Single-needle artificial kidney
First Claim
1. An artificial kidney which includes a haemodialyser (13) a semi-permeable membrane (14) which can effect dialysis and ultrafiltration of the blood, said diaphragm dividing said haemodialyser into first and second compartments (28), (29) an extracorporeal blood circuit including said first compartment (28), a blood circulation pump (15, 16) and a single needle (12) for insertion into the patient (11), a dialysis liquid circuit including said second compartment (29) and a dialysis liquid pump (27), characterized in that said dialysis liquid circuit includes means for enabling simultaneous pulsing of both blood and dialysis liquid in the haemodialyser of said single-needle artificial kidney, sufficient to provide the high efficiencies otherwise obtained with conventional double-needle artificial kidneys, including means (27a, 27b,27c,27d,27e) for periodically modulating the flow rate of said dialysis liquid in the said haemodialyser (13) between minimum and maximum values, a sensor (17) sensitive to the pulsation of the blood in said extracorporeal blood circuit at a frequency below 1 hertz, and a servo-control (28a,28b, 28c,28d) operable in response to said sensor to control said means for periodically modulating the flow of dialysis liquid as a function of said pulsations of the blood at frequencies below 1 hertz.
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Accused Products
Abstract
A single-needle artificial kidney comprising a haemodialyser divided by a semi-permeable membrane into first and second compartments, one of which forms part of an extracorporeal blood circuit including a blood circulation pump and a single needle for inserting into the patient and a dialysis liquid circuit including the second chamber and a dialysis liquid pump. The dialysis liquid circuit is provided with means for periodically modulating the flow rate of the dialysis liquid in the haemodialyser between minimum and maximum values, the flow rate of the dialysis liquid being produced by a sensing pulsations of the blood at frequencies less than one hertz and using these pulsations via a servo-control to effect changes in the dialysis liquid flow rate so that it reaches maximum and minimum values simultaneously with maximum and minimum of the blood flow rate.
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Citations
9 Claims
- 1. An artificial kidney which includes a haemodialyser (13) a semi-permeable membrane (14) which can effect dialysis and ultrafiltration of the blood, said diaphragm dividing said haemodialyser into first and second compartments (28), (29) an extracorporeal blood circuit including said first compartment (28), a blood circulation pump (15, 16) and a single needle (12) for insertion into the patient (11), a dialysis liquid circuit including said second compartment (29) and a dialysis liquid pump (27), characterized in that said dialysis liquid circuit includes means for enabling simultaneous pulsing of both blood and dialysis liquid in the haemodialyser of said single-needle artificial kidney, sufficient to provide the high efficiencies otherwise obtained with conventional double-needle artificial kidneys, including means (27a, 27b,27c,27d,27e) for periodically modulating the flow rate of said dialysis liquid in the said haemodialyser (13) between minimum and maximum values, a sensor (17) sensitive to the pulsation of the blood in said extracorporeal blood circuit at a frequency below 1 hertz, and a servo-control (28a,28b, 28c,28d) operable in response to said sensor to control said means for periodically modulating the flow of dialysis liquid as a function of said pulsations of the blood at frequencies below 1 hertz.
Specification