Device and Method for Dispensing Fluid from an Infusion Pump

Abstract

The present disclosure is directed towards a compact, modular infusion pump and a delivery mechanism for accurate dispensing of very small amounts of medication. The infusion pump comprises a tubular, curved medication reservoir, and a flexible, one-piece drive train configured to push very small amounts of medication out of the medication reservoir. A method of measuring a level of medication inside the medication reservoir or cross-checking the accuracy of medication delivery is also described.

What is claimed is: 
     
         1 . A modular infusion pump for dispensing a fluid, comprising:
 a reservoir module, comprising:
 a tubular, curved reservoir containing the fluid, the curved reservoir having a proximal end and a distal end, and 
 a flexible drive train configured to slidably fit within the curved reservoir and to expel the fluid through the proximal end of the reservoir; and 
   a control module comprising an actuation mechanism for driving the drive train through the reservoir, and electronic circuitry for measuring the level of medication inside the reservoir.   
     
     
         2 . The modular infusion pump of  claim 1 , wherein the reservoir module comprises a medication output port fluidly coupled to the proximal end of the reservoir. 
     
     
         3 . The modular infusion pump of  claim 2 , further comprising a cradle configured to mate with the medication output port of the reservoir module. 
     
     
         4 . The modular infusion pump of  claim 2 , wherein the medication output port is configured to connect interchangeably with a cradle configured to adhere direct to a patient's skin, or an infusion set comprising a medication delivery tubing. 
     
     
         5 . The modular infusion pump of  claim 1 , wherein the reservoir module comprises a hydrophobic vent configured to equalize pressure inside and outside the reservoir module. 
     
     
         6 . The modular infusion pump of  claim 1 , wherein the reservoir module further comprises a feeder track having a continuous, curved wall structure configured to guide the drive train. 
     
     
         7 . The modular infusion pump of  claim 1 , further comprising a locking mechanism configured to mate the reservoir module with the control module. 
     
     
         8 . The modular infusion pump of  claim 1 , wherein the actuation mechanism includes an electric motor, a drive shaft, and a lead screw, wherein the lead screw is configured to mechanically engage the drive train when the reservoir module is connected to the control module. 
     
     
         9 . The modular infusion pump of  claim 1 , further comprising parallel resistive traces on an underside of a lid covering the reservoir module such that the cursor is configured to provide a moving electrical short between the parallel resistive traces. 
     
     
         10 . The modular infusion pump of  claim 9 , wherein the electronic circuitry is configured to measure a voltage signal across the parallel resistive traces. 
     
     
         11 . An infusion pump for delivering medication to a user, the pump comprising:
 a reservoir module including a tubular medication reservoir having a curved configuration, the medication reservoir comprising a medication delivery outlet at a proximal end;   a flexible, and continuous drive train comprising:
 a plunger at a proximal end of the drive train, 
 a cursor at a distal end of the drive train, 
 a flexible filament extending between the cursor and the plunger, and 
 a plurality of balls positioned along and connected by the filament between the plunger and the cursor; and 
   a control module including an actuation device configured to drive the drive train through the medication reservoir.   
     
     
         12 . The infusion pump of  claim 11 , wherein the medication reservoir has at least one straight section. 
     
     
         13 . The infusion pump of  claim 11 , wherein the medication reservoir is curved throughout a length of the reservoir. 
     
     
         14 . The infusion pump of  claim 11 , wherein the cursor is configured to indicate the position of the drive train within the medication reservoir. 
     
     
         15 . The infusion pump of  claim 11 , wherein the actuation device comprises an electric motor that is mechanically coupled to a motor shaft encoder configured to sense rotation of the electric motor. 
     
     
         16 . The infusion pump of  claim 15 , wherein an output shaft of the electric motor is mechanically coupled to at least one gear that is mechanically coupled to a drive shaft. 
     
     
         17 . The infusion pump of  claim 16 , wherein the drive shaft is further coupled to a force sensor configured to sense lateral forces generated by rotation of the drive shaft. 
     
     
         18 . The infusion pump of  claim 16 , wherein the drive shaft is adapted to mount a lead screw configured to mechanically engage the drive train, and wherein the drive shaft is configured to enable the lead screw to slide on the drive shaft axially and to rotate with the drive shaft. 
     
     
         19 . A method of delivering very small amounts of medication from an infusion pump, comprising:
 providing tubular medication reservoir having a medication delivery outlet at a proximal end thereof, wherein the medication reservoir is adapted to be mounted within the infusion pump in a curved configuration;   providing a flexible, continuous drive train connected to a plunger at a proximal end thereof,   mounting the medication reservoir in a curved configuration on the infusion pump; and   mounting the drive train in a curved configuration on the infusion pump.   
     
     
         20 . A method of measuring level of medication inside a medication reservoir of an insulin pump or cross-checking the accuracy of medication delivery, comprising:
 providing a modular insulin pump, comprising:
 a reservoir module comprising:
 a tubular, curved medication reservoir; 
 a flexible, one-piece drive train configured to slidably fit within the medication reservoir; and 
 a feeder track to guide the drive train within the reservoir module; and 
 
 a control module comprising an actuating mechanism for driving the drive train through the medication reservoir and electronic circuitry for measuring the level of medication inside the medication reservoir; 
   providing parallel resistive traces on the underside of a lid covering the reservoir module; providing a plunger at a proximal end and a cursor at a distal end of the drive train,   wherein the cursor is configured to provide a moving electrical short between the parallel resistive traces; and measuring a voltage signal across the parallel resistive traces.