Fluid delivery device with autocalibration
A micro fluid delivery device is particularly useful in medical applications. The device may be worn or carried by the user and may deliver drugs or other medicaments to the user or patient. The device has a control system that accepts input from the user and controls all aspects of operation of the device. The control system measures the output of the pump and adjusts the output of the pump to achieve the desired dosage rate and size. This eliminates differences from pump to pump that result from inevitable variations in the manufacturing of such small scale affordable devices.
1. A portable drug delivery system comprising:
a disposable component comprising:
a shape memory actuated pump;
a drug reservoir; and
a calibration region, the calibration region having a first sensor having a plurality of electrodes to detect presence of a liquid at a first part of the region and a second sensor having a plurality of electrodes to detect presence of the liquid at a second part of the region; and
a reusable component comprising a processor, wherein the processor is configured to:
monitor the time it takes the liquid to pass from the first sensor to the second sensor to determine a flow rate of the drug delivery system;
determine a flow characteristic of the liquid substantially simultaneously with monitoring the time it takes the liquid to pass from the first sensor to the second sensor; and
adjust the flow rate of the drug delivery system based, at least in part, on the monitored time and the determined flow characteristic.
2. The drug delivery system of claim 1 , wherein the plurality of electrodes of the first sensor and the plurality of electrodes of the second sensor are configured to detect an interruption in the flow rate of the drug delivery system.
3. The drug delivery system of claim 1 , wherein the determined flow characteristic corresponds to a voltage of a reaction rate associated with a component of the liquid.
4. The drug delivery system of claim 1 , wherein the processor is further configured to determine a calibration ratio, wherein the calibration ratio comprises a ratio of an expected volume dose compared to an actual volume dose.
5. The drug delivery system of claim 1 , wherein the shape memory actuated pump is activated by modifying a temperature of a shape memory element of the shape memory actuated pump.
6. The drug delivery system of claim 1 , wherein the processor monitors a number of pump actuations during the time it takes for the liquid to pass from the first sensor to the second sensor.
7. The drug delivery system of claim 6 , wherein the processor of the reusable component calibrates drug delivery for each disposable component used with the system.
8. A portable drug pumping device, comprising:
a disposable component having a pumping element;
a reusable component comprising a microprocessor and a shape memory element, wherein the reusable component is configured to attach to the disposable component; and
when calibrating the pumping element, the portable drug pumping device is configured to:
initiate the flow of a liquid through a portion of the disposable component having a known volume, using at least in part, the shape memory element;
calculate a volumetric flow rate of the liquid substantially simultaneously with determining a flow characteristic of the liquid; and
adjust the flow of the liquid based at least in part on the calculated volumetric flow rate and the determined flow characteristic of the liquid.
9. The pumping system of claim 8 , further comprising a first sensor having a plurality of electrodes disposed at a first point on the portion of the disposable component having the known volume and a second sensor having a plurality of electrodes disposed at a second point on the portion of the disposable component having the known volume.
10. The pumping system of claim 8 , wherein the first sensor having the plurality of electrodes and the second sensor having the plurality of electrodes are configured to detect an interruption in the flow of the liquid.
11. The pumping system of claim 8 , wherein the disposable component includes a liquid reservoir.
12. The pumping system of claim 8 , wherein the determined flow characteristic corresponds to a voltage of a reaction rate associated with a component of the liquid.
13. The pumping system of claim 8 , wherein initiating the flow of a liquid through a portion of the disposable component having a known volume, using at least in part, the shape memory element includes modifying the temperature of the shape memory element.
14. The pumping system of claim 8 , further comprising at least one switch, wherein the at least one switch is configured to monitor the position of the pumping element.
15. A micro pump for delivering liquid, comprising:
a disposable component comprising a pump element and a plurality of sensors, wherein the plurality of sensors are configured to measure the quantity of a unit volume of liquid provided by the pump element, and wherein at least one of the plurality of sensors is configured to substantially simultaneously determine a flow characteristic of the liquid;
a reusable component removably coupled to the disposable component, wherein the reusable component comprises a processor and a shape memory element, and wherein the processor is configured to:
detect a difference of the measured unit volume of liquid from an expected unit volume of liquid; and
modify the delivery of the liquid based, at least in part, on the detected difference.
16. The micro pump of claim 15 , wherein the determined flow characteristic corresponds to a voltage of a reaction rate associated with a component of the liquid.
17. The micro pump of claim 15 , wherein the liquid is insulin.
18. The micro pump of claim 15 , wherein modifying the delivery of the liquid includes modifying a delivery profile.
19. The micro pump of claim 18 , wherein modifying the delivery profile includes modifying the timing of a subsequent delivery of the liquid.