Drug delivery device with air and backflow elimination

Abstract

A wearable drug delivery device that can deliver a liquid drug stored in a container to a patient or user is provided. A soft needle or cannula can be placed in fluid communication with the liquid drug and can be coupled to a needle insertion component that provides access to the patient. A drive system of the drug delivery device can expel the liquid drug from the container to the patient through the soft needle or cannula. The wearable drug delivery device can include components for preventing backflow and eliminating air within the liquid drug. As a result, the comfort of the patient can be enhanced and correct drug dosages can be provided when using the drug delivery device.

1 . A wearable drug delivery device, comprising:
 a top portion and a bottom portion;   a reservoir between the top portion and the bottom portion and configured to store a liquid drug;   a needle insertion component operable to extend a cannula from the bottom portion into a user, and   a fluid path coupling the reservoir to the cannula, wherein the fluid path is configured to enable delivery of the liquid drug to the user when the liquid drug is expelled from the reservoir, wherein the fluid path includes a membrane operable to retain the liquid drug while allowing air within the liquid drug to pass through the membrane and out of the fluid path.   
     
     
         2 . The wearable drug delivery device of  claim 1 , wherein the membrane covers an opening in the fluid path. 
     
     
         3 . The wearable drug delivery device of  claim 1 , wherein the membrane is directly attached to the fluid path. 
     
     
         4 . The wearable drug delivery device of  claim 1 , wherein the membrane is positioned at one or more locations along a length of the fluid path. 
     
     
         5 . The wearable drug delivery device of  claim 1 , wherein the membrane comprises a hydrophobic material. 
     
     
         6 . The wearable drug delivery device of  claim 1 , wherein the fluid path further includes a flow sensor system. 
     
     
         7 . The wearable drug delivery device of  claim 6 , wherein the flow sensor system comprising a flow sensor, a first clamping component, and a second clamping component. 
     
     
         8 . The wearable drug delivery device of  claim 7 , wherein the flow sensor is configured to detect a direction of a flow of the liquid drug in the fluid path. 
     
     
         9 . The wearable drug delivery device of  claim 7 , wherein the first and second clamping components are positioned on opposite sides of the fluid path. 
     
     
         10 . The wearable drug delivery device of  claim 9 , wherein the first and second clamping components are configured to move toward each other to constrict the fluid path to prevent the flow of the liquid drug in the fluid path. 
     
     
         11 . The drug wearable delivery device of  claim 8 , wherein the first and second clamping components are configured to constrict the fluid path to prevent the flow of the liquid drug when the flow sensor detects the direction of the flow is from the user toward the reservoir. 
     
     
         12 . The wearable drug delivery device of  claim 8 , wherein the first and second clamping components are configured to allow the flow of the liquid drug in the fluid path when the flow sensor detects the direction of the flow is from the reservoir to the user. 
     
     
         13 . The drug wearable delivery device of  claim 8 , wherein the first and second clamping components are positioned on opposite sides of the cannula. 
     
     
         14 . The wearable drug delivery device of  claim 1 , wherein the cannula comprises:
 a tip portion having a duckbill feature, wherein the duckbill feature comprises a slit positioned at approximately a center of the tip portion.   
     
     
         15 . The wearable drug delivery device of  claim 1 , wherein the cannula comprises:
 a tip portion having a one-way check valve configured to enable flow of the liquid drug out of the tip portion to the user while preventing flow into the tip portion.   
     
     
         16 . The wearable drug delivery device of  claim 1 , further comprising:
 a pumping system configured to maintain a minimum flow rate of the liquid drug of 0.25 microliters per hour through the fluid path.   
     
     
         17 . The wearable drug delivery device of  claim 16 , wherein the pumping system comprises:
 a plunger positioned within the reservoir.   
     
     
         18 . The wearable drug delivery device of  claim 1 , wherein the reservoir comprises:
 a pre-filled cartridge.   
     
     
         19 . The wearable drug delivery device of  claim 1 , further comprising:
 an adhesive to secure the wearable drug delivery device to the user.   
     
     
         20 . The wearable drug delivery device of  claim 19 , wherein:
 the adhesive is disposed on the bottom portion of the wearable drug delivery device that is against the user.