Substantially inertia free hemodialysis

• US 20040009096A1
• Filed: 06/05/2003
• Published: 01/15/2004
• Est. Priority Date: 06/08/2002
• Status: Abandoned Application

• Current Assignee: Parris S. Wellman
• Original Assignee: Parris S. Wellman
• Inventors: Wellman, Parris S.
• Application Number:
  US10/455,543
• Publication Number:
  US 20040009096A1
• Time in Patent Office: Days
• US Class Current: 422/44
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00 ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1601 Control or regulation
• CPC Class Codes: A61M 1/1627 Dialyser of the inside perfusion type, i.e. blood flow inside hollow membrane fibres or tubes
• CPC Class Codes: A61M 1/1631 having non-tubular membranes, e.g. sheets
• CPC Class Codes: A61M 1/32 Oxygenators without membranes
• CPC Class Codes: A61M 1/3623 Means for actively controlling temperature of blood
• CPC Class Codes: A61M 1/3653 Interfaces between patient blood circulation and extra-corporal blood circuit
• CPC Class Codes: A61M 1/3655 Arterio-venous shunts or fistulae
• CPC Class Codes: A61M 1/3659 Cannulae pertaining to extracorporeal circulation
• CPC Class Codes: A61M 1/3661 for haemodialysis
• CPC Class Codes: A61M 2206/11 Laminar flow

Abstract

This invention is a membraneless filtration device and a method for performing hemodialysis on a patient using it and methods of manufacturing the filtration device. In a preferred embodiment, the filter is composed of at least one channel where the dialysate circumferentially surrounds the blood to reduce or eliminate the need for anticoagulation through reduced hemolysis and thrombogenicity. In the preferred embodiment the filter is configured to be used with a typical dialysis machine and hemodialysis is separated into an iso- or hyper-volemic filtration phase, followed by a phase where the patient'"'"'s blood volume is reduced to normal levels. In another embodiment the device is adapted to be implanted or worn externally to serve as a portable artificial kidney. The device described herein could also find application as a blood oxygenator in cardiopulmonary bypass, or for use as an artificial liver or lung.

Claims

1. A system for performing hemodialysis on a patient including:

at least one blood channel and one dialysate channel

the at least one blood channel being circumferentially surrounded by the at least one dialysate channel

the flow in these channels being substantially inertia free

the transfer of solutes from the blood into the dialysate channel being substantially governed by the laws of diffusion.

2. The system of claim 1 where little or no blood anti-coagulation is required.

3. The system of claim 1 where the blood volume being dialyzed is substantially isovolemic or hypervolemic for the patient.

4. The system of claim 2 where volume control of the blood is achieved after solute clearance by convective clearance of liquid from the patient'"'"'s blood.

5. The system of claim 2 where volume control of the patient'"'"'s blood is achieved by directly removing lymph from the patient'"'"'s lymphatic system.

6. The system of claim 1 where diffusion rate is modified by varying the concentration of solutes in the dialysate solution during the course of a procedure in a regulated way.

7. The system of claim 1 where the concentration of species in the dialysate is adjusted to deliver pharmaceuticals or other beneficial agents to the patient, including for example heparin and/or protamine or erythropoetin or other red blood cell production stimulating compounds.

8. The system of claim 1 where the pressure drops within the blood flow channels are kept within physiologically normal levels (<

120 mm/Hg).

9. The system of claim 1 where the flow of dialysate is driven by gravity and the filter is portable and adapted to be worn externally by the patient and the pressure drops within the blood flow channels are kept to physiologically normal levels (<

120 mm/Hg).

10. The system of claim 9 where a dialysate and a waste reservoir are also worn by the patient.

11. The system of claim 9 where a dialysate reservoir is worn by the patient and the waste is deposited directly into the bladder of the patient.

12. The system of claim 1 where the dialysate is a fluid whose composition has been adjusted in order to remove non water soluble compounds from the other stream.

18. The system of claim 19 which is implanted in the patient.

19. The system of claim 1 where the dialysate is a fluid whose composition has been adjusted in order to remove non water soluble compounds from the other stream.

13. A device for selectively exchanging certain components of two fluid streams that incorporates

at least one primary channel and one secondary channel

the said primary channel being at least partially surrounded by and in direct

membraneless contact with the secondary channel

the time of contact between the fluids in the two channels set at a predetermined

interval to ensure that only particular chemical species have time to diffuse from one channel to another

the flow in the primary and secondary channels being substantially unaffected by inertial effects.

14. A system for exchanging blood gases in a patient including:

at least one blood channel and one channel for gas or gas enriched fluid circulation

the at least one blood channel being at least partially surrounded by the at least one gas or gas enriched fluid channel

the flow in these channels being substantially inertia free.

17. A system for performing substantially isovolemic or hypervolemic dialysis on a patient comprising:

at least one blood channel and one dialysate channel

the at least one blood channel being at least partially surrounded by the at least one dialysate channel and said channels maintaining pressure drops that are within physiologically normal levels (<

120 mm/Hg)

the flow in these channels being substantially inertia free

the transfer of solutes from the blood into the dialysate channel being substantially governed by the laws of diffusion

the concentration of species in the dialysate is adjusted to modify the diffusion profile of species of interest

at least one connection to the patient'"'"'s blood stream for removal and replacement of blood.

20. A system for performing hemodialysis containing:

at least one blood channel and one dialysate channel

the at least one blood channel being at least partially surrounded by the at least one dialysate channel and said channels maintaining pressure drops that are within physiologically normal levels (<

120 mm/Hg)

the flow in these channels being substantially inertia free

the transfer of solutes from the blood into the dialysate channel being substantially governed by the laws of diffusion

the concentration of species in the dialysate is adjusted to modify the diffusion profile of species of interest

at least one connection to the patient'"'"'s blood stream for removal and replacement of blood

the dialysate is a fluid whose composition has been adjusted in order to remove non water soluble compounds from the blood.

15. The system of claim 20 where the channels are fabricated using alternating regions of hydrophobicity and hydrophilicity.

16. The system of claim 20 where the gas enriched fluid is an hyperoxygenated fluorocarbon, chlorofluorocarbon or synthetic cerebro-spinal fluid.