Injection System With Hidden Needles

• US 20080039795A1
• Filed: 08/09/2006
• Published: 02/14/2008
• Est. Priority Date: 08/09/2006
• Status: Active Grant

• Current Assignee: Avant Medical Corporation
• Original Assignee: Avant Medical Corporation
• Inventors: Barnes, Andrew C., Magers, Corey M., Slate, John B.
• Granted Patent: US 7,618,396 B2
• Time in Patent Office: Days
• US Class Current: 604/136
• CPC Class Codes: A61M 2005/004 Magazines with multiple needles directly inserted into an injection or infusion device, e.g. revolver-like magazines
• CPC Class Codes: A61M 5/008 Racks for supporting syringes or needles A61M5/001 takes precedence
• CPC Class Codes: A61M 5/204 connected to external reservoirs for multiple refilling
• CPC Class Codes: A61M 5/32 Needles; Details of needles pertaining to their connection with syringe or hub infusion needles A61M5/158; Accessories for bringing the needle into, or holding the needle on, the body A61M5/42, A61M5/46 take precedence; guide needles for catheters A61M25/065; Devices for protection of needles apparatus specially adapted for cleaning or sterilising needles A61M5/001
• CPC Class Codes: A61M 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user
• CPC Class Codes: A61M 5/3287 Accessories for bringing the needle into the body; Automatic needle insertion A61M5/20, A61M5/31525 take precedence
• CPC Class Codes: A61M 5/34 Constructions for connecting the needle , e.g. to syringe nozzle or needle hub connecting catheter tubes to hubs A61M25/0014
• CPC Class Codes: A61M 5/425 Protruding skin to facilitate piercing, e.g. vacuum cylinders, vein immobilising means
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion

Abstract

An auto-injector confines all functional components inside an enclosed housing, to keep its needle out-of-sight, at all times. Within the housing, a needle holder positions a needle at a location. A drive mechanism then simultaneously engages the needle with a fluid source and accelerates it with a predetermined momentum for insertion into a patient. After fluid delivery, the withdrawn needle is moved to storage within the housing for subsequent disposal.

Claims

1. An auto-injector for injecting a fluid into a patient which comprises:

a housing formed with an interior;

a fluid reservoir fixed at a site on said housing;

at least one needle held in the interior of said housing, wherein each needle has a proximal end and a distal end;

a means mounted in the interior of said housing for positioning a needle at a location therein;

a means mounted in the interior of said housing for engaging the needle in fluid communication with said fluid reservoir while mechanically isolating the needle from said fluid reservoir; and

a means mounted in the interior of said housing for moving the needle from the location to extend the distal end thereof outside said housing for insertion into the patient to inject the fluid into the patient, wherein said fluid reservoir remains fixed at the site while said needle moves from the location into the patient.

2. An auto-injector as recited in claim 1 wherein said engaging means comprises:

a fluid transfer section formed with a fluid chamber and having an input port and an output port;

a septum covering the output port; and

a flexible hose connected to said input port and to said fluid reservoir to establish fluid communication between said fluid reservoir and the fluid chamber of said transfer section.

3. An auto-injector as recited in claim 2 wherein a needle for use in the auto-injector comprises:

an elongated hypodermic needle defining an axis and having a proximal end and a distal end; and

a collar mounted on said hypodermic needle between the proximal end and the distal end thereof, with said collar extending radially outward therefrom for contact with said fluid transfer section to limit axial movement of the needle in a proximal direction relative to said transfer section during insertion of the proximal end of the needle through the septum and into the fluid chamber thereof, and for contact with said housing to limit axial movement of the needle in a distal direction relative to said housing during insertion of the distal end of the needle into the patient.

4. An auto-injector as recited in claim 1 wherein said needle moving means comprises:

a drive rod mounted in the interior of said housing; and

a means for accelerating said drive rod into contact with said engaging means to connect the needle with said engaging means.

5. An auto-injector as recited in claim 1 wherein said positioning means is a holder mounted in the interior of said housing for movement into an orientation with a first station positioned to retrieve a sterile needle, with a second station positioned to present a sterile needle at the location for engagement of the needle in fluid communication with said fluid reservoir, and with a third station positioned for removal of a used needle from said holder for storage.

6. An auto-injector as recited in claim 1 wherein said positioning means is a holder mounted in the interior of said housing for movement along a first path to retrieve a sterile needle for placement of the needle at the location where fluid communication is established between the needle and the fluid reservoir, and for movement along a second path to deposit the needle, after use, for storage in the interior of said housing.

7. A system for injecting a fluid into a patient which comprises:

a housing formed with an interior;

a fluid reservoir fixed at a site on said housing;

a magazine mounted on said housing for holding at least one needle;

a means mounted in the interior of said housing for moving a needle of said magazine to a location for fluid communication engagement with said fluid reservoir;

a connector mounted inside said housing for engaging the needle at the location in fluid communication with said fluid reservoir and mechanically isolating the needle from the fluid reservoir;

a drive mechanism mounted inside said housing to accelerate the needle from the location for insertion of the needle into the patient, wherein said fluid reservoir remains fixed at the site while said needle moves from the location into the patient; and

a plunger mounted inside said housing for ejecting fluid from said fluid reservoir and through said needle into the patient after said needle is moved into the patient.

8. A system as recited in claim 7 wherein said moving means is a cassette formed to hold a plurality of said needles, said cassette being moveable in the interior of said housing to sequentially present a needle at the location.

9. A system as recited in claim 7 further comprising a vacuum system for stabilizing the skin of the patient at an injection site during an injection.

10. A system as recited in claim 7 wherein said connector comprises:

a fluid transfer section formed with a fluid chamber and having an input port and an output port;

a septum covering the output port; and

a flexible hose connected to said input port and to said fluid reservoir to establish fluid communication between said fluid reservoir and the fluid chamber of said transfer section.

11. A system as recited in claim 10 wherein a needle for use in the system comprises:

an elongated hypodermic needle defining an axis and having a proximal end and a distal end; and

a collar mounted on said hypodermic needle between the proximal end and the distal end thereof, with said collar extending radially outward therefrom for contact with said transfer section to limit proximal movement of the needle relative to said transfer section during insertion of the proximal end of the needle through the septum and into the fluid chamber thereof, and for contact with said housing to limit distal movement of the needle relative to said housing during insertion of the distal end of the needle into the patient.

12. A system for injecting a fluid into a patient which comprises:

a housing formed with an interior;

a fluid reservoir fixed at a site on said housing;

a magazine mounted on said housing for holding at least one needle;

a means for moving a needle of said magazine to a location, wherein the needle has a mass (m_needle);

a drive means mounted in the interior of said housing for accelerating a drive rod with a mass (m_rod) to a velocity (v_rod) for contact with the needle with a predetermined momentum (m_rodv_rod), to transfer momentum from the drive rod to the needle for insertion of the needle into the patient;

wherein said fluid reservoir remains fixed at the site while said needle is inserted into the patient; and

a plunger mounted in the interior of said housing for ejecting fluid from said fluid reservoir and through said needle into the patient after said needle is inserted into the patient.

13. A system as recited in claim 12 wherein the mass of the drive rod is much greater than the mass of the needle (m_rod>

>

m_needle).

14. A system as recited in claim 13 further comprising a connector which comprises:

a fluid transfer section formed with a fluid chamber and having an input port and an output port;

a septum covering the output port; and

a flexible hose connected to said input port and to said fluid reservoir to establish fluid communication between said fluid reservoir and the fluid chamber of said transfer section and to mechanically isolate the fluid transfer section and the septum from the fluid reservoir.

15. A system as recited in claim 14 wherein contact of the drive rod with the needle establishes fluid communication between the needle and the fluid chamber of the fluid transfer section and wherein the needle, the fluid transfer section, and the septum have a combined mass (m_combined).

16. A system as recited in claim 15 wherein the predetermined momentum results in a final velocity (v_f) for the needle wherein (m_rodv_rod) is substantially equal to m_combinedv_f.

17. A method for operating an auto-injector which comprises the steps of:

mounting a fluid reservoir at a site on a housing formed with an interior, with said fluid reservoir remaining fixed at the site during operation of the auto-injector;

loading a plurality of sterile needles onto the housing;

moving a sterile needle to a location in the housing to present the sterile needle for fluid communication engagement through a connector with the fluid reservoir;

positioning the housing against an injection site on the patient;

accelerating a driver rod into contact with the connector to engage the connector with the needle to establish a connector/needle combination for fluid communication between the needle and said fluid reservoir;

transferring momentum from the drive rod to the connector/needle combination, in response to the accelerating step, to move the connector/needle combination from the location and insert the needle into the patient;

ejecting fluid from said fluid reservoir and through said needle for injecting the fluid into the patient; and

disconnecting the used needle from said connector for storage of the needle in the interior of said housing.

18. A method as recited in claim 17 wherein engagement of the connector with the needle in said accelerating step and said transferring step are accomplished simultaneously.

19. A method as recited in claim 17 wherein the plurality of needles are held in a magazine.

20. A method as recited in claim 17 wherein said accelerating step is accomplished by pushing a button.

21. A housing with a system mounted thereon for injecting a fluid medicament into a patient, said system comprising:

an elongated hypodermic needle defining an axis and having a proximal end and a distal end;

a fluid reservoir fixed at a site on the housing;

a collar mounted on the hypodermic needle between the proximal end and the distal end thereof with the collar extending radially outward from the needle, wherein the collar limits travel of the needle along a pathway inside the housing between a first position wherein the proximal end of the needle is engaged in fluid communication with the fluid reservoir and a second position wherein the distal end of the needle is inserted into the patient for infusion of the fluid medicament from the reservoir to the patient while said fluid reservoir remains fixed at the site.

22. A system as recited in claim 21 further comprising:

a fluid transfer section positioned for movement along the pathway of the housing, said fluid transfer section being formed with a fluid chamber having an input port and an output port;

a septum covering the output port wherein the proximal end of the needle is inserted through the septum for engagement with the fluid chamber when the collar abuts against the fluid transfer section; and

a flexible hose interconnecting the input port of the transfer section with the fluid reservoir to establish fluid communication between the fluid reservoir and the needle.

23. A system as recited in claim 21 wherein the proximal end of the needle is sharp and the distal end of the needle is sharp.

24. A system as recited in claim 21 further comprising an abutment formed on the housing for contact with the collar to limit axial movement of the needle in a distal direction relative to the housing during insertion of the distal end of the needle into the patient.

25. A system as recited in claim 24 further comprising a recoil mechanism mounted on the abutment for engagement with the collar to bias the needle in a proximal direction relative to the housing for subsequent withdrawal of the needle from the patient when the needle is in its second position.

26. A system as recited in claim 25 wherein the recoil means is a spring.

27. A system as recited in claim 21 wherein the needle and the collar, in combination, establish a needle unit, and wherein the system incorporates a plurality of needle units and the system further comprises a holder mounted on the housing to sequentially present each needle unit for individual travel along the pathway and to subsequently remove the needle unit from the pathway.

28. An injector which comprises:

a fluid source fixed at a site on the injector;

an elongated hypodermic needle defining an axis and having a sharp proximal end and a sharp distal end;

a disk-shaped collar mounted on said hypodermic needle between the proximal end and the distal end thereof with the collar extending radially outward from the needle;

a means operable with the collar for connecting the proximal end of the needle in fluid communication with the fluid source, wherein the needle is mechanically isolated from the fluid source; and

a means operable with the collar for inserting the distal end of the needle into a body for injecting fluid from the fluid source through the needle and into the body while said fluid source remains fixed at the site on the injector.

29. An injector as recited in claim 28 wherein the connecting means comprises:

a fluid transfer section formed with a fluid chamber having an input port and an output port;

a septum covering the output port, the septum being penetrable by the proximal end of the needle to engage the needle in fluid communication with the fluid chamber of the transfer section; and

a flexible hose interconnecting the input port of the transfer section with the fluid source to establish fluid communication between the fluid source and the needle.

30. An injector as recited in claim 28 wherein the needle and collar, in combination, are mounted on a housing and wherein the inserting means comprises:

an abutment formed on the housing for engagement with the collar to limit axial movement of the needle in a distal direction relative to the housing during insertion of the distal end of the needle into the body; and

a recoil means mounted on the abutment for engagement with the collar to bias the needle in a proximal direction relative to the housing for subsequent withdrawal of the needle from the body.

31. An injector as recited in claim 30 wherein the body is a patient and the housing prevents visual contact by the patient with the needle.