Medical Treatment System and Methods Using a Plurality of Fluid Lines
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0 Petitions
Accused Products
Abstract
Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections of the apparatus being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of a diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber. Improved heater control circuitry is also disclosed, to provide added or redundant safety measures, or to reduce current leakage from a heater element during pulse width modulation control of the heater. Improvements are also disclosed in the application of negative pressure during a drain phase in peritoneal dialysis therapy, and to control the amount of intraperitoneal fluid accumulation during a therapy. Improvements in efficiency are also disclosed in the movement of fluid into and out of a two-pump cassette and heater bag of a peritoneal dialysis cycler, and in the synchronization of the operation of two or more pumps in a peritoneal dialysis cycler or other fluid handling devices using a multi-pump arrangement.
67 Citations
54 Claims
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1-28. -28. (canceled)
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29. A system for adjusting negative pressure used to withdraw fluid from a cavity of a patient, the system comprising:
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a pump configured to provide negative pressure to a fluid line connected to the cavity; a controller configured to measure and control the negative pressure provided by the pump; the controller also configured to measure a rate of flow of fluid from the fluid line to the pump; wherein the controller is arranged to control the pump by providing a first negative pressure to the fluid line, measuring the rate of fluid flow, and control the pump by providing a second negative pressure to the fluid line that is greater in magnitude than the first negative pressure if the measured rate of fluid flow exceeds a pre-determined value.
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30. A system for adjusting negative pressure used to withdraw fluid from a cavity of a patient, the system comprising:
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a pump configured to provide negative or positive pressure to a fluid line connected to the cavity; a controller configured to measure and control the pressure provided by the pump; the controller also configured to measure a rate of flow of fluid from the fluid line to the pump; wherein the controller is arranged to control the pump by providing negative pressure to the fluid line, measuring the rate of fluid flow, and control the pump by providing a positive pressure to the fluid line if the measured rate of fluid flow is less than a pre-determined value; and wherein the controller is arranged to re-apply negative pressure to the fluid line if a measured fluid flow upon application of the positive pressure is greater than a pre-determined amount.
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31. A system for adjusting negative pressure used to withdraw fluid from a cavity of a patient, the system comprising:
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a pump configured to provide negative pressure to a fluid line connected to the cavity; a controller configured to measure and control the pressure provided by the pump; the controller also configured to measure a flow rate of fluid from the fluid line to the pump; wherein the controller is arranged to control the pump by providing negative pressure in an amount that varies continuously as a function of the measured flow rate of the fluid; wherein the variation in negative pressure applied by the pump is limited to within a pre-determined range of negative pressures.
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32. A system for adjusting negative pressure used to withdraw fluid from a cavity of a patient, the system comprising:
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a pump configured to provide negative pressure to a fluid line connected to the cavity; a controller configured to measure and control the pressure provided by the pump; the controller also configured to measure a flow rate of fluid from the fluid line to the pump; a user interface configured to provide a user a measure of the negative pressure applied by the pump, and configured to receive input from the user to adjust the amount of negative pressure applied by the pump; wherein the controller is arranged to receive via the user interface a command from the user to adjust the negative pressure applied by the pump, and to effectuate the adjustment.
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33. A system for adjusting negative pressure used to withdraw fluid from a cavity f a patient, the system comprising:
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a pump configured to provide negative pressure to a fluid line connected to the cavity; a controller configured to measure and control the pressure provided by the pump; the controller also configured to measure a flow rate of fluid from the fluid line to the pump, and to compute a pumping duration based on the measured flow rate; a user interface configured to provide a user a measure of the negative pressure applied by the pump, and configured to receive input from the user to adjust the amount of negative pressure applied by the pump; wherein the controller is arranged to receive via the user interface a command from the user to adjust the negative pressure applied by the pump, to compute a change in the pumping duration resulting from the adjustment, to display information about the change in pumping duration on the user interface, and to receive from the user a command to proceed or not proceed with the adjustment.
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54. (canceled)
Specification