Medical treatment system and methods using a plurality of fluid lines
First Claim
1. A system for adjusting negative pressure used to withdraw fluid from a cavity of a patient, the system comprising:
- 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, andwherein the controller is configured to control the pump to provide a positive pressure to the fluid line if the measured rate of fluid flow does not exceed the pre-determined value.
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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.
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Citations
31 Claims
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1. 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, and wherein the controller is configured to control the pump to provide a positive pressure to the fluid line if the measured rate of fluid flow does not exceed the pre-determined value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A system for adjusting negative pressure used to withdraw fluid from a cavity of a patient, the system comprising:
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a pneumatically actuated diaphragm pump configured to provide positive or negative pressure to a fluid line connected to the cavity, the diaphragm pump having a pumping chamber connected to the fluid line and an actuation chamber having a valved connection to a source of positive or negative pneumatic pressure; a controller configured to measure and control the positive or negative pressure provided by the pump via a pressure transducer in valved communication with the actuation chamber; the controller also configured to compute a fluid flow rate through the fluid line by measuring pressures associated with the control chamber and computing the fluid flow rate from the measured pressures; wherein the controller is arranged to control the pump by providing a first negative pressure to the fluid line, computing the fluid flow rate, 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 computed fluid flow rate exceeds a pre-determined value, and wherein the controller is configured to control the pump to provide a positive pressure to the fluid line if the computed fluid flow rate does not exceed the pre-determined value. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A peritoneal dialysis system for adjusting negative pressure used to withdraw fluid from a peritoneal cavity of a patient, the system comprising:
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a pneumatically actuated diaphragm pump configured to provide positive or negative pressure to a fluid line connected to the cavity, the diaphragm pump having a pumping chamber connected to the fluid line and an actuation chamber having a valved connection to a source of positive or negative pneumatic pressure; a controller configured to measure and control the positive or negative pressure provided by the pump via a pressure transducer in valved communication with the actuation chamber; the controller also configured to compute a fluid flow rate through the fluid line by measuring pressures associated with the control chamber and computing the fluid flow rate from the measured pressures; wherein the controller is arranged to control the pump by providing a first negative pressure to the fluid line, computing the fluid flow rate, 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 computed fluid flow rate exceeds a pre-determined value, and wherein the controller is configured to control the pump to provide a positive pressure to the fluid line if the computed fluid flow rate does not exceed the pre-determined value.
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Specification