Linear pressurizing and depressurizing device

• US 4,587,974 A
• Filed: 11/13/1984
• Issued: 05/13/1986
• Est. Priority Date: 11/13/1984
• Status: Expired due to Term

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Norse Instruments
• Inventors: Link, William T.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Sykes, Angela D.
• Application Number:
  US06/670,213
• Time in Patent Office: 546 Days
• Field of Search: 128/672, 128/677, 128/680-683, 128/685, 128/686, 137/505, 137/505.11, 137/505.2, 137/505.21
• US Class Current: 600/498
• CPC Class Codes: A61B 5/0235 Valves specially adapted therefor
• CPC Class Codes: Y10T 137/7793 With opening bias [e.g., pressure regulator]

Abstract

Devices for and methods of pressurizing or depressurizing a particular pressurizable container or housing in a substantially linear, fixed manner independent of the pressurized volume of the container are disclosed herein. These devices are especially suitable in an arrangement for taking blood pressure in which a cuff wrapped around a body part of a patient is pressurized or alternatively depressurized to detect the patient'"'"'s systolic and diastolic pressures. The device acts on the cuff so that the latter is pressurized or depressurized in a substantially linear, fixed manner independent of the pressurized volume of the cuff, that is, independent of the size of the cuff.

Claims

1. In an arrangement for taking blood pressure in which a cuff wrapped around a body part of a patient is first pressurized to a given level and then depressurized sufficient to detect the patient'"'"'s systolic and diastolic pressures, the improvement comprising means acting on said cuff after the latter has been pressurized to said given level for causing it to depressurize in a substantially linear way independent of the pressurized volume of the cuff, said depressurizing means including;

a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm;

first means for placing said active and control chambers and said cuff in air-flow communication with one another whereby all three thereof are initially pressurized to said given level; and

second means cooperating with said diaphragm for placing said active chamber in air-flow communication with the ambient surroundings only as long as the pressure within said control chamber is at most greater than the pressure in said active chamber by a particular relatively small amount, said second means closing the air flow communication between said active chamber and ambient surroundings if the pressure within said control chamber is greater than the pressure with said active chamber by more than said particular amount.

2. The improvement according to claim 1 wherein said particular relatively small amount of pressure is on the order of 3 torr.

3. The improvement according to claim 1 wherein said depressurizing means includes means for changing the way in which said cuff is linearly depressurized.

4. The improvement according to claim 3 wherein said changing means includes means for changing the effective volume of said control chamber whereby the manner in which said cuff is linearly depressurized changes as a function thereof.

5. The improvement according to claim 4 wherein said volume changing means includes means for placing one of a plurality of different auxiliary chambers of varying sized in air-flow communication with said control chamber whereby the effective volume of said control chamber can be changed by changing the size of said auxiliary chamber.

6. In an arrangement for taking blood pressure in which a cuff wrapped around a body part of a patient is first pressurized to a given level and then depressurized sufficient to detect the patient'"'"'s systolic and diastolic pressures, a device configured to cooperate with said cuff for causing the latter to depressurize after it has been pressurized to a given level in a substantially linear, fixed manner independent of the pressurized volume of the cuff, said device comprising:

(a) a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm which is movable within said housing in predetermined ways responsive to the differences in pressure within said active and control chambers;

(b) an auxiliary container of fixed volume;

(c) an assembly of tubular means including a first tubular means for placing said control chamber and said auxiliary container in fluid communication with another, a second tubular means for placing said active chamber and said cuff in fluid communication with one another, and third tubular means for placing said active and control chambers in fluid communication with one another, said third tubular means including a flow constriction device having a constricted flow passage in the flow path between said chambers; and

(d) a separate tubular means extending through said housing between said active chamber and the ambient surroundings and cooperating with said diaphragm for placing said active chamber in air-flow communication with the ambient surroundings only so long as the pressure within said control chamber is at most greater than the pressure in said active chamber by a particular relatively small amount, said separate tubular means closing the air flow communication between said active chamber and ambient surroundings if the pressure within said control chamber is greater than the pressure within said active chamber by more than said particular amount, whereby the overall arrangement acts on said cuff, causing the latter to depressurize after it has been pressurized to a given level in a substantially linear, fixed manner independent of the pressurized volume of the cuff.

7. An arrangement comprising means acting on a container after the latter has been pressurized to a given level for causing it to depressurize in a substantially linear fixed manner, said depressurizing means including:

a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm;

first means for placing said active and control chambers and said container in air-flow communication with one another whereby all three thereof are initially pressurized to said given level; and

second means cooperating with said diaphragm for placing said active chamber in air-flow communication with the ambient surroundings only as long as the pressure within said control chamber is at most greater than the pressure in said active chamber by a particular relatively small amount, said second means closing the air flow communication between said active chamber and ambient surroundings if the pressure within said control chamber is greater than the pressure within said active chamber by more than said particular amount.

8. In an arrangement for taking blood pressure in which a cuff wrapped around a body part of a patient is first pressurized to a given level and then depressurized sufficient to detect the patient'"'"'s systolic and diastolic pressures, the improvement comprising means for pressurizing said cuff to said given level in a substantially linear, fixed manner, said pressurizing means including:

a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm;

first means for placing said active and control chambers and said cuff in air-flow communication with one another whereby all three thereof are initially maintained at ambient pressure; and

second means cooperating with said diaphragm for placing said active chamber in air-flow communication with a pump only as long as the pressure within said active chamber is at most greater than the pressure in said control chamber by a particular relatively small amount, said second closing the air flow communication between said active chamber and said pump means if the pressure within said active chamber is greater than the pressure within said control chamber by more than said particular amount.

9. An arrangement comprising means for pressurizing a container in a substantially linear fixed manner, said pressurizing means including:

a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm;

first means for placing said active and control chambers and said container in air-flow communication with one another whereby all three thereof are initially maintained at ambient pressure; and

second means cooperating with said diaphragm for placing said active chamber in air-flow communication with a pump only as long as the pressure within said active chamber is at most greater than the pressure in said control chamber by a particular relatively small amount, said second means closing the air-flow communication between said active chamber and said pump if the pressure within said active chamber is greater than the pressure within said control chamber by more than said particular amount.

10. In an arrangement for taking blood pressure in which a cuff wrapped around a body part of a patient is first pressurized to a given level and then depressurized sufficient to detect the patient'"'"'s systolic and diastolic pressures, a device configured to cooperate with said cuff for causing the latter to depressurize after it has been pressurized to a given level in a substantially linear, fixed manner independent of the pressurized volume of the cuff, said device comprising:

(a) a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm which is movable within said housing in predetermined ways responsive to the differences in pressure within said active and control chambers;

(b) means for placing said active chamber and said cuff in fluid communication with one another;

(c) means for placing said active and control chambers in fluid communication with one another, said last-mentioned means including a constricted flow passage in the flow path between said chambers; and

(d) means cooperating with said diaphragm for placing said active chamber in air-flow communication with the ambient surroundings only so long as the pressure within said control chamber is at most greater than the pressure in said active chamber by a particular relatively small amount, said last-mentioned means closing air flow communication between said active chamber and ambient surroundings if the pressure within said control chamber is greater than the pressure within said active chamber by more than said particular amount, whereby the overall arrangement acts on said cuff for causing the latter to depressurize after it has ben pressurized to a given level in a substantially linear, fixed manner independent of the pressurized volume of the cuff.

11. In an arrangement for taking blood pressure in which a cuff wrapped around a body part of a patient is first pressurized to a given level and then depressurized sufficient to detect the patient'"'"'s systolic and diastolic pressures, a device configured to cooperate with said cuff for causing the latter to pressurize to a given level in a substantially linear, fixed manner independent of the pressurized volume of the cuff, said device comprising:

(a) a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm which is movable within said housing in predetermined ways responsive to the differences in pressure within said active and control chambers;

(b) an auxiliary container of fixed volume;

(c) an assembly of tubular means including a first tubular means for placing said control chamber and said auxiliary container in fluid communication with another, a second tubular means for placing said active chamber and said cuff in fluid communication with one another and third tubular means for placing said active and control chambers in fluid communication with one another, said third tubular means including a flow constriction device having a constricted flow passage in the flow path between said chambers; and

(d) means cooperating with said diaphragm for placing said active chamber in air-flow communication with a pump only so long as the pressure within said active chamber is at most greater than the pressure in said control chamber by a particular relatively small amount, said last-mentioned means closing air flow communication between said active chamber and said pump if the pressure within said active chamber is greater than the pressure within said control chamber by more than said particular amount, whereby the overall arrangement acts on said cuff for causing the latter to pressurize in a substantially linear, fixed manner independent of the pressurized volume of the cuff.

12. In an arrangement for taking blood pressure in which a cuff wrapped around a body part of a patient is first pressurized to a given level and then depressurized sufficient to detect the patient'"'"'s systolic and diastolic pressures, a device configured to cooperate with said cuff for causing the latter to pressurize to a given level in a substantially linear, fixed manner independent of the pressurized volume of the cuff, said device comprising:

(a) a housing defining adjacent internal active and control pressure chambers separated from one another in an air sealed manner by a diaphragm which is movable within sealed housing in predetermined ways responsive to the differences in pressure within said active and control chambers;

(b) first means for placing said active chamber and said cuff in fluid communication with one another;

(c) means for placing said active and control chambers in fluid communication with one another, said last-mentioned means including a constricted flow passage in the flow path between said chambers; and

(d) means cooperating with said diaphragm for placing said active chamber in air-flow communication with a pump only so long as the pressure within said active chamber is at most greater than the pressure in said control chamber by a particular relatively small amount, said last-mentioned closing air flow communication between said active chamber and said pump if the pressure within said active chamber is greater than the pressure within said control chamber by more than said particular amount, whereby the overall arrangement acts on said cuff for causing the latter to pressurize in a substantially linear, fixed manner independent of the pressurized volume of the cuff.