Apparatus for the ultrafiltration control in connection with the hemodialysis

Claim 1

An apparatus for continuously controlling the liquid flow in a single pass hemodialysis treatment system, comprising at least two elongated container means (12, 13) for the unidirectional and laminar supply of fresh dialysate and for the unidirectional and laminar discharge of used dialysate, each said container means having a given length and a given diameter substantially smaller than the length, whereby the filling and emptying of said elongated container means advances with a unidirectional, laminar flow which moves always in the same direction in said container means, each container means having inlet means at one end thereof and outlet means at the opposite end thereof, said unidirectional flow flowing in each container from said inlet means to said outlet means during filling and during emptying, each of said inlet means and each of said outlet means comprising branching conduit means connected to the respective end of the corresponding container means, controllable valve means operatively interposed in each of said branching conduit means, dialysis liquid feeder container means (4) and feeder conduit means operatively connecting said feeder container means (4) to each inlet means through the respective valve means (20A, 22B) for providing fresh dialysis liquid to said inlet means, discharge conduit means (3) operatively connected to each of said outlet means through the respective valve means, dialyzer means (8, 9) having dialyzer inlet means and dialyzer outlet means for dialysis liquid, first circulatory conduit means (6) operatively connecting each outlet of said elongated container means through the respective valve means to the dialyzer inlet means, second circulatory conduit means (7) operatively connecting each inlet of said elongated container means to said dialyzer outlet means, circulatory pump means (15) operatively interposed in said second circulatory conduit means (7), said first and second circulatory conduit means (6, 7), said circulatory pump means (15) with the respective valve means and one of said container means forming a closed circulatory loop, said circulatory pump means for unidirectional pumping through said closed circulatory loop, control means (14), including conductor means (18, 19) operatively connected for controlling said controllable valve means to alternately connect said elongated container means in timed sequence into said closed circulatory loop said control means for causing at any time at least one of said elongated container means to be connected in said closed circulatory loop while at least one other elongated container means is connected between said dialysis liquid feeder container means (4) and said discharge conduit means so as to discharge used dialysis liquid without recirculation to said dialyzer means and for causing the reversal of said connections such that at the beginning of an operating phase at least one container is filled with fresh dialysis liquid and at least another continner is filled with used-up dialysis liquid and this filling status is reversed at the end of said operating cycle so that used-up and fresh dialysis liquid will not be mixed; branching pump means (17) operatively connected to said second circulatory conduit means (7) upstream of said circulatory pump means (15) for withdrawing liquid from said closed circulatory loop, liquid quantity measuring means (30, 31) operatively connected to said branching pump means for measuring dialysis liquid withdrawn per unit of time from said closed circulatory loop by said branching pump means, said liquid quantity measuring means producing a feedback control signal proportional to the withdrawn dialysis liquid, and closed loop feedback means (32, 26) operatively controlling the operation of said branching pump means in closed loop feedback fashion in response to the withdrawn proportion of dialysis liquid.

Claim 2

An apparatus for continuously controlling the liquid flow in a single pass hemodialysis treatment system, comprising at least two elongated container means (12, 13) for the unidirectional and laminar supply of fresh dialysate and for the unidirectional and laminar discharge of used dialysate, each said container means having a given length and a given diameter substantially smaller than the length, whereby the filling and emptying of said elongated container means advances with a unidirectional, laminar flow which moves always in the same direction in said container means, each container means having inlet means at one end thereof and outlet means at the opposite end thereof, said unidirectional flow flowing in each container from said inlet means to said outlet means during filling and during emptying, each of said inlet means and each of said outlet means comprising branching conduit means connected to the respective end of the corresponding container means, controllable valve means operatively interposed in each of said branching conduit means, dialysis liquid feeder container means (4) and feeder conduit means operatively connecting said feeder container means (4) to each inlet means through the respective valve means (20A, 22B) for providing fresh dialysis liquid to said inlet means, discharge conduit means (3) operatively connected to each of said outlet means through the respective valve means, dialyzer means (8, 9) having dialyzer inlet means and dialyzer outlet means for dialysis liquid, first circulatory conduit means (6) operatively connecting each outlet of said elongated container means through the respective valve means to the dialyzer inlet means, second circulatory conduit means (7) operatively connecting each inlet of said elongated container means to said dialyzer outlet means, circulatory pump means (15) operatively interposed in said second circulatory conduit means (7), said first and second circulatory conduit means (6, 7), said circulatory pump means (15) with the respective valve means and one of said container means forming a closed circulatory loop, said circulatory pump means for unidirectional pumping through said closed circulatory loop, control means (14), including conductor means (18, 19) operatively connected for controlling said controllable valve means to alternately connect said elongated container means in timed sequence into said closed circulatory loop said control means for causing at any time at least one of said elongated container means to be connected in said closed circulatory loop while at least one other elongated container means is connected between said dialysis liquid feeder container means (4) and said discharge conduit means so as to discharge used dialysis liquid without recirculation to said dialyzer means and for causing the reversal of said connections such that at the beginning of an operating phase at least one container is filled with fresh dialysis liquid and at least another continner is filled with used-up dialysis liquid and this filling status is reversed at the end of said operating cycle so that used-up and fresh dialysis liquid will not be mixed; branching pump means (17) operatively connected to said second circulatory conduit means (7) upstream of said circulatory pump means (15) for withdrawing liquid from said closed circulatory loop, liquid quantity measuring means (30, 31) operatively connected to said branching pump means for measuring dialysis liquid withdrawn per unit of time from said closed circulatory loop by said branching pump means, said liquid quantity measuring means producing a feedback control signal proportional to the withdrawn dialysis liquid, and closed loop feedback means (32, 26) operatively controlling the operation of said branching pump means in closed loop feedback fashion in response to the withdrawn proportion of dialysis liquid.