WO2009073769A2

WO2009073769A2 - Medical device including integrated steering and braking system

Info

Publication number: WO2009073769A2
Application number: PCT/US2008/085500
Authority: WO
Inventors: Robert J. Chilton Iii
Original assignee: Draeger Medical Systems Inc
Current assignee: Draeger Medical Systems Inc
Priority date: 2007-12-04
Filing date: 2008-12-04
Publication date: 2009-06-11
Anticipated expiration: 2010-06-04
Also published as: WO2009073691A2; WO2009073691A3; WO2009073769A3

Abstract

Provided is a warming therapy device comprising a cart with at least one handle and a plurality of braking casters mounted thereon. The handle has a brake control mounted thereon, which is operable between a first position and a second position. The casters extend downwardly from the cart to engage a supporting surface. The casters have a braking system contained therein, which is adapted to restrict rotational movement of the caster when in a first position. The braking system is biased in the first position when the brake control Ls in the first position and in a second position when the brake control is in the second position. Steering controls mid a steering system may also be provided in connection with the handle and casters. Also provided is a method of moving a medical device including applying pressure to a brake control to disengage a braking system and facilitate movement of the medical device.

Description

MEDICAL DEVICE INCLUDING INTEGRATED STEERING AND BRAKING SYSTEM

Cross Reference to Related Applications [0001] This application claims priority to US Provisional Patent Application No. 61/005,359, filed December 4, 2007, the entire contents of which is incorporated herein by reference, as if fully set forth herein.

Technical Field [0002] The present invention relates generally to a warming therapy device (e.g., incubator, warmer, etc.) for medical patients. Specifically, the present invention relates to a movable incubator for infant patients with an integrated steering and braking system.

Background [0003] Infant care apparatus, such as warming therapy devices in the form of incubators and radiant warmers, have been used to maintain the appropriate body temperature of small or premature infants. In many cases, warming therapy devices are mounted on wheeled carts. The carts are generally moved around areas such as hospitals by attendants by pulling or pushing the carts. In some cases, the wheels of the carts have casters with tabbed brakes. Tabbed brakes generally allow a user to lock a caster in position by stepping on a tab or pedal. While these may be effective in certain circumstances, it may be difficult to stop the device using the tabbed brakes. Further, traditional medical device carts have casters, at least two of which are generally permitted to rotate freely about an axis perpendicular to the supporting surface. In such devices, it is sometimes difficult to maintain a straight course while maneuvering the device. It would be desirable to provide an integrated braking and steering system for medical device carts to minimize the effort required to stop or steer the device.

Summary [0004] Provided is a cart having a handle mounted thereon and a plurality of casters extending downwardly therefrom. Each caster has a wheel with an axis of rotation and providing rolling engagement with a supporting surface. A brake control is mounted on the handle operable between first and second positions. A steering control is mounted on the handle and operable between first and second positions. A braking system is located within the caster and operable to brake the caster, said braking system having a braking contact surface and a brake member adapted to engage the braking contact surface in a first position and restrict movement of the braking contact surface with respect to the brake member in a second position, the brake member being normally biased in the first position and operable to the second position. The braking system is linked to the brake control and the brake member remains in the first position when the brake control is in the first position and the brake member moves away to the second position as the brake control is moved from the first position to the second position; and a steering system adapted to selectively restrict rotational movement of the caster about an axis that is generally perpendicular to the axis of rotation of the wheel, wherein the steering system is linked to the steering control and the steering control does not restrict rotational movement of the caster when the steering control is in the first position and the steering system restricts rotational movement of the caster when the steering control is in the second position. [0005] Also provided is a warming therapy device comprising a handle having a brake control. The brake control is operable between first and second positions. The warming therapy device has at least one caster having a brake system. The brake system includes a wheel, a braking surface, a biasing member and a brake member. The wheel is adapted for rolling engagement with a supporting surface and the braking surface is adapted for rotation with the wheel. The brake member is adapted to frictionally engage the braking surface and the brake member is biased against the braking surface as the result of force exerted on the brake member by the biasing member in the direction of the braking surface. The brake system is linked to the brake control such that the brake member is moved away from the braking surface when the brake control is moved from the first position to the second position.

[0006] Further provided is a method for moving a cart. The method includes providing a cart including a handle and plurality of casters mounted on the cart. The handle has a brake control and a steering control mounted thereon. The brake control is operable between first and second positions and the steering control is operable between first and second positions. The plurality of casters extend downwardly from a bottom portion of the cart to engage a supporting surface and have a braking system and a steering system contained therein. The braking system is adapted to restrict rotational movement of the caster when engaged and is biased in the engaged position. The braking system is engaged when the brake control is in the first position and disengaged when the brake control is in the second position. The steering system is operable to selectively restrict directional movement of the caster. The steering system is linked to the steering control such that when the steering control is in the first position, the steering system does not restrict directional movement of the caster and when the steering control is in the second position, the steering system restricts directional movement of the caster. The method further includes the steps of gripping the handle of the cart and applying pressure to the brake control. When pressure is applied to the brake control, the brake control is moved from the first position to the second position. The method also includes the step of applying lateral force to the handle while maintaining pressure on the brake control thereby moving the cart in an intended direction. The method also includes the step of applying pressure to the steering control thereby moving the steering control from the first position to the second position and restricting the directional movement of the caster.

Brief Description of the Drawings

[0007] Figure 1 is a perspective view of a first exemplary embodiment of a warming therapy device.

[0008] Figure 2 is a second perspective view of the warming therapy device shown in

Figure 1. [0009] Figure 3 is a top plan view of the warming therapy device shown in Figure 1.

[0010] Figure 4 is a side elevational view of the warming therapy device shown in Figure

I .

[0011] Figure 5 is a rear elevational view of the wanning therapy device shown in Figure

1. [0012] Figure 5A is a schematic view of a first exemplary embodiment of a handle incorporating brake and steering controls.

[0013] Figure 6 is perspective view of a first exemplary embodiment of a caster for use in connection with the warming therapy device shown in Figure 1.

[0014] Figure 7 is a front elevational view of the caster shown in Figure 6. [0015] Figure 8 is a top plan view of the caster shown in Figure 6.

[0016] Figure 9 is a perspective view of the caster shown in Figure 6 with a hub cap removed. [0017] Figure 10 is a side elevational view of the caster shown in Figure 6 with the caster removed.

[0018] Figure 1 1 is a perspective view of a first exemplary embodiment of a caster frame assembly. [0019] Figure 12 is a front elevational view of the caster frame assembly shown in Figure

1 1.

[0020] Figure 13 is a side elevational view of the caster frame assembly shown in Figure

1 1.

[0021] Figure 14 is a top plan view of the caster frame assembly shown in Figure 1 1. [0022] Figure 15 is a cross-sectional view of the caster frame assembly shown in Figure

1 1, taken along line 15-15.

[0023] Figure 16 is a partial cut away view of the caster shown in Figure 1 1.

[0024] Figure 17 is a cross-sectional view of a second exemplary embodiment of a caster.

[0025] Figure 18 is a partial cross sectional view of a third exemplary embodiment of a caster.

Detailed Description

[0026] It will be appreciated that the following description is intended to refer to exemplary embodiments selected for illustration in the drawings, and such exemplary embodiments are not intended to define or limit the scope of the invention described herein. Additionally, although the following description focuses on an incubator, those of ordinary skill in the art will realize that the structures described herein may be used in connection with other types of warming therapy devices, such as radiant warmers and open care devices. [0027] Referring now to Figures 1-5, a first exemplary embodiment of a warming therapy device 10 is shown in the form of an incubator having incubation chamber 12 mounted on a cart 14. The warming therapy device may also be a radiant heater or some other type of warming device. The incubation chamber 12 has a base 18 for supporting an infant and a cover portion 16 adapted to mate with the base 18. Preferably, the warming therapy device 10 is adapted to maintain a constant temperature and humidity within the incubation chamber 12. The cart 14 has a lower portion 20, which is generally flat and has four casters 22, with one caster 22 disposed at each corner. On one side of the cart 14, a vertical spine 24 extends upwardly from the lower portion 20 to support the base 18. It will be appreciated that other forms of warming therapy devices, such as radiant warmers or other open care devices, may also be provided. Preferably such other devices have at least a cart 14 with at least one caster 22 mounted on the cart 14.

[0028] In many cases, infants remain in the incubation chamber 12 for extended periods of time. As a result, it may be necessary to move the warming therapy device 10 with the infant inside the incubation chamber 12. In some cases warming therapy devices 10 may weigh hundreds of pounds and be cumbersome to maneuver. However, when navigating a clinical environment, it is desirable that the warming therapy device 10 be as easy to handle and control as possible. It is further desirable that, should a caretaker lose control of a warming therapy device 10 during transport, the warming therapy device 10 be adapted to stop in a manner that will not create trauma on a patient within the incubation chamber 12 or damage surrounding articles.

[0029] Brgonomic front and rear handles 26, 28 are provided on the warming therapy device 10 to facilitate gripping of the warming therapy device 10 during transport. The front handles 26 extend forward from the base 14 of the incubation chamber 12 and are preferably angled slightly from the horizontal, with the portion of the handles 26 closest to the center of the warming therapy device 10 raised above the outer portion of the handle 26. The angle of the front handles 26 reduces stress on a caretaker or attendant gripping the front handles 26 as it allows the wrist to be at a more natural angle during transport. [0030] The angled configuration of the front handles 26 is suited to facilitate an attendant standing directly in front of the warming therapy device 10 (see position A in Figure 3) and placing one hand on each of the front handles 26 for pushing the warming therapy device 10. The angle of the front handles 26 may also facilitate an attendant standing in front and to the side of the warming therapy device 10 (see position B in Figure 3) and pulling the warming therapy device 10 with one hand on the nearest front handle 26.

[0031] As best seen in Figure 3, the rear handle 28 preferably spans across most, if not all, of the width of the vertical spine 24. The rear handle 28 extends outwardly from the vertical spine 24 to provide a sufficient spacing for an attendant's hands to fit between the rear handle 28 and the vertical spine 24. As best seen in Figure 5, the rear handle 28 is preferably configured in a generally horizontal manner with side portions 30 being generally horizontal and a raised center portion 32 extending upwardly from the side portions 30 in an arcuate configuration. Like the front handles 26, the rear handle 28 facilitates an attendant using one or two hands to push or pull the warming therapy device 10. [0032] The front and rear handles 26, 28 preferably have brake controls 34, 36 respectively mounted on the inner portion of the handles 26, 28. The brake controls 34, 36 are preferably rcsiliently mounted to their respective handles 26, 28 and depressible, towards the front or rear handles 26, 28 while gripping the handles 26, 28, such as by squeezing the handles 26, 28 and brake controls 34, 36 together. As shown with the front handles 26. the brake controls 34 may be fitted within the handles and are preferably biased in a first, non- depressed position. As shown with the rear handles, the brake control 36 may also be a separate bar or tab that is mounted adjacent the rear handle 28. Squeezing the brake controls 34, 36 towards the handles 26, 28 moves the brake controls 34, 36 to a second, depressed position. Although not shown, the handles may also have steering controls for controlling or limiting the direction of the casters 22. [0033] Figure 5A shows a schematic view of a first exemplary embodiment of a handle 26 for use with the warming therapy device 10. The numeral for the front handle 26 will be used for ease of explanation, but the handle 26 in Figure 5 A may be either of the front or rear handles 26, 28 described herein. The brake control 34 may be mounted along a longitudinal side of the handle 26 with a post mechanism 100. The post mechanism 100 allows the brake control and is operable between a first position 102 and a second position 104 (shown in phantom).

[0034] A steering control 106 is also mounted on the handle 26 and is linked to a steering system. The steering control 106 is operable between a first position 108 and a second position 1 10 (shown in phantom). Preferably the steering control 106 is spring loaded with detents, such that a single press of the steering control 106 will operate a steering control system. By way of example, when the steering control 106 is in the first position 108, the casters 22 will be allowed to rotate freely about a vertical axis. However, when the steering control 106 is operated into the second position 110, the steering control system will lock the caster 22 into position such that the caster 22 will only facilitate movement in the forward and backward directions, rather than being freely rotatable about the vertical axis. In the embodiment pictured, a user may press the steering control 106 towards the handle 26 to operate the steering control 106 from the first position 108 and second position 1 10. Likewise, a user may operate the steering control 106 from the second position 1 10 to the first position 108 with another inward push to clear an internal detent and then allow the steering control 106 to revert back to the first position 108 as the result of internal bias, such as by a spring.

[0035] Referring now to Figures 6-8, there is shown a caster 22 according to a first exemplary embodiment of the present invention. The caster 22 is adapted to pivot around a central pin 38 which fits into the lower portion 20 of the cart 14 and is linked to the brake controls 34, 36. The central pin 38 extends downwardly into a caster shroud 40. A frame 42 extends downwardly from the central pin 38 and caster shroud 40. Opposing wheels 44 are mounted on the frame 42 and adapted for engagement with a supporting surface (not shown). Each of the wheels 44 has a removable hub cap 46, which provides for access to various internal components of the caster 22 as will be described in more detail below. [0036] Referring now to Figures 9 and 10, the wheel 44 is made up of a wheel frame 48 and a tire 50. The hub cap 46 is adapted to snap fit into a circular rim formed by the wheel frame 48. The wheel frame 48 has a plurality of spokes 52 extending outwardly from a central hub 54. The caster frame 42 has a wheel axle 56 extending outwardly therefrom. Preferably, the wheel axle 56 is threaded so that the wheel 44 may be retained in place by a bolt 58. A bearing 60 is disposed between the central hub 54 of the wheel 44 and the wheel axle 56 and facilitates rotation of the wheel 44 about the wheel axle 56. Open areas extend between each spoke 52 and allow access to portions of the caster frame 42, when the hub cap 46 is removed.

[0037] Referring now to Figures 1 1 -14. a portion of the caster 22 is shown with the wheels 44 removed. The caster 22 includes a brake system 62 integrated therein which has a brake plunger 64 extending downwardly through the central pin 38. The brake plunger 64 shares a central longitudinal axis with the central pin 38 and is vertically operable along the longitudinal axis thereof.

[0038] The braking system 62 is located within the casters 22 and mechanically connected to the brake controls 34, 36. As will be described in more detail below, when the brake controls 34, 36 are in the first position, the braking system 62 is engaged, thereby restricting rolling movement of the warming therapy device 10. When the brake controls 34, 36 are in the second position, the braking system 62 is released, allowing rolling movement of the caster 22. [0039] Referring briefly to Figure 15, there is shown a cross-sectional view of the caster 22 shown in Figures 1 1-14. The braking system 62 of the caster 22 also includes a ball bearing 66, a brake release pin 68, a brake lever 70, a brake pin 72, a compression spring 74, and a set screw 76, all disposed within the frame 42. [0040] Referring again to Figures 1 1-14, the wheels 44 of the caster 22 (shown in Figures 6-10) are adapted to rotate around wheel axles 56 that extend laterally from the frame 42. As mentioned above, the wheel axles 56 may have threads 78 to facilitate attachment of the wheels 44 using bolts 58. Alternatively, some other attachment means may be used to mount the wheels 44 on the wheel axles 56. [0041] The braking system 62 within the caster 22 includes a brake pin 72 which extends laterally and generally parallel to the wheel axles 56, from the brake lever 70 through an elongated aperture 80 in the frame 42. The brake pin 72 is normally biased upwardly by a biasing member, such as the compression spring 74 shown here, which exerts an upward force on the brake lever 70. The brake pin 72 is mechanically linked to the plunger 64, such that when the plunger 64 is depressed, the brake pin 72 moves downwardly. The aperture 80 is shaped to facilitate the brake pin 72 moving up and down through its entire range of motion, thereby allowing engagement and disengagement of the braking system 62, as will be further discussed below. [0042] Extending downwardly from the bottom of the caster 22 is the set screw 76. The set screw 76 is adjustably threaded through the bottom of the caster 22 and may be adjusted upwardly and downwardly. Above the set screw 76 is a spring disc 82, which serves as a bottom plate for the compression spring 74. The set screw 76 may be adjusted to adjust the force of the braking system 62. The set screw 76 may also be adjusted to compensate for wear of the braking system 62, thereby maintaining a constant breaking force throughout the life cycle of the parts in the braking system 62.

[0043] With reference to Figure 16, there is shown a partial cut away view of the caster 22. Cutaway section A is taken through the hub cap 46 and the wheel frame 48 and shows a cross section of the central hub 54 area. For purposes of clarity, the wheel axle 56, bolt 58 and bearing 60 are not shown in cross section. [0044] Cutaway section B is taken through a portion of the hub cap 46 and wheel frame 48 adjacent the outer rim of the wheel frame 48. As shown in cutaway section B, a brake member, such as a brake shoe 84, is mounted on the brake pin 72. For purposes of clarity, the brake shoe 84 and brake pin 72 are not shown in cross section, while the wheel frame 48 is shown in cross section. The brake shoe 84 is adapted to engage a braking contact surface, such as an inner surface 86 of the wheel frame 48, which is located radially inward of a wheel frame rim 88. The inner surface 86 which serves as a braking surface similar to the inner surface of a traditional brake drum. The brake shoe 84 and brake pin 72 are shown in a raised position, engaged with the inner surface 86. It is contemplated that the braking surface may be on a separate structure from the wheel frame 48, or the wheel frame 48 itself may serve as the braking surface. The brake shoe 84 is removable and replaceable by mounting a new brake shoe 84 on the brake pin 72. Access to the brake shoe 84 and brake pin 72 are provided through removal of the hub cap 46 and through vacancies in the wheel frame 42, as best seen in Figures 9 and 10.

[0045] Referring again to Figure 15, the brake system 62 resides within the caster 22. In particular, the braking system 62 operates to engage the brake pin 72 in response to the brake controls 34, 36 which are mounted on the front and rear handles 26, 28. As mentioned above, the plunger 64 is vertically operable within the central pin 38. Vertical operation of the plunger 64 moves the brake pin 72, which is mechanically linked to the plunger 64, through various parts of the braking system 62. As discussed above, the braking system 62 is preferably housed within a cavity in the frame 42 and held in place by a brake cap 90. [0046] In a normal state, when the brake controls 34, 36 are in the first position, with no depression or actuation of the brake controls 34, 36, coupled to the front and rear handles 26, 28, the braking system 62 holds the brake pin 72 in an upwardly disposed position, thereby engaging the brake shoe 84 with the inner surface 86 of the wheel rim 88. The braking system 62 biases the brake pin 72 in the upward position through a compression spring 74 disposed within the bottom portion of the caster 22. The compression spring 74 engages a spring disk 82 located between the compression spring 74 and the set screw 76. The set screw 76 is adjustable to control the amount of upward force exerted by the compression spring 74. As the set screw 76 is threaded into the frame 42 of the caster 22. the braking force is increased and vice versa. As mentioned above, this type of adjustment may also be used to compensate for wear of the brake shoe 84 and the wheel rim 88. [0047] The brake pin 72 is coupled to a brake lever 70 that is located above, and engages with, the compression spring 74. The brake lever 70 extends upwardly from the brake pin 72 and engages a brake release pin 68. A ball bearing 66 is located between the plunger 64 and the brake release pin 68 to allow for rotation of the plunger 64 with respect to the structure that links the braking system 62 to the brake controls 34, 36 (linking structure not shown). The brake controls 34, 36 may be linked to the braking system 62 by means of cable, pneumatic link, electronically, remote control or some other means for actuating the braking system 62 in response to an input at the brake control 34, 36.

[0048] In operation, when a user depresses one of the brake controls 34, 36 of the front or rear handles 26, 28. thereby moving the brake controls 34, 36 from the first position to the second position, the plunger 64 is pressed downwardly and, via the ball bearing 66 and brake release pin 68, the brake lever 70 is lowered against the bias of the compression spring 74. The lowering of the brake lever 70 lowers the actuator brake pin 72, thereby releasing the engagement of the brake shoe 84 with the inner surface 86 of the wheel rim 88, to remove the restriction on rotation of the wheel 44.

[0049] The downward movement of the brake lever 70 is damped by a damping spring 92 that engages a dowel pin 94, which extends through a slot 96 in the brake lever 70. The dowel pin 94 is positioned horizontally within the slot 96 and vertically movable within the slot 96. The damping spring 92 biases the dowel pin 94 against the top of the slot 96. During operation, where a damping spring is used, an extension of the brake release pin 68 (not shown) mechanically engages the dowel pin 94. instead of the brake release pin 68 directly engaging the brake lever 70 (as described in connection with an alternative embodiment of the braking system below). The downward force exerted by the brake release pin 68 would not be fully transferred to the brake lever 70 until the damping spring 92 is sufficiently compressed, or the dowel pin 94 engages the bottom of the slot 96. Once sufficient force is applied to overcome the damping spring 92, the brake lever 70, and thus the brake pin 72 will begin to move downwardly. Once force is released, the brake lever 70 will spring upward as the result of the compression spring 74. During this upward movement, the damping spring 92 may also serve to damp the engagement of the brake shoe 84 with the inner surface 86 of the wheel rim 88.

[0050] As mentioned above, the braking system 62 is adjustable by virtue of selecting the spring rates for the compression spring 74 and the damping spring 92, as well as turning the set screw 76 to compress the compression spring 74 in its normal state. By adjusting the aforementioned structures, an operator can adjust the level of force required to disengage the brake shoe 84 from the inner surface 86 of the wheel rim 88, the speed with which the brake shoe 84 engages the inner surface 86 of the wheel rim 88 after one or more of the brake controls 34, 36 of the front and rear handles 26, 28 are released, and the overall force exerted by the brake shoe 84 on the inner surface 86 of the wheel rim 88.

[0051] A braking system 162 according to a second exemplary embodiment of the present invention is shown in Figure 17. The braking system according to the second exemplary embodiment is housed primarily within a caster 122, which comprises a central pin 138, a shroud 140 and a frame 142. The shroud 140 is disposed at the top of the frame 142 and the central pin 138 extends upwardly from the shroud 140. Unlike the braking system 62 described above with respect to the caster 22, no damping spring (74) is used with the caster 122. Instead, a brake release pin 168 directly engages a brake lever 170 directly when a plunger 164 is pushed downwardly in response to the brake handles as discussed above.

[0052] The plunger 164 drives a ball bearing 166 forcing the brake release pin 168 downwardly. The brake lever 170, which has a brake pin 172 extending laterally therefrom, is normally biased in an upward position by a compression spring 174 located at the bottom of the caster frame 142. The compression spring 174 is adjustable by turning a set screw 176. [0053] Figure 18 shows a partial cross sectional view of a third exemplary embodiment of a caster 222 with the braking components not shown. Like the casters 22, 122 above, the caster 222 has a wheel 244, a caster frame 242 and a central pin 238. The caster 222 comprises a steering system including a ring of teeth 239 and a steering block 243. At the bottom end of the central pin 238 is a ring of teeth 239 extending downwardly from a flange 241. The caster 222 also has a steering block 243 adapted to engage the teeth 239 and restrict directional movement of the caster 222. In the embodiment shown, directional movement of the caster 222 is rotational movement of the caster 222 about a vertical axis that extends through the center of the central pin 238. The steering block 243 is normally disposed in a position away from the teeth 239, allowing the flange 241 and teeth 239 to spin freely within the caster frame 242, which facilitates the rotation of the caster 222 because the central pin 238 remains in a fixed rotational position with respect to the warming therapy device 10. However, when a user of the warming therapy device 10 depresses a steering control (not shown), the steering block 243 is slid laterally and engages the teeth 239, thereby restricting rotation of the caster frame 242 with respect to the central pin 238. The steering control 106 may be linked to the steering system by means of cable, pneumatic link, electronically. remote control or some other means for actuating the steering system in response to an input at the steering control 106.

[0054] While the foregoing detailed description of this disclosure has been described in relation to certain representative structures thereof, and many details have been set forth for purposes of illustration, it will be apparent to those skilled in the art that the disclosure can be varied considerably without departing from the basic principles of the disclosure.

Claims

CLAIMSWhat is claimed is:

1. An apparatus comprising: a cart having a handle mounted thereon and a plurality of casters extending downwardly therefrom, each caster having a wheel having an axis of rotation; a brake control mounted on the handle and being operable between a first position and a second position; and a braking system located within the caster and operable to provide braking force to the caster, said braking system having a braking contact surface and a brake member adapted to engage the braking contact surface and restrict movement of the braking contact surface with respect to the brake member, the brake member being normally biased in a first position, against the brake contact surface, and operable to a second position, spaced away from the brake contact surface. wherein the braking system is linked to the brake control and wherein the brake member remains the first position when the brake control is in the first position.

2. The apparatus according to claim 1 , wherein the brake member moves from the first position to the second position as the brake control is moved from the first position to the second position.

3. The apparatus according to claim 1, further comprising a steering control mounted on the handle and being operable between a first position and a second position and a steering system adapted to selectively restrict rotational movement of the caster about an axis that is generally perpendicular to the axis of rotation of the wheel, wherein the steering system is linked to the steering control and the steering control does not restrict rotational movement of the caster when the steering control is in the first position and the steering system restricts rotational movement of the caster when the steering control is in the second position.

4. The apparatus according to claim 3, wherein the force of the bias of the brake member in the first position is adjustable.

5. The apparatus according to claim 4 wherein the brake control is biased in the first position and requires the application of force to move the brake control from the first position to the second position.

6. The apparatus according to claim 1, wherein steering control is biased in the first position and operable to the second position.

7. The apparatus according to claim 1, wherein the first position of the brake control is a raised position and the second position of the brake control is a depressed position.

8. The apparatus according to claim I , wherein the bias of the brake member in the first position is provided by a spring.

9. The apparatus according to claim 1 , wherein the brake member is removable.

10. The apparatus according to claim 1, wherein the handle is disposed on an angle from a horizontal plane.

1 1. An apparatus comprising: a cart mounted medical device; a handle mounted on the cart and having a brake control mounted in connection with the handle, said brake control operable between a first position and a second position; at least one caster mounted on the cart and having a brake system biased to restrict rotational movement of the caster; wherein the brake system is linked to the brake control such that brake system allows rotational movement of the caster when the brake control is moved from the first position to the second position.

1 1. The apparatus according to claim 10, wherein the brake control is normally disposed in the first position.

12. The apparatus according to claim 10, wherein the brake system comprises a wheel, a braking surface, a brake member adapted to engage the braking surface and a biasing member adapted to bias the brake member against the braking surface.

13. The apparatus according to claim 12, wherein the biasing member is a spring located within the caster.

14. The apparatus according to claim 12, wherein the force exerted by the biasing member is adjustable.

15. The apparatus according to claim 10, the handle further comprising a steering control operable between a first position and a second position and the caster further comprising a steering system adapted to selectively restrict rotational movement of the caster about an axis that is generally perpendicular to the axis of rotation of the wheel, wherein the steering system is linked to the steering control and the steering control does not restrict rotational movement of the caster when the steering control is in the first position and the steering system restricts rotational movement of the caster when the steering control is in the second position.

16. The apparatus according to claim 10, wherein the steering control is biased in the first position.

17. A method for moving a cart comprising: providing a cart including plurality of casters mounted thereon and a handle having a brake control, said brake control being biased in a first position and operable between the first position and a second position wherein a brake is applied to at least one of the casters when the brake control is in the first position and no brake is applied when the brake control is in the second position; gripping the handle of the cart; applying pressure to the brake control thereby moving the brake control from the first position to the second position; and applying lateral force to the handle while maintaining pressure on the brake control thereby moving the cart in an intended direction.

18. The method according to claim 17, wherein the handle further comprises a steering control biased in a first position and operable between the first position and a second position and at least one of the casters comprises a steering system that restricts directional movement of the caster when the steering control is in the second position and allows movement in the caster in all lateral directions when the steering control is in the first position, the method further comprising the step of moving the steering control from the first position to the second position to control the direction of the caster.

19. A medical device comprising: a cart having a handle mounted thereon and a plurality of casters extending downwardly therefrom, each caster having a wheel having an axis of rotation; a brake control mounted on the handle and being operable between a first position and a second position; a steering control mounted on the handle and being operable between a first position and a second position; a braking system located within the caster and operable to provide braking force to the caster, said braking system having a braking contact surface and a brake member adapted to engage the braking contact surface in a first position and restrict movement of the braking contact surface with respect to the brake member in a second position, the brake member being normally biased in the first position and operable to the second position. wherein the braking system is linked to the brake control and the brake member remains the first position when the brake control is in the first position and the brake member moves to the second position as the brake control is moved from the first position to the second position; and a steering system adapted to selectively restrict rotational movement of the caster about an axis that is generally perpendicular to the axis of rotation of the wheel, wherein the steering system is linked to the steering control such that the steering control does not restrict rotational movement of the caster when the steering control is in the first position, but restricts rotational movement of the caster when the steering control is in the second position.

20. A warming therapy device comprising: a handle having a brake control mounted in connection with the handle, said brake control operable between a first position and a second position; at least one caster having a brake system including a wheel, a braking surface, a biasing member and a brake member, wherein the braking surface is adapted for rotation with the wheel and wherein the brake member is adapted to frictionally engage the braking surface and the brake member is biased against the braking surface as the result of force exerted on the brake member by the biasing member in the direction of the braking surface; wherein the brake system is linked to the brake control such that the brake member is moved away from the braking surface when the brake control is moved from the first position to the second position.

21. A method for moving a cart comprising: providing a cart including a handle and plurality of casters mounted on the cart, said handle having a brake control and a steering control mounted thereon, said brake control being operable between a first position and a second position and said steering control being operable between a first position and a second position; and said plurality of casters extending downwardly from a bottom portion of the cart and having a braking system and a steering system contained therein, said braking system adapted to restrict rotational movement of the caster when engaged and being biased in an engaged position when the brake control is in the first position and disengaged when the brake control is in the second position, said steering system operable to selectively restrict directional movement of the caster, wherein the steering system is linked to the steering control such that when the steering control is in the first position, the steering system does not restrict directional movement of the caster and when the steering control is in the second position, the steering system restricts directional movement of the caster; gripping the handle of the cart; applying pressure to the brake control thereby moving the brake control from the first position to the second position; applying lateral force to the handle while maintaining pressure on the brake control thereby moving the cart in an intended direction; and applying pressure to the steering control thereby moving the steering control from the first position to the second position and restricting the directional movement of the caster.