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Publication numberUS3882861 A
Publication typeGrant
Publication dateMay 13, 1975
Filing dateSep 24, 1973
Priority dateSep 24, 1973
Also published asDE2445403A1, DE2445403C2
Publication numberUS 3882861 A, US 3882861A, US-A-3882861, US3882861 A, US3882861A
InventorsDonald E Kettering, Morris E Jones
Original AssigneeVital Assists
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Auxiliary control for a blood pump
US 3882861 A
Abstract
An auxiliary control for a blood pump used in hemodialysis which acts upon an existing blood pump controller to continuously vary the pump rate in direct correspondence with changes in flow of a patient's blood reflected as variations in negative pressure in a blood line. The auxiliary control regulates the pump rate by producing an electrical pulse train in which the duration of the pulses corresponds to changes in negative pressure corresponding to changes in the blood flow rate. The control presents means for achieving a rapid response to changes in the flow of the patient's blood.
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United States Patent 1191 1 1111 3,882,861

Kettering et a1. May 13, 1975 1 AUXILIARY CONTROL FOR A BLOOD 3,656,478 4/1972 Swersey 128/214 E PUMP 3,731,680 5/1973 Wright et a1. 123/214 F 3,756,234 9/1973 Kopp 128/214 R [751 Inventors: Donald ettering. Salt a ty; 3,778,694 12/1973 Hubby et a1. 318/474 Morris E. Jones, Bountiful. both Of 3,799,702 3/1974 Weishaar 128/278 X Utah Primary Examiner-Dalton L. Truluck 7 3] Asslgnee Assists Inc Salt Lake Clty Attorney, Agent, or Ftrm--H. Ross Workman [22] Filed: Sept. 24, 1973 57 CT pp 399,904 An auxiliary control for a blood pump used in hemodialysis which acts upon an existing blood pump controller to continuously vary the pump rate in direct corre- [52] CL 128/214 E; 28/214 F; ZS/DIG l2; spondence with changes in flow of a patient's blood 417/44 [51} Int. Cl A6lm 01/03 reflected as f' m negatwe pressure m a blood [58] Field of Search 128/213 214 R 214 E line. The auxihary control regulates the pump rate by producing an electrical pulse train in which the duration of the pulses corresponds to changes in negative pressure corresponding to changes in the blood flow 128/214 F, 214.2, DIG. l2, DIG. 13; 417/44 56 References Cited 7 1 rate. The control presents means for achievmg a rap1d UNITED STATES PATENTS response to changes in the flow of the patients blood. 3,091,239 5/1963 Moeller 128/214 F D F 3,496,878 2/1970 Hargest et a1 1. 417 14 7 Clam", 3 "awmg gums 39\ PUMP BLOOD. gfl zo CONTROLLER PUMP """i 37 1 22 I so A 1 I 1 PRESSURE AVERAGING COMPARATOR ELECTRONIC TRANSDUCER CIRCUIT SWITCH 1 mp 56 y 28 3| NEGATIVE INITIAL l i 24 PRESSURE REFERENCE Z 'Z PUMP I READOUT CONTROL R TOR POWER //55 i 23 52 34 SUPPLY 1. ..J

1 AUXILIARY CONTROL FOR A BLOOD PUMP BACKGROUND 1. Field of the Invention The present invention relates to an improved auxiliary control for an extracorporeal blood pump used in hemodialysis and more particularly to novel apparatus for controlling the blood pump rate in an extracorporeal hemodialysis system.

2. The Prior Art Historically, kidney diseases have been of critical concern to human life. Many kinds of kidney diseases interfere with the function of the kidney such that the kidney ceases to remove waste and excess water from the blood. When the kidney is sufficiently impaired that a large portion of the waste products and water are not removed from the blood, the life of the patient cannot be preserved unless a way is provided for artificially performing the functions of the impaired kidney through extracorporeal hemodialysis.

Many of the presently known hemodialysis apparatus require the use of a blood pump to provide additional pressure in the withdrawn blood in order to conduct it through the hemodialysis unit. A major problem presented by the presently known blood pumps and associated control apparatus is the inability of such apparatus to provide a minimum time for dialysis while simultaneously preventing pump starvation and the resulting collapse of the supply blood lines. It is well-known that blood should be withdrawn from the patient at a rapid rate so as to reduce the time for dialysis. However, when the blood supply at the patient is insufficient to supply the blood pump, the blood lines and even the patients blood vessels collapse which interrupts effective hemodialysis until adequate blood flow is restored. The collapse of blood lines resulting from insufficient blood supply to a continuously operating blood pump is defined herein as pump starvation." To avoid time consuming and sometimes dangerous pump starvation, it has conventionally been necessary to adjust the pump speed well below an optimum rate to a level which pro vides a wide safety margin in order to avoid pump starvation.

Even with this precaution, however, it is common for the patients blood flow rate to fluctuate significantly during the course of dialysis. Accordingly, the attending physician must choose between (a) lowering the pump rate to accommodate the lowest possible blood flow rate as a safety margin and thereby significantly extending the dialysis time or (b) risk collapse of blood lines and premature interruption of dialysis through pump starvation in the event of a drop in the patients blood flow rate.

Several attempts have been made to produce a pump which is able to compensate for changes in the amount of available blood while the patient is undergoing dialysis. The prior art shows the use of step-wise regulation apparatus which only vary the volume of blood pumped in a series of discrete steps and do not allow for continuously variable changes in the volume of blood pumped. That type of pump and control apparatus requires a threshold level of pressure change before any responsive action is taken. One such step-wise system is shown in U.S. Pat. No. 3,698,381.

Other types of control apparatus have employed specially designed pumps which are mechanically capable of increasing the force applied to a collapsible blood reservoir in order to thereby increase the pressure of blood supplied from the reservoir. One such specialized blood pump and associated control is shown in U.S. Pat. No. 3,592,183.

A major deficiency which is observed in the attempts to solve the regulation of pump starvation is that the solution involves the replacement of all existing pump controllers and/or blood pumps. Until the present invention, it has not been possible to continuously vary the rate of a continuous flow blood pump in response to the availability of blood while retaining the existing conventional blood pump and controller.

BRIEF DESCRIPTION AND OBJECTS OF THE INVENTION The present invention includes novel apparatus for continuously varying the pump rate of a blood pump used in hemodialysis in response to changes in blood flow from the patient so as to maximize the rate of hemodialysis while avoiding pump starvation. Furthermore, the invention provides apparatus which can accomplish the previously described function in combination with existing conventional blood pumps and control mechanisms.

It is, therefore, a primary object of the present invention to provide improved extracorporeal hemodialyzing pump control apparatus.

It is another primary object of the present invention to provide extracorporeal hemodialysis pump control apparatus which cooperates with presently known pumps and associated controls to achieve a continuously variable pump rate responsive to changes in blood flow.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a block diagram illustrating a presently preferred embodiment of the invention;

FIG. 2 illustrates a waveform taken at point A in FIG. 1, the waveform particularly showing a signal representation when the patients blood flow has increased during the course of dialysis; and

FIG. 3 illustrates a waveform taken at point A of FIG. 1, the waveform particularly showing a signal representation when the patients blood flow has decreased during the course of dialysis.

DETAILED DESCRIPTION OF THE INVENTION dialyzer by blood pump 37. Accordingly, a negative pressure will exist in blood lines upstream from the pump. If outflow of the patients blood should be limited through stricture, clotting, hypotension or any other of a variety of common circumstances, negative pressureupstream from the pump will increase proportionately. Conversely, negative pressure will decrease as blood becomes more available to the pump.

According to one presently preferred embodiment of the invention, a conventional pressure transducer 22 provides a direct conversion between negative pressure in the blood line 24 and electrical voltage. Blood line 24 connects the pressure transducer to a conduit (not shown) which carries blood from a blood vessel of a patient to the blood pump 37. The electrical qualities of the pressure transducer may be characterized as either a variable resistance or a variable voltage source. Whichever type of transducer is employed or whichever electrical characterization is used, the electrical quantity varies in proportion to the blood flow as measured by the negative blood pressure in line 24. The negative pressure is preferably observable on a conventional readout device 23.

The electrical output signal of the pressure transducer is fed into an averaging circuit 28. The averaging circuit 28 may be any one of a wide variety of known discrete or integrated circuits, the most simplified of which would merely be a capacitor in parallel with the transducer output conductors to accomplish averaging of the systolic and diastolic pressure signal from the transducer 22.

Certain types of pressure transducers which maintain a reservoir of blood and mechanically measure expansion and contraction of a chamber would not require the averaging circuit since the output signal from that type of transducer would be averaged mechanically.

The averaged transducer signal is then conducted to and appears at one of the inputs to a conventional operational amplifier 31 which forms part of the comparator 30. The initial reference control 32 provides a reference signal for the second comparing input of the operational amplifier 31. The initial reference control may be either a fixed or variable voltage divider which provides a pre-established signal level at one of at least two operational amplifier inputs.

The operational amplifier portion 31 of the comparator 30 is used in the summing mode, where the two inputs are added together to form an output to the electr nic switch 36 which output is proportional to the sum of the inputs. The electronic switch 36 preferably comprises a conventional threshold trigger circuit capable of converting the output signal of the operational amplifier 31 into a pulse of duration proportional to the amplitude of the output signal of the operational amplifier. A common, readily available device for performing the function of the electronic switch would be any suitable type of current controlled current source such as a unijunction transistor with an external base to emitter timing capacitance which acts to fire a triac or the like.

The power supply for the operational amplifier portion of the comparator is a pulse generator 34 which produces a generally square wave voltage signal causing the output of the operational amplifier to turn on and off at a constant rate. Any suitable conventional pulse generator having sufficient voltage output to drive the operational amplifier would be acceptable.

It should be recognized that the signal from the operational amplifier is a periodic pulse having an amplitude proportional to the sum of the initial reference signal and the averaged transducer signal. It should be recognized that the higher the output signal from the comparator, the greater the time increment that switch 36 is on, and conversely the lower the signal from the comparator, the shorter the time increment that switch 36 is on.

As shown in FIG. 1, the regular power supply line to a conventional blood pump and controller is diverted through the electronic switch 36. The waveforms shown in FIGS. 2 and 3 are taken at point A in the diagram of FIG. 1, assuming an alternating current power supply like that available at a standard utility outlet. The solid portions of the waveforms represent that portion of the waveforms during which the electronic switch 36 is off. When the switch 36 turns on, it remains on until the AC cycle goes through zero. Because the switch 36 is open or off through most of the AC cycle in FIG. 3, the energy delivered from the pump power supply 35 to the pump controller 39 is compara tively small. Thus, the blood pump 37 operates slowly. Conversely, when the switch 36 is on through most of the AC cycle (see FIG. 2), the energy delivered to the controller 39 is comparatively high and the blood pump 37 will operate comparatively rapidly.

The existing conventional blood pump controller remains useful for the purpose of setting upper limits in the speed of the blood pump. However, the invention 20 provides for immediate and continuous compensation of the speed of the blood pump in response to changes in the patients blood flow. When blood flow decreases, the output of the comparator 30 is reduced and therefore the electronic switch 36 allows a smaller proportion of the pump power supply signal to be conducted to the blood pump (see FIG. 3). Also, if the blood flow of the patient should increase during the course of dialysis, the amount of power supplied to the blood pump increases thereby increasing the speed of the pump (see FIG. 2). Accordingly, pump starvation caused by a vacuum-induced collapse of blood lines and blood vessels will be avoided because the pump 37 will operate only at the maximum rate accommodated by the available blood supply.

In using the invention, the patient is connected to the dialyzer in a method well-known in the art, the supply line 24 being normally in direct communication with the dialyzer blood circuit upstream from the pump. In one preferred method embodiment, the auxiliary control 20 is first switched off so as to have no effect on power delivered from the supply 35 to the pump controller 39. Alternatively, the auxiliary control 20 may remain on but the initial reference control 32 adjusted to the maximum so as not to interfere with the selection of a desirable maximum flow rate at the controller 39.

Subsequently, the blood pump 37 is energized and the speed of the blood pump is increased by adjusting the pump controller 39 to the desired maximum blood flow. The desired maximum blood flow may be ascertained by observing the negative pressure read-out 23 and increasing the speed ofthe blood pump until the negative pressure reaches a level prescribed by the attending physician. Alternatively, the maximum desired flow can be obtained by increasing the pump speed until the blood line or associated accumulator collapses and then reducing the speed of the blood pump 37 through the controller 39 slightly until full flow results.

Once the maximum desired flow has been established in the blood pump 37, the auxiliary controller 20 is activated by adjusting the initial reference control 32 at least until it appears from the negative pressure readout 23 that the auxiliary control 20 is monitoring blood flow at essentially the maximum desired rate set by the pump controller 39. It has been found frequently desir able to set the initial reference control on a specific negative pressure reading representing a desirable blood flow rate.

When the initial reference control has been set, the auxiliary control will continuously vary the blood pump speed so as to maintain the negative pressure reading at the preset level. Thus, if the patients blood flow reduces, the auxiliary control 20 will reduce the speed of the blood pump 37 so that the negative pressure reading will not significantly change. Conversely, if the patients blood flow increases, the auxiliary control 20 will increase the speed of the blood pump and prevent the negative pressure level from changing significantly.

The most advantageous physical housing for the invention has been found to be an enclosure (not shown) which provides an electrical outlet for the service plug of the conventional blood pump and controller, a meter for reflecting the negative pressure, and a dial plate and dial for setting the initial reference control. Of course, various power switches, pilot lights, or other indicators may be used in order to monitor the status of the circuit during operation.

The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiment is to be considered in all respects only as illustrative and not restrictive and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

What is claimed and desired to be secured by United States Letters Patent is:

l. A blood pump controller responsive to changes in blood flow comprising:

a conventional blood pump for displacing blood through an extracorporeal hemodialysis system including a blood-conducting conduit;

a conventional power source and means for delivering electrical power to the blood pump, the pumping capacity of the pump being proportional to the electrical power delivered to the pump;

means electrically interposed between the power source and the blood pump said means comprising an attachment site means for detachably coupling the blood pump to the power source through the said means; sensing means in said bloodconducting conduit for monitoring the availability of extracorporeal blood to the pump upstream from the pump; and means responsive to the sensing means for selectively and continuously varying the amount of electrical power delivered to the blood pump from the power source thereby continuously varying the pumping flow rate of the blood pump, the magnitude of pumping variation being constantly proportional to extracorporeal blood flow upstream from the blood pump during the course of dialysis.

2. A blood pump controller responsive to changes in blood flow comprising:

a conventional blood pump for displacing blood through an extracorporeal hemodialysis system;

a blood conduit for conducting blood from a patient to the blood pump; and

a conventional power source and means for delivering electrical power to the blood pump;

means electrically interposed between the power source and the blood pump, said electrically interposed means comprising:

transducer means connected to the blood conduit producing an electrical signal representing the availability of blood to the pump;

comparing means for comparing the transducer signal with a pre-established reference signal and producing a proportional output signal; and

switching means responsive to the output of the comparing means for producing a periodic pulse train wherein the duration of each pulse is proproportional to the output signal of the comparing means, the speed of the blood pump being a direct function of the duration of the pulse.

3. A blood pump controller as defined in claim 2 wherein said transducer means comprises averaging means for averaging the systolic and diastolic blood pressures.

4. A blood pump controller as defined in claim 2 further comprising means for sensing negative blood pressure upstream from the pump and wherein the switching means comprises means for (a) producing a medium duration pulse when the proportional output signal is at an initial reference level representing a predetermined negative blood pressure, (b) decreasing the pulse duration when the proportional output signal indicates reduced patients blood flow represented by increased negative value of the blood pressure, and (c) increasing the pulse duration when the proportional output signal indicates increased patients blood flow represented by decreased negative value of the blood pressure.

5. A blood pump controller as defined in claim 4 wherein said pulse responsive switching means further comprises means for closing the circuit between the pump and its corresponding power supply for the duration of each pulse.

6. A blood pump controller as defined in claim 2 wherein said comparing means comprises an operational amplifier.

7. A blood pump controller as defined in claim 2, further comprising means responsive to the transducer means for terminating the operation of the blood pump when blood flow is reduced below a predetermined

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3091239 *Aug 25, 1959May 28, 1963Wilhelm MoellerApparatus for intravasal injection of gaseous and liquid media
US3496878 *Apr 7, 1967Feb 24, 1970Bio Medical Systems IncSystem and apparatus for transfer of human fluids
US3656478 *Apr 13, 1970Apr 18, 1972Brookline Instr CoInfusion monitor utilizing weight detecting means
US3731680 *Oct 21, 1971May 8, 1973F WrightPressure regulating controller
US3756234 *Jun 4, 1971Sep 4, 1973Vital AssistsSingle needle dialysis
US3778694 *Jun 5, 1972Dec 11, 1973Texaco IncElectric motor control system for a beam-type pumping load
US3799702 *Nov 15, 1972Mar 26, 1974Weishaar EApparatus for draining blood from a surgical wound and transmission to a heart-lung machine
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3966358 *May 17, 1974Jun 29, 1976Medac Gesellschaft Fur Klinische Spezialpraparate MbhPump assembly
US4063824 *Aug 5, 1975Dec 20, 1977E. I. Du Pont De Nemours And CompanyChemical dosimeter having a constant flow air sampling pump
US4076458 *May 7, 1975Feb 28, 1978Whittaker CorporationAutomatic pump speed controller
US4123932 *May 25, 1977Nov 7, 1978E. I. Du Pont De Nemours And CompanyDosimeter for monitoring working areas
US4231366 *Aug 8, 1977Nov 4, 1980Dr. Eduard Fresenius Chemisch-Pharmazeutische Industrie Kg Apparatebau KgBlood flow monitoring and control apparatus
US4260333 *Feb 28, 1979Apr 7, 1981Robert Bosch GmbhMethod and apparatus for controlling a fuel injection system
US4269059 *Mar 19, 1979May 26, 1981E. I. Du Pont De Nemours And CompanyDosimeter having constant flow pump
US4392847 *May 6, 1981Jul 12, 1983Whitney Douglass GInjection and monitoring system
US4468219 *Dec 20, 1983Aug 28, 1984International Business Machines CorporationPump flow rate compensation system
US4492524 *Sep 17, 1981Jan 8, 1985Bruker-Analytische Messtechnik GmbhMultiple piston pump with a constant discharge capacity
US4499903 *May 3, 1979Feb 19, 1985University Of Arizona FoundationMethods and apparatus for testing a blood pressure monitoring system of the hydraulic type
US4533346 *Aug 25, 1982Aug 6, 1985Pharmacontrol CorporationSystem for automatic feedback-controlled administration of drugs
US4566858 *Jun 12, 1984Jan 28, 1986Nikkiso Co., Ltd.Pulsation-free volumetric pump
US4566868 *Sep 11, 1981Jan 28, 1986Geotechnical Digital Systems LimitedPressure source
US4710165 *Sep 16, 1985Dec 1, 1987Mcneil Charles BWearable, variable rate suction/collection device
US4778445 *Nov 28, 1986Oct 18, 1988Minnesota Mining And Manufacturing CompanyCentrifugal blood pump with backflow detection
US4870392 *Apr 5, 1982Sep 26, 1989Outboard Marine CorporationFluid flow restriction warning indicator
US4963253 *Jan 3, 1989Oct 16, 1990Yen Richard C KAnti-clogging and dialysis device for filtration systems
US4990076 *May 31, 1989Feb 5, 1991Halliburton CompanyPressure control apparatus and method
US5045057 *May 30, 1989Sep 3, 1991Akzo NvApparatus and method for withdrawing an optimum amount of blood per unit of time from a donor
US5171212 *Feb 8, 1991Dec 15, 1992Minnesota Mining And Manufacturing CompanyBlood pumping system with backflow warning
US5368554 *Nov 20, 1992Nov 29, 1994Minnesota Mining And Manufacturing CompanyBlood pumping system with selective backflow warning
US5564420 *Apr 14, 1995Oct 15, 1996Minnesota Mining And Manufacturing CompanyMedical device with EMI detection and cancellation
US5772403 *Mar 27, 1996Jun 30, 1998Butterworth Jetting Systems, Inc.Programmable pump monitoring and shutdown system
US6090048 *Sep 11, 1996Jul 18, 2000Gambro AbMethod and arrangement for detecting the condition of a blood vessel access
US7022098Apr 10, 2002Apr 4, 2006Baxter International Inc.Access disconnection systems and methods
US7138088Apr 10, 2002Nov 21, 2006Baxter International Inc.Access disconnection system and methods
US7147615Jun 22, 2001Dec 12, 2006Baxter International Inc.Needle dislodgement detection
US7648477Jan 22, 2008Jan 19, 2010Gambro Lundia AbProcess for controlling blood flow in an extracorporeal blood circuit
US7682328Jan 16, 2006Mar 23, 2010Baxter International Inc.Access disconnection systems and methods
US7794419May 18, 2005Sep 14, 2010Gambro Lundia AbApparatus for controlling blood flow in an extracorporeal circuit
US7824354Dec 20, 2002Nov 2, 2010Gambro Lundia AbProcess for controlling blood flow in an extracorporeal blood circuit
US7959594Jan 25, 2006Jun 14, 2011Baxter International Inc.Access disconnection systems and methods
US7993297May 26, 2009Aug 9, 2011Gambro Lundia AbApparatus for controlling blood flow in an extracorporeal blood circuit
US8114043Jul 25, 2008Feb 14, 2012Baxter International Inc.Electromagnetic induction access disconnect sensor
US8137300Mar 19, 2010Mar 20, 2012Baxter International Inc.Access disconnection systems and methods using conductive contacts
US8152751Feb 9, 2007Apr 10, 2012Baxter International Inc.Acoustic access disconnection systems and methods
US8192388Jul 25, 2008Jun 5, 2012Baxter International Inc.System and method for detecting access disconnection
US8197431Sep 21, 2007Jun 12, 2012Baxter International Inc.Acoustic access disconnect detection system
US8246826Feb 27, 2008Aug 21, 2012Deka Products Limited PartnershipHemodialysis systems and methods
US8273049Oct 12, 2007Sep 25, 2012Deka Products Limited PartnershipPumping cassette
US8292594Apr 13, 2007Oct 23, 2012Deka Products Limited PartnershipFluid pumping systems, devices and methods
US8317492Oct 12, 2007Nov 27, 2012Deka Products Limited PartnershipPumping cassette
US8357298Aug 27, 2008Jan 22, 2013Deka Products Limited PartnershipHemodialysis systems and methods
US8393690Aug 27, 2008Mar 12, 2013Deka Products Limited PartnershipEnclosure for a portable hemodialysis system
US8409441Aug 27, 2009Apr 2, 2013Deka Products Limited PartnershipBlood treatment systems and methods
US8425471Aug 27, 2008Apr 23, 2013Deka Products Limited PartnershipReagent supply for a hemodialysis system
US8444392 *Jun 20, 2008May 21, 2013Smith & Nephew PlcPressure control
US8459292Jun 8, 2011Jun 11, 2013Deka Products Limited PartnershipCassette system integrated apparatus
US8491184Feb 27, 2008Jul 23, 2013Deka Products Limited PartnershipSensor apparatus systems, devices and methods
US8499780Oct 24, 2011Aug 6, 2013Deka Products Limited PartnershipCassette system integrated apparatus
US8529490Jun 9, 2011Sep 10, 2013Baxter International Inc.Systems and methods for dialysis access disconnection
US8545698Aug 8, 2012Oct 1, 2013Deka Products Limited PartnershipHemodialysis systems and methods
US8562834 *Aug 27, 2008Oct 22, 2013Deka Products Limited PartnershipModular assembly for a portable hemodialysis system
US8603020Feb 20, 2012Dec 10, 2013Baxter International Inc.Ultrasound access disconnection systems and methods
US8632486Jan 4, 2012Jan 21, 2014Baxter International Inc.Electromagnetic induction access disconnect systems
US8708946Mar 5, 2012Apr 29, 2014Baxter International Inc.Access disconnection systems using conductive contacts
US8721879Jan 18, 2013May 13, 2014Deka Products Limited PartnershipHemodialysis systems and methods
US8721884Aug 8, 2012May 13, 2014Deka Products Limited PartnershipHemodialysis systems and methods
US8795217Mar 6, 2012Aug 5, 2014Baxter International Inc.Acoustic access disconnection systems and methods
US8801646Dec 10, 2012Aug 12, 2014Baxter International Inc.Access disconnection systems with arterial and venous line conductive pathway
US8870549Oct 22, 2012Oct 28, 2014Deka Products Limited PartnershipFluid pumping systems, devices and methods
US8888470Oct 12, 2007Nov 18, 2014Deka Products Limited PartnershipPumping cassette
US8920355Feb 20, 2012Dec 30, 2014Baxter International Inc.Acoustic access disconnection systems and methods
US8920356Jun 30, 2011Dec 30, 2014Baxter International Inc.Conductive polymer materials and applications thereof including monitoring and providing effective therapy
US8926294Nov 26, 2012Jan 6, 2015Deka Products Limited PartnershipPumping cassette
US8926544Apr 20, 2012Jan 6, 2015Baxter International Inc.System and method for detecting access disconnection
US8985133Jun 10, 2013Mar 24, 2015Deka Products Limited PartnershipCassette system integrated apparatus
US8992075Sep 14, 2012Mar 31, 2015Deka Products Limited PartnershipSensor apparatus systems, devices and methods
US8992189Sep 14, 2012Mar 31, 2015Deka Products Limited PartnershipCassette system integrated apparatus
US9028691 *Aug 27, 2008May 12, 2015Deka Products Limited PartnershipBlood circuit assembly for a hemodialysis system
US9039648Sep 17, 2010May 26, 2015Baxter International Inc.Dialysis system with enhanced features
US9044555 *Aug 9, 2010Jun 2, 2015Miami Children's Hospital Research InstituteExtracorporeal blood circuit for cardiopulmonary bypass
US9089654Jul 16, 2014Jul 28, 2015Baxter International Inc.Acoustic access disconnection systems and methods
US9115708Apr 25, 2014Aug 25, 2015Deka Products Limited PartnershipFluid balancing systems and methods
US9138528Dec 4, 2013Sep 22, 2015Baxter International Inc.Acoustic access disconnection systems and methods
US9272082Sep 21, 2012Mar 1, 2016Deka Products Limited PartnershipPumping cassette
US9302037Aug 19, 2013Apr 5, 2016Deka Products Limited PartnershipHemodialysis systems and methods
US9352078Nov 24, 2014May 31, 2016Baxter International Inc.Electrical heartbeat access disconnection systems
US9383288May 5, 2014Jul 5, 2016Gambro Lundia AbMethod and device for processing a time-dependent measurement signal
US9408954Aug 17, 2012Aug 9, 2016Smith & Nephew PlcSystems and methods for controlling operation of negative pressure wound therapy apparatus
US9433356Jun 24, 2010Sep 6, 2016Gambro Lundia AbDevices, a computer program product and a method for data extraction
US9442036Jun 26, 2009Sep 13, 2016Gambro Lundia AbMethods and devices for monitoring the integrity of a fluid connection
US20030194894 *Apr 10, 2002Oct 16, 2003Ramesh WariarAccess disconnection systems and methods
US20030195453 *Apr 10, 2002Oct 16, 2003James HanAccess disconnection systems and methods
US20030195454 *Apr 10, 2002Oct 16, 2003Ramesh WariarAccess disconnection systems and methods
US20050043665 *Dec 20, 2002Feb 24, 2005Luca VinciEquipment for controlling blood flow in an extracorporeal blood circuit
US20060116623 *Jan 16, 2006Jun 1, 2006James HanAccess disconnection systems and methods
US20070117010 *Jan 23, 2007May 24, 2007Baxter International Inc.Conductive polymer materials and applications thereof including monitoring and providing effective therapy
US20080065006 *Feb 16, 2007Mar 13, 2008Baxter International, Inc.Enhanced signal detection for access disconnection systems
US20080119777 *Jan 22, 2008May 22, 2008Luca VinciProcess for controlling blood flow in an extracorporeal blood circuit
US20080208103 *Oct 12, 2007Aug 28, 2008Deka Products Limited PartnershipPumping Cassette
US20080253911 *Oct 12, 2007Oct 16, 2008Deka Products Limited PartnershipPumping Cassette
US20080275377 *May 18, 2005Nov 6, 2008Gambro Lundia AbApparatus for Controlling Blood Flow in an Extracorporeal Circuit
US20090004033 *Oct 12, 2007Jan 1, 2009Deka Products Limited PartnershipPumping Cassette
US20090082676 *Sep 21, 2007Mar 26, 2009Baxter International Inc.Acoustic access disconnect detection system
US20100022934 *Jul 25, 2008Jan 28, 2010Baxter International Inc.System and method for detecting access disconnection
US20100022935 *Jul 25, 2008Jan 28, 2010Baxter International Inc.Electromagnetic induction access disconnect sensor
US20100185132 *Mar 19, 2010Jul 22, 2010Baxter International Inc.Access disconnection systems and methods using conductive contacts
US20100324465 *May 26, 2009Dec 23, 2010Gambro Lundia AbApparatus for controlling blood flow in an extracorporeal blood circuit
US20110000832 *Sep 17, 2010Jan 6, 2011Baxter International Inc.Dialysis system with enhanced features
US20110008179 *Jun 20, 2008Jan 13, 2011Smith & Nephew PlcPressure control
US20110040229 *Aug 9, 2010Feb 17, 2011Hannan Robert LExtracorporeal blood circuit for cardiopulmonary bypass
DE2822697A1 *May 24, 1978Nov 30, 1978Du PontDosimeter
DE2939957A1 *Oct 2, 1979Apr 10, 1980Du PontDosimeter mit niedriger luftdurchflussleistung
DE102014111665A1Aug 14, 2014Feb 18, 2016B. Braun Avitum AgVerfahren zum Einstellen eines Blutflusses in einer Dialysevorrichtung und Dialysevorrichtung
EP0154681A1 *Nov 9, 1984Sep 18, 1985International Business Machines CorporationPeristaltic pump control
EP2985045A1Aug 6, 2015Feb 17, 2016B. Braun Avitum AGMethod for adjusting a blood flow in a dialysis device and dialysis device
Classifications
U.S. Classification604/66, 417/43, 417/44.1, 128/DIG.120, 417/44.2
International ClassificationA61M1/16, A61M1/10, A61M1/36
Cooperative ClassificationA61M1/3639, A61M1/1086, Y10S128/12, A61M1/1037, A61M1/16
European ClassificationA61M1/36C5, A61M1/10R