Blood purification apparatus

• US 4,897,189 A
• Filed: 01/15/1988
• Issued: 01/30/1990
• Est. Priority Date: 10/23/1987
• Status: Expired due to Fees

• Current Assignee: James E. Tattersall
• Original Assignee: Research Incorporated
• Inventors: Greenwood, Roger N., Tattershall, James E., Barrett, Rodney V., Aldridge, Colin
• Primary Examiner(s): JONES, WILLIAM G
• Application Number:
  US07/144,488
• Time in Patent Office: 746 Days
• Field of Search: 422/45, 422/48, 422/44, 604/4, 604/5, 604/6, 210/195.2, 210/257.1, 210/257.2, 210/258, 210/321.72, 210/321.73, 210/321.74, 210/321.75, 210/321.76, 210/321.77, 210/321.78 , 210/321.79, 210/321.8, 210/416.1, 210/321.82, 210/321.83, 210/321.84, 210/321.85, 210/321.86, 210/321.87, 210/321.88, 210/321.89
• US Class Current: 210/195.2
• CPC Class Codes: A61M 1/1698 Blood oxygenators with or without heat-exchangers intracorporal A61M1/1678; manufacturing of membranes therefor B01D67/00; 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 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/303 having a reservoir for treated blood to be returned
• CPC Class Codes: A61M 1/308 Volume control, e.g. with open or flexible containers, by counting the number of pump revolutions, weighing
• 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 1/3604 in opposite directions
• CPC Class Codes: A61M 1/3679 by absorption A61M1/3675 takes precedence
• CPC Class Codes: A61M 5/1486 the bags being substantially completely surrounded by fluid
• 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 60/37 Haemodialysis, haemofiltration or diafiltration
• CPC Class Codes: A61M 60/427 the force acting on the blood contacting member being hydraulic or pneumatic
• CPC Class Codes: A61M 60/432 with diastole or systole switching by stopping or reversing the blood pump operating at a much higher cyclical speed than the heart beat
• CPC Class Codes: A61M 60/515 Regulation using real-time patient data
• CPC Class Codes: A61M 60/538 Regulation using real-time blood pump operational parameter data, e.g. motor current

Abstract

Blood purification apparatus comprises a dead-end system in which blood from the patient is allowed to flow through one or more purification modules, such as a dialyzer, a hemofilter, a hemoperfusion column and an oxygenator, into a resiliently walled reservoir, which is conveniently a standard blood bag. The direction of flow of the blood is then reversed by exertion of sufficient pressure on the bag to push the blood back through the purification module to the patient'"'"'s circulation. Thus, since the reservoir is of available capacity, being of resilient material for example, the capacity of the apparatus remains equal to the volume of extra-corporeal blood.

Claims

1. Blood purification apparatus comprising means for withdrawing blood from a patient into a blood conduit, a blood purification module in fluid flow communication with said conduit, a blood reservoir for receiving blood from said module, pump means for withdrawing blood and returning blood from said reservoir to the patient via the blood purification module, said reservoir being flexible and having variable capacity and forming part of said pump means, the pump means comprising hydraulic fluid which can act on the exterior of said reservoir to control blood flow into and out of said blood purification module.

2. Apparatus as claimed in claim 1, wherein the blood purification module is a device selected from the group consisting of a dialyzer, a hemoperfusion unit, a hemofilter and an oxygenator.

3. Apparatus as claimed in claim 2, in which the blood purification module is a dialyzer of the hollow fibre membrane type.

4. Apparatus as claimed in claim 1, which includes a first reservoir for fresh dialysis fluid, pump means for passing fluid from the first reservoir to the blood purification module and a second reservoir for receiving and holding the entire effluent dialysis fluid or ultrafiltrate from the blood purification module.

5. Apparatus as claimed in claim 4, in which the pump means comprises a first pump intermediate the first reservoir and the blood purification module and a second pump intermediate the blood purification module and the second reservoir.

6. Apparatus as claimed in claim 5, in which the first and second pumps are of a type permitting selection of the direction of pumping.

7. Apparatus as claimed in claim 1, in which the pump means comprises a first chamber for hydraulic fluid, a second chamber separated from the first by a common flexible wall member, a flexible blood reservoir located within the second chamber proximate the flexible wall and in fluid flow communication with the blood purification module, and piston means within the first chamber disposed to act upon the hydraulic fluid.

8. Apparatus as claimed in claim 7, in which the piston is motor driven.

9. Apparatus as claimed in claim 8, in which the motor is a microprocessor controlled stepper motor.

10. Apparatus as claimed in claim 1, including means for introducing physiological fluid into the blood before return of the blood to the patient.

11. Apparatus as claimed in claim 1 comprising a dead-end system wherein the total blood volume of the apparatus is equal to and varies with the extracorporeal blood volume.

12. Apparatus as claimed in claim 1 in which the pump means includes a motor driven piston.

13. Apparatus as claimed in claim 12 in which the motor is a microprocessor controlled stepper motor.