Methods and devices for determination of flow reservoir volume
View Patent ↗A novel enhanced infusion pump system is adapted for dispensing medicament from a flow material reservoir Software used in conjunction with a pressure sensor can determine a backstroke volume of medicament that can be used to calculate the volume of medicament in the flow material reservoir.
1. An infusion pump system, comprising:
a cavity;
an actuation shaft disposed in the cavity and movable between a first position within the cavity and a second position within the cavity;
an input conduit fluidly connectable to a medicament reservoir configured to contain a medicament, the input conduit in fluid communication with a proximal flow space defined by the cavity when the actuation shaft is in both the first position and the second position;
a flow metering device chamber in fluid communication with the input conduit through the proximal flow space when the actuation shaft is in the first position for filling the flow metering device chamber with medicament from the medicament reservoir and not in fluid communication with the input conduit when the actuation shaft is in the second position;
an output conduit adapted to dispense medicament from the flow metering device chamber when the actuation shaft is in the second position; and
a sensor adapted to obtain data for determining a backstroke volume of medicament from the proximal flow space into the medicament reservoir when the actuation shaft is moved from the first position that fills the flow metering device chamber with medicament to the second position that dispenses the medicament from the flow metering device chamber through the output conduit.
2. The infusion pump system of claim 1 , wherein the medicament reservoir comprises a first chamber configured to hold the medicament and a second chamber.
3. The infusion pump system of claim 1 , wherein the sensor is a pressure sensor.
4. The infusion pump system of claim 1 , further comprising a pump that houses the sensor.
5. The infusion pump system of claim 4 , wherein the pump includes a user interface and a processor adapted to control movement of the actuation shaft and determine the change in volume based on the data acquired by the sensor.
6. The infusion pump system of claim 5 , wherein the processor is adapted to control the sensor to acquire data before positioning the actuation shaft in the second position and after positioning the actuation shaft in the second position.
7. The infusion pump system of claim 5 , wherein the processor is adapted to determine the difference between a volume of the medicament in the medicament reservoir before positioning the actuation shaft in the second position and a volume of the medicament in the medicament reservoir after positioning the actuation shaft in the second position.
8. The infusion pump system of claim 5 , wherein the processor is adapted to determine the backstroke volume from the data acquired by the sensor each time the actuation shaft is moved from the first position to the second position, and wherein the processor is adapted to stop movement of the actuation shaft if a first determined backstroke volume is not substantially the same as a second backstroke volume.
9. The infusion pump system of claim 5 , wherein the processor is adapted to determine the backstroke volume from the data acquired by the sensor each time the actuation shaft is moved from the first position to the second position, and wherein the processor is adapted to indicate an error state on the user interface if a first determined backstroke volume is not about equal to a second backstroke volume.
10. The infusion pump system of claim 1 , wherein the medicament is insulin.
11. An infusion pump system, comprising:
a cavity defining a proximal flow space;
an actuation shaft disposed in the cavity;
a flow metering device chamber;
a sensor; and
a computer processor, the computer processor adapted to:
position the actuation shaft in a first position in the cavity such that the flow metering device chamber is in fluid communication with the proximal flow space;
cause an aliquot of medicament to flow into the flow metering device chamber from a medicament reservoir through an input conduit and the proximal flow space;
position the actuation shaft in a second position in the cavity to dispense the medicament from the flow metering device chamber out an output conduit with the medicament reservoir in fluid communication with the proximal flow space such that positioning of the actuation shaft to the second position causes a backstroke volume of medicament to flow from the proximal flow space into the medicament reservoir;
observe a change in volume of the medicament in the medicament reservoir after the actuation shaft is moved to the second position with data gathered from the sensor; and
determine the backstroke volume from the data.
12. The infusion pump system of claim 11 , where the processor is adapted to gather data with the sensor before positioning the actuation shaft in the second position and after positioning the actuation shaft in the second position.
13. The infusion pump system of claim 11 , wherein the processor is adapted to determine the backstroke volume by measuring a difference of a volume of medicament in the medicament reservoir before positioning the actuation shaft in the second position and a volume of the medicament in the medicament reservoir after positioning the actuation shaft in the second position.
14. The infusion pump system of claim 11 , further comprising the medicament reservoir, the medicament reservoir comprising a first chamber holding the medicament and a second chamber.
15. The infusion pump system of claim 11 , wherein the sensor is a pressure sensor.
16. The infusion pump system of claim 11 , wherein the processor is further adapted to stop actuation of the actuation shaft if a first determined backstroke volume is not substantially the same as a second backstroke volume.
17. The infusion pump system of claim 11 , wherein the processor is further adapted to trigger an error state if a first determined backstroke volume is not about equal to a second backstroke volume.
18. The infusion pump system of claim 11 , further comprising a pump that houses the sensor.
19. The infusion pump system of claim 11 , wherein the medicament is insulin.