WO2006024871A1 - Methods and apparatus for the measurement of blood pressure - Google Patents

Methods and apparatus for the measurement of blood pressure Download PDF

Info

Publication number
WO2006024871A1
WO2006024871A1 PCT/GB2005/003409 GB2005003409W WO2006024871A1 WO 2006024871 A1 WO2006024871 A1 WO 2006024871A1 GB 2005003409 W GB2005003409 W GB 2005003409W WO 2006024871 A1 WO2006024871 A1 WO 2006024871A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
arterial
brachial
cuff pressure
cuff
Prior art date
Application number
PCT/GB2005/003409
Other languages
French (fr)
Inventor
Phil Chowienczyk
Sally Brett
Original Assignee
King's College London
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by King's College London filed Critical King's College London
Publication of WO2006024871A1 publication Critical patent/WO2006024871A1/en

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/021—Measuring pressure in heart or blood vessels
    • A61B5/022—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers

Definitions

  • This invention relates to the measurement of blood pressure and is directed to the provision of methods and apparatus of improved accuracy in the determination of blood pressure of patients especially during high cardiac output states, including exercise and pregnancy.
  • Exercise diastolic pressure may be influenced by endothelial function; exercise systolic pressure by endothelial function and large artery stiffness.
  • Mercury sphygmomanometry requires a trained observer and is becoming obsolete due to the requirement to phase out mercury based devices. Many automated methods for measuring blood pressure are available but these are of limited accuracy in high cardiac output states.
  • the present invention provides an automatic, objective and mercury free measurement of blood pressure that may be particularly important in high cardiac output states.
  • the method involves a novel approach combining the application of pressure and measurement of pressure to/within a cuff applied to the upper arm and around the brachial artery (brachial cuff) and the non ⁇ invasive recording of pressure fluctuations distal to the brachial cuff (i.e., at any position between the brachial cuff and the tips of the fingers).
  • the present invention provides apparatus comprising a combination of a brachial cuff and a non-invasive arterial pressure detector operatively connected to means for recording the effect of varying cuff pressure on the arterial pulse.
  • the apparatus of the present invention comprises 3 distinct components, namely a brachial cuff, a non-invasive arterial pressure detector and means for recording.
  • the brachial cuff and the non-invasive arterial pressure detector are operatively connected to the recording means.
  • the brachial cuff and the non-invasive arterial pressure detector may be connected to the recording means by any suitable connection, for example, wires or via a radio signal.
  • the brachial cuff may be any suitable brachial cuff known to those skilled in the art.
  • the non-invasive arterial pressure detector can be any suitable arterial pressure detector.
  • a preferred arterial pressure detector is an arterial tonometer.
  • Radial artery tonometry generally comprises the application of a piezo electric pressure sensor over the radial artery, and thereby provides a non-invasive means of obtaining a high fidelity arterial pressure waveform.
  • a number of instruments are commercially available. In the specific example of the invention described herein a Colin 7000 (Colin medical instrumentation corporation, USA) was used. This device applies a tonometer using a servo-controlled wrist strap and provides a continuous radial artery waveform.
  • Another preferred arterial pressure detector is a blood pressure cuff placed distal to the brachial cuff.
  • a further preferred arterial pressure detector that can be used is a photoplethysmograph.
  • a photoplethysmograph can be used to optically measure the movement of the arterial wall which is proportional to pressure.
  • the arterial pressure detector can be positioned anywhere distal to the brachial cuff (i.e., at any position between the brachial cuff and the tips of the fingers).
  • the preferred position of the arterial pressure detector will depend on the type of detector being used. For example, when the arterial pressure detector is a tonometer, it is preferably positioned around the wrist. When the arterial pressure detector is a photoplethysmograph it is preferably positioned to enable measurement of the radial artery.
  • the means for recording the effects of varying cuff pressure on the arterial pulse of an individual can be any suitable means. Preferably, the means for recording comprises a visual display system.
  • the means for recording also controls brachial cuff pressure and processes the data from the cuff and from the arterial pressure detector in order to calculate diastolic blood pressure, and preferably the systolic blood pressure, of an individual.
  • the diastolic and systolic blood pressures may be calculated by software using the methods described below.
  • the means for recording is preferably a computer that can display the calculated blood pressures in a suitable form.
  • the present invention also provides a method of measuring diastolic blood pressure of an individual, using the apparatus of the present invention comprising measuring the arterial pulse and brachial cuff pressure, determining the brachial cuff pressure at which the amplitude of the normal arterial pressure signal starts to decrease.
  • the amplitude of the normal arterial pressure signal is the amplitude when the brachial cuff does not apply any pressure to the brachial artery of the individual.
  • the oscillation from the arterial pressure detector placed distal to the brachial cuff start to decrease in amplitude (the difference between the maximum and minimum values within one cardiac cycle decrease).
  • the amplitude is monitored on a cycle by cycle basis.
  • pressure in the brachial cuff is taken as diastolic blood pressure.
  • the amplitude of pressure oscillations detected by the pressure sensor becomes substantially zero, pressure in the brachial cuff is taken as systolic blood pressure.
  • the method of measuring diastolic blood pressure comprises measuring the arterial pulse and brachial cuff pressure, increasing the brachial cuff pressure and recording the brachial cuff pressure at which the amplitude of the arterial pressure signal starts to decrease.
  • the brachial cuff pressure recorded is then considered to be the diastolic blood pressure.
  • the method of measuring diastolic blood pressure preferably comprises measuring the arterial pulse and brachial cuff pressure, increasing the brachial cuff pressure so that the amplitude of the arterial pressure signal starts to decrease and then slowly reducing the cuff pressure and recording the point at which the initial amplitude of the arterial pulse is restored.
  • the brachial cuff pressure recorded is then considered to be the diastolic blood pressure.
  • the present invention also provides a method of measuring systolic blood pressure of an individual, using the apparatus of the present invention comprising measuring the arterial pulse and brachial cuff pressure and determining the brachial cuff pressure at which the oscillations of the arterial signal are abolished.
  • the method of measuring systolic blood pressure comprises measuring the arterial pulse and brachial cuff pressure, and increasing brachial cuff pressure to identify the cuff pressure at which the oscillations of the arterial signal are abolished.
  • the identified brachial cuff pressure is considered to be the systolic blood pressure.
  • the method of measuring systolic blood pressure comprises measuring the arterial pulse and brachial cuff pressure, wherein the brachial cuff pressure is increased to abolish the oscillations of the arterial signal, and then decreasing the brachial cuff pressure to identify the cuff pressure at which the oscillations of the arterial signal re-appear.
  • the brachial cuff pressure identified is considered to be the systolic blood pressure.
  • Figure IA shows schematically apparatus for determining blood pressure by the method of the present invention.
  • a wrist tonometer (1) is used to obtain a non-invasive recording of a signal that closely follows pressure in the radial artery.
  • a brachial blood pressure cuff (2) is inflated to modulate the signal from the tonometer (1).
  • a control and processing unit (3) controls cuff pressure, reads cuff pressure and the tonometer signal and calculates diastolic and systolic blood pressure during inflation of the brachial cuff (2) according to set algorithms.
  • Figure IB shows schematically the control and processing unit (3).
  • Figure 2 shows a graph of the tonometer signal and the brachial cuff pressure.
  • the amplitude of the tonometer signal starts to decrease when cuff pressure equals diastolic blood pressure (A) and oscillations in the tonometer trace are obliterated when cuff pressure equals systolic blood pressure (B).
  • Figure 3 shows a graph of the tonometer signal and the brachial cuff pressure, wherein the method has been modified for more accurate but equally rapid determination of diastolic blood pressure.
  • Cuff pressure is increased rapidly until the amplitude of the tonometer signals starts to decrease (A). It is then decreased slowly until the amplitude returns to previous values (B). This occurs when cuff pressure equals diastolic blood pressure.
  • a similar modification can be applied to the determination of systolic blood pressure.
  • Tonometry (even when calibrated by reference to a standard cuff method) cannot be used to determine diastolic and systolic blood pressure due to drift of the pressure signal over the course of several tens of seconds due to movement artefact. Thus, although pressure is faithfully reproduced over a single or a few cardiac cycles, longer term measurements are inaccurate especially during exercise. To overcome this we have combined simultaneous cuff inflation with radial artery tonometry, "cuff- tonometry" as shown in Figure IA and IB.
  • the Colin 7000 tonometer (1) is positioned around the wrist of an individual so that the arterial pulse can be measured.
  • a brachial cuff (2) is positioned around the upper arm of the individual in accordance with standard procedures.
  • Both the tonometer and the brachial cuff are connected to control and processing unit (3).
  • the control and processing unit (3) controls cuff pressure, and reads cuff pressure and the tonometer signal.
  • the radial tonometry signal is continually monitored during cuff inflation. At the instant when cuff pressure exceeds diastolic pressure the amplitude of the tonometer signal decreases abruptly as shown in Figure 2. With increasing cuff pressure there is a progressive decrease in amplitude of the tonometer signal until, when cuff pressure reaches systolic pressure, the oscillations in the tonometer signal are obliterated: the signal remains constant over the whole cardiac cycle ( Figure 2). By simultaneously displaying cuff pressure and the tonometer signal diastolic and systolic pressure can be determined.
  • Diastolic pressure is the cuff pressure at the point at which the amplitude of the tonometer signal starts to change, systolic pressure cuff pressure at the point at which oscillations in the tonometer signal are obliterated.
  • Various modifications to this method are possible to improve its accuracy and ease of use:
  • the above method can be applied using a relatively rapid rate of cuff inflation. This allows approximate determination of systolic and diastolic blood pressure. The method can then be repeated using a slower rate of inflation when pressure is close to diastolic and systolic pressure. This will provide a more accurate determination of systolic and diastolic blood pressure.
  • the brachial cuff can be rapidly inflated until there is a decrease in tonometer amplitude. It can then be slowly deflated with subsequent increase in tonometer amplitude until the amplitude becomes similar to that before cuff inflation. This allows diastolic pressure to be accurately determined as the cuff pressure at which the amplitude of tonometer oscillations starts to change as shown in Figure 3. Similarly, to determine systolic blood pressure, the cuff can be rapidly inflated until tonometer oscillations are obliterated. It can then be slowly deflated until oscillations return. This allows systolic pressure to be accurately determined as the cuff pressure at which tonometer oscillations change from being present to being obliterated.
  • diastolic and systolic pressure may be automatically calculated using analogue to digital conversion of these signals and a software algorithm.
  • the most basic algorithm consists of monitoring the amplitude of the tonometer signal during inflation of the brachial cuff.
  • Diastolic blood pressure is taken as brachial cuff pressure at the time when the amplitude decreases by an amount that exceeds a threshold Ai (dependent on the rate of brachial cuff inflation).
  • Systolic pressure is taken as brachial cuff pressure at the time when the amplitude of the tonometer signal decreases below a second threshold A 2 (again dependent on the rate of brachial cuff inflation).
  • CT Cod Occlusion Tonometry
  • DBP mean difference 2.2 mmHg 1.2 mmHg SD 2.8 mmHg 2.1 mmHg
  • DBP mean difference -0.3 mmHg 1.3 mmHg SD 3.7 mmHg 6.3 mmHg
  • SBP Systolic blood pressure
  • DBP Diastolic blood pressure

Abstract

This invention relates to the measurement of blood pressure and is directed to the provision of methods and apparatus of improved accuracy in the determination of blood pressure of patients especially during high cardiac output states, including exercise and pregnancy. The apparatus comprising the combination of a brachial cuff and a non-invasive arterial pressure detector operatively connected to means for recording the effect of varying cuff pressure on the arterial pulse.

Description

Methods and apparatus for the measurement of blood pressure
This invention relates to the measurement of blood pressure and is directed to the provision of methods and apparatus of improved accuracy in the determination of blood pressure of patients especially during high cardiac output states, including exercise and pregnancy.
Existing methods for measuring blood pressure other than mercury sphygmomanometry perform poorly in high cardiac output states. The most important of high cardiac output states occur in pregnancy, during exercise and in critical illness (septic shock). Blood pressure is closely monitored in pregnancy to screen for pre-eclampsia (a condition characterised by hypertension and proteinuria). There is also a requirement to monitor blood pressure during clinical exercise testing, a widely used procedure for screening for the presence of ischaemic heart disease. Exercise blood pressure may be a better predictor of cardiovascular risk than resting blood pressure, because it is more strongly influenced by characteristics of arterial structure and function that determine cardiovascular risk. Exercise diastolic pressure may be influenced by endothelial function; exercise systolic pressure by endothelial function and large artery stiffness. Mercury sphygmomanometry requires a trained observer and is becoming obsolete due to the requirement to phase out mercury based devices. Many automated methods for measuring blood pressure are available but these are of limited accuracy in high cardiac output states.
The present invention provides an automatic, objective and mercury free measurement of blood pressure that may be particularly important in high cardiac output states. The method involves a novel approach combining the application of pressure and measurement of pressure to/within a cuff applied to the upper arm and around the brachial artery (brachial cuff) and the non¬ invasive recording of pressure fluctuations distal to the brachial cuff (i.e., at any position between the brachial cuff and the tips of the fingers).
In particular, the present invention provides apparatus comprising a combination of a brachial cuff and a non-invasive arterial pressure detector operatively connected to means for recording the effect of varying cuff pressure on the arterial pulse.
It has been found that by using the combination of a brachial cuff and a non-invasive arterial pressure detector it is possible to accurately and easily determine the diastolic blood pressure of an individual. It is also possible to additionally determine the systolic blood pressure of the individual using the apparatus of the present invention enabling the blood pressure of the individual to be accurately and easily determined even during high cardiac output states.
The apparatus of the present invention comprises 3 distinct components, namely a brachial cuff, a non-invasive arterial pressure detector and means for recording. The brachial cuff and the non-invasive arterial pressure detector are operatively connected to the recording means. Accordingly, the brachial cuff and the non-invasive arterial pressure detector may be connected to the recording means by any suitable connection, for example, wires or via a radio signal.
The brachial cuff may be any suitable brachial cuff known to those skilled in the art.
The non-invasive arterial pressure detector can be any suitable arterial pressure detector. A preferred arterial pressure detector is an arterial tonometer. Radial artery tonometry generally comprises the application of a piezo electric pressure sensor over the radial artery, and thereby provides a non-invasive means of obtaining a high fidelity arterial pressure waveform. A number of instruments are commercially available. In the specific example of the invention described herein a Colin 7000 (Colin medical instrumentation corporation, USA) was used. This device applies a tonometer using a servo-controlled wrist strap and provides a continuous radial artery waveform. Another preferred arterial pressure detector is a blood pressure cuff placed distal to the brachial cuff. Pressure within this blood pressure cuff is increased to a pressure similar to mean arterial blood pressure. Low amplitude oscillations in the pressure are then proportional to arterial pressure. A further preferred arterial pressure detector that can be used is a photoplethysmograph. A photoplethysmograph can be used to optically measure the movement of the arterial wall which is proportional to pressure.
The arterial pressure detector can be positioned anywhere distal to the brachial cuff (i.e., at any position between the brachial cuff and the tips of the fingers). The preferred position of the arterial pressure detector will depend on the type of detector being used. For example, when the arterial pressure detector is a tonometer, it is preferably positioned around the wrist. When the arterial pressure detector is a photoplethysmograph it is preferably positioned to enable measurement of the radial artery. The means for recording the effects of varying cuff pressure on the arterial pulse of an individual can be any suitable means. Preferably, the means for recording comprises a visual display system. It is also preferably that the means for recording also controls brachial cuff pressure and processes the data from the cuff and from the arterial pressure detector in order to calculate diastolic blood pressure, and preferably the systolic blood pressure, of an individual. The diastolic and systolic blood pressures may be calculated by software using the methods described below.
The means for recording is preferably a computer that can display the calculated blood pressures in a suitable form.
The present invention also provides a method of measuring diastolic blood pressure of an individual, using the apparatus of the present invention comprising measuring the arterial pulse and brachial cuff pressure, determining the brachial cuff pressure at which the amplitude of the normal arterial pressure signal starts to decrease. The amplitude of the normal arterial pressure signal is the amplitude when the brachial cuff does not apply any pressure to the brachial artery of the individual.
During brachial cuff inflation, the oscillation from the arterial pressure detector placed distal to the brachial cuff start to decrease in amplitude (the difference between the maximum and minimum values within one cardiac cycle decrease). Preferably, the amplitude is monitored on a cycle by cycle basis. When amplitude decreases compared to the amplitude of the preceding cycle, pressure in the brachial cuff is taken as diastolic blood pressure. When, during continued inflation of the brachial cuff, the amplitude of pressure oscillations detected by the pressure sensor becomes substantially zero, pressure in the brachial cuff is taken as systolic blood pressure.
Preferably the method of measuring diastolic blood pressure comprises measuring the arterial pulse and brachial cuff pressure, increasing the brachial cuff pressure and recording the brachial cuff pressure at which the amplitude of the arterial pressure signal starts to decrease. The brachial cuff pressure recorded is then considered to be the diastolic blood pressure.
In an alternative embodiment, the method of measuring diastolic blood pressure preferably comprises measuring the arterial pulse and brachial cuff pressure, increasing the brachial cuff pressure so that the amplitude of the arterial pressure signal starts to decrease and then slowly reducing the cuff pressure and recording the point at which the initial amplitude of the arterial pulse is restored. The brachial cuff pressure recorded is then considered to be the diastolic blood pressure.
The present invention also provides a method of measuring systolic blood pressure of an individual, using the apparatus of the present invention comprising measuring the arterial pulse and brachial cuff pressure and determining the brachial cuff pressure at which the oscillations of the arterial signal are abolished.
Preferably, the method of measuring systolic blood pressure comprises measuring the arterial pulse and brachial cuff pressure, and increasing brachial cuff pressure to identify the cuff pressure at which the oscillations of the arterial signal are abolished. The identified brachial cuff pressure is considered to be the systolic blood pressure.
In an alternative embodiment, the method of measuring systolic blood pressure comprises measuring the arterial pulse and brachial cuff pressure, wherein the brachial cuff pressure is increased to abolish the oscillations of the arterial signal, and then decreasing the brachial cuff pressure to identify the cuff pressure at which the oscillations of the arterial signal re-appear. The brachial cuff pressure identified is considered to be the systolic blood pressure.
The method and apparatus are hereinafter described by way of example only with reference to the following Figures.
Figure IA shows schematically apparatus for determining blood pressure by the method of the present invention. A wrist tonometer (1) is used to obtain a non-invasive recording of a signal that closely follows pressure in the radial artery. A brachial blood pressure cuff (2) is inflated to modulate the signal from the tonometer (1). A control and processing unit (3) controls cuff pressure, reads cuff pressure and the tonometer signal and calculates diastolic and systolic blood pressure during inflation of the brachial cuff (2) according to set algorithms.
Figure IB shows schematically the control and processing unit (3). Figure 2 shows a graph of the tonometer signal and the brachial cuff pressure. During brachial cuff inflation the amplitude of the tonometer signal starts to decrease when cuff pressure equals diastolic blood pressure (A) and oscillations in the tonometer trace are obliterated when cuff pressure equals systolic blood pressure (B).
Figure 3 shows a graph of the tonometer signal and the brachial cuff pressure, wherein the method has been modified for more accurate but equally rapid determination of diastolic blood pressure. Cuff pressure is increased rapidly until the amplitude of the tonometer signals starts to decrease (A). It is then decreased slowly until the amplitude returns to previous values (B). This occurs when cuff pressure equals diastolic blood pressure. A similar modification can be applied to the determination of systolic blood pressure.
EXAMPLES
Tonometry (even when calibrated by reference to a standard cuff method) cannot be used to determine diastolic and systolic blood pressure due to drift of the pressure signal over the course of several tens of seconds due to movement artefact. Thus, although pressure is faithfully reproduced over a single or a few cardiac cycles, longer term measurements are inaccurate especially during exercise. To overcome this we have combined simultaneous cuff inflation with radial artery tonometry, "cuff- tonometry" as shown in Figure IA and IB.
As shown in Figure IA the Colin 7000 tonometer (1) is positioned around the wrist of an individual so that the arterial pulse can be measured. A brachial cuff (2) is positioned around the upper arm of the individual in accordance with standard procedures. Both the tonometer and the brachial cuff are connected to control and processing unit (3). The control and processing unit (3) controls cuff pressure, and reads cuff pressure and the tonometer signal.
The radial tonometry signal is continually monitored during cuff inflation. At the instant when cuff pressure exceeds diastolic pressure the amplitude of the tonometer signal decreases abruptly as shown in Figure 2. With increasing cuff pressure there is a progressive decrease in amplitude of the tonometer signal until, when cuff pressure reaches systolic pressure, the oscillations in the tonometer signal are obliterated: the signal remains constant over the whole cardiac cycle (Figure 2). By simultaneously displaying cuff pressure and the tonometer signal diastolic and systolic pressure can be determined. Diastolic pressure is the cuff pressure at the point at which the amplitude of the tonometer signal starts to change, systolic pressure cuff pressure at the point at which oscillations in the tonometer signal are obliterated. Various modifications to this method are possible to improve its accuracy and ease of use:
1. The above method can be applied using a relatively rapid rate of cuff inflation. This allows approximate determination of systolic and diastolic blood pressure. The method can then be repeated using a slower rate of inflation when pressure is close to diastolic and systolic pressure. This will provide a more accurate determination of systolic and diastolic blood pressure.
2. The brachial cuff can be rapidly inflated until there is a decrease in tonometer amplitude. It can then be slowly deflated with subsequent increase in tonometer amplitude until the amplitude becomes similar to that before cuff inflation. This allows diastolic pressure to be accurately determined as the cuff pressure at which the amplitude of tonometer oscillations starts to change as shown in Figure 3. Similarly, to determine systolic blood pressure, the cuff can be rapidly inflated until tonometer oscillations are obliterated. It can then be slowly deflated until oscillations return. This allows systolic pressure to be accurately determined as the cuff pressure at which tonometer oscillations change from being present to being obliterated.
3. Applicable to the basic method and to variations 1 and 2, several measurements can be averaged over a period of a few minutes to improve accuracy.
4. Rather than diastolic and systolic pressure being determined by reading from a visual display of brachial cuff pressure and tonometer signals, it may be automatically calculated using analogue to digital conversion of these signals and a software algorithm.
5. The most basic algorithm consists of monitoring the amplitude of the tonometer signal during inflation of the brachial cuff. Diastolic blood pressure is taken as brachial cuff pressure at the time when the amplitude decreases by an amount that exceeds a threshold Ai (dependent on the rate of brachial cuff inflation). Systolic pressure is taken as brachial cuff pressure at the time when the amplitude of the tonometer signal decreases below a second threshold A2 (again dependent on the rate of brachial cuff inflation). 6. Different types of sensors can be used to detect the arterial pulse - the same principle would apply.
Example 1 - Evaluation of the new method
The accuracy of the new method "Cuff Occlusion Tonometry" (CT) as applied during exercise was assessed by comparison with conventional mercury sphygmomanometry. 9 healthy volunteers were studied on 2 separate occasions. On each occasion blood pressure (BP) was measured using CT at 3 minute intervals, 3 times seated at rest and 3 times during exercise on a bicycle ergometer at 50 Watts. A T-tube was attached to the brachial cuff allowing for measurement of blood pressure using mercury sphygmomanometry by an experienced trained observer during brachial cuff deflation. Agreement between the two methods was quantifiec as the mean difference between results obtained using the two methods and variability of agreement by the SD of the difference. Reproducibility of the two methods of measurement was evaluated as the mean difference between measurements made on two different occasions and the SD of these differences [Bland JM and Altaian DG. Lancet 1086; 1:307-310]. Results are summarised in table 1 below:
Table 1
Rest Exercise
Agreement (cuff occlusion tonometry - mercury sphygmomanometry) SBP mean difference 2.0 mmHg -0.9 mmHg
SD 4.8 mmHg 5.9 mmHg
DBP mean difference 2.2 mmHg 1.2 mmHg SD 2.8 mmHg 2.1 mmHg
Reproducibility (cuff occlusion tonometry) SBP mean difference 0.5 mmHg -1.8 mmHg
SD 7.9 mmHg 6.5 mmHg
DBP mean difference 1.7 mmHg 0.0 mmHg SD 3.6 mmHg 4.5 mmHg
Reproducibility (mercury sphygmomanometry) SBP mean difference -0.3 mmHg -1.6 mmHg
SD 5.2 mmHg 6.4 mmHg
DBP mean difference -0.3 mmHg 1.3 mmHg SD 3.7 mmHg 6.3 mmHg
SBP = Systolic blood pressure DBP = Diastolic blood pressure
Conclusion:
These results show that cuff occlusion tonometry shows good agreement with BP measured using mercury sphygmomanometry by an experienced trained observer and similar reproducibility.

Claims

1. Apparatus comprising the combination of a brachial cuff and a non-invasive arterial pressure detector operatively connected to means for recording the effect of varying cuff pressure on the arterial pulse.
2. The apparatus according to claim 1 , in which the means for recording comprises a visual display system.
3. The apparatus according to claim 1, in which the means for recording comprises a computer processing unit.
4. The apparatus according to claim 3, wherein the means for recording also controls brachial cuff pressure and processes the data from the cuff and from the arterial pressure detector in order to calculate diastolic and/or systolic blood pressure.
5. The combination according to any one of claims 1 to 4, in which the arterial pressure detector is an arterial tonometer.
6. The combination according to any one of claims 1 to 4, in which the arterial pressure detector is a blood pressure cuff for positioning distal to the brachial cuff.
7. The combination according to any one of claims 1 to 4, in which the arterial pressure detector is a photoplethysmograph.
8. A method of measuring diastolic blood pressure of an individual using the apparatus according to any one of claims 1 to 7, comprising measuring the arterial pulse and brachial cuff pressure, determining the brachial cuff pressure at which the amplitude of the normal arterial pressure signal starts to decrease.
9. The method of claim 8 comprising measuring the arterial pulse and brachial cuff pressure, increasing the brachial cuff pressure and recording the brachial cuff pressure at which the amplitude of the arterial pressure signal starts to decrease as the diastolic blood pressure.
10. The method of claim 8 comprising measuring the arterial pulse and brachial cuff pressure, increasing the brachial cuff pressure so that the amplitude of the arterial pressure signal starts to decrease and then slowly reducing the cuff pressure and recording the point at which the - initial amplitude of the arterial pulse is restored as the diastolic blood pressure.
11. A method of measuring systolic blood pressure of an individual, using the apparatus according to any one of claims 1 to 7, comprising measuring the arterial pulse and brachial cuff pressure and determining the brachial cuff pressure at which the oscillations of the arterial signal are abolished.
12. The method of claim 11 comprising measuring the arterial pulse and brachial cuff pressure, and increasing brachial cuff pressure to identify the cuff pressure at which the oscillations of the arterial signal are abolished.
13. The method of claim 11 comprising measuring the arterial pulse and brachial cuff pressure, wherein the brachial cuff pressure is increased to abolish the oscillations of the arterial signal, and then decreasing the brachial cuff pressure to identify the cuff pressure at which the oscillations of the arterial signal re-appear.
14. A method of measuring diastolic blood pressure, using a combination according to any of claims 1 to 7, which comprises measuring the arterial pulse and brachial cuff pressure, increasing the brachial cuff pressure and recording the cuff pressure at which the amplitude of the arterial pressure signal starts to decrease.
15. A modification of the method of claim 14, in which, after the decrease of the arterial pressure signal, the cuff pressure is slowly reduced and then recorded at the point at which the initial amplitude of the arterial pulse is restored.
16. A method of measuring systolic blood pressure, using a combination according to any of claims 1 to 7, which comprises measuring the arterial pulse and brachial cuff pressure, increasing brachial cuff pressure to identify the cuff pressure at which the oscillations of the arterial signal are abolished.
17. A modification of the method of claim 16, in which, after abolition of the arterial signal, the brachial cuff pressure is decreased to identify the cuff pressure at which the oscillations of the arterial signal re-appear.
PCT/GB2005/003409 2004-09-03 2005-09-02 Methods and apparatus for the measurement of blood pressure WO2006024871A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0419633.3 2004-09-03
GB0419633A GB0419633D0 (en) 2004-09-03 2004-09-03 Method and apparatus for the measurement of blood pressure

Publications (1)

Publication Number Publication Date
WO2006024871A1 true WO2006024871A1 (en) 2006-03-09

Family

ID=33156007

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2005/003409 WO2006024871A1 (en) 2004-09-03 2005-09-02 Methods and apparatus for the measurement of blood pressure

Country Status (2)

Country Link
GB (1) GB0419633D0 (en)
WO (1) WO2006024871A1 (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7717855B2 (en) 2006-12-06 2010-05-18 The Hospital For Sick Children System for performing remote ischemic preconditioning
EP2269502A1 (en) * 2009-06-29 2011-01-05 Enverdis GmbH Method and device for determining an arterial closing and/or opening pressure in a blood vessel
US8057400B2 (en) 2009-05-12 2011-11-15 Angiologix, Inc. System and method of measuring changes in arterial volume of a limb segment
US8764789B2 (en) 2011-04-15 2014-07-01 CellAegis Devices Inc. System for performing remote ischemic conditioning
US9393025B2 (en) 2010-04-08 2016-07-19 The Hospital For Sick Children Use of remote ischemic conditioning for traumatic injury
US10098779B2 (en) 2013-03-15 2018-10-16 The Hospital For Sick Children Treatment of erectile dysfunction using remote ischemic conditioning
US10136895B2 (en) 2010-03-31 2018-11-27 The Hospital For Sick Children Use of remote ischemic conditioning to improve outcome after myocardial infarction
US10213206B2 (en) 2013-03-15 2019-02-26 CellAegis Devices Inc. Gas powered system for performing remote ischemic conditioning
US10238306B2 (en) 2006-02-20 2019-03-26 Everist Genomics, Inc. Method for non-evasively determining an endothelial function and a device for carrying out said method
US10252052B2 (en) 2013-03-15 2019-04-09 The Hospital For Sick Children Methods relating to the use of remote ischemic conditioning
US10272241B2 (en) 2013-03-15 2019-04-30 The Hospital For Sick Children Methods for modulating autophagy using remote ischemic conditioning

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2562414A1 (en) * 1984-04-06 1985-10-11 Lefebvre Jean Paul Method and apparatus for detecting blood pressure
EP0298620A1 (en) * 1987-07-06 1989-01-11 The BOC Group, Inc. Blood pressure monitoring methods and apparatus
DE3941777A1 (en) * 1989-12-18 1991-06-20 Siemens Ag Measuring blood pressure by oscillation method - calculating value(s) from 2 series of pulsation pressure waves received during contrary sense changes in pressure
US6554773B1 (en) * 1997-09-12 2003-04-29 Polar Electro Oy Method and arrangement for blood pressure measurement

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2562414A1 (en) * 1984-04-06 1985-10-11 Lefebvre Jean Paul Method and apparatus for detecting blood pressure
EP0298620A1 (en) * 1987-07-06 1989-01-11 The BOC Group, Inc. Blood pressure monitoring methods and apparatus
DE3941777A1 (en) * 1989-12-18 1991-06-20 Siemens Ag Measuring blood pressure by oscillation method - calculating value(s) from 2 series of pulsation pressure waves received during contrary sense changes in pressure
US6554773B1 (en) * 1997-09-12 2003-04-29 Polar Electro Oy Method and arrangement for blood pressure measurement

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
NISSILA S ET AL: "Non-invasive blood pressure measurement based on the electronic palpation method", PROCEEDINGS OF THE 20TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. VOL.20 BIOMEDICAL ENGINEERING TOWARDS THE YEAR 2000 AND BEYOND (CAT. NO.98CH36286) IEEE PISCATAWAY, NJ, USA, vol. 4, 1998, pages 1723 - 1726 vol., XP010320834, ISBN: 0-7803-5164-9 *

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10238306B2 (en) 2006-02-20 2019-03-26 Everist Genomics, Inc. Method for non-evasively determining an endothelial function and a device for carrying out said method
US7717855B2 (en) 2006-12-06 2010-05-18 The Hospital For Sick Children System for performing remote ischemic preconditioning
US8790266B2 (en) 2006-12-06 2014-07-29 The Hospital For Sick Children Methods and system for performing remote ischemic preconditioning
US9119759B2 (en) 2006-12-06 2015-09-01 The Hospital For Sick Children System for performing remote ischemic preconditioning
US9119761B2 (en) 2006-12-06 2015-09-01 The Hospital For Sick Children Methods and system for performing remote ischemic preconditioning
US8057400B2 (en) 2009-05-12 2011-11-15 Angiologix, Inc. System and method of measuring changes in arterial volume of a limb segment
US8657755B2 (en) 2009-05-12 2014-02-25 Angiologix, Inc. System and method of measuring changes in arterial volume of a limb segment
EP2269502A1 (en) * 2009-06-29 2011-01-05 Enverdis GmbH Method and device for determining an arterial closing and/or opening pressure in a blood vessel
US10136895B2 (en) 2010-03-31 2018-11-27 The Hospital For Sick Children Use of remote ischemic conditioning to improve outcome after myocardial infarction
US10194918B2 (en) 2010-04-08 2019-02-05 The Hospital For Sick Children Use of remote ischemic conditioning for traumatic injury
US11045207B2 (en) 2010-04-08 2021-06-29 The Hospital For Sick Children Use of remote ischemic conditioning for traumatic injury
US9393025B2 (en) 2010-04-08 2016-07-19 The Hospital For Sick Children Use of remote ischemic conditioning for traumatic injury
US8764789B2 (en) 2011-04-15 2014-07-01 CellAegis Devices Inc. System for performing remote ischemic conditioning
USRE47219E1 (en) 2011-04-15 2019-02-05 CellAegis Devices Inc. System for performing remote ischemic conditioning
US9205019B2 (en) 2011-04-15 2015-12-08 CellAegis Devices Inc. System for performing remote ischemic conditioning
US10213206B2 (en) 2013-03-15 2019-02-26 CellAegis Devices Inc. Gas powered system for performing remote ischemic conditioning
US10098779B2 (en) 2013-03-15 2018-10-16 The Hospital For Sick Children Treatment of erectile dysfunction using remote ischemic conditioning
US10252052B2 (en) 2013-03-15 2019-04-09 The Hospital For Sick Children Methods relating to the use of remote ischemic conditioning
US10272241B2 (en) 2013-03-15 2019-04-30 The Hospital For Sick Children Methods for modulating autophagy using remote ischemic conditioning

Also Published As

Publication number Publication date
GB0419633D0 (en) 2004-10-06

Similar Documents

Publication Publication Date Title
WO2006024871A1 (en) Methods and apparatus for the measurement of blood pressure
US7137955B2 (en) Methods and systems for distal recording of phonocardiographic signals
US9131859B2 (en) Blood pressure measurement apparatus, recording medium that records blood pressure derivation program, and blood pressure derivation method
US20110257539A1 (en) Electronic sphygmomanometer and blood pressure measurement method
US9049993B2 (en) Apparatus for biological signal measurement at point of end-tidal
US7678059B2 (en) Non-invasive blood pressure monitor with improved performance
JP5644325B2 (en) Blood pressure information measuring device and method for calculating an index of arteriosclerosis in the device
JP2938234B2 (en) Blood pressure monitor device with finger cuff calibration device
US10213116B2 (en) Methods for measuring blood pressure
US6796946B2 (en) Arteriostenosis inspecting apparatus and ankle-blood-pressure measuring apparatus
EP1292221A1 (en) Method and apparatus for monitoring cardiovascular condition
US8282567B2 (en) Method and system for determination of pulse rate
CN101138493A (en) Method and system utilizing spo
US6440080B1 (en) Automatic oscillometric apparatus and method for measuring blood pressure
JP4289850B2 (en) Automatic indirect non-invasive device and method for determining diastolic blood pressure by calibrating vibration waveforms
JP2015519112A (en) Method for monitoring blood pressure using pulse oximetry signals
EP2369984B1 (en) Method of measuring blood pressure and apparatus for performing the same
US20040059232A1 (en) Blood pressure measuring apparatus with pulse wave detecting function
EP4173555A1 (en) Device, system and method for calibrating a blood pressure surrogate for use in monitoring a subject's blood pressure
Koohi et al. Dynamic threshold algorithm to evaluate trustworthiness of the estimated blood pressure in oscillometry
JP5092885B2 (en) Electronic blood pressure monitor
EP4173556A1 (en) Device, system and method for calibrating a blood pressure surrogate for use in monitoring a subject's blood pressure
Jones et al. Monitoring the peripheral vascular system

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase