Method of injecting fluid

• US 4,342,312 A
• Filed: 03/30/1981
• Issued: 08/03/1982
• Est. Priority Date: 01/08/1979
• Status: Expired due to Fees

• 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): YASKO JR, JOHN D
• Application Number:
  US06/248,868
• Time in Patent Office: 491 Days
• Field of Search: 128/214 R, 128/214 E, 128/214 F, 128/213, 128/215, 128/216, 128/218 R, 128/218 A, 128/253, 128/260, 222/63, 222/70, 222/77
• US Class Current: 604/28
• 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. A method of injecting a fluid into a patient at an average prescribed rate over a prolonged period of time comprising the steps of:

alternatively injecting the fluid into the patient at a first prescribed rate greater than the desired average prescribed rate for a first prescribed short period of time of fixed duration much less than the prolonged period of time;

alternatively stopping the injection of the fluid into the patient for a second prescribed short period of time less than the prolonged period of time so that the fluid is injected into the patient at the desired average prescribed rate over the sum of the first and second prescribed short periods of time; and

selectively varying the duration of only the second prescribed short period of time without varying the duration of the first prescribed short period of time to selectively vary the selected prescribed average rate at which the fluid is injected into the patient.