Administration apparatus for medical use

• US 8,206,351 B2
• Filed: 10/10/2008
• Issued: 06/26/2012
• Est. Priority Date: 03/05/2004
• Status: Active Grant

• Current Assignee: PHC Holdings Corporation
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Matsuda, Kouichi, Iio, Toshiaki, Kikuchi, Seiji, Sugimoto, Hirofumi, Takeuchi, Yoshiki
• Primary Examiner(s): Sirmons, Kevin C
• Assistant Examiner(s): Gilbert, Andrew
• Application Number:
  US12/249,165
• Publication Number:
  US 20090054832A1
• Time in Patent Office: 1,355 Days
• Field of Search: 604/151, 604232-235
• US Class Current: 604/151
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2073 preventing premature release, e.g. by making use of a safety lock
• CPC Class Codes: A61M 2005/208 Release is possible only when device is pushed against the skin, e.g. using a trigger which is blocked or inactive when the device is not pushed against the skin
• CPC Class Codes: A61M 2005/2411 from the front
• CPC Class Codes: A61M 2005/2496 via pivot
• CPC Class Codes: A61M 2005/3126 Specific display means related to dosing
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• CPC Class Codes: A61M 2005/31588 electrically driven
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• CPC Class Codes: A61M 5/3146 Priming, e.g. purging, reducing backlash or clearance
• CPC Class Codes: A61M 5/31535 Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• CPC Class Codes: A61M 5/31546 Electrically operated dose setting, e.g. input via touch screen or plus/minus buttons

Abstract

An expansion/compression mechanism of a piston rod assembly is composed of a bush shaft, a first cylindrical piston rod that is screwed with the bush shaft, a second cylindrical piston rod that is screwed with the first piston rod, and a piston rod holding member for housing the bush shaft and these piston rods. Therefore, the piston rods move linearly in multiple stages.

Claims

1. An administration apparatus for medical use which performs administration of a drug using an electric driving source, said apparatus comprising:

a drug cartridge having an end closed with a plunger, and containing a drug inside;

a cartridge holder for holding the drug cartridge;

a piston rod for pressing the plunger held in the drug cartridge to move the plunger;

a needle assembly having an injection needle for insertion into a target region and administering the drug that is emitted from the other end of the drug cartridge with a movement of the piston rod; and

an air releasing input portion which outputs a starting signal for starting an air releasing operation,

a needle-insertion drive portion which moves the injection needle between a position of a needle-removal state and a position of a needle-insertion possible state,

an injection drive portion which moves the piston rod, and

a control circuit which controls the needle-insertion drive portion and the injection drive portion so as to perform the air releasing operation upon receiving the starting signal of the air releasing input portion, wherein in the air releasing operation, said control circuit executes;

a first operation which controls the needle-insertion drive portion to move the injection needle from the position of the needle-removal state to the position of the needle-insertion possible state in a forward direction at a speed lower than a speed of drug administration;

a second operation which controls the injection drive portion to move the piston rod by an interval required for the air releasing operation at a speed lower than the speed of drug administration; and

a third operation which controls the needle-insertion drive portion to move the injection needle from the position of the needle-insertion possible state to the position of the needle-removal state in a backward direction at a speed lower than the speed of drug administration.

2. An administration apparatus for medical use as defined in claim 1 wherein

in the second operation, the operation of the piston rod is performed by PWM (Pulse Width Modulation) control for controlling the piston rod with the ON-OFF ratio of the pulse width being varied.

3. An administration apparatus for medical use as defined in claim 1 wherein

the second operation controls the injection drive portion to move the piston rod at the speed lower than the speed of drug administration during the air releasing operation using voltage control.

4. An administration apparatus for medical use as defined in claim 1, wherein said control circuit controls the needle-insertion drive portion and the injection drive portion so that the air releasing operation is always carried out before performing a drug administration operation.

5. An administration apparatus for medical use as defined in claim 4 further including

an air releasing switch for performing the air releasing operation, and an administration switch for injecting the drug,

wherein the control circuit permits an operation by turn-on of the administration switch after the air releasing operation.

6. An administration apparatus for medical use as defined in claim 1 further including

a contact sensor for detecting whether a portion of the administration apparatus in the vicinity of the needle assembly contacts a target region or not,

wherein the air releasing operation is suppressed when the contact sensor contacts the target region.

7. An administration apparatus for medical use as defined in claim 4 further including

a contact sensor for detecting whether a portion of the administration apparatus in the vicinity of the needle assembly contacts a target region or not,

wherein the air releasing operation is suppressed when the contact sensor contacts the target region.