Patent ID: 8631683

Claim:
A dialysis system, comprising: a dialysis machine; a tube connected to the dialysis machine; a sensor system, comprising a head having a slot configured to receive the tube; and a plurality of sensors secured to the head adjacent the slot, wherein the plurality of sensors comprise: a light emitting element configured to transmit light through the tube when the tube is disposed in the slot; a light receiving element configured to receive the light emitted by the light emitting element after the light passes through the tube, and an infrared temperature sensor element configured to project infrared energy into the tube when the tube is disposed in the slot, wherein the sensor system further comprises a temperature sensing circuit responsive to infrared energy sensed by the infrared temperature sensor element to determine a temperature of fluid in the tube; a resistive heater; and a microprocessor in communication with the plurality of sensors, wherein the microprocessor is configured to activate the resistive heater to adjust a temperature of dialysate flowing through a dialyzer of the dialysis system based on a temperature of fluid in the tube determined by the temperature sensing circuit, wherein fluid in the tube is blood, the tube is a venous line, and the dialysis system further comprises an arterial line and a second temperature sensor configured to measure a temperature of blood flowing through the arterial line, and wherein the microprocessor is configured to control the resistive heater in a manner to heat a bolus of dialysate to a temperature greater than a temperature of blood flowing through the dialysis system in order to heat blood flowing through the dialyzer, and to compare a temperature of blood in the arterial line as detected by the second temperature sensor to a temperature of blood in the venous line as detected by the infrared temperature sensor to determine whether recirculation is present.