High convection home hemodialysis/hemofiltration and sorbent system

• US 8,029,454 B2
• Filed: 11/04/2004
• Issued: 10/04/2011
• Est. Priority Date: 11/05/2003
• Status: Expired due to Fees

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Childers, Robert W., Din, Shahid, El Sayyid, Waleed Mutasem, Kelly, Thomas, Busby, Don, Roger, Rodolfo
• Primary Examiner(s): Deak; Leslie
• Assistant Examiner(s): WIEST, PHILIP R
• Application Number:
  US10/982,170
• Publication Number:
  US 20050131332A1
• Time in Patent Office: 2,525 Days
• Field of Search: 604 401- 616, 604/406, 604/19, 604 28- 30, 210 85- 88, 210/104, 210/321.6, 210645-647, 210/739, 210/767, 210/744, 137/101.25
• US Class Current: 604/5.01
• CPC Class Codes: A61M 1/1522 the interface being evacuated interfaces to enhance contact
• CPC Class Codes: A61M 1/153 the cassette being adapted for heating or cooling the treating fluid, e.g. the dialysate or the treating gas
• 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 1/1561 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/15625 the reservoirs acting as balance chambers
• CPC Class Codes: A61M 1/1563 Details of incorporated filters
• 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 1/1607 before use, i.e. upstream of dialyser
• CPC Class Codes: A61M 1/1613 Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/1621 Constructional aspects thereof semi-permeable membranes for separation processes characterised by their properties B01D69/00; semi permeable membranes characterised by their material B01D71/00
• CPC Class Codes: A61M 1/1629 with integral heat exchanger
• CPC Class Codes: A61M 1/1633 with more than one dialyser unit
• CPC Class Codes: A61M 1/1635 with volume chamber balancing devices between used and fresh dialysis fluid
• CPC Class Codes: A61M 1/1656 Apparatus for preparing dialysates
• CPC Class Codes: A61M 1/166 Heating for sterilisation A61M1/1686
• CPC Class Codes: A61M 1/1668 Details of containers
• CPC Class Codes: A61M 1/167 Flexible packaging for solid concentrates
• CPC Class Codes: A61M 1/1672 : using membrane filters, e.g. for sterilising the dialysate
• CPC Class Codes: A61M 1/1696 : with dialysate regeneration
• CPC Class Codes: A61M 1/267 : used for pumping
• CPC Class Codes: A61M 1/288 : Priming priming in extracorporeal blood circuits A61M1/3643
• CPC Class Codes: A61M 1/3401 : Cassettes therefor
• CPC Class Codes: A61M 1/341 : by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/3417 : using distinct filters for dialysis and ultra-filtration
• CPC Class Codes: A61M 1/342 : Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• CPC Class Codes: A61M 1/3427 : back through the membrane, e.g. by inverted trans-membrane pressure [TMP]
• CPC Class Codes: A61M 1/3431 : upstream of the filter
• 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 1/3444 : in which the collected ultra-filtrate expels an equal volume of substitution fluid from a reservoir
• CPC Class Codes: A61M 1/3451 : the difference in weight between both ultra-filtrate and substitution reservoir being used as control signal
• CPC Class Codes: A61M 1/3458 : having electrolytes not present in the dialysate
• CPC Class Codes: A61M 1/3465 : using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3468 : using treated filtrate as substitution fluid
• CPC Class Codes: A61M 1/3472 : with treatment of the filtrate
• CPC Class Codes: A61M 1/3486 : Biological, chemical treatment, e.g. chemical precipitation; treatment by absorbents
• CPC Class Codes: A61M 1/3621 : Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/362223 : the interface being evacuated interfaces to enhance contact
• 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 1/362261 : at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/362265 : Details of valves
• CPC Class Codes: A61M 1/3624 : Level detectors; Level control
• CPC Class Codes: A61M 1/3626 : Gas bubble detectors
• CPC Class Codes: A61M 1/3627 : Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 1/3643 : Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 : Mode of operation
• CPC Class Codes: A61M 1/3646 : Expelling the residual body fluid after use, e.g. back to the body
• CPC Class Codes: A61M 1/3647 : with recirculation of the priming solution
• CPC Class Codes: A61M 1/3649 : using dialysate as priming or rinsing liquid
• 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 1/3656 : Monitoring patency or flow at connection sites; Detecting disconnections
• 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 2205/127 : with provisions for heating or cooling
• CPC Class Codes: A61M 2205/13 : with means for the detection of operative contact with patient, e.g. lip sensor
• CPC Class Codes: A61M 2205/15 : Detection of leaks
• CPC Class Codes: A61M 2205/18 : with alarm
• CPC Class Codes: A61M 2205/276 : preventing unwanted use
• 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 2205/3327 : Measuring
• CPC Class Codes: A61M 2205/3331 : Pressure; Flow
• CPC Class Codes: A61M 2205/3334 : Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3337 : Controlling, regulating pressure or flow by means of a valve by-passing a pump
• CPC Class Codes: A61M 2205/3344 : Measuring or controlling pressure at the body treatment site
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/3379 : Masses, volumes, levels of fluids in reservoirs, flow rates
• CPC Class Codes: A61M 2205/3393 : by weighing the reservoir
• CPC Class Codes: A61M 2205/3553 : remote, e.g. between patient's home and doctor's office
• CPC Class Codes: A61M 2205/3561 : local, e.g. within room or hospital
• CPC Class Codes: A61M 2205/3584 : using modem, internet or bluetooth
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/505 : Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/52 : with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/75 : with filters
• CPC Class Codes: A61M 60/113 : in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/258 : Piston pumps
• CPC Class Codes: A61M 60/279 : Peristaltic pumps, e.g. roller pumps
• CPC Class Codes: A61M 60/37 : Haemodialysis, haemofiltration or diafiltration
• CPC Class Codes: A61M 60/43 : using vacuum at the blood pump, e.g. to accelerate filling
• CPC Class Codes: A61M 60/508 : Electronic control means, e.g. for feedback regulation
• CPC Class Codes: A61M 60/847 : arranged in a cassette
• CPC Class Codes: A61M 60/849 : Disposable parts
• CPC Class Codes: A61M 60/851 : Valves

Abstract

A system, method and apparatus for performing a renal replacement therapy is provided. In one embodiment, two small high flux dialyzers are connected in series. A restriction is placed between the two dialyzers in the dialysate flow path. The restriction is variable and adjustable in one preferred embodiment. The restriction builds a positive pressure in the venous dialyzer, causing a high degree of intentional backfiltration. That backfiltration causes a significant flow of dialysate through the high flux venous membrane directly into the patient'"'"'s blood. That backfiltered solution is subsequently ultrafiltered from the patient from the arterial dialyzer. The diffusion of dialysate into the venous filter and removal of dialysate from the arterial dialyzer causes a convective transport of toxins from the patient. Additionally, the dialysate that does not diffuse directly into the patient but instead flows across the membranes of both dialyzers provides a diffusive clearance of waste products.

Claims

1. A medical fluid therapy system comprising:

a blood line configured and arranged to be coupled to a patient;

a blood pump connected to the blood line;

a blood filter in communication with the blood line, the filter operable to allow a liquid portion of a patient'"'"'s blood to pass from the filter to a therapy fluid flow path;

a pair of peristaltic fluid pumps positioned and arranged to pump therapy fluid to one of the blood filter and the blood line and from the blood filter; and

at least one balance tube, including a tube and a separator mechanically free from first and second fluidly sealed closed ends of the balance tube, the separator fitted tightly and moveably back and forth between end-of-stroke positions within the tube for volumetric control that assumes a constant volume is maintained collectively between (i) the first closed end and the separator and (ii) the separator and the second closed end, regardless of an orientation of the balance tube, or tortuous path volume control device, the balance tube or tortuous path volume control device in fluid communication with the pair of peristaltic pumps and operable to control an amount of therapy fluid that is pumped to the blood filter or the blood line and an amount of the fluid that is pumped from the filter.

2. The medical fluid therapy system of claim 1, which includes a plurality of valves operable to control the balance tube or tortuous path volume control device.

3. The medical fluid therapy system of claim 1, which is programmed to selectively pump therapy fluid to the blood line upstream or downstream of the filter.

4. The medical fluid therapy system of claim 1, which is configured to pump therapy fluid to the filter to perform convective blood clearance, diffusive blood clearance or a combination thereof.

5. The medical fluid therapy system of claim 1, wherein the at least one balance tube or tortuous path volume control device is further operable to control an amount of ultrafiltrate pumped from the filter.

6. The medical fluid therapy system of claim 1, which includes a pair of one of the balance tubes and the tortuous paths, the pair configured to operate such that one of the pair pumps to the filter/blood line while the other of the pair pumps from the filter.

7. The medical fluid therapy system of claim 1, wherein the volume control device is part of a disposable cassette positioned and arranged to operate with the pair of peristaltic pumps.

8. A dialysis system comprising:

a dialysis instrument including first and second dialysate pump actuators; and

a disposable cassette operable with the dialysis instrument, the disposable cassette including first and second portions configured to operate respectively with the first and second dialysate pump actuators, the disposable cassette further including at least one balance tube configured to meter an amount of fresh dialysate delivered to and an amount of spent dialysate removed from a patient, the balance tube defining a longitudinal axis and including a separator within the tube, the separator mechanically free from first and second fluidly sealed closed ends of the balance tube and to move back and forth along the longitudinal axis within the tube to meter the dialysate to and from the patient.

9. The dialysis system of claim 8, wherein the at least one balance tube is further configured to meter an amount of ultrafiltrate removed from the patient.

10. The dialysis system of claim 8, which is a blood treatment dialysis system, and wherein the at least one balance tube is configured to meter the amount of spent fluid removed from the patient through a blood filter.

11. The dialysis system of claim 8, including first and second balance tubes, the first and second pump portions of the disposable cassette located upstream of the first and second balance tubes.

12. The dialysis system of claim 11, the first pump portion valved to alternating drive fresh dialysate to a fresh dialysate inlet of the first balance tube and the second balance tube, the second pump portion valved to alternatingly drive spent dialysate to a spent dialysate inlet of the first balance tube and the second balance tube.

13. The dialysis system of claim 11, the first and second balance tubes each including a fresh fluid outlet in fluid communication with the patient and a spent fluid outlet in fluid communication with a drain.

14. The dialysis system of claim 8, including first and second balance tubes each having a fresh dialysate outlet leading to a common fresh dialysate line, the line valved such that fresh dialysate from the fresh dialysate outlet of the first balance tube can be directed to the fresh dialysate outlet of the second balance tube to meter an amount of ultrafiltration from the second balance tube.

15. The dialysis system of claim 8, which includes at least one sensor positioned to sense an end of travel of the separator within the at least one balance tube.

16. The dialysis system of claim 8, wherein the separator is at least substantially spherical.

17. The dialysis system of claim 8, including first and second tees connected to first and second ends of the at least one balance tube, each tee further connected to a fresh dialysate line and a spent dialysate line.