Browse Prior Art Database

Centrifugal Artificial Kidney

IP.com Disclosure Number: IPCOM000076772D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 3 page(s) / 84K

Publishing Venue

IBM

Related People

Kellogg, RM: AUTHOR

Abstract

Known artificial kidneys contain a semipermeable membrane, which separates the liquid being dialyzed (i.e. whole blood) from the dialyzing solution (dialysate). The purpose of the membrane is to allow certain chemicals to selectively diffuse from the whole blood into the dialysate without allowing the two fluids to mix. The membrane, however, impedes the diffusion and thereby limits the rate at which wastes can be removed from whole blood.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Centrifugal Artificial Kidney

Known artificial kidneys contain a semipermeable membrane, which separates the liquid being dialyzed (i.e. whole blood) from the dialyzing solution (dialysate). The purpose of the membrane is to allow certain chemicals to selectively diffuse from the whole blood into the dialysate without allowing the two fluids to mix. The membrane, however, impedes the diffusion and thereby limits the rate at which wastes can be removed from whole blood.

There are other physical principles which can be used to keep the whole blood from mixing with the dialysate, while at the same time allowing selective diffusion to occur. The present arrangement uses density differences and centrifugal force to maintain separation of the two fluids, while diffusion of the waste products takes place.

Referring to the drawing, whole blood is withdrawn from the patient by pump 1 and delivered to the fluid buffer 2. The fluid buffer 2 isolates the pressure drop at the bleeding site from the centrifugal unit input, insuring adequate seal operation with no air entrainment. From there it is drawn through the centrifugal unit 3 by pump 4. The processing whole blood flow rate is established by pump
4. Pump 1 is under control of a sensor 5 which senses the weight of the fluid buffer 2. Increased weight of buffer 2 slows pump 1. Decreased weight of buffer 2 speeds pump 1 up. This causes the average flow rate of pump 1 to be equal to that set by pump 4. The output of pump 4 can be returned to the patient or be passed through an ultrafiltration unit 6 for the removal of water, depending on requirements.

Dialysate is withdrawn from the dialysate supply reservoir 7 by pump 8 and is delivered to the centrifugal unit 3. While flowing through the centrifugal unit 3, the dialysate is brought into intimate contact (but not mixed) with the whole blood. During this contact, waste products selectively diffuse from the whole blood into the dialysate. The processed dialysate is withdrawn from the centrifugal unit 3 by pump 9 and returned to the reservoir 7. The means for continual mixing of the dialysate in reservoir 7 is not shown. The dip alysate level in reservoir 7 is adjusted so that the free surface 10 is located in standpipe 11, as shown. Sensor 12 then...