Apparatus and method for temporarily pausing an infusion pump during a medication stroke to improve blockage detection.

Abstract

Detect and mitigate pre-occluding leak pressure within the drug delivery stroke of the infusion device. [Solution] The injection pump acquires pump measurements indicating pressure, controls the pump mechanism, and pauses if the pump measurements meet a pre-occlusion pressure threshold. During the pause, additional pump measurements can be obtained, and pressure-related conditions may be alleviated. When the pump measurements no longer meet the pre-occlusion pressure criterion, the injection pump can resume the dosing stroke and pause again. The number and frequency of pauses, the analysis of pump measurements, and the resumption of dosing strokes can be predetermined or dynamically determined. Pausing can also be predetermined regardless of the current pressure condition. Pausing the pump to increase the sampling or sampling rate of the measured parameters indicating pressure provides a much higher resolution for detecting occlusion.

Claims

1. A wearable injection device, A pump comprising a fluid chamber and a pump mechanism configured to control the volume of fluid dispensed from the chamber during a dispensing stroke, wherein the pump is operated to deliver multiple dispensing strokes and to deliver the entire intended dose, A pump measuring device configured to generate pump measurements indicating pressure, A processing device configured to analyze one or more of the pump measurements obtained during a portion of the dispensing stroke, and to temporarily suspend the pump mechanism during the dispensing stroke when one or more of the pump measurements during the portion of the dispensing stroke meet a specified criterion related to a specified pre-occlusion pressure, The processing device is located downstream of the pump and is coupled to a downstream fluid path having low compliance by containing an incompressible fluid within a small internal volume made of a rigid material. The pre-blockage pressure is higher than the normal operating pressure of the pump and lower than the leakage pressure threshold at which leakage may occur in the low-compliance downstream fluid path, and the processing device is such that A housing that can be attached to the patient's skin and is configured to surround the pump, the pump measuring device, and the processing device, A wearable injection device characterized by having the following features.

2. The wearable infusion device according to claim 1, wherein the processing device is configured to control the pump mechanism to restart the drug delivery stroke.

3. The wearable infusion device according to claim 2, wherein the processing device is configured to acquire another pump measurement during the infusion stroke that has been resumed after the pause, and to pause the pump mechanism again when the pump measurement meets a specified criterion related to a specified pre-occlusion pressure.

4. The wearable infusion device according to claim 3, wherein the processing device is configured to control the pump mechanism to restart the drug delivery stroke.

5. The wearable infusion device according to claim 2, wherein the number of times the processing device pauses and resumes the drug delivery stroke can be pre-configured or dynamically determined based on criteria selected from pump motor current, pump motor voltage, encoder count, pump motor drive count, pump motor drive time, drug delivery stroke energy, volume of the chamber, type of fluid in the chamber, and ambient air pressure.

6. The wearable infusion device according to claim 2, wherein the frequency at which the processing device pauses and resumes the drug delivery stroke is constant or varies throughout the drug delivery stroke or within a specified portion of the drug delivery stroke.

7. The wearable infusion device according to claim 2, configured to acquire pump measurements and execute a feedback loop to decelerate or accelerate the drug delivery stroke based on the pump measurements.

8. The wearable infusion device according to claim 1, wherein the pump measurement value is a motor current, and the pump measurement device comprises a current sensing device configured to detect the motor current of the pump during the medication stroke.

9. The wearable infusion device according to claim 1, wherein the pump is selected from a positive displacement pump and a syringe-style pump.

10. The wearable injection device according to claim 1, wherein the specified measurement criterion related to the specified pre-occlusion pressure is selected from a range of measurements corresponding to pressures above the normal pump operating pressure and pressures below the minimum leak pressure, and is different from transient pressures related to pump startup or changes in pump operating state.

11. The wearable infusion device according to claim 1, wherein the processing device is configured to acquire at least additional pump measurements during the pause, control the pump mechanism, and resume the medication stroke when the additional pump measurements correspond to a normal pump operating pressure and do not meet the specified criterion related to a specified pre-occlusion pressure.

12. The wearable injection device according to claim 9, wherein the pump is a positive displacement pump and the pre-occlusion pressure corresponds to a pressure range of 20 to 40 psi.

13. The wearable infusion device according to claim 1, wherein the time point in the infusion stroke at which one or more of the pump measurements are obtained, corresponding to the portion of the infusion stroke, is determined by the processing device.

14. The wearable injectable device according to claim 13, wherein the aforementioned time is predetermined or dynamically determined by the processing device.

15. The specified measurement criteria related to the specified pre-occlusion pressure are selected from a range of measurements corresponding to pressures above the normal pump operating pressure and pressures below the minimum leak pressure, and are different from transient pressures related to pump startup or changes in pump operating conditions. The wearable infusion device according to claim 13, wherein the time is determined by the processing device based on criteria selected from one or more increments of the pump measurements within the specified pre-occlusion pressure range and the number of multiple medication strokes remaining to deliver the entire intended dose.

16. The wearable infusion device according to claim 11, wherein the paused time for determining the additional pump measurement is determined to vary based on at least one or more of the pump measurements and the pressure curve indicated by the additional pump measurement.

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