Apparatus and method for controlling fluid flow in dialysis and the like
First Claim
1. Apparatus for controlling the flow of a fluid past one side of a membrane in a dialyzer comprising means for providing very rapid control independent of transmembrane pressure (TMP), including, fluid conduit means for conducting said flow of said fluid towards and away from said dialyzer, first constant flow means for producing a first constant flow in said fluid conduit means upstream of said dialyzer, and second constant flow means for producing a second constant flow in said fluid conduit means downstream of said dialyzer, said first constant flow means comprising first constriction means for creating a pressure drop in the flow of said fluid in said fluid conduit means from a first predetermined substantially constant pressure to a second lower pressure, pump means downstream of said first constriction means for pumping said fluid through said fluid conduit means, and pressure measuring means for measuring said second lower pressure, said second constant flow means comprising second constriction means for creating a pressure drop in the flow of said fluid in said fluid conduit means from a third pressure to a fourth predetermined substantially constant lower pressure, pump means upstream of said second constriction means for pumping said fluid through said fluid conduit means, and pressure measuring means for measuring said third pressure whereby said first and second constant flow means can be controlled thereby, based upon said measured second pressure and said measured third pressure, respectively.
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Accused Products
Abstract
Apparatus and methods are disclosed for controlling the flow of a fluid past a membrane in a dialyzer. The apparatus disclosed includes a fluid conduit for conducting the fluid both towards and away from the dialyzer, a flow constrictor for creating a pressure drop in the fluid conduit either upstream or downstream of the dialyzer, a pump for pumping the fluid through that conduit, and a pressure detector for measuring a pressure corresponding to that pressure drop so as to control the flow therein. The method disclosed includes flowing the fluid through an upstream fluid conduit to the dialyzer and through a downstream fluid conduit away from the dialyzer, producing a relatively constant flow in both the upstream and downstream fluid conduits, creating a pressure drop in one of the fluid conduits, pumping the fluid through that conduit, and measuring the pressure corresponding to that pressure drop so that the flow of the fluid in that conduit can be controlled thereby.
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Citations
28 Claims
- 1. Apparatus for controlling the flow of a fluid past one side of a membrane in a dialyzer comprising means for providing very rapid control independent of transmembrane pressure (TMP), including, fluid conduit means for conducting said flow of said fluid towards and away from said dialyzer, first constant flow means for producing a first constant flow in said fluid conduit means upstream of said dialyzer, and second constant flow means for producing a second constant flow in said fluid conduit means downstream of said dialyzer, said first constant flow means comprising first constriction means for creating a pressure drop in the flow of said fluid in said fluid conduit means from a first predetermined substantially constant pressure to a second lower pressure, pump means downstream of said first constriction means for pumping said fluid through said fluid conduit means, and pressure measuring means for measuring said second lower pressure, said second constant flow means comprising second constriction means for creating a pressure drop in the flow of said fluid in said fluid conduit means from a third pressure to a fourth predetermined substantially constant lower pressure, pump means upstream of said second constriction means for pumping said fluid through said fluid conduit means, and pressure measuring means for measuring said third pressure whereby said first and second constant flow means can be controlled thereby, based upon said measured second pressure and said measured third pressure, respectively.
- 13. A method for controlling the flow of a fluid past one side of a membrane in a dialzyer comprising providing very rapid control, independent of transmembrane pressure (TMP), by, flowing said fluid through an upstream fluid flow portion to said dialyzer and from said dialyzer through a downstream fluid flow portion, producing a first constant flow in said upstream fluid flow portion, producing a second constant flow in said downstream portion, creating a pressure drop at a first predetermined location in said upstream fluid flow portion from a first predetermined substantially constant pressure to a second lower pressure, pumping said upstream fluid flow portion from a position downstream of said first predetermined location, measuring said second lower pressure, creating a pressure drop at a second predetermined location in said downstream fluid flow portion from a third pressure in a fourth predetermined substantially constant lower pressure, pumping said downstream fluid flow portion from a position upstream of said second predetermined location, measuring said third pressure, and controlling the flow of said fluid in said upstream and downstream fluid flow portions, based upon said measured second pressure and said measured third pressure, respectively.
- 15. Apparatus for controlling the flow of a fluid past one side of a membrane in a dialyzer comprising means for providing very rapid control independent of transmembrane pressure (TMP), including, fluid supply means for supplying a flow of a predetermined quantity of fluid, fluid conduit means for conducting said flow of said entire predetermined quantity of said fluid towards and away from said dialyzer, first constant flow means for producing a first constant flow in said fluid conduit means upstream of said dialyzer, and second constant flow means for producing a second constant flow in said fluid conduit means downstream of said dialyzer, said first constant flow means comprising first constriction means for creating a pressure drop in the flow of said entire predetermined quantity of said fluid in said fluid conduit means from a first predetermined substantially constant pressure to a second lower pressure, pump means downstream of said first constriction means for pumping said entire predetermined quantity of said fluid through said fluid conduit means, and pressure measuring means for measuring said second lower pressure, said second flow means comprising second constriction means for creating a pressure drop in the flow of said entire predetermined quantity of said fluid in said fluid conduit means from a third pressure to a fourth predetermined substantially constant lower pressure, pump means upstream of said second constriction means for pumping said entire predetermined quantity of said fluid through said fluid conduit means, and pressure measuring means for measuring said third pressure whereby said first and second constant flow means can be controlled thereby, based upon said measured second pressure and said measured third pressure, respectively.
- 27. A method for controlling the flow of a fluid past one side of a membrane in a dialyzer comprising providing very rapid control, independent of transmembrane pressure (TMP), by, providing a flow of a predetermined quantity of fluid, flowing said entire predetermined quantity of said fluid through an upstream fluid flow portion to said dialyzer and from said dialyzer through a downstream fluid flow portion, producing a first constant flow in said upstream fluid flow portion, producing a second constant flow in said downstream portion, creating a pressure drop in said entire predetermined quantity of said fluid at a first predetermined location in said upstream fluid flow portion from a first predetermined substantially constant pressure to a second lower pressure, pumping said upstream fluid flow portion from a position downstream of said first predetermined location, measuring said second lower pressure, creating a pressure drop in said entire predetermined quantity of said fluid at a second predetermined location in said downstream fluid flow portion from a third pressure to a fourth predetermined substantially constant lower pressure, pumping said downstream fluid flow portion from a position upstream of said second predetermined location, measuring said third pressure, and controlling the flow of said fluid in said upstream and downstream fluid flow portions, based upon said measured second pressure and said measured third pressure, respectively.
Specification