Aksys Gmbh

Thomas M Feldsein

Frederick H Peter, Jr

Rodney S Kenley

Dennis M Treu

Kenneth E Pawlak

Dawn Matthews

Eric Bell

Wayne F Adolf

Tom L Brose

Douglas L Wilkerson

H Gordon Minns

Linda Roettger

A hemodialysis machine is described that has an extracorporeal circuit that is primed automatically prior to connection of the patient to the machine. The priming is accomplished by filling the extracorporeal circuit with a priming fluid, such as a saline or dialysate solution or blood. The blood pump and clamps in the arterial and venous lines are operated by a control system in a fashion to create multiple brief pressure pulses in the priming fluid. The pressure pulses shear air bubbles present on the blood side of the dialyzer membrane off the membrane. The blood pump is then operated to clear the bubbles from the dialyzer compartment where they are removed from the priming fluid by conventional bubble trap apparatus.

Hemodialysis machine with automatic priming by induced pressure pulses

Methods and apparatus for increasing the accuracy of ultrafiltration in a dialysis machine and decreasing the time required for dialysis. The machine inclused a substantially non-compliant tank for mixing and storing a batch of dialsyate. In a preferred form, the tank is a hollow vessel made from a lightweight and chemically inert material, such as polypropylene, reinforced on its exterior. The machine further includes an ultrafiltration pump for pumping fluid from an extracorporeal circuit to an ultrafiltration tank commensurate with the removal of water from the patient. The pump is calibrated with the volume of fluid in the tank. The reduction in the time to conduct hemodialysis of the patient is achieved by introducing the patient's blood into the arterial line and conducting the blood to the blood pump, measuring the pressure of the blood in the arterial line, increasing the pump rate of the blood pump, and in the event that the pressure measured in the arterial line drops below a predetermined threshold value, slowing the pump rate of the blood pump.

Methods for ultrafiltration control in hemodialysis

A method is described for determining the sodium clearance of a dialyzer. Dialysate containing sodium ions is circulated through the dialysate side of the dialyzer. Water is continuously circulated through the blood side of the dialyzer, the water being single passed through the blood side of the dialyzer. Measurements of the conductivity of the dialysate are made prior to the dialysate entering the dialyzer, and measurements of the conductivity of the dialysate are made after the dialysate has passed through the dialyzer. The clearance of the sodium ions by the dialyzer is calculated from the measurements of conductivity. The measurements of conductivity of the dialysate after passing through the dialyzer becomes substantially constant as the dialysate and water are circulated through the dialyzer. The sodium clearance corresponds to urea clearance of the dialyzer, since the two molecules are approximately the same size.

Method for determining sodium clearance of dialyzer

A hemodialysis machine has ports of a disinfection manifold for receiving the arterial and venous line connectors terminating the arterial and venous lines. The ports are in fluid communication with a hydraulic system that circulates disinfection fluid through the machine including the extracorporeal circuit. The ports are constructed so as to provide a gap extending circumferentially around the arterial and venous line connectors. When the disinfection fluid circulates through the ports of the disinfection manifold, the fluid circulates around the external surfaces of the connectors as well as through the internal fluid passages, thereby insuring a complete disinfection of the connectors.

Disinfection of arterial and venous line connectors hemodialysis machine

A method is described for priming a dialyzer placed in an extracorporeal circuit of a hemodialysis machine in situ. The method comprises the steps of substantially filling the extracorporeal circuit and the blood side of the dialyzer with fluid (such as dialysate, RO water, saline, etc.), and inducing pressure pulses in the fluid. The pressure pulses cause air bubbles from the blood side of the dialyzer to be sheared off the dialyzer membrane. The air bubbles are then conducted from the dialyzer and removed from the extracorporeal circuit. Backfiltering of fluid across the dialyzer from the dialysate circuit into the extracorporeal circuit is performed in synchrony with the pressure pulses to assist in the shearing off of air bubbles from the blood side of the dialyzer membrane.

Method of priming dialyzer

A loading platform and chemical addition system are described for a machine that prepares a batch of dialysate. The loading platform is in fluid communication with a dialysate preparation tank, and receives chemical vessels that contain a batch quantity of dialysate chemicals. The chemicals are released from the vessels automatically and fall onto a shelf in the loading platform. Nozzles and spray equipment are provided for insuring the complete release of the chemicals from the vessels and their dispersion into the tank. Novel mixing techniques are implemented in the tank to insure complete mixing of the dialysate solution and prevention of settling of dialysate solution at the bottom of the tank.

Apparatus for supplying a batch of chemicals to a dialysate tank

A method is described herein for automatically rinsing blood back to a patient. The method comprises the steps of pumping dialysate (or, alternatively, saline solution) through a dialyzer into an extracorporeal circuit, and pumping blood in the extracorporeal circuit out the arterial and venous lines back to the patient. Optical sensors monitor the concentration of blood in the arterial and venous lines as the blood is being pumped from the extracorporeal circuit back to the patient. The return flow of blood is ceased when the concentration of blood in the arterial and venous lines drops to a predetermined threshold level, thereby preventing excess fluids from being returned to the patient.

Method of rinsing back blood to hemodialysis patient

A method is described for automatically testing the integrity of a dialyzer filter within a dialysis machine. The method consists of substantially removing fluids which may be present from the blood side of the dialyzer filter, pumping air into the blood side of the dialyzer filter with a blood pump to pressurize the dialyzer filter, and measuring the pressurization of the dialyzer filter. If the dialyzer filter pressurizes, the rate of decay of pressurization is measured. The pressurization and rate of decay are indicative of the integrity of the membrane of the dialyzer filter.

Filter integrity test method for dialysis machines

A method for maintaining separation of old and new dialysate in a dialysate preparation tank is disclosed. The new dialysate is stored in the tank at a first temperature and withdrawn from the bottom of the tank. The dialysate is circulated through a dialyzer, and then returned to the tank at the top of the tank at a higher temperature in a substantially non-turbulent manner. The temperature differential between old and new dialysate and the manner of withdrawing and reintroducing the dialysate to the tank cooperate to form discrete zones of old and new dialysate without substantial mixing of the dialysate in the two zones.

Dialysate separation method

A dialysis machine is disclosed that incorporates a water treatment module, a dialysate preparation module having a dialysate circuit, and an extracorporeal circuit including a dialyzer and arterial and venous blood lines that connect to the patient. The machine accomplishes on-line disinfection of all the fluid circuits of the machine, including the water treatment module, the dialysate preparation module and extracorporeal circuit, the arterial and venous lines, and the dialyzer, by circulating water heated to a high level disinfection temperature (e.g., 80 degrees C.) through the fluid passages of the machine for a sufficient time (such as an hour) to achieve high level disinfection. After the dialysis session is ended, the patient connects the arterial and venous lines to ports in a disinfection manifold that places the arterial and venous lines into fluid communication with the heated water. Thereafter, the machine is ready to disinfect the fluid circuits including the extracorporeal circuit. In a preferred embodiment, the ports of the disinfection manifold ports include recessed features that permit the hot water to circulate on the interior and exterior surfaces of the arterial and venous line connectors, thereby insuring that the surfaces of connectors themselves are also disinfected.

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Palatine, IL, United States of America

Thomas M Feldsein