Pulse oximeters give biased results for people with darker skin • Hacker News Board

Re: Pulse oximeters give biased results for people with darker skin

#31

Post by tssva » Thu, Aug 06, 2020, 3:02 PM UTC

diydsp wrote: post #28

treis wrote: post #13

This really isn't a big deal. Doctors know that these pulse ox meters aren't very accurate and use them accordingly. Nobody's changing their plan because you have a pulse ox of 93 instead of 95. They're there to quickly measure big changes that indicate a problem. In other words, they're looking for patients going from 98 to 75, not 98 to 95.

FTA: "At a reading of 88 or 89, Medicare will reimburse for oxygen at home, but at 90 it won’t"

Getting oxygen at home reimbursed by Medicare also requires diagnoses with certain conditions and specific testing. If oxygen at home is required the testing to satisfy Medicare requirements won't be conducted using the common finger tip pulse ox meter.

Re: Pulse oximeters give biased results for people with darker skin

#32

Post by m463 » Thu, Aug 06, 2020, 3:04 PM UTC

PascLeRasc wrote: post #21

I'm a student EMT and our instructor told us not to rely on a pulse ox reading if our patient has dark skin, or if they were in a fire, or are a lifelong smoker, or if they have any nail polish or dirt/grease on their fingertips. We just look for the 94-100% range and would only take action if we get a reading around 87% or lower, or see a sudden drop during treatment. There are a few alternatives designs that aim to…

here is one:

https://web.archive.org/web/20200708064647/https://www.howeq...

Re: Pulse oximeters give biased results for people with darker skin

#33

Post by rzmnzm » Thu, Aug 06, 2020, 3:07 PM UTC

A company I worked for decided one day to purchase budget fingerprint readers for door access. They were installed with much fanfare.

Unfortunately it turned out that the fingerprint readers were racist, and refused to allow black people into the building.

They were swiftly removed.

Re: Pulse oximeters give biased results for people with darker skin

#34

Post by openasocket » Thu, Aug 06, 2020, 3:07 PM UTC

diydsp wrote: post #28

treis wrote: post #13

This really isn't a big deal. Doctors know that these pulse ox meters aren't very accurate and use them accordingly. Nobody's changing their plan because you have a pulse ox of 93 instead of 95. They're there to quickly measure big changes that indicate a problem. In other words, they're looking for patients going from 98 to 75, not 98 to 95.

FTA: "At a reading of 88 or 89, Medicare will reimburse for oxygen at home, but at 90 it won’t"

There might actually be room for a lawsuit there, if that regulation has a demonstrable impact on people with darker skin

Re: Pulse oximeters give biased results for people with darker skin

#35

Post by x86_64Ubuntu » Thu, Aug 06, 2020, 3:09 PM UTC

jrajav wrote: post #26

treis wrote: post #13

This really isn't a big deal. Doctors know that these pulse ox meters aren't very accurate and use them accordingly. Nobody's changing their plan because you have a pulse ox of 93 instead of 95. They're there to quickly measure big changes that indicate a problem. In other words, they're looking for patients going from 98 to 75, not 98 to 95.

What's the point of casually dismissing this article's premise? Whether the conclusions are fully sound or not isn't the goal of this article, this is journalistic not academic. The goal is to raise awareness of a potential bias, and I think it achieves that (assuming the facts all check out). For one, according to the article the discrepancy was found to be up to 8 points in some cases, not 3. And it seems reasonabl…

This thread because it has race as a secondary theme will be rife with such statements dismissing the premise.

Re: Pulse oximeters give biased results for people with darker skin

#36

Post by exikyut » Thu, Aug 06, 2020, 3:10 PM UTC

ravenstine wrote: post #15

ceejayoz wrote: post #14

Reminds me of the automatic soap dispenser at Facebook that can't see black people. https://gizmodo.com/why-cant-this-soap-dispenser-identify-da...

I can believe this because automatic doors seem more prone to having a hard time opening when I wear black clothes. It's not a big deal or anything, but I occasionally have to step back and then forth again to get it to open. Is this a common experience of black people, or am I crazy?

Oh, THAT'S why entrance barriers at supermarkets only occasionally fail, but fail consistently on a given day...

Wait. Would this happen to PIR-based systems?

Re: Pulse oximeters give biased results for people with darker skin

#37

Post by x86_64Ubuntu » Thu, Aug 06, 2020, 3:11 PM UTC

jeffreyrogers wrote: post #29

And people with sweaty hands. And people with low iron levels. There's this push to show that everything is biased against certain classes. I'm sure some of the examples are true, but I can't imagine that constantly seeking evidence of problematic issues is good for individuals or society.

It sounds like you are suffering from anxiety over the phrase "darker skin".

Re: Pulse oximeters give biased results for people with darker skin

#38

Post by tashi » Thu, Aug 06, 2020, 3:14 PM UTC

treis wrote: post #13

This really isn't a big deal. Doctors know that these pulse ox meters aren't very accurate and use them accordingly. Nobody's changing their plan because you have a pulse ox of 93 instead of 95. They're there to quickly measure big changes that indicate a problem. In other words, they're looking for patients going from 98 to 75, not 98 to 95.

My insurance company didn't authorize a full sleep study because my overnight pulse oximeter results were normal, so it took me an extra couple of years to find out I needed a CPAP machine. It might have helped to know that my skin color could cause inaccurate results.

Re: Pulse oximeters give biased results for people with darker skin

#39

Post by function_seven » Thu, Aug 06, 2020, 3:18 PM UTC

oneplane wrote: post #22

And darker coloured textiles are less visible on people with darker skin. Grass is green and bananas tend to be curved. I get that it is interesting to research optically measuring systems to 'search for bias' and I'm sure there are going to be biases in varying degrees, but that doesn't mean it's always for the same reason or with the same result. There are very real problems of course, take the example with the pho…

> Both of those are mostly examples of errors made during engineering (apply Hanlon's razor when in doubt - it's not always malice like people often assume), and might be preventable if there were more different samples and interactions available during development.

When I see these types of examples brought up, I don't see malice being assumed. Rather, these are good illustrations of structural bias. "Structural" (or "systemic") is often used in contrast to overt bigotry or malice. It's sometimes the result of a certain workforce or industry being substantially skewed with respect to the wider population. You're right, Hanlon and his razor do work here to show that it's a naive error rather than intentional harm. But the result is still traceable to the disparities between the designers and the population at large.

As for the soap dispenser: If the team of engineers designing the module had a mix of skin colors, then they would have quickly seen that their product failed sometimes. They would, at the outset, have known that they needed to tune the photoreceptor better, or switch to a different method of detection.

Though it is funny that Nikon, a Japanese company, made cameras with an blink detector that falsely triggered on Asian eyes. That either refutes my own point above, or it indicates they imported that functionality.

Re: Pulse oximeters give biased results for people with darker skin

#40

Post by exikyut » Thu, Aug 06, 2020, 3:18 PM UTC

ceejayoz wrote: post #23

vinay427 wrote: post #20

Earlier quoted context omitted.

The Apple Watch doesn't have a pulse oximeter (EDIT: it does have one that is not approved and therefore is disabled), so it would be difficult for it to have this issue. You might be thinking of optical HR measurement, for which sensors have also been shown to have skin color biases in some cases. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7010823/

> The Apple Watch doesn't have a pulse oximeter Yes, it does. The FDA blocked its use. https://www.city-journal.org/fda-blocks-apple-watch-blood-ox... https://www.cultofmac.com/320322/apple-watch-sensors-are-cap...

Wow.

Is it possible to jailbreak iOS and gain access to... hmm, probably not. Even if the driver ships in iOS, it would be a fair question how much "disabled" was implemented by removing secret/irreplaceable code rather than simply disabling flags (potentially because the former approach was more convenient).