[HN Gopher] Clinical validation of a blood-pressure sensor for c...
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       Clinical validation of a blood-pressure sensor for continuous
       health monitoring
        
       Author : bookofjoe
       Score  : 62 points
       Date   : 2023-05-21 15:28 UTC (1 days ago)
        
 (HTM) web link (onlinelibrary.wiley.com)
 (TXT) w3m dump (onlinelibrary.wiley.com)
        
       | midland_trucker wrote:
       | I'm yet to see a study that convinces me of the potential of this
       | concept. All of them when you get down to the details have at
       | least one of:                 - An unrepresentative test set ,
       | i.e. a population with similar blood pressure at recording in
       | which merely predicting a constant 'typical' reading would
       | perform well in terms of accuracy.       - A major methodology
       | flaw, such as 'demonstrating' an ability to detect fluctuations
       | from a baseline calibration cuff reading in situations where you
       | would expect no significant fluctuations to occur.
       | 
       | I don't have access to this particular paper, but suspect it has
       | the same issue owing to the relatively small sample size.
        
       | z3ugma wrote:
       | I'm not surprised this works - accurate cuffless blood pressure
       | has been validated from other physiological sources like PPG /
       | pulse oximetry.
       | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7141397/
       | 
       | and is even now FDA-cleared for clinical use: e.g.
       | https://www.bio-beat.com/post/the-biobeat-cuffless-wrist-blo...
        
         | jsharf wrote:
         | Wait isn't PPG for heart rate?
        
           | throwaway5752 wrote:
           | Not specifically. Photoplethysmography just means, roughly,
           | light based volume measurement. It can measure pulse when
           | done crudely. If you have a baseline for blood pressure and a
           | sensitive enough PPG sensor you can detect different levels
           | of volume and infer pressure. It is analogous to measuring
           | water pressure based on the diameter of a filled rubber hose.
           | 
           | To the GP's point, the largest blood pressure monitor company
           | is Omron. Portable monitors have been around. https://www.omr
           | on.com/global/en/technology/omrontechnics/vol... is a good
           | place to learn more about the advantages and disadvantages of
           | different approaches. Piezoelectric and PPG would have the
           | advantage of lower cost, lower mechanical complexity, and
           | continuous monitoring instead of point measurements.
        
             | felideon wrote:
             | > Portable monitors have been around.
             | 
             | Not reliable/valid _cuffless_ monitors, though. That 's
             | relatively new, if I understand correctly.
        
       | abnry wrote:
       | I love wearables. It is a pain in the neck to take a measurement.
       | Anything that can be worn and sense automatically is awesome. I
       | studious update an SQLite database of my Fitbit data. I just wish
       | I had more measurements to track!
        
       | ijustlovemath wrote:
       | This is a very early stage study; at 175 data points over 35
       | patients, that's just 5 data points per person. Barely enough to
       | make a convincing linear regression.
        
       | felideon wrote:
       | It'd be interesting to read the study limitations, but, at 35
       | participants, a larger and diverse cohort would be warranted to
       | see how this translates in the real world.
       | 
       | Aktiia has done some studies for its product and works by taking
       | a BP cuff measurement to calibrate its PPG sensor-based
       | algorithm. If you can get rid of the cuff and can sell an
       | affordable wearable device, that would be a promising future.
        
         | LorenPechtel wrote:
         | The Aktiia device only required periodic recalibration with the
         | cuff. We'll see if it makes it through the FDA.
        
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       (page generated 2023-05-22 23:01 UTC)