Self contained powered injection system

• US 4,273,122 A
• Filed: 01/08/1979
• Issued: 06/16/1981
• Est. Priority Date: 11/12/1976
• Status: Expired due to Term

• Current Assignee: Douglass G. Whitney, John K. Martin III
• Original Assignee: Douglass G. Whitney, John K. Martin III
• Inventors: Whitney, Douglass G., Martin, John K. III
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US06/001,091
• Time in Patent Office: 890 Days
• Field of Search: 128/213 R, 128/214 R, 128/214 E, 128/214 F, 128/214.2, 128/218 A, 128/DIG. 1, 128/DIG. 12, 128/DIG. 13, 222/63, 222/70, 222/77
• US Class Current: 604/67
• 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 drive 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:

carriage means defining a fluid chamber therein carrying fluid to be dispensed and an outlet from said fluid chamber 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;

an electrical power supply;

electrically operated driving means for moving said piston toward said outlet when said electrically operated driving means is connected to said power supply, said electrically operated driving means constructed and arranged to move said piston only a prescribed distance toward said outlet each time said electrical power supply is connected to said electrically operated driving means regardless of the length of time said electrical power supply is connected to said electrically operated driving means, said piston forcing a volume of the fluid from said outlet much less than the total volume of fluid to be injected over the prolonged period of time each time said piston is moved said prescribed distance; and

,

control means for selectively connecting said electrical power supply to and disconnecting said electrical power supply from said electrically operated driving means at a rate such that fluid is injected into the patient at the desired average 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 electrically operated driving means, said piston will be moved only said incremental prescribed distance toward said outlet to prevent overdosing the patient, said control means including;

switching means for selectively connecting said electrical power supply to said electrically operated driving means;

timing pulse generator means for operating said switching means; and

programming means for selectively controlling the timing pulse rate output of said timing pulse generator, said programming means including encoding means;

manually operated input means for selectively encoding said encoding means with the volume of fluid to be injected over a selected time period;

manually adjustable time period selector means for selecting the time period over which the fluid is to be injected; and

dosage rate logic means operatively connected to said encoding means, said time period selector means, and said timing pulse generator for calculating the required timing pulse output from said timing pulse generator to cause the volume of fluid encoded into said encoding means to be injected within the time period selected in said time period selector means and for causing said timing pulse generator to generate the required timing pulse output.

2. The apparatus of claim 1 wherein said electrically operated driving means is a solenoid.

3. The apparatus of claim 2 wherein said driving means further includes ratchet means operatively connecting said solenoid to said piston so that the reciprocating motion output of said solenoid moves said piston in a first direction toward said outlet.

4. The apparatus of claim 3 wherein said driving means further includes clutch means operatively connected to said piston for permitting said solenoid to move said piston only in said first direction.

5. The apparatus of claim 4 wherein said driving means further includes:

a first threaded member carried by said housing;

a second threaded member threadedly engaging said first threaded member so that relative rotation between said threaded members causes said second threaded member to be axially moved to selectively engage and move said piston in said first direction toward the fluid outlet to force the fluid out of the fluid outlet in said container into the patient, said ratchet means operatively connecting said solenoid to said second threaded member to effect relative rotation between said first and second threaded members.

6. The apparatus of claim 1 wherein said electrically operated driving means is a stepping motor.

7. The apparatus of claim 1 wherein said electrically operated driving means includes resettable stop means for physically limiting the amount of movement transmitted from said electrically operated driving means to said piston each time said electrically operated driving means is connected to said electrical power supply, said resettable stop means resetting itself while said electrically operated driving means is disconnected from said power supply to permit further movement to be transmitted to said piston when said electrically operated driving means is reconnected to said power supply.

8. The apparatus of claim 7 wherein said control means further includes mode selector means having a first position selectively activating said manually operated input means, said manually adjustable time period selector means and said dosage rate logic means so that the volume of fluid and the time over which the fluid is to be injected encoded in said encoding means can be changed, and disabling said timing pulse generator to prevent said timing pulse generator from operating said driving means;

and having a second position disabling said input means and said time period selector means to prevent changing the volume of fluid and the time period over which the volume of fluid is to be injected encoded into said encoding means, and enabling said timing pulse generator to operate said solenoid to cause the volume of fluid encoded into said encoding means to be injected within the time period selected in said time period selector means and for causing said timing pulse generator to generate the required timing pulse output.

9. The apparatus of claim 1 wherein said control means further includes:

display means for providing a visual output; and

monitoring means operatively connecting said timing pulse generator means to said display means to cause said visual output of said display means to be indicative of the average prescribed injection rate.

10. The apparatus of claim 9 wherein said display means includes a liquid crystal display.

11. The apparatus of claim 1 wherein said control means further includes disabling means operatively connected to said timing pulse generator means and said switching means to cause said swiching means to disconnect said driving means from said electrical power supply upon malfunction of said timing pulse generator means.

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

carriage means defining a fluid chamber therein carrying fluid to be dispensed and an outlet from said fluid chamber 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;

an electrical power supply;

electrically operated driving means for moving said piston toward said outlet when said electrically operated driving means is connected to said power supply, said electrically operated driving means constructed and arranged to move said piston only a prescribed distance toward said outlet each time said electrical power supply is connected to said electrically operated driving means regardless of the length of time said electrical power supply is connected to said electrically operated driving means, said piston forcing a volume of the fluid from said outlet much less than the total volume of fluid to be injected over the prolonged period of time each time said piston is moved said prescribed distance, said driving means including;

a first threaded member carried by said housing;

a second threaded member threadedly engaging said first threaded member so that relative rotation between said threaded members causes said second threaded member to be axially moved to selectively engage and move said piston in said first direction toward the fluid outlet to force the fluid out of the fluid outlet in said container into the patient;

a drive member mounted in said housing coaxially with said second threaded member, said drive member axially fixed with respect to said first threaded member and rotatable about its axis;

a slip joint interconnecting that end of said second threaded member opposite said piston with said drive member so that said second threaded member is axially movable with respect to said drive member while remaining rotationally fixed with respect to said drive member whereby rotation of said drive member rotates said second threaded member;

an electrically operated solenoid; and

ratchet means operatively connecting said solenoid to said drive member so that the reciprocating motion output of said solenoid rotates said drive member and said second threaded member to move said piston in a first direction toward said outlet; and

,

control means for selectively connecting said electrical power supply to and disconnecting said electrical power supply from said electrically operated driving means at a rate such that fluid is injected into the patient at the desired average rate over the prolonged period of time so that, of said control means fails so as to continuously connect said electrical power supply to said electrically operated driving means, said piston will be moved only said incremental prescribed distance toward said outlet to prevent overdosing the patient, said control means including;

switching means for selectively connecting said solenoid to and disconnecting said solenoid from said electrical power supply;

timing pulse generator means generating a timing pulse output to said switching means to cause said switching means to alternately energize and de-energize said solenoid to cause the fluid to be injected into the patient at the desired average injection rate; and

programming means for selectively controlling the timing pulse rate output of said timing pulse generator to selectively change the desired average injection rate, said programming means including encoding means;

manually operated input means for selectively encoding said encoding means with the volume of fluid to be injected over a selected time period;

manually adjustable time period selector means for selecting the time period over which the fluid is to be injected; and

dosage rate logic means operatively connected to said encoding means, said time period selector means and said timing pulse generator for calculating the required timing pulse output from said timing pulse generator to cause the volume of fluid encoded into said encoding means to be injected with the time period selected in said time period selector means and for causing said timing pulse generator to generate the required timing pulse output.

13. The apparatus of claim 12 wherein said control means further includes:

display means for generating a visually perceptive quantified output;

monitoring means operatively connected to the timed pulse output of said timing pulse generator for generating an electronic output indicative of the average fluid injection in response to the timed pulse output; and

mode selector means having a first position connecting said encoding means to said display means to cause said output of said display means to be a quantification of the volume of fluid encoded in said encoding means, activating said manually operated input means to allow the volume of fluid encoded into said encoding means to be changed, and disabling said timing pulse generator to prevent said timing pulse generator from operating said solenoid; and

having a second position disabling said input means to prevent changing the volume of fluid encoded into said encoding means, enabling said timing pulse generator to operate said solenoid, and connecting the electronic output of said monitoring means to said display means to cause the output of said display means to be a quantification of the average fluid injection rate in response to the timed pulse output of said timing pulse generator.

14. The apparatus of claim 13 wherein said display means includes a liquid crystal display.

15. The apparatus of claim 14 further including connection means intraveneously connecting said fluid outlet on said container means to the patient so that the fluid is injected into the patient at the average prescribed fluid injection rate.

16. The apparatus of claim 14 further including connection means subcutaneously connecting said fluid outlet on said container means to the patient so that the fluid is injected into the patient at the average prescribed fluid injection rate.

17. The apparatus of claim 14 wherein said carriage means includes an ampule assembly comprising a seamless tubular side wall defining a passage therethrough opening onto opposite ends of said side wall, and a penetrable member closing one end of said passage at one end of said side wall, said piston member slidably received in said passage from that end of said tubular side wall opposite said penetrable member and in sealing engagement with said tubular side wall, said tubular side wall, said piston member and said penetrable member defining the closed fluid chamber filled with the fluid;

and said container means further including a piercing assembly defining said fluid outlet therethrough for selectively penetrating said penetrable member to place said fluid outlet in communication with the fluid in the fluid chamber so that, as said piston member is forced toward said penetrable member, the fluid will be expelled through said fluid outlet.

18. The apparatus of claim 17 wherein said second threaded member, said side wall of said ampule assembly are coaxially aligned along a common expelling axis;

wherein said second threaded member defines a pointed driving projection on that end facing said piston and coaxially aligned with said expelling axis;

wherein said piston includes a driven member defining a conical bearing surface thereon opening toward said pointed driving projection and having an apex in registration with said expelling axis, said conical bearing surface angling away from said expelling axis with equal angles therearound so that said pointed driving projection engages said conical bearing surface in said apex to axially move said piston along said expelling axis with the force exerted on said piston by said second threaded member equally distributed circumferentially about said piston to prevent canting of said piston in said ampule side wall.