3 ms·

“The device takes its measurements by shooting an electrical current into the skin and then analyzing the body’s response, which is known as bioimpedance. There

“The device takes its measurements by shooting an electrical current into the skin and then analyzing the body’s response, which is known as bioimpedance. There is a correlation between bioimpedance and changes in blood pressure that has to do with blood volume changes. However, the correlation is not particularly obvious, so the team had to create a machine learning model to analyze the connection to get accurate blood pressure readings.” Yikes. Sounds like something that would have huge variations depending on the person’s skin type, hydration, age, and a bunch of other factors. Probably a pipe dream, since it’s a university press release.

wongarsu 4y ago
You could probably calibrate it to each person, and maybe recalibrate every couple months. Still leaves you with a bunch of factors, but maybe those can be controlled for (measuring skin conductivity in addition to impedance?).
- hansvm 4y ago
  Sounds prone to errors from moisture, activity, salt, and all kinds of things.
  - adrian_b 4y ago
    Even if the device would be much less precise than claimed in the paper, it would still be good enough to save the lives of many people. One can always measure the blood pressure with a classic instrument every few days and recalibrate the tattoo resistance measurement. What is important is to be able to measure the blood pressure continuously and trigger an alarm whenever it becomes too high or too low. My mother died a few years ago, precisely because I did not have such a device for continuous blood pressure monitoring. Having her arm compressed was painful and very unpleasant for her, so I could not measure her blood pressure more than once per day. She had a very dangerous condition, where she needed to take some medication to avoid a too high blood pressure, which could cause a hemorrhagic stroke, while simultaneously taking high quantities of salt and potassium supplements, because she eliminated them too quickly, so in a very short time she could reach a too low sodium/potassium content in the blood, which would trigger severe neurological problems. It was very difficult to balance the 2 kinds of medication with contrary effects and every day their doses had to be adjusted. Without continuous blood pressure monitoring, the daily doses could be based only on guesses, taking into account the recent history. With great efforts, her health state has been kept stable for a couple of years, but then one day, for unknown reasons, she had a sudden fluctuation in the blood pressure, which became double the normal value, so soon she had a fatal stroke. With continuous blood pressure monitoring, an alarm would have allowed the immediate use of blood pressure lowering medication, which could have prevented the stroke. Therefore I believe that the development of such devices is very important, despite their shortcomings.
  - N_A_T_E 4y ago
    A direct proxy to BP seems valuable, could save many lives. I agree we'll want clinical studies to validate how precise/accurate this measurement is.

wongarsu 4y ago

You could probably calibrate it to each person, and maybe recalibrate every couple months. Still leaves you with a bunch of factors, but maybe those can be controlled for (measuring skin conductivity in addition to impedance?).

hansvm 4y ago
Sounds prone to errors from moisture, activity, salt, and all kinds of things.
- adrian_b 4y ago
  Even if the device would be much less precise than claimed in the paper, it would still be good enough to save the lives of many people. One can always measure the blood pressure with a classic instrument every few days and recalibrate the tattoo resistance measurement. What is important is to be able to measure the blood pressure continuously and trigger an alarm whenever it becomes too high or too low. My mother died a few years ago, precisely because I did not have such a device for continuous blood pressure monitoring. Having her arm compressed was painful and very unpleasant for her, so I could not measure her blood pressure more than once per day. She had a very dangerous condition, where she needed to take some medication to avoid a too high blood pressure, which could cause a hemorrhagic stroke, while simultaneously taking high quantities of salt and potassium supplements, because she eliminated them too quickly, so in a very short time she could reach a too low sodium/potassium content in the blood, which would trigger severe neurological problems. It was very difficult to balance the 2 kinds of medication with contrary effects and every day their doses had to be adjusted. Without continuous blood pressure monitoring, the daily doses could be based only on guesses, taking into account the recent history. With great efforts, her health state has been kept stable for a couple of years, but then one day, for unknown reasons, she had a sudden fluctuation in the blood pressure, which became double the normal value, so soon she had a fatal stroke. With continuous blood pressure monitoring, an alarm would have allowed the immediate use of blood pressure lowering medication, which could have prevented the stroke. Therefore I believe that the development of such devices is very important, despite their shortcomings.
- N_A_T_E 4y ago
  A direct proxy to BP seems valuable, could save many lives. I agree we'll want clinical studies to validate how precise/accurate this measurement is.