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US4322201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
IV Pump with back pressure control
Assignee: Graseby Medical Ltd
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Filing: 1979-09-21
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Granted: 1982-03-30
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Expires: 1999-09-21
Abstract
Abstract A volumetric infusion pump of the type having a rolling diaphragm pumping chamber includes a back pressure sensor between the rolling diaphragm pumping chamber and the pump outlet for sensing back pressure. A valve is positioned between the back pressure sensor and the pump outlet for controlling fluid flow to the pump outlet in order to control back pressure supplied to the rolling diaphragm pumping chamber. Back pressure is maintained within the rolling diaphragm pump chamber so that the rolling diaphragm maintains close contact with the piston even in the event of a negative head pressure at the pump outlet. The valve and the back pressure sensor are preferably linked so that the valve restricts fluid flow to the pump outlet only when the sensed back pressure is less than a predetermined level.
Inventors
- 👤 G. Kent Archibald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:42
CPC Classifications
F; F04; F04B; F04B43/00; F04B43/08; F04B43/082; A; A61; A61M; A61M5/00; A61M5/14; A61M5/142; A61M5/14212; A61M5/14224; A61M5/168; A61M5/16831; A61M5/16854; A61M5/36; A61M5/365; F04B43/02; F04B43/021; F04B7/00; F04B9/00; F04B9/02; F04B9/04; F04B9/042; A61M2205/00; A61M2205/33; A61M2205/3331; A61M2205/3355
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
229 words
A volumetric infusion pump for pumping fluid from a reservoir to a patient, the volumetric infusion pump comprising: a pump inlet for connection to the reservoir; a pump outlet for connection to the patient; rolling diaphragm pumping chamber means connected between the pump inlet and the pump outlet; pressure sensing means connected between the rolling diaphragm pumping chamber means and the pump outlet for sensing pressure; wherein the pressure sensing means comprises: a cylinder; a piston movable in the cylinder; flexible diaphragm means between the cylinder and the piston defining a pressure sensing chamber; and spring bias means for applying a force urging the piston in a direction which reduces the volume of the pressure sensing chamber, and wherein pressure in the pressure sensing chamber applies a force urging the piston in a direction which increases the volume of the pressure sensing chamber; and valve means between the pressure sensing means and the pump outlet for controlling fluid pressure in the rolling diaphragm pumping chamber means wherein the valve means restricts a flow passage between the pumping chamber means and the pump outlet to increase pressure in the rolling diaphragm pumping chamber means if the pressure sensed by the pressure sensing means is less than a predetermined level, and wherein the valve means does not restrict the flow passage if the pressure sensed is greater than the predetermined level.
Claim 2
Dependent Claim
229 words
A volumetric infusion pump for pumping fluid from a reservoir to a patient, the volumetric infusion pump comprising: a pump inlet for connection to the reservoir; a pump outlet for connection to the patient; rolling diaphragm pumping chamber means connected between the pump inlet and the pump outlet; pressure sensing means connected between the rolling diaphragm pumping chamber means and the pump outlet for sensing pressure; wherein the pressure sensing means comprises: a cylinder; a piston movable in the cylinder; flexible diaphragm means between the cylinder and the piston defining a pressure sensing chamber; and spring bias means for applying a force urging the piston in a direction which reduces the volume of the pressure sensing chamber, and wherein pressure in the pressure sensing chamber applies a force urging the piston in a direction which increases the volume of the pressure sensing chamber; and valve means between the pressure sensing means and the pump outlet for controlling fluid pressure in the rolling diaphragm pumping chamber means wherein the valve means restricts a flow passage between the pumping chamber means and the pump outlet to increase pressure in the rolling diaphragm pumping chamber means if the pressure sensed by the pressure sensing means is less than a predetermined level, and wherein the valve means does not restrict the flow passage if the pressure sensed is greater than the predetermined level.
Claim 3
Dependent Claim
29 words
The volumetric infusion pump of claim 1 and further comprising: linkage means for linking the valve means and the piston when the pressure is less than the predetermined level.
Claim 4
Dependent Claim
119 words
The volumetric infusion pump of claim 2 wherein the linkage means comprises: a longitduinal slot in the piston; and arm means fixedly connected to the valve means and having a free end extending into the slot, wherein the arm engages one end of the slot and imparts force from the spring bias means to the valve means when pressure in the pressure sensing chamber is less than the predetermined level, and where a pressure in the pressure sensing chamber of greater than the predetermined level causes the piston to move to a position in which the end of the arm means is not engaging an end of the slot, thereby disconnecting the spring bias means and the valve means.
Claim 5
Dependent Claim
207 words
A volumetric infusion pump for pumping fluid from a reservoir to a patient, the volumetric infusion pump comprising: a pump inlet for connection to the reservoir; a pump outlet for connection to the patient; pumping chamber means connected between the pump inlet and the pump outlet; and pressure sensing and regulating means connected between the pumping chamber means and the pump outlet for sensing a pressure indicative of fluid pressure in the pumping chamber means and controlling the fluid pressure in the pumping chamber means as a function of the sensed pressure to maintain the fluid pressure in the pumping chamber means at least at a predetermined level even if pressure at the pump outlet is less than the predetermined level; wherein the pressure sensing and regulating means allows the fluid pressure in the pumping chamber means to equal the pressure at the pump outlet if the pressure at the pump outlet exceeds the predetermined level; and wherein the pressure sensing and regulating means comprises: a cylinder; a piston movable in the cylinder; flexible diaphragm means between the cylinder and the piston defining a pressure sensing chamber; valve means for occluding an outlet of the pressure sensing chamber as a function of the position of the piston.
Claim 6
Dependent Claim
207 words
A volumetric infusion pump for pumping fluid from a reservoir to a patient, the volumetric infusion pump comprising: a pump inlet for connection to the reservoir; a pump outlet for connection to the patient; pumping chamber means connected between the pump inlet and the pump outlet; and pressure sensing and regulating means connected between the pumping chamber means and the pump outlet for sensing a pressure indicative of fluid pressure in the pumping chamber means and controlling the fluid pressure in the pumping chamber means as a function of the sensed pressure to maintain the fluid pressure in the pumping chamber means at least at a predetermined level even if pressure at the pump outlet is less than the predetermined level; wherein the pressure sensing and regulating means allows the fluid pressure in the pumping chamber means to equal the pressure at the pump outlet if the pressure at the pump outlet exceeds the predetermined level; and wherein the pressure sensing and regulating means comprises: a cylinder; a piston movable in the cylinder; flexible diaphragm means between the cylinder and the piston defining a pressure sensing chamber; valve means for occluding an outlet of the pressure sensing chamber as a function of the position of the piston.
Claim 7
Dependent Claim
20 words
The volumetric infusion pump of claim 4 wherein the pumping chamber means includes at least one rolling diaphragm pumping chamber.
Claim 8
Dependent Claim
30 words
The volumetric infusion pump of claim 4 and further comprising: linkage means for linking the valve means and the piston when the sensed pressure is less than the predetermined level.
Claim 9
Dependent Claim
119 words
The volumetric infusion pump of claim 6 wherein the linkage means comprises: a longitudinal slot in the piston; and arm means fixedly connected to the valve means and having a free end extending into the slot, wherein the arm engages one end of the slot and imparts force from the spring bias means to the valve means when pressure in the pressure sensing chamber is less than the predetermined level, and wherein a pressure in the pressure sensing chamber of greater than the predetermined level causes the piston to move to a position in which the end of the arm means is not engaging an end of the slot, thereby disconnecting the spring bias means and the valve means.
Claim 10
Dependent Claim
277 words
A volumetric infusion pump for pumping fluid from a reservoir to a patient, the volumetric infusion pump comprising: a pump inlet for connection to the reservoir; a pump outlet for connection to the patient; pumping chamber means connected in a fluid flow path between the pump inlet and the pump outlet; a pressure sensing chamber connected in the fluid flow path between the pumping chamber means and the pump outlet for receiving fluid from the pumping chamber means and including a cylinder and a piston movable in the cylinder as a function of fluid pressure of the fluid contained in the pressure sensing chamber, the fluid pressure of the fluid in the pressure sensing chamber being a function of the fluid pressure in the pumping chamber means; spring bias means for applying a force urging the piston in a direction which reduces the volume of the pressure sensing chamber, and wherein fluid pressure of the fluid contained in the pressure sensing chamber applies a force urging the piston in a direction which increases the volume of the pressure sensing chamber; and valve means positioned along the fluid flow path between the pressure sensing chamber and the pump outlet for occluding an outlet of the pressure sensing chamber as a function of the position of the piston to maintain the fluid pressure in the pumping chamber at least at a predetermined level even if pressure at the pump outlet is less than the predetermined level; and wherein the valve means allows the fluid pressure in the pumping chamber means to equal the pressure at the pump outlet if the pressure at the pump outlet exceeds the predetermined level.
Claim 11
Dependent Claim
277 words
A volumetric infusion pump for pumping fluid from a reservoir to a patient, the volumetric infusion pump comprising: a pump inlet for connection to the reservoir; a pump outlet for connection to the patient; pumping chamber means connected in a fluid flow path between the pump inlet and the pump outlet; a pressure sensing chamber connected in the fluid flow path between the pumping chamber means and the pump outlet for receiving fluid from the pumping chamber means and including a cylinder and a piston movable in the cylinder as a function of fluid pressure of the fluid contained in the pressure sensing chamber, the fluid pressure of the fluid in the pressure sensing chamber being a function of the fluid pressure in the pumping chamber means; spring bias means for applying a force urging the piston in a direction which reduces the volume of the pressure sensing chamber, and wherein fluid pressure of the fluid contained in the pressure sensing chamber applies a force urging the piston in a direction which increases the volume of the pressure sensing chamber; and valve means positioned along the fluid flow path between the pressure sensing chamber and the pump outlet for occluding an outlet of the pressure sensing chamber as a function of the position of the piston to maintain the fluid pressure in the pumping chamber at least at a predetermined level even if pressure at the pump outlet is less than the predetermined level; and wherein the valve means allows the fluid pressure in the pumping chamber means to equal the pressure at the pump outlet if the pressure at the pump outlet exceeds the predetermined level.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-03-29 | 1985-09-28 | 1986-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-29 | 1989-09-28 | 1990-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-29 | 1993-09-28 | 1994-03-30 | $7700.00 | Window Closed / Lapsed |