Injector with ratchet drive and reproducing system

• US 4,405,318 A
• Filed: 03/27/1981
• Issued: 09/20/1983
• Est. Priority Date: 11/12/1976
• Status: Expired due to Fees

• Current Assignee: Douglas S.G. Whitney, John K. Martin III
• Original Assignee: Douglas S.G. Whitney, John K. Martin III
• Inventors: Martin, John K. III, Whitney, Douglas S. G.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US06/248,512
• Time in Patent Office: 907 Days
• Field of Search: 128/218 A, 128/214 F, 128/DIG. 12, 128/213 R, 128/DIG. 1, 604/154, 604/155
• US Class Current: 604/155
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61M 2005/14506 mechanically driven, e.g. spring or clockwork
• CPC Class Codes: A61M 2205/0294 Piezoelectric materials
• CPC Class Codes: A61M 39/04 having pierceable self-sealing members
• CPC Class Codes: A61M 5/1422 with double acting or multiple pistons
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/155 pressurised by gas introduced into the reservoir
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: Y10S 128/01 Motorized syringe
• CPC Class Codes: Y10S 128/12 Pressure infusion
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

Method and apparatus for injecting fluids into patients at a controlled rate from an ampule containing the injecting fluid with a sliding piston therein to force the fluid from the ampule into the patient using a drice system which incrementally and successively advances the piston in the ampule to meter the fluid into the patient.

Claims

1. Apparatus for injecting fluid into a patient at an average prescribed rate over a prolonged period of time comprising:

a housing;

carriage means mounted on said housing and defining a fluid chamber therein carrying fluid to be dispensed and an outlet from said fluid chamber adapted to be connected to the patient;

a piston slidably mounted in said fluid chamber for forcing fluid from said outlet as said piston is moved toward said outlet;

drive screw means operatively associated with said piston for moving said piston toward said outlet as said drive screw means is rotated;

ratchet drive means including a mounting shaft having a central ratchet axis, an output ratchet member fixedly mounted on said mounting shaft about the ratchet axis and operatively connected to said drive screw means for rotating said drive screw means as said output ratchet member is rotated;

an input ratchet member rotatably and slidably mounted on said mounting shaft about said ratchet axis, said output and input ratchet members defining a plurality of complementary ratchet teeth thereon facing each other so that said ratchet teeth on said output and input ratchet members engage when said input ratchet member is moved toward said output ratchet member;

spring means for resiliently urging said input ratchet member toward said output ratchet member, said complementary ratchet teeth arranged so that said output ratchet member is rotated in a first direction and so that said input ratchet member can ratchet with respect to said output ratchet member as said input ratchet member is rotated in the opposite direction without rotating said output ratchet member; and

a drive projection connected to said input ratchet member so that said drive projection rotates said input ratchet member about said ratchet axis as said drive projection is pivoted back and forth about said ratchet axis;

an electrically operated solenoid including an actuator member moved in response to electrically energizing said solenoid;

connection means operatively connecting said actuator member on said solenoid to said drive projection on said ratchet drive means so that said connection means will pivot said drive projection and said input ratchet member in said first direction to drivingly rotate said output ratchet member therewith when said solenoid is energized, yet said connection means will not pivot said drive projection in the direction opposite said first direction when said solenoid is de-energized so as to isolate said ratchet drive means from said solenoid;

return spring means operatively connected to said drive projection to pivot said drive projection in said opposite direction when said solenoid is de-energized;

an electrical power supply; and

control means for selectively connecting said electrical power supply to and disconnecting said electrical power supply from said solenoid to successively and alternatively energize and de-energize said solenoid at a rate such that fluid is incrementally injected into the patient at the desired average prescribed rate over the prolonged period of time so that, if said control means fails so as to continuously connect said electrical power supply to said solenoid, said piston will be moved only an incremental prescribed distance toward said outlet to prevent overdosing the patient.

2. The apparatus of claim 1 further including clutch means operatively connected to said output ratchet member for permitting rotation of said output ratchet member only in said first direction with said input ratchet member such that said drive screw is rotated to move said piston toward said outlet.

3. The apparatus of claim 2 wherein said electrically operated solenoid further includes first actuator stop means for limiting the movement of said actuator member in one direction and second actuator stop means for limiting movement of said actuator member in the opposite direction.

4. The apparatus of claim 3 wherein said connection means includes a drive arm pivotally mounted on said housing, said drive arm including a first projection thereon adapted to be engaged by said actuator member as said actuator member is moved when said solenoid is energized and a second projection thereon adapted to engage said drive projection in said ratchet drive means and pivot said drive projection so as to rotate said output ratchet member as said actuator member pivots said drive arm.