notices, an eccentric and a vibration sensor warning and other confrol circuit warnings. a. In one embodiment, a vibration sensor operably monitors the unit during each cycle and optionally provides a visual warning, an audible warning, and a break function operation when vibration exceeds a predetermined undesirable level. 3. In yet another alternative embodiment, the present invention may include a PJD (proportional, integrative, and derivative) controller programmable via an operator keypad allowing specific control and maintenance of sample rpm and accelerometer control. Such a PID controller may be integrated with a self-calibration circuit or may remain separate from such a circuit.

4. An optional self-calibration system enables constant, or set time, monitoring ofthe present invention. This system may monitor at least one of motor rpm, motor cunent/voltage/power output, while also optionally tracking the number of centrifugation runs or total time at speed, total on- time (running) activity, or a predetermined amount of acceptable/unacceptable vibration. a. In one example, the self-calibration system monitors a centrifugation run and senses that a desired rpm is not being maintained via a sensor 111 and sensible pattern 112 compared to a desired standard. As a consequence, the self-calibration system may electronically regulate the motor power to achieve the desired rpm. b. In a second example, the self-calibration system monitors successive centrifugation operations (runs), and logs an amount of coπection/motor regulation required to achieve a desired rpm into a tracking unit. The system monitors an acceptable amount of motor conection against this log (or a specific in-put set-point), and where the amount of conection/motor regulation exceeds the acceptable amount the system may generate a warning (audible/visual), shutdown the device (power confrol), or provide another indication of the need to conduct machine maintenance. c. In another example, the self-calibration system enables true repeatable scientific analysis through a series of specimens. During conventional centrifugation specimens are often centrifuged for slightly different length times, resulting in sample variability. The present electronic control system enables sample exposure to a consistent and repeatable sample treatment run-to-run. This consistency enables improved scientific analysis and improves scientific research. d. In another example, the self-calibration system may track runs and require a standard mandatory service repairs, for example at 5000 runs or at 10,000 runs, or more urgently if the system determines an unacceptable variation is occurring. hi another embodiment, one or more elecfronic brake function circuits or mechanisms are operably linked with selected motor, time, speed confrol, and various circuit systems, optionally including lid-open circuits, excessive vibration circuits, or maintenance monitoring circuits. Where a desired function is programmed, the break function circuits may be operated to apply either a physical-friction type break, or a motor-function break, thereby operably stopping one or more of a sample rotation and a motor operation a smooth and non-jerky manner. An elecfronic break serves to minimize jerky operation and specimen perturbations during start/stop and concomitant specimen holder rotation while improving safety. a. In one embodiment, the lid-open-solenoid is operably linked with at least one of the rotation/speed sensor and a motor control sensor, thereby prohibiting operation of the lid-open-solenoid until the rotor stops. Typically, the elecfronic brake employed is effective to stop rotation within about 20 seconds. This function serves to improve unit safety and minimize product liability risk. b. In another alternative embodiment, a balance/off-balance sensor is provided and electronically and operably linked with the brake function, allowing the brake system to actuate and prevent operation when the system is inappropriately off-balance, thereby minimizing damage risk and sample disturbance.

6. In another embodiment an audible warning or cycle finished circuit may exist integrated with the other confrol circuits described above. This type of circuit may be triggered upon the end of an operation cycle, end of time limit, excessive vibration limit, or break operation, motor malfunction, circuit malfunction, or other unit control operation. Referring now to Figs. 13 and 14, in one embodiment an operable electronic assembly 250 includes multiple units, described respectively below including:

A. A microprocessor unit: A centrifuge controlled by a U8 microprocessor containing at least one executable program. The executable program is stored in the processor's FLASH memory. The U7 reset circuit, the U9 NV memory, the Yl, CI and C2 timing circuit belongs directly to the processor. During operation, the processor receives signals and sends commands through a data bus (D0-D7) and some direct port pins.

B. A display unit: The centrifuge display unit displays information about operation through a four-digit or other type display. The display is driven by the display driver circuit (U2, U3, U6, Ql, Q2, Q3, Q4, Q5) controlled by the processor. The visual display unit depends upon the operating mode, and can display at least the following: - Speed (RPM) and remaining time (mm:ss) in normal running mode - The desired speed or time in setup mode - The result of the calibration function result ( TN RANGE, OUT OF RANGE) - Enor messages ( OUT OF BALANCE, ? )

C. One or more push buttons: The centrifuge can be set up or operate by pressing the proper pushbutton or combination of pushbuttons. As shown in this embodiment, the pushbuttons are connected to the data bus through the Ul. D. A Motor driver unit: The motor driver unit consists of two circuits, generally described as the motor driver and the motor brake circuits. As shown, the Q101 triac with the U102 triac driver supply the AC power to the motor. The triac controlled by the microprocessor according to the set up speed and the real speed. The real speed sensor is the ISO2 photo sensor. The Q102 MOSFET and ISO102 opto-isolator brakes the motor when the cycle finished or the STOP button was pressed. E. A lid lock unit: During the operation the lid must be closed and locked for safety. In the present embodiment, the Lid-Lock mechanism is actuated by a solenoid and the solenoid is driven by the Q103 transistor.

F. A power supply unit: The power supply unit generates the necessary voltages for the controller circuit, the brake and the Lid-Lock circuit (T101, BR101, C101, C102, U101). Also the power supply generates the 60Hz synchronizing signal for the speed confrol (ISO101, D101, R101).

G. Audible signals: If the cycle is finished or the centrifuge is in improper operation condition (excessive vibration, improper rpm, off balance, etc.), an audible signal sounds. This signal is controlled by the processor and generated by the BZ1 buzzer and may assume different tones, notes, or operation dependent upon the type of operation condition. Alternatively, a speaker and audio memory file system may be accessed to produce a predetermined recording.

H. Vibration sensor: In case of an unbalanced load the centrifuge can make uncontrolled movements, cause specimen perturbations, damage sample results, and cause remixing - often disastrous in particularly small sample sizes. To prevent this situation, the centrifuge equipped a motion sensor (Y2) connected to the processor. If the vibration is over the limit, the processor stops the centrifuge, the OUT OF BALANCE message appears on the display and an audible warning signal sounds. In view ofthe above ready adaptively, a manufacturer may wish to market the present invention solely in kit form (housing assembly with a select sample holding unit), or in a basic kit (housing assembly with a default sample holding unit) and thereafter provide specialty kits for bioassay, film-forming or other particular customer needs. In the claims, means- or step-plus-function clauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface, a screw's helical surface positively engages the wooden part, and a bolt's head and nut compress opposite sides of a wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures. Having described at least one of the prefened embodiments ofthe present invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes, modifications, and adaptations may be effected therein by one skilled in the art without departing from the scope or spirit ofthe invention as defined in the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A centrifuge comprising: a drive motor; a rotatable assembly operably connected to the drive motor; and means for mounting said drive motor and said rotatable assembly, whereby the drive motor drives the rotatable assembly without bearing a weight of said rotatable assembly.

2. The centrifuge of claim 1, further comprising: means for resiliently mounting the drive motor.

3. The centrifuge of claim 2, wherein: said means for resiliently mounting the drive motor comprises: a wave spring disposed below the drive motor.

4. The centrifuge of claim 3, wherein: said wave spring resiliently bears the weight of the drive motor.

5. The centrifuge of claim 3 , wherein: said means for resiliently mounting the drive motor further comprises: a compression spring operably engaged with and operably disposed above the motor.

6. The centrifuge of claim 1, wherein: said rotatable assembly further comprising means for receiving sample tubes.

7. The centrifuge of claim 6, wherein: said means for receiving the sample tubes further comprises: a contoured surface for enabling upwardly pivoting of the sample tubes with rotation ofthe rotatable assembly by the drive motor

8. The centrifuge of claim 1, further comprising: means for self-centering the drive motor during rotation of the rotatable assembly.

9. The centrifuge of claim 8, wherein: said means for self-centering further comprises at least one of means for lateral self-centering and means for vertical self-centering.

10. A centrifuge comprising: a drive motor; a rotatable assembly operably connected to the drive motor; and means for resiliently mounting the drive motor.

11. A centrifuge comprising; a drive motor; a rotatable assembly operably connected to the drive motor; and means for self-centering the drive motor during rotation ofthe assembly.

12. A centrifuge comprising; a drive motor; a rotatable assembly operatively connected to the drive motor; said rotatable assembly including a member for receivably holding sample tube members; said member having a plurality of contoured surfaces for receivably holding said sample tube members; said contoured surfaces slidably engaging said sample tube members, whereby with rotation of the assembly said sample tube members slidably engage the member contoured surfaces to enable a smooth upward pivot motion to the tubes.

13. A centrifuge comprising: an asynchronous drive motor; a rotatable assembly; and means for operably connecting said rotatable assembly to said asynchronous drive motor.

14. A centrifuge assembly, comprising: a vertically mounted motor assembly; means for mounting said motor assembly on a first mounting assembly proximate a first distance from a support surface; a rotatable carrier assembly; means for rotatably mounting said rotatable carrier assembly on a second mounting assembly proximate a second distance from said support surface; said first distance being larger than said second distance, and means for operably connecting said motor assembly to said rotatable carrier assembly enabling a driving rotation during a use, whereby said motor assembly and said rotatable carrier are independently mounted and operably connected.

15. A centrifuge assembly, according to claim 13, wherein: said vertically mounted motor assembly has a first center of gravity a first distance from a support surface; said rotatable carrier assembly has a second center of gravity a second distance from a support surface; and said first distance being greater than said second distance, whereby said centrifuge assembly has an improved stability during said use.

16. A centrifuge assembly, according to claim 14, further comprising: a thermal management system; said thermal management system including an air movement system comprising: a first portion of said rotatable carrier assembly having a motor cover member bounding at least a portion of said vertically mounted motor assembly and defining an air-flow gap therebetween; said second mounting assembly including an impeller in flow communication with said air-flow gap effective to urge an air flow through said air-flow gap, whereby said thermal management system enables a cooling of said vertically mounted motor assembly.

17. A centrifuge comprising a drive motor; rotatable assembly means, and means for operably connecting the rotatable assembly means to the drive motor; impeller means for directing an air flow; and means for operably mounting the impeller means with respect to said drive motor and said rotatable assembly; whereby, in rotating the impeller means, air flows adjacent the drive motor.

18. A centrifuge comprising: a drive motor; and means for self-calibrating the rpm actually delivered by the drive motor

19. The centrifuge of claim 18, further comprising means for programming the drive motor.

20. A housing for a sample tube, said housing comprising: a body having an opening for receiving the sample tube; said body having a bottom, said bottom being formed so that the housing with the sample tube is self-standing.

21. The housing of claim 20, further comprising: a removable cap, said cap being formed to removably cover said opening. ^•

22. A combination, comprising: a rotatable fray; a sample tube; a housing for holding the sample tube; said rotatable tray and said housing being formed with respective shdably engaging contoured surfaces; and whereby during a rotation of said housing about a pivot center, said sample tube pivots upwardly guided by a motion of said housing contoured surface slidably engaging said respective rotatable tray contoured surface.

23. The combination of claim 22, wherein: said rotatable fray contoured surfaces forming a plurality of circumferentially disposed orifices; and said plurality of housings for holding said sample tubes being circumferentially disposed in said orifices.

24. The combination of claim 23, further comprising: identifying indicia adjacent each orifice.

25. The combination of claim 24, wherein: two orifices, being diametrically disposed, may have the same identifying indicias.

26. The combination of claim 24, wherein: said identifying indicates comprises at least one of a color, a pattern, and a combination of a color and a pattern.

27. In combination: a drive motor; and in a first operational mode; a first rotatable assembly operably connected to the drive motor; said first rotatable assembly comprising means for holding tubes; and in a second operational mode; a second rotatable assembly operably connected to the drive motor, said second assembly comprising means for holding a tray member.

28. The combination of claim 27, wherein: said means for holding tubes further comprises sample tubes.

29. The combination of claim 27, further comprising: means for mounting said first assembly, and alternatively, for mounting said second assembly.

30. The combination of claim 27, wherein: said tray member further comprising means for forming a sheet from flowable material disposal in the fray member upon rotation of said second assembly.

31. The combination of claim 27, wherein: said tray member further comprises means for holding a plurality of pipette sample trays.