Extended use medical device
Provided is an extended use self-contained, wearable medical device. The device is preferably configured with an infusion deployment mechanism for variably inserting and retracting an infusion needle to different depths, or completely retracting the infusion needle from the infusion site and then re-inserting the infusion needle after a predetermined period of time, throughout an infusion cycle for extending the viability of the infusion site. Another embodiment comprises dual needle deployment mechanisms which may also variably insert and retract the infusion needles. A flow sensor is preferably provided for detecting the stoppage of flow through the infusion cannula and signaling the needle deployment mechanism to attempt infusion at a different depth or to deploy a second infusion needle. A re-fillable reservoir assembly is preferably provided for supplying a drug over the extended use of the device. Another embodiment comprises a partially reusable and partially disposable medical device implementing the above features.
1. A medical device for administering drug therapy to a user over an extended period of use, said medical device comprising:
a pump mechanism for administering a drug to the user;
first and second delivery cannulas for infusing said drug transdermally into the user at first and second infusion sites;
first and second mechanisms for separately controlling deployment of the first and second cannulas into said user at said first and second infusion sites; and
a flow sensing unit for detecting whether the first infusion site is no longer viable by sensing whether the first delivery cannula is blocked or otherwise incapable of delivering a desired flow of drug to the user;
wherein the first delivery cannula is retracted from the user when the flow sensing unit detects that the infusion site is no longer viable.
2. The medical device of claim 1 , wherein the first delivery cannula is retracted from the user after a predetermined period of use.
3. The medical device of claim 1 , wherein the second delivery cannula is deployed into the user when the first delivery cannula is retracted.
4. The medical device of claim 1 , wherein the first and second mechanisms for controlling deployment of the first and second delivery cannulas are manually actuated.
5. The medical device of claim 1 , wherein the first and second mechanisms for controlling the deployment of the first and second delivery cannulas are automatically actuated.
6. The medical device of claim 1 , further comprising a reservoir supplying a volume of drug necessary for the extended duration of use of the medical device.
7. The medical device of claim 1 , further comprising first and second reservoirs for supplying the drug to the respective first and second delivery cannulas.
8. The medical device of claim 1 , further comprising a refillable reservoir supplying the drug infused into the user, said reservoir including a port or septum for receiving a supply of the drug.
9. The medical device of claim 1 , further comprising a receptacle for receiving a pre-filled reservoir assembly.
10. The medical device of claim 1 , wherein the pump mechanism and the first and second mechanisms for controlling deployment of the first and second cannulas are housed in a reusable portion of the medical device.
11. The medical device of claim 1 , wherein the medical device is affixed to a user's skin with a flexible, zigzag shaped adhesive strip provided along the perimeter of said medical device.
12. The medical device of claim 11 , wherein the adhesive strip comprises an elastomer or foam layer.
13. The medical device of claim 1 , wherein the pump mechanism is controlled to administer a preprogrammed drug delivery profile to the user.
14. A medical device for administering drug therapy to a user over an extended period of use, said medical device comprising:
a pump mechanism for administering a drug to the user;
a delivery cannula for infusing said drug transdermally into the user at an infusion site; and
a mechanism for controlling deployment of the cannula into said user, wherein said mechanism is configured to variably move said cannula to a first depth in the user and a second depth in the user; wherein the mechanism is adapted to move the cannula from said first depth to said second depth after said cannula has been at said first depth for at least one day.
15. The medical device of claim 14 , wherein the mechanism for controlling deployment of said cannula is configured to retract said cannula after a predetermined period of use and further re-deploy said cannula into said user after a predetermined period of non-use.
16. The medical device of claim 14 , wherein the pump mechanism and mechanism for controlling deployment of the cannula are contained in a reusable portion of the medical device.
17. A medical device for administering drug therapy to a user over an extended period of use, said medical device comprising:
a pump mechanism for administering a drug to the user;
a delivery cannula for infusing said drug transdermally into the user at an infusion site; and
a mechanism for controlling deployment of the cannula into said user, wherein said mechanism is configured to automatically move said cannula from a first depth in the user to a second depth in the user.