Hemodialysis systems and methods

• US 8,721,879 B2
• Filed: 01/18/2013
• Issued: 05/13/2014
• Est. Priority Date: 02/27/2007
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: van der Merwe, Dirk A., Wilt, Michael J.
• Primary Examiner(s): Kim, John
• Application Number:
  US13/745,730
• Publication Number:
  US 20130126413A1
• Time in Patent Office: 480 Days
• Field of Search: 210/97, 210/108, 210/195.2, 210/252, 210/258, 210/321.6, 210/321.65, 210/321.69, 210/393, 210/411, 210/416.1, 210/427, 210/109, 210/134, 210/143, 604/4.01, 604/5.01, 604/5.04, 604/6.09, 604/6.11
• US Class Current: 210/134
• CPC Class Codes: A61M 1/1524 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/154 with sensing means or components thereof
• CPC Class Codes: A61M 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/156 Constructional details of the cassette, e.g. specific details on material or shape
• CPC Class Codes: A61M 1/15625 the reservoirs acting as balance chambers
• CPC Class Codes: A61M 1/1565 Details of valves
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1601 Control or regulation
• CPC Class Codes: A61M 1/1613 Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/1635 with volume chamber balancing devices between used and fresh dialysis fluid
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/3434 with pre-dilution and post-dilution
• CPC Class Codes: A61M 1/3437 downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3441 Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 1/3465 using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/362227 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/36226 Constructional details of cassettes, e.g. specific details on material or shape
• CPC Class Codes: A61M 1/362265 : Details of valves
• CPC Class Codes: A61M 1/362266 : Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/3623 : Means for actively controlling temperature of blood
• CPC Class Codes: A61M 1/3646 : Expelling the residual body fluid after use, e.g. back to the body
• CPC Class Codes: A61M 1/365 : through membranes, e.g. by inverted trans-membrane pressure [TMP]
• CPC Class Codes: A61M 1/3652 : using gas, e.g. air
• CPC Class Codes: A61M 2202/0413 : Blood
• CPC Class Codes: A61M 2205/12 : with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/18 : with alarm
• CPC Class Codes: A61M 2205/3317 : Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 : PH measuring means
• CPC Class Codes: A61M 2205/3331 : Pressure; Flow
• CPC Class Codes: A61M 2205/3334 : Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: F04B 45/0536 : the actuating fluid being controlled by one or more valves
• CPC Class Codes: G16H 20/40 : relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/63 : for local operation

Abstract

Hemodialysis dialysis systems are disclosed. Hemodialysis systems of the invention may include a dialysate flow path including a balancing circuit, a mixing circuit, and/or a directing circuit. The circuits may be defined within one or more cassettes. The fluid circuits may be at least partially isolated, spatially and/or thermally, from electrical components of the system. A gas supply may be provided in fluid communication with the dialysate flow path and/or the dialyzer to, urge dialysate through the dialyzer and blood back to the patient. The hemodialysis systems may include fluid handling devices actuated using a control fluid, optionally delivered using detachable pump. Fluid handling devices may be generally rigid and of a spheroid shape, optionally with a diaphragm dividing the device into compartments.

Claims

1. A hemodialysis system, comprising:

a blood flow path through which untreated blood is drawn from a patient and passed through a dialyzer;

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialysate flow path and the blood flow path being in fluidic communication;

a reciprocating positive displacement blood pump configured to pump blood in the blood flow path, resulting in blood flow through the dialyzer;

a reciprocating positive displacement dialysate pump configured to pump dialysate in the dialysate flow path, resulting in dialysate flow through the dialyzer; and

a controller configured to receive pressure information associated with the blood flow path and/or pressure information associated with the dialysate flow path, and configured to control the dialysate pump and/or the blood pump;

wherein the controller uses the pressure information during dialysis to control the dialysate pump and/or the blood pump such that the pressure of the dialysate exiting the dialyzer is lower than the pressure of the blood exiting the dialyzer.

2. The hemodialysis system of claim 1, wherein the blood flow path comprises a blood flow cassette.

3. The hemodialysis system of claim 1, wherein the dialysate flow path comprises at least one cassette.

7. The hemodialysis system of claim 1, wherein the controller is configured to detect when the blood pump is not delivering blood to the dialyzer, and is configured to prevent or stop delivery of dialysate by the dialysate pump during this time.

8. The hemodialysis system of claim 1, further comprising a second reciprocating positive displacement dialysate pump,

the second dialysate pump configured to receive dialysate exiting the dialyzer, and

the first dialysate pump configured to deliver dialysate to the dialysate flow path, wherein

the controller is configured to control the dialysate pumps or the blood pump to ensure that a pumping chamber of the second dialysate pump is completely filled with dialysate exiting the dialyzer during a fill stroke of the second dialysate pump.

10. The hemodialysis system of claim 1, wherein

the dialyzer comprises a blood flow side comprising a blood flow inlet and blood flow outlet in fluid communication with the blood flow path, and a dialysate flow side in fluid communication with the dialysate flowpath, and wherein the blood flow side of the dialyzer is separated from the dialysate flow side of the dialyzer by a semi-permeable membrane;

the blood pump is configured to pump blood in the blood flow path, resulting in blood flow through the dialyzer from the blood flow inlet of the dialyzer to the blood flow outlet of the dialyzer;

the dialysate pump is configured to pump dialysate in the dialysate flow path, resulting in dialysate flow through the dialyzer from the dialysate flow inlet of the dialyzer to the dialysate flow outlet of the dialyzer; and

wherein

the controller is configured to control the dialysate pump and/or the blood pump such that the pressure of the dialysate exiting the dialyzer via the dialysate flow outlet is lower than the pressure of the blood exiting the dialyzer via the blood flow outlet.

4. A hemodialysis system, comprising:

a blood flow path through which untreated blood is drawn from a patient and passed through a dialyzer;

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialysate flow path and the blood flow path being in fluidic communication;

a reciprocating positive displacement blood pump configured to pump blood in the blood flow path, resulting in blood flow through the dialyzer;

a reciprocating positive displacement dialysate pump configured to pump dialysate in the dialysate flow path, resulting in dialysate flow through the dialyzer; and

a controller configured to receive pressure information associated with the blood flow path and/or pressure information associated with the dialysate flow path, and configured to control the dialysate pump and/or the blood pump;

wherein the controller uses the pressure information during dialysis to control the dialysate pump and/or the blood pump device such that the pressure of the dialysate entering the dialyzer is greater than the pressure of the blood entering the dialyzer.

5. The hemodialysis system of claim 4, wherein the blood flow path comprises a blood flow cassette.

6. The hemodialysis system of claim 4, wherein the dialysate flow path comprises at least one cassette.

9. The hemodialysis system of claim 4, wherein the controller is configured to control the dialysate pump or the blood pump to ensure that the dialysate pump delivers a complete pump stroke to the dialysate flow path during a delivery stroke of the dialysate pump.

11. The hemodialysis system of claim 4, wherein the controller is configured to detect when the blood pump is not delivering blood to the dialyzer, and is configured to prevent or stop delivery of dialysate by the dialysate pump during this time.

12. The hemodialysis system of claim 4, wherein

the dialyzer comprises a blood flow side comprising a blood flow inlet and blood flow outlet in fluid communication with the blood flow path, and a dialysate flow side in fluid communication with the dialysate flowpath, and wherein the blood flow side of the dialyzer is separated from the dialysate flow side of the dialyzer by a semi-permeable membrane;

the blood pump is configured to pump blood in the blood flow path, resulting in blood flow through the dialyzer from the blood flow inlet of the dialyzer to the blood flow outlet of the dialyzer;

the dialysate pump is configured to pump dialysate in the dialysate flow path, resulting in dialysate flow through the dialyzer from the dialysate flow inlet of the dialyzer to the dialysate flow outlet of the dialyzer; and

wherein

the controller is configured to control the dialysate pump and/or the blood pump such that the pressure of the dialysate exiting the dialyzer via the dialysate flow outlet is lower than the pressure of the blood exiting the dialyzer via the blood flow outlet.