Apparatus and methods for tracking administering of medication by medication injection devices

Abstract

A method of tracking injections includes depressing a plunger of a medication injection device, and sending and receiving ultrasonic signals from a plunger head installed within a barrel of the medical injection device. The method also includes measuring a time of flight for the signals to travel through the medication, and determining a position of the plunger head based on the time of flight of the signals. Additionally, a plurality of data samples representative of the position of the plunger are logged, and a distance the plunger head travels is calculated. This is used to calculate the quantity of the medication dispensed based on the distance the plunger head travels. An external device is then used to back-interpolate a time corresponding to each data sample logged in order to determine the time the quantity of medication was dispensed.

1 . A method of tracking injections of a medication delivered by a medication injection device, the method comprises:
 depressing a plunger of the medication injection device;   sending and receiving ultrasonic signals from a plunger head installed within a barrel of the medical injection device;   measuring a time of flight for the signals to travel through the medication to an end of the barrel and return to the plunger head;   determining a position of the plunger head based on the time of flight of the signals and logging a data sample representative of the position;   logging a plurality of the data samples representative of the position of the plunger at an approximately regular interval;   calculating a distance the plunger head travels based on a change in the position;   calculating a quantity of the medication dispensed based on the distance the plunger head travels;   transmitting wirelessly the quantity of the medication dispensed to a remote device;   back-interpolating a time corresponding to each data sample logged in order to determine the time the quantity of medication was dispensed, using a timekeeper in the remote device as a reference.   
     
     
         2 . The method of  claim 1 , wherein an oscillator is used to determine the approximately regular interval. 
     
     
         3 . The method of  claim 2 , further comprising measuring and logging a temperature and a voltage associated with the oscillator. 
     
     
         4 . The method of  claim 3 , further comprising using the logged temperature and the logged voltage to correct for drift of the approximately regular intervals caused by variability in the temperature and the voltage. 
     
     
         5 . The method of  claim 4 , further comprising using factory determined offsets for the oscillator in addition to the logged temperature and voltage to correct for the drift. 
     
     
         6 . The method of  claim 1 , wherein the approximately regular interval is 60 minutes or less. 
     
     
         7 . The method of  claim 1 , wherein the remote device includes at least one of a smart phone, a glucose monitor, an insulin pump, or a computer. 
     
     
         8 . The method of  claim 1 , wherein transmitting wirelessly includes at least one of radio data transmission, BLUETOOTH or (BLE), near field communication (NFC), infrared data transmission. 
     
     
         9 . A plunger head for a medication injection device, comprising:
 a transducer that sends and receives ultrasonic signals;   an antenna;   a temperature sensor coupled to measure a temperature;   a controller coupled to the transducer, the antenna, and the temperature sensor, wherein the controller includes logic that when executed by the controller causes the controller to perform operations including:
 placing the plunger head in a low-power sleep mode; and 
 placing the plunger head in a high-power mode, relative to the low power sleep mode, to measure the temperature. 
   
     
     
         10 . The plunger head of  claim 9 , wherein the controller further includes logic that when executed by the controller causes the controller to perform operations including:
 transitioning the plunger head into an initialization mode after detecting a temperature change, wherein the temperature change corresponds to an increase in temperature from a storage temperature to a room temperature.   
     
     
         11 . The plunger head of  claim 10 , wherein the controller further includes logic that when executed by the controller causes the controller to perform operations including:
 pairing the plunger head with a remote device while in initialization mode.   
     
     
         12 . The plunger head of  claim 11 , wherein the controller further includes logic that when executed by the controller causes the controller to perform operations including:
 transitioning the plunger head into an operational mode after successfully pairing with the remote device.   
     
     
         13 . A method of operation for a medication injection device that has a temperature sensor that measures an ambient temperature, the method comprising:
 placing the medication injection device into a low-power sleep mode;   measuring the ambient temperature while in the low-power sleep mode at a regular interval;   detecting a temperature change with the temperature sensor,   transitioning the medication injection device into an initialization mode, in response to the temperature change;   pairing the medication injection device with a remote device while in the initialization mode;   entering an operational mode after a successful pairing of the medication device with the remote device; and   measuring and logging a plunger head position of the medication injection device once the medication injection device is in the operational mode.   
     
     
         14 . The method of  claim 13 , wherein the medication injection device enters the low-power sleep mode as part of a manufacturing and testing process for the medication injection device. 
     
     
         15 . The method of  claim 13 , further comprising returning to the low-power sleep mode after a period of inactivity. 
     
     
         16 . The method of  claim 13 , wherein the temperature change that triggers the transition into the initialization mode is an increase in temperature from a storage temperature to a room temperature. 
     
     
         17 . The method of  claim 13 , further comprising returning to the low-power sleep mode when a subsequent temperature change is detected, wherein the subsequent temperature change is a decrease in temperature. 
     
     
         18 . The method of  claim 13 , further comprising
 transitioning the medical injection device from the low-power sleep mode directly back to the operational mode after the pairing of the medication injection device with a remote device.