Method and device for monitoring blood pressure

• US 6,918,879 B2
• Filed: 07/09/2002
• Issued: 07/19/2005
• Est. Priority Date: 10/09/2000
• Status: Expired due to Term

• Current Assignee: HealthSTATS International Pte Ltd.
• Original Assignee: HealthSTATS International Pte Ltd.
• Inventors: Ting, Choon Meng, Chua, Ngak Hwee
• Primary Examiner(s): Nasser, Robert L.
• Assistant Examiner(s): Mallari, Patricia C.
• Application Number:
  US10/191,887
• Publication Number:
  US 20030004421A1
• Time in Patent Office: 1,106 Days
• Field of Search: 600/485, 600/490, 600500-507
• US Class Current: 600/485
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/681 Wristwatch-type devices

Abstract

A device for continuously monitoring a user'"'"'s arterial blood pressure has a sensor adapted to continuously detect the blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery. The sensor is securely held in operable contact with the user'"'"'s body at the location. A microprocessor interprets the signals generated by the sensor to determine the actual arterial blood pressure. The sensor includes a projecting portion for detecting and transmitting changes in blood pressure, wherein the projecting portion is adapted to effect at least partial occlusion of the artery at the location.

Claims

1. A device for non-invasive continuous monitoring of a user'"'"'s arterial blood pressure that is capable of being used as an ambulatory beat-to-beat blood pressure monitor (ABMP) including,

sensing means adapted to continuously detect said blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery;

microprocessing means for interpreting said signals generated by the sensing means to determine actual arterial blood pressure;

wherein the microprocessing means is programmed to;

record a complete and continuous arterial pulse waveform,

detect at least the dicrotic notch and the diastolic trough within a continuous arterial pulse waveform,

calculate a mean diastolic pressure as the mean sensed pressure between said detected dicrotic notch and the immediately following diastolic trough,

calculate a mean arterial pressure as the average pressure between two consecutive said diastolic troughs, and

calculate a mean diastolic pressure index as the quotient of the calculated mean diastolic pressure divided by the mean arterial pressure.

2. A device for non-invasive continuous monitoring of a user'"'"'s arterial blood pressure that is capable of being used as an ambulatory beat-to-beat blood pressure monitor (ABMP) including,

sensing means adapted to continuously detect said blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery;

microprocessing means for interpreting said signals generated by the sensing means to determine actual arterial blood pressure;

wherein the microprocessing means is programmed to;

record a complete and continuous arterial pulse waveform,

detect at least the dicrotic notch and the diastolic trough within a continuous arterial pulse waveform, and

calculate a mean systolic pressure as the average pressure between the diastolic trough and the immediately subsequent dicrotic notch.

3. A device for non-invasive continuous monitoring of a user'"'"'s arterial blood pressure that is capable of being used as an ambulatory beat-to-beat blood pressure monitor (ABMP) including,

sensing means adapted to continuously detect said blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery;

microprocessing means for interpreting said signals generated by the sensing means to determine actual arterial blood pressure;

wherein the microprocessing means is programmed to;

record a complete and continuous arterial pulse waveform,

detect at least the dicrotic notch and the diastolic trough within a continuous arterial pulse waveform,

calculate a mean diastolic pressure as the mean sensed pressure between said detected dicrotic notch and the immediately following diastolic trough,

calculate a mean arterial pressure as the average pressure between two consecutive said diastolic troughs, and

calculate a mean systolic pressure index as the quotient of the calculated mean systolic pressure divided by the mean arterial pressure.

4. A device for non-invasive continuous monitoring of a user'"'"'s arterial blood pressure that is capable of being used as an ambulatory beat-to-beat blood pressure monitor (ABMP) including,

sensing means adapted to continuously detect said blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery;

microprocessing means for interpreting said signals generated by the sensing means to determine actual arterial blood pressure;

wherein the microprocessing means is programmed to;

record a complete and continuous arterial pulse waveform;

detect the peak systolic pressure and record the peak systolic pressure for at least a selection of recorded arterial pulses, and

detect the diastolic trough and record a pressure at the diastolic trough for each pulse of said at least selection of arterial pulses.

5. A device as claimed in claim 4 wherein said device includes an alarm and said microprocessing means is programmed to operate said alarm in response to an indicator falling outside a preselected range, said indicator being selected from:

said systolic peak pressure, said diastolic trough pressure or the difference between said systolic peak pressure.

6. A device as claimed in claim 5 wherein said device includes user input means, and said microprocessing means is programmed to allow setting or selection of a threshold for said indicator.

7. A device as claimed in claim 6 wherein said microprocessing means is programmed to calculate an average systolic pressure as the average of the pressure as recorded at said systolic peak for said at least selection of arterial pulses and an average diastolic pressure as the average pressure recorded at said diastolic trough for said at least selection of arterial pulses.

8. A device for non-invasive continuous monitoring of a user'"'"'s arterial blood pressure that is capable of being used as an ambulatory beat-to-beat blood pressure monitor (ABMP) including,

sensing means adapted to continuously detect said blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery;

microprocessing means for interpreting said signals generated by the sensing means to determine actual arterial blood pressure, wherein the microprocessing means is programmed to record a complete and continuous arterial pulse waveform;

a first housing holding said sensor sensing means;

a second housing enclosing said microprocessing means; and

at least one strap connecting said first housing and said second housing and together therewith forming a band to encircle the wrist of a wearer, said first housing having an outwardly facing pressure surface, with at least one said strap passing freely over said pressure surface.

9. A device for non-invasive continuous monitoring of a user'"'"'s arterial blood pressure that is capable of being used as an ambulatory beat-to-beat blood pressure monitor (ABMP) including,

sensing means adapted to continuously detect said blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery;

microprocessing means for interpreting said signals generated by the sensing means to determine actual arterial blood pressure, wherein the microprocessing means is programmed to record a complete and continuous arterial pulse waveform;

a first housing holding said sensing means;

a second housing enclosing said microprocessing means; and

at least one strap connecting said first housing and said second housing and together therewith forming a band to encircle the wrist'"'"'of a wearer, said first housing having an outwardly facing pressure surface, with at least one said strap being an elastic strap passing freely over said pressure surface;

wherein said at least one strap includes a second strap connecting between said first and second housing and a third strap connected with said second housing and said elastic strap, said elastic strap being connected at one end to said first housing, extending from there to said third strap before turning back upon itself to form a loop, said loop being connected to said third strap, to then pass over said pressing surfaces of said first housing, with the other end of said elastic strap being connected to said second housing or to said second strap.

10. A device as claimed in claim 9 including a joining ring, said elastic strap passing through said joining ring at said loop, and said third strap passing through said joining ring and back upon itself to have inner and outer portions and to hold said joining ring within a loop thereof, said third strap including adjustable connection means operating between said inner and outer portions.

11. A device for non-invasive continuous monitoring of a user'"'"'s arterial blood pressure that is capable of being used as an ambulatory beat-to-beat blood pressure monitor (ABMP) including,

sensing means adapted to continuously detect said blood pressure and to generate signals representative thereof by contact with an external surface of the user'"'"'s body at a location adjacent an artery;

microprocessing means for interpreting said signals generated by the sensing means to determine actual arterial blood pressure wherein the microprocessing means is programmed to record a complete and continuous arterial pulse waveform;

a first housing holding said sensing means;

a second housing enclosing said microprocessing means;

at least one strap connecting said first housing and said second housing and together therewith forming a band to encircle the wrist of a wearer, said first housing having an outwardly facing pressure surface, with at least one said strap passing freely over said pressure surface; and

a padding cuff disposed within said band, said padding cuff including an aperature, said sensor including a plunger protruding from said first housing through said aperture, and said cuff being adhered to an inner face of said first housing.

12. A method for continuous monitoring of a user'"'"'s arterial blood pressure including the steps of:

recording a complete and continuous arterial pulse pressure waveform,

locating at least the dicrotic notch and the diastolic trough within said continuous arterial pulse waveform, and

calculating at least one parameter using said waveform and said diastolic trough and dicrotic notch locations including calculating a mean diastolic pressure as the mean recorded pressure between a said detected dicrotic notch and the immediately following diastolic trough and including calculating a mean arterial pressure as the average pressure between two consecutive said diastolic troughs, and calculating a mean diastolic pressure index as the quotient of the calculated mean diastolic pressure divided by the mean arterial pressure.

13. A method as claimed in claim 12 including calculating a mean systolic pressure as the average pressure between a diastolic trough and the immediately subsequent dicrotic notch.

14. A method as claimed in claim 13 including calculating a mean arterial pressure as the average pressure between two consecutive diastolic troughs, and calculating a mean systolic pressure index as the quotient of the calculated mean systolic pressure divided by the mean arterial pressure.