Method and apparatus for kidney dialysis

An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer, the apparatus further comprising:

• (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.

An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer, the apparatus further comprising:

• (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.

An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer having a dialysate compartment and a blood compartment, the apparatus further comprising:

• (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.

An apparatus for delivering dialysate comprising a dialysate circuit including a dialyzer having a dialysate compartment and a blood compartment, the apparatus further comprising:

• (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.