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WO1998030275A1 - Dispositif de commande de l'apport de fluides - Google Patents

Dispositif de commande de l'apport de fluides Download PDF

Info

Publication number
WO1998030275A1
WO1998030275A1 PCT/US1998/000021 US9800021W WO9830275A1 WO 1998030275 A1 WO1998030275 A1 WO 1998030275A1 US 9800021 W US9800021 W US 9800021W WO 9830275 A1 WO9830275 A1 WO 9830275A1
Authority
WO
WIPO (PCT)
Prior art keywords
anticoagulant
flow
pressure transducer
fluids
fluid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US1998/000021
Other languages
English (en)
Inventor
James R. Ellsworth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Harvest Technologies Inc
Original Assignee
Harvest Technologies Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Harvest Technologies Inc filed Critical Harvest Technologies Inc
Publication of WO1998030275A1 publication Critical patent/WO1998030275A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M31/00—Devices for introducing or retaining media, e.g. remedies, in cavities of the body
    • A61M31/002—Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/71—Suction drainage systems
    • A61M1/77—Suction-irrigation systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/02—Blood transfusion apparatus
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2202/00—Special media to be introduced, removed or treated
    • A61M2202/04—Liquids
    • A61M2202/0468—Liquids non-physiological
    • A61M2202/0478—Heparin

Definitions

  • This invention relates to the art of devices for controlled delivery of fluids.
  • the invention provides controlled delivery of an anticoagulant for a blood recovery system.
  • shed blood is collected by a vacuum system that is carefully regulated to provide vacuum pressures that do not harm the cells of the blood being collected.
  • An anticoagulant such as citrate, is added to the blood as it is collected to prevent clotting.
  • Heparin may also be used to prevent clotting by applying it to foreign surfaces or by adding it to the collected blood.
  • a prescribed anticoagulant concentration preferably from five to twenty parts blood to one part anticoagulant, because blood with too little anticoagulant will clot, whereas blood with too much anticoagulant requires washing to remove the excess anticoagulant. It is at present difficult to maintain a flow rate of anticoagulant that achieves this. Such is particularly true for most systems in practice because the rate of collection of shed blood generally varies as a function of time, whereas the rate of flow of the anticoagulant through a tube of give size is time invariant.
  • One known device for controlling the flow of anticoagulant is a roller clamp that is positioned to occlude to a desired degree a tube carrying the anticoagulant. These roller clamps are not precision devices, and it is difficult to set the flow rate accurately with this device.
  • a flow meter monitors the rate at which shed blood is collected through an aspiration tube in a vacuum-operated collection system.
  • the flow meter employs the combination of a precision restriction in the flow path and a pressure transducer to accurately measure the flow rate. As increased volumes of blood are entrained in the aspiration tube, the flow rate of the fluids in the tube decreases, and this information is used in the system of the invention to control the supply of anticoagulant to the collected blood.
  • a pressure sensor detects the pressure differential across the precision restriction as a measure of the flow rate of the collected fluids in the aspiration tube.
  • a first circuit includes a transducer for converting this pressure differential to a voltage, and the voltage is applied to an electrical device for controlling the flow of anticoagulant.
  • the electrical device includes a solenoid that controls the amount by which a flexible tube carrying the anticoagulant is pinched.
  • the control mechanism preferably includes a platen that receives the tube carrying the anticoagulant and a lever for squeezing the tube against the platen.
  • the lever is biased by a spring to occlude the tube to stop the flow of anticoagulant.
  • the solenoid is arranged to move the lever by pushing against the force of the spring to reduce the amount by which the tube is occluded, thereby increasing the flow of anticoagulant.
  • a second circuit operating in parallel with the first is a timing circuit, which includes a pulse generator for applying periodic electric signals to the solenoid. These periodic signals release the pressure applied by the lever periodically to provide a constant "drip" flow rate of the anticoagulant at a rate that is independent of the rate at which blood is collected. This flow prevents drying of the passages.
  • Figure 1 is a schematic diagram of a blood collection system using a controller in accordance with the invention.
  • Figure 2 is a side view of a controller in accordance with the invention.
  • FIG. 3 is a circuit diagram of a control circuit in accordance with the invention.
  • FIG 1 shows an overall schematic diagram of a system employing the invention.
  • a blood collection system 2 includes a vacuum source that applies vacuum to an aspiration tube 4 for aspirating shed blood and carrying it to a reservoir as is known in the art.
  • a container 6 of anticoagulant is connected to a tube 8 for supplying the anticoagulant to the collected blood or other fluids.
  • the anticoagulant is supplied to the blood as it flows in the aspiration tube 4.
  • a sucker handle 10 is connected to the ends of the aspiration tube and the anticoagulant tube by a connector 12.
  • This connector includes Y-shaped interior channels that connect the sucker handle to the aspiration and anticoagulant tubes such that the anticoagulant is drawn into the aspirated fluids as they flow through the handle into the aspiration tube.
  • the aspiration and anticoagulant tubes are preferably provided in a dual-lumen tube as illustrated.
  • the anticoagulant tube 8 is directed through a flow controller 14, which is shown schematically in figure 1 and in more detail in figure 2.
  • an enclosure 16 supports a platen 18 and a movable element, such as a lever 20, for pressing the tube 8 carrying anticoagulant against the platen.
  • the lever 20 is pivotally mounted to the enclosure 16 at a pin 22 such that one end of the lever engages the tube 8 and an opposite end engages a bias spring 24 and the plunger of a control solenoid 26 .
  • One end of the bias spring is held by a bracket 28, and the other end engages the lever 20. In operation, the spring pulls on one end of the lever, which causes the other end of the lever to press the tube 8 against the platen 18 to occlude the tube.
  • the normal condition of the mechanism is for the anticoagulant tube 8 to be pinched closed.
  • the solenoid 26 is arranged to engage the lever such that energization of the solenoid pushes against the lever in a direction opposite to the direction of the force applied by the bias spring.
  • energization of the solenoid releases the occlusive pressure on the tube and allows increased flow of anticoagulant into the aspiration tube through the connector 12 illustrated in figure 1.
  • the end of the lever 20 opposite the spring includes a ramp portion 30 which terminates adjacent the platen 18. This facilitates insertion of the tube 8 into the gap formed between the lever and the platen.
  • the tube is placed against the ramp and urged toward the platen against the force of the spring. This moves the lever away from the platen to allow the tube to be located in the gap between these elements.
  • a vacuum line 32 is connected between a source of vacuum 34 and the aspiration tube 4.
  • the vacuum line connects to a collection chamber 36, and the aspiration line also connects to that chamber.
  • the vacuum source and collection chamber are elements of the blood collection system 2 shown in figure 1. It will be appreciated that the collection chamber may be a disposable element.
  • the vacuum line 32 is provided with a precision flow restriction 38, which creates a pressure differential that is a function of the flow rate of the fluids undergoing collection.
  • a pressure transducer 40 measures the pressure drop across the flow restriction, and the output of the transducer is connected to a flow meter function circuit 42.
  • This circuit produces a voltage that is a function of the pressure drop across the flow restriction and, hence, a function of the flow of collected blood in the aspiration tube.
  • the voltage produced by the flow meter function circuit is applied to the solenoid 26 of figure 2 through an "or" gate 44. It will be appreciated that as the collection system collects blood, the flow rate of collected blood through the aspiration tube decreases, and the pressure differential across the restriction decreases. This decrease is detected by the pressure transducer 40, which is of known construction, and a voltage is produced that is an inverse function of the pressure across the restriction. As the voltage applied to the solenoid increases, the pressure applied to the anticoagulant tube by the lever decreases, and the flow rate of anticoagulant increases. The parameters of the circuitry are adjusted such that the increase or decrease in flow of collected blood is matched by a proportional increase or decrease in flow of anticoagulant, whereby the ratio between the two is maintained.
  • a timing function circuit 46 produces regular pulses to the "or" gate. These pulses are provided to the solenoid irrespective of the voltage applied by the flow meter function circuit whereby a constant, small, flow of anticoagulant is provided to prevent drying of the passages.

Landscapes

  • Health & Medical Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Engineering & Computer Science (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Anesthesiology (AREA)
  • Biomedical Technology (AREA)
  • General Health & Medical Sciences (AREA)
  • Hematology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Chemical & Material Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Pulmonology (AREA)
  • Vascular Medicine (AREA)
  • External Artificial Organs (AREA)

Abstract

Dans ce dispositif de commande d'écoulement, on utilise un circuit de rétroaction pour réguler la vitesse d'apport d'un anticoagulant à du sang versé, sang que l'on récupère dans un système de conservation de sang. Un circuit électronique (46) détecte la vitesse d'écoulement du sang à laquelle l'anticoagulant est ajouté au sang recueilli, de façon que la vitesse d'écoulement de l'anticoagulant soit fonction de la vitesse d'écoulement du sang recueilli. Un second circuit de synchronisation (42) commande l'apport d'un écoulement additionnel d'anticoagulant, à une vitesse indépendante de la vitesse d'écoulement du sang recueilli. On régule la vitesse d'écoulement de l'anticoagulant en faisant passer un tube (8) contenant l'anticoagulant à travers un mécanisme de serrage, lequel est commandé électriquement par le circuit de synchronisation et par le circuit détectant la vitesse d'écoulement du sang recueilli, par détection de la pression dans la conduite sous vide de réception du sang (32).
PCT/US1998/000021 1997-01-09 1998-01-09 Dispositif de commande de l'apport de fluides Ceased WO1998030275A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US3498797P 1997-01-09 1997-01-09
US60/034,987 1997-01-09

Publications (1)

Publication Number Publication Date
WO1998030275A1 true WO1998030275A1 (fr) 1998-07-16

Family

ID=21879909

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/000021 Ceased WO1998030275A1 (fr) 1997-01-09 1998-01-09 Dispositif de commande de l'apport de fluides

Country Status (1)

Country Link
WO (1) WO1998030275A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8088091B2 (en) 2009-03-09 2012-01-03 New Jersey Institute Of Technology No clog shunt using a compact fluid drag path
US20120053501A1 (en) * 2010-08-24 2012-03-01 Brown Richard I Methods and systems for anticoagulating blood
US10226193B2 (en) 2015-03-31 2019-03-12 Medtronic Ps Medical, Inc. Wireless pressure measurement and monitoring for shunts

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5460602A (en) * 1989-01-23 1995-10-24 Shapira; Nadiv Smoke evacuator for smoke generating devices
US5713849A (en) * 1994-07-19 1998-02-03 Cordis Corporation Suction catheter and method
US5735833A (en) * 1996-12-11 1998-04-07 Bristol-Myers Squibb Co. Lavage tip

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5460602A (en) * 1989-01-23 1995-10-24 Shapira; Nadiv Smoke evacuator for smoke generating devices
US5713849A (en) * 1994-07-19 1998-02-03 Cordis Corporation Suction catheter and method
US5735833A (en) * 1996-12-11 1998-04-07 Bristol-Myers Squibb Co. Lavage tip

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8088091B2 (en) 2009-03-09 2012-01-03 New Jersey Institute Of Technology No clog shunt using a compact fluid drag path
US20120053501A1 (en) * 2010-08-24 2012-03-01 Brown Richard I Methods and systems for anticoagulating blood
US9603989B2 (en) * 2010-08-24 2017-03-28 Fenwal, Inc. Methods for anticoagulating blood
US10058645B2 (en) 2010-08-24 2018-08-28 Fenwal, Inc. Systems for anticoagulating blood
US10226193B2 (en) 2015-03-31 2019-03-12 Medtronic Ps Medical, Inc. Wireless pressure measurement and monitoring for shunts
US11375915B2 (en) 2015-03-31 2022-07-05 Medtronic Navigation, Inc. Wireless pressure measurement and monitoring for shunts
US11844597B2 (en) 2015-03-31 2023-12-19 Medtronic Navigation, Inc. Wireless pressure measurement and monitoring for shunts
US12295709B2 (en) 2015-03-31 2025-05-13 Medtronic Navigation, Inc. Wireless pressure measurement and monitoring for shunts

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