Comment by anigbrowl | Hacker News Reader

Comment by anigbrowl | Hacker News Reader

Hmm. As a geek I like Gray code and think it has many useful applications, but this is not one of them: Iris stood against the post and the nurse adjusted the bracket to exactly the top of her head. Then she read off Iris's height from an attached display.

How is this an advance on looking at a conventionally numbered ruler (with a similar bracket to touch the top of the head) and writing down the number? It's technological and presumably expensive, but it isn't delivering any discernible benefit that I can see. Measuring height via computer vision + Gray code would be very useful in security applications where you want to log biometric information for a large number of people efficiently (camera + abstract-looking wall design in an access corridor or at a security checkpoint), but if you're paying a human to take the measurement you might as well use a scale that's easily human-readable (ie at a glance). I hope the doctor's scale was at least using bluetooth or similar to automatically update the patient's digital record...but I wouldn't bet on it.

Presumably it's considered useful because there's a measurable error rate in the nurse a) reading -and/or- b) recording the observed data. Assuming this thing works properly more often, you've not only guaranteed you get the data entered properly, but it's more likely to be right.

I imagine this is compounded by the subject matter being measured. A simple "click and lock the measurement" button would be invaluable when trying to measure the height of a squirming child.

Simple, easy to read numbers that eliminate guesswork would seem to make a nurse's job much simpler (or allow them to utilize people who are not registered nurses to collect this data). There have been similar advances in scales, blood pressure cuffs, heart rate monitors, etc. All are readable using analog gauges, yet they progressed to digital devices.

What people here don't seem to realize is that a doctors' scale or measuring tapes are not used for precision measurements anyway.

If the doctor sees the patient only every few months, individual variations (kids will grow, adults will gain (or, sometimes, hopefully) loose weight)) in body height or weight will exceed the precision you can get even out of the cheapest scale or measurement tape.

And as for the purpose of the measurements: The doctor will use the values acquired from the tools to categorize patients in categories: E.g. a obese person has a higher risk of cardiac arrest, someone looking quite anorexic will have other problems with his blood chemistry... And here a few kilograms/centimeters don't influence the general statement at all.

The same question came up on Reddit (in the agressive know-it-all tone typical of Reddit (http://www.reddit.com/r/programming/comments/8ufl1/gray_code...) when I first posted this blog article. So I asked the pediatrician, and the answer (http://www.reddit.com/r/programming/comments/8ufl1/gray_code...) was surprising:

>I was back at the office today and I asked one of the senior doctors about it. She said that the manual stadiometers were always giving inaccurate readings and that they constantly had to have the service guys in to recalibrate them. The electronic stadiometer, she said, is much more reliable.

>"But it's a really expensive stadiometer," I said.

>"The service calls on the manual stadiometers were costing us a fortune."

>The radio connection to the portable readout is a red herring. They had the display mounted on the wall right next to the stadiometer. I asked if they ever took it down and moved it around; the doctor said they never did.

>So there's your answer. It's nothing clever, but it's totally reasonable, and it's nothing you could deduce from your armchair. This is why it's important to suspend judgment of someone's actions when you don't have any direct knowledge of their situation.

Hope this helps.

The article didn't say, but I would imagine the actual records would receive the vitals directly from the machine, rather than going through a nurse (it also may be a work in progress as an office moves to electronic records and streamlining vitals). The nurse reads the number off the indicator for the benefit of the patient, not the records.

I agree, as the article reads, it would just be silly to add the additional cost with no change other than needing a machine to read the numbers.

I assume that the reason is to reduce error from having a person read the height from a scale. It would also make the nurse's job easier because they wouldn't need to have to fiddle with the analog scale. I know my kid hates getting his height/weight measured, so anything that speeds up the process is good.

Another potential benefit is that the digitized scale could be directly attached to a wall without regard for it's height relative to the ground. There could be a defined calibration offset stored in the reader, so the contractor wouldn't need to be exact when the bar is installed.

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