3 ms·

A little off-topic but does anyone know of pressure sensors suitable for home-baked blood pressure monitor? I'm planning to build a little Arduino- or raspi-ba

by voytec 3y ago

A little off-topic but does anyone know of pressure sensors suitable for home-baked blood pressure monitor? I'm planning to build a little Arduino- or raspi-based device to own the data. All I managed to find were (non-blood) pressure sensors and I'm unsure whether these could be used for blood pressure monitoring and how I'd place them against the hand to get readings of reasonable quality. If this approach is a no-go, a ready device with some physical interface (and no "cloud"-related garbage) allowing readings would do.

bmitc 3y ago
> a ready device with some physical interface (and no "cloud"-related garbage) allowing readings would do. https://omronhealthcare.com/blood-pressure/ https://omronhealthcare.com/blood-pressure/
- Mayzie 3y ago
  Yep! I have the Evolv, and I use the third-party MedM BP apps[1][2] to sync the readings from the device via bluetooth to my phone (and HealthKit). No first-party app needed. [1] (iOS) https://apps.apple.com/au/app/medm-blood-pressure/id1040909532 https://apps.apple.com/au/app/medm-blood-pressure/id10409095... [2] (Android) https://play.google.com/store/apps/details?id=com.medm.medmbp.diary https://play.google.com/store/apps/details?id=com.medm.medmb...
  - voytec 3y ago
    Is it possible to connect to these devices from BT-enabled device like raspi with a dongle? I'd like to avoid sharing any health-related data with VC-funded businesses (Apple, Google, not only app developers)
- voytec 3y ago
  Thanks! The smartwatch-like thingie looks nice, albeit pricey as hell. Think I'll go with one of the bigger devices for now.
jaclaz 3y ago
The usual blood pressure measure instruments[1] work AFAIK just like the "old" manual way, what is measured is the (air) pressure in the band, though they use an oscillometric (tiny variations in the pressure) approach to detect the heart beats as opposed to the stethoscope (auscultatory). The idea (the traditional way) is: https://en.wikipedia.org/wiki/Sphygmomanometer https://en.wikipedia.org/wiki/Sphygmomanometer 1) you place the stethoscope between the arm and the inflatable band 2) you pump air in the band 3) at a certain pressure you will start hearing the heart beats 4) you continue pumping until you cannot hear them anymore + a little bit more 5) you start slowly release pressure until you can hear the heart beats (at this point what you read on the manometer is the max pressure or systolic) 6) you continue slowly releasing pressure until you cannot hear the heart beats anymore (at this point what you read on the manometer is the min pressure or diastolic) The electronic device replace the hand pump with an electric pump, the manometer with a pressure sensor and the stethoscope with the capability to detect oscillations in the pressure from the same sensor. See: https://en.wikipedia.org/wiki/Blood_pressure_measurement#Auscultatory https://en.wikipedia.org/wiki/Blood_pressure_measurement#Aus... https://en.wikipedia.org/wiki/Blood_pressure_measurement#Oscillometric https://en.wikipedia.org/wiki/Blood_pressure_measurement#Osc... I believe that the issue in a home made electronic device is not so much the sensor but rather the conversion from raw data of the sensor (oscillometric waveform) into heartbeats and the speed with which the band is inflated and deflated (size and speed of pump, accuracy of the release valve). [1] both the ones that take pressure on the arm and those that take it at the wrist

by voytec 3y ago

bmitc 3y ago

> a ready device with some physical interface (and no "cloud"-related garbage) allowing readings would do. https://omronhealthcare.com/blood-pressure/ https://omronhealthcare.com/blood-pressure/

Mayzie 3y ago
Yep! I have the Evolv, and I use the third-party MedM BP apps[1][2] to sync the readings from the device via bluetooth to my phone (and HealthKit). No first-party app needed. [1] (iOS) https://apps.apple.com/au/app/medm-blood-pressure/id1040909532 https://apps.apple.com/au/app/medm-blood-pressure/id10409095... [2] (Android) https://play.google.com/store/apps/details?id=com.medm.medmbp.diary https://play.google.com/store/apps/details?id=com.medm.medmb...
- voytec 3y ago
  Is it possible to connect to these devices from BT-enabled device like raspi with a dongle? I'd like to avoid sharing any health-related data with VC-funded businesses (Apple, Google, not only app developers)
voytec 3y ago
Thanks! The smartwatch-like thingie looks nice, albeit pricey as hell. Think I'll go with one of the bigger devices for now.

jaclaz 3y ago

The usual blood pressure measure instruments[1] work AFAIK just like the "old" manual way, what is measured is the (air) pressure in the band, though they use an oscillometric (tiny variations in the pressure) approach to detect the heart beats as opposed to the stethoscope (auscultatory). The idea (the traditional way) is: https://en.wikipedia.org/wiki/Sphygmomanometer https://en.wikipedia.org/wiki/Sphygmomanometer 1) you place the stethoscope between the arm and the inflatable band 2) you pump air in the band 3) at a certain pressure you will start hearing the heart beats 4) you continue pumping until you cannot hear them anymore + a little bit more 5) you start slowly release pressure until you can hear the heart beats (at this point what you read on the manometer is the max pressure or systolic) 6) you continue slowly releasing pressure until you cannot hear the heart beats anymore (at this point what you read on the manometer is the min pressure or diastolic) The electronic device replace the hand pump with an electric pump, the manometer with a pressure sensor and the stethoscope with the capability to detect oscillations in the pressure from the same sensor. See: https://en.wikipedia.org/wiki/Blood_pressure_measurement#Auscultatory https://en.wikipedia.org/wiki/Blood_pressure_measurement#Aus... https://en.wikipedia.org/wiki/Blood_pressure_measurement#Oscillometric https://en.wikipedia.org/wiki/Blood_pressure_measurement#Osc... I believe that the issue in a home made electronic device is not so much the sensor but rather the conversion from raw data of the sensor (oscillometric waveform) into heartbeats and the speed with which the band is inflated and deflated (size and speed of pump, accuracy of the release valve). [1] both the ones that take pressure on the arm and those that take it at the wrist