Method and apparatus for kidney dialysis
First Claim
1. A kidney dialysis machine comprising:
- a dialyzer with a dialysate compartment, a blood compartment separated from the dialysate compartment by a dialysis membrane, a dialysate input, a dialysate output, a blood input, and a blood output;
means for preparing dialysate and means for circulating the dialysate through a dialysate circuit, the dialysate circuit including the dialysate compartment, the dialysate input and the dialysate output of the dialyzer;
means for effecting extracorporeal circulation of blood from a dialysis patient through a blood circuit, the blood circuit including the blood compartment, the blood input, and the blood output of the dialyzer;
shunting means for directing flow of dialysate away from the dialysate compartment;
sensing means for sensing that no dialysate is flowing to the dialysate compartment whenever said shunting means is directing dialysate flow away from the dialysate compartment; and
means responsive to said sensing means for turning off said means for circulating dialysate through the dialysate circuit whenever said shunting means should be directing dialysate flow away from the dialysate compartment but said sensing means detects dialysate flow to the dialysate compartment.
1 Assignment
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Accused Products
Abstract
A number of improvements relating to methods and apparatuses for kidney dialysis are disclosed. These include checking of dialysate bypass status using flow measurement; using a flow sensor to confirm the absence of ultrafiltration during bypass; automatic testing of ultrafiltration function by removal of a discrete volume from a portion of the dialysate flow path coupled with a pressure test of that part of the flow path; using a touch screen user interface; bar graph profile programming of ultrafiltration, sodium, and bicarbonate parameters; using a RAM card to upload treatment instructions to, and to download treatment data from, the machine; automatic setting of proportioning mode (acetate or bicarbonate) based on connections of concentrate lines; predicting dialysate conductivity values based on brand and formulation of concentrates; minimizing no-flow dead time between dialysate pulses; initiating operation in a timed mode from a machine power-off condition; preserving machine mode during machine power-fail condition; calibration scheduling and reminding; automatic level adjusting; and blood leak flow rate detecting.
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Citations
15 Claims
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1. A kidney dialysis machine comprising:
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a dialyzer with a dialysate compartment, a blood compartment separated from the dialysate compartment by a dialysis membrane, a dialysate input, a dialysate output, a blood input, and a blood output; means for preparing dialysate and means for circulating the dialysate through a dialysate circuit, the dialysate circuit including the dialysate compartment, the dialysate input and the dialysate output of the dialyzer; means for effecting extracorporeal circulation of blood from a dialysis patient through a blood circuit, the blood circuit including the blood compartment, the blood input, and the blood output of the dialyzer; shunting means for directing flow of dialysate away from the dialysate compartment; sensing means for sensing that no dialysate is flowing to the dialysate compartment whenever said shunting means is directing dialysate flow away from the dialysate compartment; and means responsive to said sensing means for turning off said means for circulating dialysate through the dialysate circuit whenever said shunting means should be directing dialysate flow away from the dialysate compartment but said sensing means detects dialysate flow to the dialysate compartment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer, the apparatus further comprising:
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(a) a pump hydraulically connected to a dialysate supply, the pump being operative to urge flow of dialysate from the dialysate supply through the dialysate circuit and dialyzer; (b) a bypass valve disposed in the dialysate circuit upstream of the dialyzer, the bypass valve being operative to stop dialysate, flowing through the dialysate circuit, from flowing to the dialyzer during an unsafe dialysis condition; and (c) a flow sensor means disposed in the dialysate circuit between the bypass valve and the dialyzer, the flow sensor means being operative to (1) sense the presence or absence of dialysate flow to the dialyzer, and (2) turn off the pump during an unsafe dialysis condition in which the flow sensor means detects dialysate flow to the dialyzer and the bypass valve should be stopping flow of dialysate to the dialyzer. - View Dependent Claims (10, 11)
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12. An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer, the apparatus further comprising:
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(a) a pump hydraulically connected to a dialysate supply, the pump being operative to urge flow of dialysate from the dialysate supply through the dialysate circuit and dialyzer; (b) a bypass valve disposed in the dialysate circuit upstream of the dialyzer, the bypass valve being operative to stop dialysate, flowing through the dialysate circuit, from flowing to the dialyzer during an unsafe dialysis condition; and (c) first and second thermistors each in thermal contact with dialysate in the dialysate circuit between the bypass valve and the dialyzer, the first thermistor being energized by a constant electrical current, and the second thermistor being energized by an electrical current that is less than the electrical current energizing the first thermistor, thereby causing the first and second thermistors to exhibit a differential electrical resistance whenever dialysate is flowing past the first and second thermistors but not when dialysate is not flowing past the first and second thermistors, thereby enabling the first and second thermistors to (1) sense the presence or absence of dialysate flow to the dialyzer, and (2) turn off the pump during an unsafe dialysis condition in which the bypass valve should be stopping flow of dialysate to the dialyzer.
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13. An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer having a dialysate compartment and a blood compartment, the apparatus further comprising:
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(a) a pump hydraulically connected to a dialysate supply, the pump being operative to urge flow of dialysate from the dialysate supply through the dialysate circuit and the dialysate compartment of the dialyzer; (b) a bypass valve disposed in the dialysate circuit upstream of the dialyzer, the bypass valve being operative to stop dialysate, flowing through the dialysate circuit, from flowing to the dialysate compartment of the dialyzer during an unsafe dialysis condition; and (c) a flow sensor means disposed in the dialysate circuit between the bypass valve and the dialyzer, the flow sensor means being operative to (1) sense the presence or absence of dialysate flow to the dialysate compartment of the dialyzer, and (2) turn off the pump during an unsafe dialysis condition in which the flow sensor means detects dialysate flow to the dialysate compartment and the bypass valve should be stopping flow of dialysate to the dialysate compartment. - View Dependent Claims (14)
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15. An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer having a dialysate compartment and a blood compartment, the apparatus further comprising:
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(a) a pump hydraulically connected to a dialysate supply, the pump being operative to urge flow of dialysate from the dialysate supply through the dialysate circuit and dialyzer; (b) a bypass valve disposed in the dialysate circuit upstream of the dialyzer, the bypass valve being operative to stop dialysate, flowing through the dialysate circuit, from flowing to the dialyzer during an unsafe dialysis condition; and (c) a flow sensor means disposed in the dialysate circuit between the bypass valve and the dialyzer, the flow sensor means being operative to (1) sense the presence or absence of flow of liquid from the blood compartment to the dialysate compartment, and (2) stop flow of blood to the blood compartment during said unsafe dialysis condition.
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Specification