Method and apparatus for kidney dialysis

#The present invention relates to improvements in kidney dialysis machines.

#Kidney dialysis machines are well known in the art and are illustrated, for example, in U.S. Pat. Nos., 3,598,727, 4,172,033, 4,267,040, and 4,769,134.

#While machines according to the prior art provide a number of advantageous features, they nonetheless have certain limitations. The present invention seeks to overcome certain drawbacks of the prior art and to provide new features not heretofore available.

#FIGS. 1A and 1B show a schematic hydraulic diagram of a preferred embodiment of a kidney dialysis machine according to the present invention.

#FIG. 2 is a schematic diagram showing flow path locations and components of a pre-dialyzer flow sensor and a post-dialyzer, flow sensor according to the present invention.

#FIGS. 3A and 3B are isometric and schematic diagrams, respectively, of a concentrate-line proximity sensor comprising a portion of the automatic proportioning mode setting feature of the present invention.

#A hydraulic circuit 10 representing a preferred embodiment of an improved hemodialysis machine according to the present invention is illustrated in FIGS. 1A and 1B. The hydraulic circuit 10 is comprised of the following principal components: an incoming water pressure regulator 12, a water on/off valve 14, a heat exchanger 16, a heater 18, a safety thermostat 20, an “A” concentrate pump 22, a supply valve 24, an air gap chamber 26, an “A” rinse fitting 28, a “B” rinse fitting 30, a deaeration sprayer 32, an air removal pump 34, a vented air trap 36, an “A” conductivity probe 38, a “B” concentrate pump 40, a supply pump 42, a “B” mix chamber 44, a “B” conductivity probe 46, a dialysate filter 48, a supply regulator 50, an input pressure equalizer 52, a flow equalizer 54, an output pressure equalizer 56, end-of-stroke sensors 58, 59, a dialysate conductivity probe 60, a pre-dialyzer flow sensor 62, a dialysate pressure transducer 64, a bypass valve 66, a dialysate sample port 68, a post-dialyzer flow sensor 70, a dialysate pressure pump 72, a UF removal regulator 74, a UF flow meter 76, a blood-leak detector 78, and a rinse valve 80. The aforementioned components are interconnected as shown in FIGS. 1A and 1B.

#The incoming water pressure regulator 12 is coupled to a pressurized water source 82 and reduces and stabilizes the water supply pressure to a level of about 20 psig.

#The water on/off valve 14 opens when machine power is on, thereby allowing water to flow from the source 82 into the hydraulic circuit 10. When the machine power is off, the water on/off valve 14 is closed.