Abstract: A transmitter unit has a housing adapted to be coupled in association with a trailing vehicle. The housing also has a multiple axis accelerometer adapted to sense the status of the transmitter unit and a trailing vehicle. The housing also has electronic components coupled with the accelerometer. A receiver unit has a housing adapted to be coupled in association with a leading vehicle. A user in audio proximity to the receiver unit is wirelessly signaled in the event of an anomaly at the transmitter unit.

Abstract: A valveless positive displacement pump including a closed end cylinder having two fluid inlet and outlet ports adjacent the closed end. A piston reciprocably and rotatably driven in the cylinder and including a reduced area portion on one free end which communicates cyclically with the inlet and outlet ports to pump fluid through the positive displacement pump. The piston reduced area is a reduced radius portion to minimize air bubble buildup and to minimize fluid volume at the end of the piston stroke. The piston also has a gland area formed in the piston which cyclically communicates with a pair of ports to clean the piston and cylinder and prevent the buildup of solids. The piston and cylinder can be formed from a hard ceramic material for accuracy and wear resistance. The cylinder is closed by a resilient end cap to relieve pressures caused by piston movement when the inlet and outlet ports are closed.

Abstract: A pressure regulating system for a hemodialysis machine utilizes a deaeration pump and a regulator in a deaeration loop for minimizing pressure and flow transients in a heated water supply. The deaeration loop has the pump, a deaeration pressure regulator, a deaerator, and a back pressure regulator. The pump produces a negative pressure in heated water entering the deaeration pressure regulator to circulate the water in the deaeration loop and to enhance removal of air from the water. The back pressure regulator controls the loop water pressure to a value greater than the incoming water pressure and supplies water to the dialyzer system of the machine isolated from supply water pressure and flow variations.

Abstract: A flow rate measurement system and method suitable for monitoring filtrate flow in a hemodialysis apparatus, provides a pair of flow meters in series at the input of a dialyzer for producing electrical signals indicative of dialysate flow rate and a pair of flow meters in series at the output of the dialyzer for producing electrical signals indicative of dialysate plus filtrate flow rate. A computer receives the flow rate signals and is programmed to calibrate each flow meter during a calibration phase to correct for any variations in each pair to thereby produce corrective scale factors. During an operational phase of the apparatus, the program monitors the flow meters and provides an alarm if any changes between the readings of either of the pairs of flow meters occurs.

Abstract: A system for controlling the output flow rate of a second pump to proportionately track the output flow rate of a first pump in which the first pump produces an electrical signal at each successive stroke thereof. An electrical circuit produces an electrical control signal from the first pump stroke signal for controlling the flow rate of the second pump.

Abstract: A water purification system includes a water purifying module having an inlet, a first outlet for purified product water and a second outlet for untreated concentrate water. An inlet line is connected to the module inlet, a purified water line is connected to the first outlet, and a drain line is connected to the second outlet. A first return line including a check valve is connected between the purified water line and the inlet line, and a second return line is connected between the drain line and the inlet line. Water to be treated is supplied to the inlet line by a pressure regulator, which provides regulated water pressures in the inlet line, the first and second return lines, and the purified water line.

Abstract: Apparatus for heating or cooling fluids, particularly physiological fluids such as blood or plasma or fluids, such as dialysis fluid, which are used in the treatment of physiological fluids. Also disclosed are containers in which or through which fluids may be contained or circulated in order to effect heating or cooling.

Abstract: A module containing a reverse osmosis membrane for a water purification system is provided. A membrane assembly is mounted in the center of a pressure vessel with a seal surrounding the membrane assembly between the outside of the assembly and the inner wall of the pressure vessel. An inlet port passes through the pressure vessel and enters the vessel between the seal and one end of the pressure vessel in close prximity to the seal. An outlet port passes through the pressure vessel at a point between the seal and the other end of the pressure vessel, also in close proximity to the seal. The water pressure differential between the two ports maintains the integrity of the seal and their location insures a turbulent water flow throughout the module.

Abstract: Flexible container means for the warming or cooling of fluids. A preferred embodiment, useful for the warming of plasma following cryogellation techniques prior to its return to the patient, comprises container means formed by the heat sealing of polymeric materials thereby defining a winding passageway of tapered walls whereby the container becomes air self-evacuating.

Abstract: A transmembrane pressure regulator especially useful in artificial kidney systems. The regulator will maintain a pre-selected dialysate pressure at a substantially constant value despite changes in dialysate flow. The regulator of the invention will adjust dialysate pressure in response to changes in a patient's venous blood pressure so as to maintain a transmembrane pressure substantially constant at a preselected value.

Abstract: An apparatus for heating or cooling physiological fluids, such as whole blood and blood plasma, or liquids which are used in the treatment of such physiological fluids, wherein at least one thermoelectric device is used for the heating or cooling.

Abstract: Dialysis apparatus is arranged to enable convenient measuring of ultrafiltration rate from liquid, such as blood, that is to be dialyzed. Dialyzer can have, downstream of a dialysis chamber, a dialyzate passageway through which the ultrafiltration flow rate can be readily measured as by introducing a gas bubble into the dialyzate and timing its movement through the passageway. An air-injection attachment can be fitted to the dialyzer or to a dialyzate supply system, to inject the gas bubble for such measurement. Bubble injection can also be effected in a flow rate measuring passageway downstream of the dialyzer. Flow rates of dialyzate into and out of dialyzer can be compared to show ultrafiltration while dialyzing. The gas injector can be valve-containing unit also equipped with a paddle-wheel dialyzate flow indicator.

Abstract: Dialysis apparatus is arranged to enable convenient measuring of ultrafiltration rate from liquid, such as blood, that is to be dialyzed. Dialyzer can have, downstream of a dialysis chamber, a dialyzate passageway through which the ultrafiltration flow rate can be readily measured as by introducing a gas bubble into the dialyzate and timing its movement through the passageway. An air-injection attachment can be fitted to the dialyzer or to a dialyzate supply system, to inject the gas bubble for such measurement. Bubble injection can also be effected in a flow rate measuring passageway downstream of the dialyzer. Flow rates of dialyzate into and out of dialyzer can be compared to show ultrafiltration while dialyzing.