IV pump and disposable flow chamber with flow control

• US 4,857,048 A
• Filed: 03/21/1988
• Issued: 08/15/1989
• Est. Priority Date: 05/29/1987
• Status: Expired due to Term

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Stawitcke, Frederick A., Reed, William M., Simons, Tad D., Tessier, Paul A.
• Primary Examiner(s): Smith, Leonard E.
• Application Number:
  US07/173,021
• Time in Patent Office: 512 Days
• Field of Search: 604/65, 604/67, 604/50, 604/153, 604/151, 604/245, 604/152, 417/26
• US Class Current: 604/503
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: F04B 43/021 the plate-like flexible member is pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the plane of the plate-like flexible member and each having its own driving mechanism

Abstract

An apparatus and method are disclosed for an IV pump which can act also as a passive infusion controller. The apparatus has a disposable flow chamber with two pumping subchambers connected by a first collapsible passageway. A pump drive is used to operate the pumping subchambers and includes a first control valve for depressing the first collapsible passageway to control flow between the subchambers and an outlet control valve for depressing an outlet collapsible passageway to control flow of infusate out of the flow chamber. The flow chamber has a base surface and first and second caps, each cap being spaced apart from the base surface and having means for attachment to one of two moveable connector rods. The caps each act as one side of the first and second pumping subchambers, respectively, the base surface being the other side. A flexible wall is connected to the base surface and to each of the caps providing the subchamber volumes therebetween. The flexible wall is constructed of a material having a thickness and modulus of elasticity such that when the connector rods are not moving the flexible wall element does not collapse when subjected to a negative gauge pressure.

Claims

1. A method of calibrating an infusion system to achieve a given flow rate for infusing fluids into patients comprising the steps of:

connecting a drip chamber, which is adapted to receive an infusate, to a volumetric pump;

pumping said volumetric pump for a first time period at a rate to achieve said given flow rate;

counting the number of drops per unit time through said drip chamber during said pumping step to arrive at a drip rate corresponding to said given flow rate in order to calibrate the drop size;

stopping said pumping; and

while said pumping is stopped, adjusting said drip rate to be equal to the number of drops counted per unit time to achieve said given flow rate for a passive infusion.

2. A method of infusing fluids into patients at a given flow rate comprising the steps of:

connecting a source of said fluid through a drip chamber to a volumetric pump;

pumping said volumetric pump at a rate to achieve said given flow rate;

counting the number of drops per unit time during said pumping step to arrive at a drip rate corresponding to said given flow rate;

stopping said pumping; and

while said pumping is stopped, adjusting said drip rate to be equal to the number of drops counted per unit time to achieve said given flow rate for a passive infusion.

3. The method of claim 2 further comprising the steps of:

interrupting said passive infusion;

pumping said volumetric pump during said interruption for a second time period at a rate to achieve said given flow rate;

counting the number of drops per unit time during said second time period to arrive at a drip rate corresponding to said given flow rate;

stopping said pumping; and

while said pumping is stopped, adjusting said drip rate to be equal to the number of drops counted per unit time to achieve said flow rate for a passive infusion.