Method to sense temperature in an implantable pump

Abstract

An implantable drug infusion pump for delivering drug therapy is made more reliable and its performance improved by monitoring drug pump temperature. Monitoring pump temperature can also provide for temperature-related drug therapy modification. A pump temperature sensor is read by the infusion pump's microprocessor. Pump temperature data is stored in pump memory for later access by a remote controller. A simple thermistor or semiconductor temperature sensor can provide fast and reliable temperature monitoring of the pump and/or of a patient by reading the temperature sensor's value and calculating a temperature therefrom.

1 . A method of evaluating an implantable device, comprising:
 (A) automatically storing in a memory of the implantable device information corresponding to sensed temperatures associated with the implantable device; and   (B) determining whether to implant the implantable device based on the information stored in the memory.   
   
   
       2 . The method of  claim 1 , wherein the storing in step (A) comprises:
 (i) obtaining from a sensor a value corresponding to a temperature that the implantable device is exposed to; and   (ii) storing the value in the memory.   
   
   
       3 . The method of  claim 2 , wherein the storing in step (ii) comprises:
 (1) determining whether the value is associated with a temperature outside a normal temperature range; and   (2) if the value is associated with a temperature outside the normal temperature range, storing the value and a time corresponding to when the value was obtain in the memory.   
   
   
       4 . The method of  claim 2 , wherein the sensor is positioned inside the implantable device. 
   
   
       5 . The method of  claim 1 , wherein the determining in step (B) comprises:
 (i) retrieving the information from the memory;   (ii) determining an amount of time that the implantable device was exposed to temperatures outside the normal range; and   (iii) if the amount of time indicates a reliability of the implantable device was affected by the exposure to temperatures outside the normal range, not implanting the implantable device.   
   
   
       6 . The method of  claim 1 , wherein the information stored relates the period of time that the sensed temperature was not within a normal temperature range. 
   
   
       7 . The method of  claim 6 , wherein the information relates to the period of time that the sensed temperature was below the normal temperature range. 
   
   
       8 . The method of  claim 1 , wherein the determining in step (B) comprises:
 (i) downloading the information from the memory; and   (ii) rendering the information on a display.   
   
   
       9 . The method of  claim 8 , wherein the rendering only disclosed a period of time that the implantable device was exposed to temperatures outside the normal temperature range. 
   
   
       10 . The method of  claim 1 , wherein the information stored in the memory corresponds to an accumulated time that the implantable device has been exposed to a range of temperatures. 
   
   
       11 . A method of evaluating an implantable pump, comprising:
 (A) storing in a memory a plurality of values corresponding to a temperature associated with the implantable pump;   (B) retrieving a plurality of values stored in the memory; and   (C) determining whether to implant the implantable pump based on the retrieved plurality of values.   
   
   
       12 . The method of  claim 11 , wherein the storing in step (A) comprises:
 (i) determining a first value associated with a sensor;   (ii) storing the first value in memory; and   (iii) repeating steps (i)-(ii) after a predetermined period of time.   
   
   
       13 . The method of  claim 12 , wherein the first and second value are selected from the list consisting of a voltage value and a resistance value. 
   
   
       14 . The method of  claim 11 , wherein the temperature is associated with a temperature sensor positioned inside the implantable pump. 
   
   
       15 . The method of  claim 11 , wherein the determining in step (C) is based on whether the implantable pump has been exposed to a temperature outside a safe range of temperatures associated with a medicament being stored within the implantable pump. 
   
   
       16 . The method of  claim 15 , further comprising:
 (D) if the medicament has been exposed to temperatures outside the safe range, replacing the medicament in the implantable pump.   
   
   
       17 . The method of  claim 11 , wherein the retrieved plurality of values provides a history of temperatures the implantable pump has been exposed to. 
   
   
       18 . The method of  claim 11 , wherein the values being stored correspond to temperatures outside a normal temperature range. 
   
   
       19 . The method of  claim 11 , wherein the retrieving in step (B) is done wirelessly. 
   
   
       20 . A method of evaluating an implantable device, comprising:
 (A) determining a period of time that the implantable device was exposed to a temperature outside a normal range; and   (B) determining whether to implant the implantable device based on the determined period of time.   
   
   
       21 . The method of  claim 20 , wherein determining in step (A) comprises:
 (i) periodically determining a temperature that is associated with the implantable device;   (ii) if the temperature is outside the normal range, storing information in memory corresponding to the temperature and a time the temperature was sensed; and   (iii) using the stored information to determine the period of time that the implantable device was exposed to temperatures outside the normal temperature range.   
   
   
       22 . The method of  claim 20 , wherein the determining to implant in step (B) is based on a component of the implantable device that is susceptible to damage when exposed to temperature outside the normal range. 
   
   
       23 . The method of  claim 20 , wherein the determining in step (A) is based on sensed temperature of at least a portion of the implantable device.