Injector display

• US 5,509,905 A
• Filed: 10/13/1993
• Issued: 04/23/1996
• Est. Priority Date: 02/24/1992
• Status: Expired due to Term

• Current Assignee: TecPharma Licensing AG (Ypsomed Holding AG)
• Original Assignee: Medimpex Ets
• Inventors: Michel, Peter
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US08/133,125
• Time in Patent Office: 923 Days
• Field of Search: 604/207-211, 604/30-34, 604/51, 604/52, 604/67, 604/246-249, 128/DIG. 1, 128/DIG. 13
• US Class Current: 604/207
• CPC Class Codes: A61J 7/0481 working on a schedule basis
• CPC Class Codes: A61M 15/0068 Indicating or counting the number of dispensed doses or of remaining doses
• CPC Class Codes: A61M 15/008 Electronic counters
• CPC Class Codes: A61M 2005/3125 specific display means, e.g. to indicate dose setting
• CPC Class Codes: A61M 5/1684 by detecting the amount of infusate remaining, e.g. signalling end of infusion
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31556 Accuracy improving means

Abstract

The invention concerns a display for a medical injection device (1) wherein an injection dose is pre-selected by rotating an operating head (2) and then is administered by axially displacing said head. Switching devices (7, 8) are apposed to the operating head (2) to actuate switches (7, 8) of which the switch positions are transmitted to a printed circuit board (13). The printed circuit board (13) preferably contains a processor, so that values such as set injection dose, the sum of administered injection doses etc. and signals concerning operational states are shown on a display system (15).

Claims

1. An injection device and display for expelling doses of liquid from a liquid-containing ampoule having a plunger therein and for displaying the status of the dosage and remaining liquid comprising the combination of

a generally cylindrical housing having a longitudinal axis;

an operating head having an axially extending cylindrical part, said head and cylindrical part being rotatably carried in said housing;

means in said housing and cylindrical part for permitting axial displacement of said cylindrical part relative to said housing only at selected angular positions of said head and cylindrical part to expel a dose of liquid from said ampoule, said cylindrical part being axially movable between a rest position and a fully depressed end position;

a liquid-crystal display on said housing;

first switch means operated by rotation of said head for producing signals representative of rotation of said head to said angular positions and of direction of rotation;

second switch means for producing signals representative of axial displacement of said cylindrical part relative to said housing; and

printed circuit means having a battery, said printed circuit means being connected to receive said signals from said first and second switch means and to operate said display,

said signals from said first switch means in one direction of rotation being added by said printed circuit means and signals in an opposite direction being subtracted to thereby determine a number of doses, and

said signals from said second switch means being accumulated to indicate a number of expelled doses.

2. A device according to claim 1 wherein said means for permitting axial displacement comprises a plurality of axially extending bosses on said cylindrical part corresponding in number to a selected number of fractional turns required for a full revolution of said head and cylindrical part, and an equal number of axially extending channels in said housing, said bosses engaging said channels only when said head and cylindrical part are rotated to align said bosses and channels and said cylindrical part is displaced to expel liquid from said ampoule, rotation between said head and said housing being possible only when said bosses and channels are not engaged.

3. A device according to claim 2 wherein said first switch means includes cam rings penetrated by said cylindrical part and rotatable therewith.

4. A device according to claim 3 wherein said cam rings include means defining internal recesses engaging said bosses whereby said cam rings are rotatively driven by said bosses.

5. A device according to claim 1 wherein said first switch means includes cam rings penetrated by said cylindrical part and rotatable therewith.

6. A device according to claim 5 wherein one said cam ring includes means defining axially offset cam surfaces having switch operating shoulders, each for operating one of a plurality of switches.

7. A device according to claim 6 wherein said cam surfaces are shaped so that, during rotation of said head, one said shoulder of a cam surface turns a switch on and another said shoulder of said cam surface turns said switch off.

8. A device according to claim 7 wherein said shoulders are circumferentially positioned so that said switch is turned off shortly before the end of a fractional turn of said head.

9. A device according to claim 1 wherein said second switch means comprise a switch ring non-rotatively penetrated by said cylindrical part and restrained against axial movement.

10. A device according to claim 9 wherein said switch ring holds a switch in a single position when said cylindrical part is between said rest position and said end position, and moves said switch to a second position only in said end position.

11. A device according to claim 10 wherein said cylindrical part includes an annular channel to receive said switch ring in said end position, permitting lateral movement of said switch ring to move said switch to said second position.