Personal health data collection
The present application provides a personal hand-held monitor for the measurement of a subject's blood pressure and, optionally, one or more other vital signs, comprising a housing located on a personal hand-held computing device or a hand-held component of a computing system; a blood flow occlusion means located in the housing; a pressure sensor adapted to provide an electrical signal indicative of the pressure applied; a means for detecting the flow of blood in the body part of the subject when pressure is applied; and means for receiving electrical signals from the pressure sensor and the blood flow detecting means and for transmitting electrical signals indicative of the pressure and blood flow to the processor of the personal hand-held computing device or the computing system, wherein the processor of the personal hand-held computing device or computing system provide at least a measurement of the blood pressure of a subject. The processor is further adapted to carry out a process to measure a diastolic blood pressure value and a systolic blood pressure value.
1. A personal hand-held monitor (PHHM) for the measurement of a subject's blood pressure (BP), comprising:
a housing located on a personal hand-held computing device (PHHCD) or a hand-held component of a computing system;
a blood flow occlusion device located in the housing such that, when the housing is located on the PHHCD or the hand-held component, an open surface of the blood flow occlusion device is available to be pressed against a body part of the subject or to have a body part of the subject pressed against it;
a pressure sensor adapted to provide an electrical signal indicative of the pressure applied to or by the open surface;
an optical blood flow detecting device configured to detect the flow of blood in the body part of the subject when pressure is applied to or by the open surface; and
a device configured to receive electrical signals from the pressure sensor and the optical blood flow detecting device and for transmitting electrical signals indicative of the pressure and blood flow to a processor of the PHHCD or the computing system,
wherein the processor of the PHHCD or computing system is adapted to process signals acquired by the pressure sensor and the optical blood flow detecting device to provide at least a measurement of a diastolic blood pressure (DBP) and a systolic blood pressure (SBP) of the subject using a non-linear parametric function that predicts optical signals from a decay law of optical intensity, and
wherein the subject's DBP and the SBP values are estimated by:
using the parametric function to generate predicted optical signals from one or more candidate DBP and SBP values;
comparing the predicted optical signals to the measured optical signals; and
adjusting the candidate DBP and SBP values to find the candidate DBP and SBP values that minimize the difference between the predicted optical signals and the measured optical signals, and using those candidate DBP and SBP values that minimize the difference as the estimate of the subject's DBP and SBP values.
2. The PHHM of claim 1 , wherein the processor is adapted to take account of the difference in pressure at which the peak of the pressure fluctuations and the peak of the optical signals is detected.
3. The PHHM of claim 1 , wherein the processor is adapted to measure a gradient of the absolute optical signal at systole as a function of the measured external pressure and to use said slope in order to estimate an error due to a misplaced body part.
4. The PHHM of claim 1 , wherein the processor is adapted to measure a relative amplitude of red and infrared optical signals as a function of the pressure measured by the pressure sensor and to use said ratio to estimate an error due to a misplaced body part.
5. The PHHM of claim 1 , wherein the processor is adapted to derive, from the measured pressure and optical signal, estimates of the degree to which the body part is displaced.
6. The PHHM of claim 1 , wherein the processor is adapted to combine the results of the analysis to make an estimate of an error due to a misplaced body part.
7. The PHHM of claim 6 , wherein the processor is adapted to use a misplacement to estimate and correct for an error in the estimated SBP and/or DBP due to the misplacing of the body part.
8. The PHHM of claim 7 , wherein the error in the measured SBP is used to estimate and correct for the error in the measured DBP or vice versa.
9. The PHHM of claim 3 , wherein the processor is adapted to use said gradient to determine if the body part is so misplaced as to render resulting estimates of SBP and DBP unreliable and to warn the subject by way of audible and/or visual signals.
10. The PHHM of claim 1 , wherein the PHHM is further adapted to generate a correction factor based on relative locations of the body part of the subject and the blood flow occlusion device, wherein said correction factor is used to increase the accuracy of estimation of the value of BP.
11. The PHHM of claim 1 , wherein the body part is a finger.
12. The PHHM of claim 1 , wherein processor of the PHHM is adapted to carry out the generating and comparing by use of a genetic algorithm.