METHOD FOR AUTOMATIC CONTINUOUS MEASURING AND RECORDING OF BLOOD PRESSURE AND ARRANGEMENTS FOR EXECUTING SAID METHOD

• US 3,585,987 A
• Filed: 08/05/1968
• Issued: 06/22/1971
• Est. Priority Date: 08/11/1967
• Status: Expired due to Term

• Current Assignee: Svensson Arne Bejert
• Original Assignee: Svensson Arne Bejert
• Inventors: SVENSSON ARNE BEJERT
• Application Number:
  US04/750,320
• Time in Patent Office: 1,051 Days
• US Class Current: 600/485
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval

Abstract

A method of automatic, continuous measurement and recording of blood pressure, by means of a blood pressure cuff, in e of a pressure externally applied by means of the cuff automatically is maintained substantially at an intended level. A signal determined by the relationship between the systolic pressure and the cuff pressure actuates the cuff pressure in such a way that when the relationship is altered, this alteration is counteracted by means of a raising or a lowering of the cuff pressure.

Claims

1. In a method of automatic, continuous measurement and recording of blood pressure by a blood pressure cuff surrounding one of a patient'"'"''"'"'s limbs wherein the size of a pressure externally applied by the cuff and approximately corresponding to the systolic pressure of a blood vessel automatically is kept close to the systolic pressure, the improvement comprising:

the steps of generating a first signal by a sensing means that is dependent on the difference between the systolic pressure and the cuff pressure, generating a second signal dependent on a reference pressure and essentially independent of the cuff pressure, comparing said first signal with said second signal, and adjusting the cuff pressure in response to the comparison of the first and second signals to maintain the cuff pressure somewhat below the systolic pressure.

2. A method according to claim 1, wherein the second signal is essentially proportional to the existing pulse pressure.

3. A method according to claim 1, wherein said reference pressure has a predetermined fixed value.

4. A method according to claim 1, wherein the adjusting of the cuff pressure is carried out at a speed amounting to a maximum of 5 mm. Hg. per second.

5. A device for carrying out the method according to claim 1, comprising a blood pressure cuff, a sensor positioned at the cuff, an instrument connected to the cuff for indicating and recording the pressure of the cuff, an amplifying and rectifying transfer mechanism connected to and actuated by said sensor, means connected to said cuff for regulating the cuff pressure, said regulating means being connected to and controlled by said transfer mechanism, and a second sensor connected to the transfer mEchanism, said second sensor being arranged in the cuff and being essentially independent of the cuff pressure.

6. A device according to claim 5, further comprising a signal generator, the outgoing signal of which is adjustable and independent of the pressure existing in the cuff and the blood vessel, and means are provided for connecting said second sensor or said signal generator to the transfer mechanism.

7. A device according to claim 5, wherein the means regulating the pressure of the cuff comprises a pump assembly, and a motor driving said pump assembly.

8. A device according to claim 5, wherein the means regulating the pressure of the cuff comprises an electrically driven pump assembly having a container of variable volume.

9. A device according to claim 7, wherein the indicating and recording instrument is provided with pressure sensitive paper and a manometer having a movable manometer arm which is adapted to press upon the pressure sensitive paper, the frequency of pressure movements of said arm being proportional to the speed of the motor driving the pump assembly.

10. A device according to claim 7, wherein the indicating and recording instrument is provided with pressure sensitive paper and a manometer having a movable manometer arm pressing upon the pressure sensitive paper, the frequency of pressure movements of said arm being proportional to the speed of the motor driving the pump assembly, and wherein means are provided for pressing said manometer arm against the pressure sensitive paper at regular time intervals.

11. A device according to claim 7, wherein the indicating and recording instrument is provided with pressure sensitive paper and a manometer having a movable manometer arm pressing upon the pressure sensitive paper, the frequency of pressure movements of said arm being proportional to the speed of the motor driving the pump assembly, and wherein means are provided for pressing said manometer arm against the pressure sensitive paper when the motor is at a stand still.