Method and apparatus to measure blood flow and reirculation in hemodialysis shunts
AssigneeTransonic Systems, Inc.
InventorNikolai M. Krivitski
Life of this patent
Estimating the term…
Abstract
The measurement of blood flow in a dialysis shunt is obtained by injection of an indicator material into a venous line leading from dialysis equipment to the shunt. The blood flow in an arterial line leading from the shunt at a location downstream of the venous line to the dialysis equipment is monitored by an arterial line sensor for the presence of the indicator material. A detector connected to the sensor provides a dilution curve in response to the presence of the indicator material and the blood flow in the shunt is calculated from the area under the dilution curve. The locations of the arterial and venous lines in the shunt can be reversed to obtain a measurement of blood recirculation from the venous line into the arterial line.
Claims14
A method of identifying a blood flow rate in a dialysis shunt, comprising:
- (a) fluidly connecting a venous line of a dialysis system to deliver blood from the dialysis system to an upstream location in a dialysis shunt, and fluidly connecting an arterial line of the dialysis system to remove blood from a downstream location in the dialysis shunt;
- (b) identifying an amount of recirculation in the dialysis shunt between the downstream location and the upstream location;
- and
- (c) identifying a rate of blood flow in the dialysis shunt corresponding to the amount of recirculation.
A method of identifying a blood flow rate in a dialysis shunt, comprising:
- (a) changing a blood parameter in blood removed from a downstream location in a dialysis shunt;
- (b) returning the blood having the changed blood parameter to an upstream location in the dialysis shunt;
- (c) measuring an amount of change in a blood parameter of the blood flowing through the dialysis shunt resulting from the return of blood having the changed blood parameter to the dialysis shunt;
- and
- (d) identifying, from the measured amount of change in the blood parameter, a blood flow rate in the dialysis shunt.
A method of identifying a blood flow rate in a dialysis shunt, comprising:
- (a) arranging an arterial line and a venous line of a dialysis system to deliver blood from the dialysis system via the venous line to an upstream location in a dialysis shunt and remove blood from a downstream location in the dialysis shunt via the arterial line;
- (b) introducing an indicator at the upstream location in the dialysis shunt via the venous line, such that the indicator mixes with blood flowing in the dialysis shunt;
- (c) withdrawing a mixture of blood and the indicator from the downstream location in the dialysis shunt via the arterial line;
- (d) measuring a change in a blood parameter caused by the introduction of the indicator;
- and
- (e) identifying, from the measured blood parameter, a blood flow rate in the dialysis shunt.
A system for identifying a blood flow rate in a dialysis shunt, comprising:
- (a) a sensor configured to measure a change in a blood characteristic resulting from the introduction of an indicator to the blood flowing in the dialysis shunt via a venous line of a dialysis system;
- and
- (b) a computer coupled to the sensor, the computer configured to compute, from the measured amount of change, a rate at which blood is flowing through the dialysis shunt.
Dependencies are inferred from the claim text.