Injection device with secondary reservoir

• US 20060229562A1
• Filed: 04/11/2005
• Published: 10/12/2006
• Est. Priority Date: 04/11/2005
• Status: Active Grant

• Current Assignee: Embecta Corporation
• Original Assignee: Becton, Dickinson & Co
• Inventors: Follman, Mark, Marsh, Ronald W., Browka, Edward P.
• Granted Patent: US 7,645,264 B2
• Time in Patent Office: Days
• US Class Current: 604/164.10
• CPC Class Codes: A61M 2005/3128 Incorporating one-way valves, e.g. pressure-relief or non-return valves
• CPC Class Codes: A61M 5/204 connected to external reservoirs for multiple refilling
• CPC Class Codes: A61M 5/283 by telescoping of ampoules or carpules with the syringe body
• CPC Class Codes: A61M 5/3155 by rotational movement of dose setting member, e.g. during setting or filling of a syringe
• CPC Class Codes: A61M 5/31561 using freely adjustable volume steps
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion

Abstract

A method and apparatus for injecting fluid into areas having high density tissue that creates a high backpressure resistance on the injection device is disclosed. The high backpressure resistance is overcome through a mechanical advantage achieved by using a secondary reservoir having a cross-sectional area smaller than the cross-sectional area of a primary reservoir. Exemplary injection device reservoir housings may comprise a primary reservoir, a secondary reservoir, a check valve, a septum penetrating cannula, travel limits, a pen needle connecting portion, sliding seal guide ribs, a sliding seal, a pen needle assembly, a needle stop, and a patient needle.

Claims

1. An injection mechanism for injecting fluid into a targeted tissue layer comprising:

a primary reservoir for storing fluid prior to injection having a first axis;

a secondary reservoir for holding the amount of fluid to be injected having a second axis, wherein the secondary reservoir is located co-axially and in series with the primary reservoir and has a smaller cross-sectional area than the cross-sectional area of the primary reservoir.

2. The injection mechanism of claim 1, further comprising:

a needle connecting portion comprising a sliding seal, a needle assembly, a needle stop, wherein the sliding seal comprises a needle septum through which the fluid to be injected passes during the injection; and

a patient needle intersecting the needle septum of the sliding seal for penetrating the skin of the patient to inject the fluid in the targeted tissue layer.

3. The injection mechanism of claim 2, wherein said patient needle has an exposed length of between approximately 0.5 mm and approximately 5 mm.

4. The injection mechanism of claim 2, wherein said patient needle has an exposed length of between approximately 0.5 mm and approximately 3.5 mm.

5. The injection mechanism of claim 2, wherein said patient needle has an exposed length of between approximately 1.5 mm and approximately 3.0 mm.

6. The injection mechanism of claim 2, wherein said patient needle delivers fluid in the intradermal or the shallow subcutaneous tissue space.

7. The injection mechanism of claim 1, further comprising:

a check valve located between the primary and secondary reservoirs for preventing fluid from leaking from the secondary reservoir back into the primary reservoir or medicament cartridge.

8. The injection mechanism of claim 1, wherein the fluid is at least one of a therapeutic drug, vaccine or diagnostic material.

9. The injection mechanism of claim 1, wherein the primary reservoir is adapted to receive a medicament cartridge for administering a dosage of medication.

10. The injection mechanism of claim 9, wherein a dose means is used to transfer said dosage of medication into said secondary reservoir in preparation for giving an injection.

11. The injection mechanism of claim 1, wherein said secondary reservoir is filled with fluid causing said sliding seal to move proximal in said secondary reservoir.

12. The injection mechanism of claim 2, wherein the patient needle penetrates said patient skin until stopped by a needle stop, wherein said needle stop has an area larger than that of said patient needle.

13. The injection mechanism of claim 12, wherein an injection is administered by applying pressure to said primary reservoir thereby causing said fluid in said secondary reservoir to flow through said needle septum and patient needle to be injected into said intradermal tissue.

14. A method for injecting fluid into an intradermal tissue layer of a patient comprising the steps of:

transferring fluid from a primary reservoir with a first cross-sectional area into a secondary reservoir having a second cross-sectional area less than that of said first cross-sectional area;

preventing said fluid from flowing from the secondary reservoir back into the primary reservoir;

pressurizing the fluid in said secondary reservoir to force it into said intradermal tissue layer of a patient.

15. The method of claim 14, further comprising the step of:

penetrating the skin of said patient with a needle in fluid communication with said secondary reservoir prior to said pressurizing step.

16. The method of claim 14, wherein the transferring step comprises turning a dosage knob to set the amount of fluid in the primary reservoir that is transferred to said secondary reservoir.

17. The method of claim 14, wherein said preventing step comprises using a check valve, wherein said check valve allows fluid to flow from the primary reservoir to the secondary reservoir and prevents the medication from substantially flowing from the secondary reservoir back into the primary reservoir.

18. The method according to claim 15, wherein in the penetrating step comprises limiting the depth that the needle penetrates into the skin.

19. The method of claim 18, wherein the depth that the needle penetrates into the skin is limited by a needle stop.

20. A method of injecting a solution into a patient comprising the steps of:

providing solution into a first reservoir;

collapsing the first reservoir to transfer the solution into a second reservoir; and

collapsing the second reservoir to deliver the solution into a targeted space.

21. The method of claim 20, wherein the collapsing the first reservoir step transfers the solution into a secondary reservoir with a smaller cross-sectional area than the first reservoir.

22. The method of claim 21, wherein the pressure of the solution expelled from the secondary reservoir is greater than the pressure of the solution when transferred from the first reservoir into the second reservoir.

23. An apparatus for delivery of compounds to the intradermal tissue of a patient'"'"'s skin, the apparatus comprising:

a reservoir housing having a distal end and a proximal end, and defining a primary reservoir, and a secondary reservoir in fluid communication;

a pen needle assembly mounted to the distal end of the reservoir housing;

a needle securely mounted to the pen needle assembly in fluid communication with the secondary reservoir and extending distally from the pen needle assembly

a needle stop having a skin-engaging surface disposed in a preselected position with respect to the pen needle assembly such that a preselected portion of the needle extends distally from the skin-engaging surface;

wherein the reservoir housing comprises a lower sleeve slidingly engaged to an upper sleeve, movable from a first position to a second position;

wherein, when the lower sleeve is in the first position, the secondary reservoir has a first volume and when the lower sleeve is in the second position, the secondary reservoir has a second volume, and wherein the second volume is less than the first volume.

24. The apparatus of claim 23, wherein the pen needle assembly is selectively and directly mounted to the reservoir housing.

25. The apparatus of claim 23, wherein the pen needle assembly is fixedly mounted to the reservoir housing.

26. The apparatus of claim 23, wherein the needle stop is integrally formed with either the pen needle assembly or the reservoir housing.

27. An apparatus for delivery of compounds to the intradermal tissue of a patient'"'"'s skin, the apparatus comprising:

a reservoir housing having a distal end and a proximal end, and defining a primary reservoir, and a secondary reservoir in fluid communication;

a pen needle assembly mounted to the distal end of the reservoir housing;

a needle securely mounted to the pen needle assembly in fluid communication with the secondary reservoir and extending distally from the pen needle assembly

a needle stop having a skin-engaging surface disposed in a preselected position with respect to the pen needle assembly such that a preselected portion of the needle extends distally from the skin-engaging surface;

wherein the reservoir housing comprises a lower sleeve slidingly engaged to an upper sleeve, movable from a first position to a second position; and

a sliding seal operably engaged to the lower housing and disposed, at least in part, within the secondary reservoir for sliding movement.

28. The apparatus of claim 27, wherein the pen needle assembly is selectively and directly mounted to the reservoir housing.

29. The apparatus of claim 27, wherein the pen needle assembly is fixedly mounted to the reservoir housing.

30. The apparatus of claim 27, wherein the needle stop is integrally formed with either the pen needle assembly or the reservoir housing.