Automatic needle insertion mechanism

• US 5,980,491 A
• Filed: 07/03/1997
• Issued: 11/09/1999
• Est. Priority Date: 07/05/1996
• Status: Expired due to Term

• Current Assignee: Novo Nordisk A/S
• Original Assignee: Novo Nordisk A/S
• Inventors: Hansen, Niels-Aage
• Primary Examiner(s): Coggins, Wynn Wood
• Assistant Examiner(s): Blyveis, Deborah
• Application Number:
  US08/887,871
• Time in Patent Office: 859 Days
• Field of Search: 604/117, 604/156, 604/157, 604/134-138, 604/207, 604/211
• US Class Current: 604/157
• CPC Class Codes: A61M 5/31551 including axial movement of dose setting member
• CPC Class Codes: A61M 5/3287 Accessories for bringing the needle into the body; Automatic needle insertion A61M5/20, A61M5/31525 take precedence

Abstract

An automatic needle insertion device for a pen shaped syringe comprising a cartridge holder (2) wherein a cartridge with a drug can be accommodated, and a dose setting and injection part (1) by which a wanted dose may be set an subsequently pressed out from the cartridge by pressing a button (12) projecting from the dose setting and injection part (1). The device comprises a mainly tubular housing (31) in which a tubular pen holder (22) in which a pen can be mounted can be axially displaced in a proximal direction to cock a spring (30) which can thereafter be released to drive the pen holder (22) with the pen a set distance in a distal direction.

Claims

1. An automatic needle insertion device for a pen-shaped syringe of the type including a cartridge holder for containing a cartridge with a drug to be administered, and a dose-setting and injection part by which a desired dose can be set and subsequently injected, said device comprising:

a mainly tubular housing having proximal and distal ends, and including a rest portion at said distal end which can be placed against the skin;

a cartridge holder mounted in said tubular housing so as to be axial displaceable, wherein the cartridge holder includes a distal end with a needle mount for receiving an injection needle, and a proximal end for receiving a dose-setting and injection part;

a spring mounted in said tubular housing and engaging, at opposite ends, said tubular housing and said cartridge holder such that moving said cartridge holder in said proximal direction, relative to said tubular housing, cocks said spring;

wherein said cartridge holder is axially moveable between an injection position, in which a needle mounted thereon projects in a distal direction from said rest portion by a predetermined distance, and a cocked position, in which a needle mounted thereon lies a proximal distance from said rest portion, whereby an injection can be administered by mounting a cartridge in, and a dose-setting and injection mechanism and an injection needle on, said cartridge holder;

moving said cartridge holder, and with it said dose-setting and injection mechanism and needle, to said cocked position, thereby cocking said spring;

placing said rest portion against the skin at the desired injection location, and releasing said spring to cause said needle to penetrate the skin by the predetermined distance; and

finally injecting a predetermined dose using said dose-setting and injection mechanism.

2. A device according to claim 1, wherein said cartridge holder has an inner thread at said proximal end for receiving a corresponding outer thread on a dose-setting and injection mechanism of a pen shaped syringe.

3. A device according to claim 2, wherein said cartridge holder has at least one inspection window allowing visual inspection of a cartridge as in the case of a conventional cartridge holder of a pen-shaped syringe.

4. A device according to claim 2, wherein said rest portion is obliquely cut so that the needle pierces the skin at an angle.