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Hemodialysis system

  • US 4,366,051 A
  • Filed: 11/19/1976
  • Issued: 12/28/1982
  • Est. Priority Date: 11/19/1976
  • Status: Expired due to Term
First Claim
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1. A compact hemodialysis system including a dialyzer comprising:

  • canister means having an interior chamber for receiving a dialysate solution and means for draining solution in excess of a selected amount;

    a proportioning pump responsive to control signals for feeding dialysate solution to the interior chamber of the canister means, the proportioning pump receiving an inlet water flow and an inlet saline concentrate flow and providing outlet water and concentrate flows in specific proportions comprising a feed rate flow of dialysate solution;

    circulation pump means including conduit means coupled to the canister means for delivering dialysate solution to the dialyzer at a rate which may be independent of the feed rate flow;

    means for returning the solution through the dialyzer to the canister means, the canister means time averaging variations in concentrate from the proportioning pump to prevent abrupt changes in dialysate properties delivered to the dialyzer and draining off excess from the canister means;

    means including conduit means coupled to the circulation pump means and to said canister means for defining a suction loop, the suction loop including negative pressure means for circulating the dialysate solution from the canister means in the suction loop independent of the feed flow from the proportioning pump to the canister means, and wherein the suction loop in addition include means responsive to the dialysate for providing control signals for control of the proportioning pump;

    means internal to the hemodialysis system for passing steam throughout the conduit means and the canister means to sterilize the system so that the unit may be used thereafter with different patients without danger of contamination, said means internal to the hemodialysis system comprising a resistive heating element having an exterior casing in the feed flow path, and a cylindrical sleeve about and larger than the casing and means for admitting water at a lower end of the heater between the sleeve and casing and for allowing the escape of saturated steam at the upper end of the heater, the heater being disposed in an upright position so that forced vertical convection drives steam upwardly preventing steam collection and overheating adjacent the heated core surface;

    means for shunting exterior couplings of the conduit means to provide a confined pressurizable multi-path volume having a drain outlet, a liquid retaining lower cavity along the flow path and a conduit coupled to the drain outlet from the lower end of the cavity, and pressure release means coupled to the drain oulet for regulating the maximum pressure available in the system to develop a pressure-temperature equilibrium upon generation of adequate steam in the presence of liquid water to sterilize the dialysis system by steam at temperatures substantially in excess of the atmospheric boiling point of water to adequately destroy bacterial and viral germs;

    means for enclosing the canister means to enable steam to contact all exposed surfaces of the canister means, said means for enclosing including safety valve means operable at a higher pressure than said means for maintaining pressure;

    anddrain valve means in the conduit having a lower operating pressure than the means for maintaining steam at pressure, so that liquid is driven out of the lower cavity through the drain valve means prior to the flow path reaching equilibrium temperature, and thereby allowing complete flow path surface steam penetration.

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