Abstract: A dialysis machine is described which has a batch dialysate preparation system comprising a lightweight, substantially noncompliant dialysate tank and volumetrically closed dialysate circuit. The tank is made from a polymeric material, such as polypropylene, with fiberglass windings on the exterior of the tank. The noncompliance of the tank and dialysate circuit allows for greater control over ultrafiltration of the patient.

Abstract: Water treatment and pretreatment methods and processes for use in a dialysate preparation machine are described. In one aspect, water is passed through a first filter having chlorine removal properties and then passed into a line. Water is removed from the line at a sample location. The removed water is periodically sampled for the presence of chlorine or chloramines. The presence of chlorine or chloramines indicates that the filtration capacity for chlorine of the first filter is substantially exhausted. The method further includes the step of filtering the water downstream from the sample location in a second filter having chlorine removal properties, and replacing the first filter if chlorine or chlorine is detected during the sampling step. Water pretreatment may be provided by mixing hot and cold water from a source with a temperature-controlled mixing valve and passing the water through the first filter, so as to provide warm, filtered water to the dialysate preparation machine.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A connector for a tube and a port construction for sealingly and securely receiving the connector. The connector has a male luer comprising a locking hub and a cylindrical tubing port. The cylindrical tubing port receives the free end of the tube. A second piece is provided that envelops the male luer, comprising a elongate cylindrical housing having a interior surface. The male luer and the tube are snugly inserted within the interior surface of the second piece to form a unitary connector.The port receives the connector and has a housing having a first end and a second end and an open interior region defining first and second chambers and a housing axis. The first and second chambers are disposed within the first and second ends of the housing, respectively. A locking knob is movably mounted on the first end of the port apparatus and movable along the housing axis relative to the first end between first and second positions.

Abstract: An apparatus is described for automatically opening and dispensing the contents of a vessel, for example, a vessel containing dialysate chemicals for dispersion into a dialysate preparation tank. The apparatus comprises a housing having an open interior region, with the vessel mounted above the housing, and a spike reciprocable within the interior of the housing between upper and lower positions. The spike pierces the vessel when the spike is moved to the upper position. The spike has an upper spike element that pierces the bottle and an integral spike body concentric with the housing permitting passage of dialysate chemicals therethrough after the spike has pierced the vessel. A drive means is proved for moving the spike relative to the housing between the upper and lower positions, so as to control the operation of the spike and the automatic release of the contents of the vessel.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A dialysis machine is described which provides for the detection of leakage anywhere in the machine. The machine includes integral water treatment, dialysate preparation and extracorporeal circuit modules. The floor of the machine is constructed in a non-horizontal manner so as to provide a fluid catchment chamber with a fluid sensor. The extracorporeal circuit is mounted above the dialysate preparation module and the water treatment module. In one embodiment, a drain and drain tube allows fluid that leaks from the extracorporeal circuit module to be conducted to the floor of the machine, where the leak can be detected, along with a fluid leak in the water treatment or dialysate preparation modules. In another embodiment, a separate fluid leakage detector is placed at the base of the extracorporeal circuit module for detection of leakage in situ in the extracorporeal circuit, while the catchment chamber and sensor in the base of the machine detect leaks from the other modules.

Abstract: Apparatus for removing air bubbles from blood and from a dialysate solution are described herein. In one cassette-style embodiment of a blood debubbler, the debubbler includes front and rear covers, a fluid circuit board between the front and rear covers and defining a blood chamber between the fluid circuit board and the front cover and an air chamber between the fluid circuit board and the rear cover, and a microporous membrane separating the blood chamber from the air chamber. A support means is provided for supporting the microporous membrane from the air side of the membrane. A pressure sensor is provided within the front and rear covers for measuring the blood pressure in the blood chamber. The debubbler has a blood inlet port and a blood outlet port for conducting blood to and from the blood chamber. An air port is provided in communication with the air chamber, which allows for air passing through the microporous membrane to escape.

Abstract: 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.

Abstract: A method for detecting the presence of blood in a dialysate solution is disclosed. The method provides for certain measurement of light intensity passing through solutions both before and during the dialysis session. Before dialysis is commenced, measurements are made of the intensity of light passing through a chamber containing a control dialysate solution that is free of blood. The light source is a first condition. The light source's state is changed from a first condition to a second condition different from the first condition. Next, a second measurement of the intensity of light is made. The first and second measurements are stored. During dialysis, the method continues with the following steps: conducting a third measurement of the intensity of light of the light source that passes though the chamber, the chamber containing dialysate solution that may contain the patient's blood, with the light source in the first condition.

Abstract: A vessel storing a batch of chemicals for delivery into a dialysate preparation tank includes a machine readable indicator, permitting automatic identification of the contents of the vessel prior to operating the vessel and introduction of chemicals into a tank where the dialysate solution is mixed. Various types of machine-readable indicators may be used, such as, for example, "touch" memory buttons, bar codes, or magnetic strips. Suitable reading devices for the machine-readable indicators are provided for reading the contents of the bottle.

Abstract: High level disinfection of a home hemodialysis machine is achieved without the use of disinfection chemicals. The machine has a water treatment module, an extracorporeal circuit and a dialysate circuit. Purified water is heated to a high level disinfection temperature, such as 75 or 80 degrees C. The water is circulated though the water treatment module, the extracorporeal circuit and the dialysate circuit for a time sufficient to achieve a high level disinfection of the machine, for example at least one hour. After the high level disinfection is obtained, the water is drained from the machine and the machine is placed in condition for another treatment session.

Abstract: 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.