rcomeau

AppleZulu said:

This is irresponsible reporting. The headline and lede make it seem like this was somehow a failure on the part of the iPad itself. It was not.

Read on, and you'll understand that the issue was that, once dropped, the iPad became a wedged-in obstruction to flight control mechanisms. The same would've been the case if the dropped item had been a Microsoft Surface, or a paper notebook in a rigid binder. There is no fault in the hardware design or software operation of the iPad itself.

thinkman100000000 said:

I wonder how much consideration GM gave to the multitudes of iPhone users who, like me, wouldn't consider a car that doesn't support CarPlay. 

StrangeDays said:

omasou said:

At no time was she smart enough to inform the police so that they could apprehend the United baggage handler who is stealing luggage?

Instead she posts to Twitter to guaranteeing the perp will not be identified.

Ah yes, when all else fails - blame the victim! Insult her intelligence for trying to get the airline charged with her belongings to handle it. 

Had she gone to the police first you people would be saying she could have dealt with the business first. Roll eyes 

9secondkox2 said:

ravnorodom said:

9secondkox2 said:

zimmie said:

MacPro said:

I can't see what Apple could do?  If they improved the sensitivity wouldn't that just make measurements better for light skins too, thus maintaining the differential?  It's physics not bias. 

Not necessarily. All pulse oximeters use a measurement correction curve to convert from the amount of reflected light to an oxygenation percentage. That curve needs to change based on skin tone and possibly other characteristics we don’t even know about today (since only recently did a million people start carrying an oximeter around with them everywhere). Correcting the curve for darker skin would make readings for lighter skin less accurate, so it would need to be adjustable.

There should be a calibration setting. 

I can't imagine the calibrating process would be "what color shade is your skin: choose 1 to 10" and Apple Watch will adjust LED strength accordingly.

Seems to be the simplest effort toward a solution. And sometimes that’s where the fruit is. Of course it’s not exactly so simple, otherwise it wouldn’t be an issue for so long. But if anyone can figure it out, it’s Apple. 

Just a few years ago, watches told time and played really bad Atari 2600 style video games. Now they tell the time, control your phone, use the internet,  do email, messsging, manage your fitness, check your pulse, etc. that’s crazy. 

And now we just expect everything to be perfect on this little watch - even when dedicated industrial grade equipment isn’t doing a better job. 

And now there are actually people who want to SUE this company that has made such great strides in saving lives with a little watch by throwing the race card up when something doesn’t work perfectly?  The heck? No wonder they haven’t tried blood pressure monitoring yet. 

So the idea of a calibration setting to get a better reading of blood oxygen seems logical, but actually accomplishing that will take some dedicated time if it’s possible at all. 

And most importantly, as others have stated, Apple explicitly notes that the feature is not meant for medical purposes. Just to provide a general idea of health and wellness. As the lawsuit seems to be focused on the idea of a medical feature, it’s most likely to be tossed out by any competent judge not totally indoctrinated with critical race theory. 

mikethemartian said:

rcomeau said:

mikethemartian said:

MacPro said:

I can't see what Apple could do?  If they improved the sensitivity wouldn't that just make measurements better for light skins too, thus maintaining the differential?  It's physics not bias. 

I don’t know what wavelength of light they use for these but there probably is a range in the non visible spectrum that could be used where skin tone would be irrelevant.

Pulse oximetry depends on the differential absorbance of 2 (or more) different frequencies of IR light in the blood, specifically the oxygenated and deoxygenated haemoglobin. You can pick 2 IR wavelengths where the absorbance curves of oxi and de-oxi cross each other (typically pick one <700nm and one >800nm. Acquire relative intensity (changes in time) of both these wavelengths and you can fit them to a curve using something called the modified Beer-Lambert law to get an estimated change in blood oxygenation. You have to pick wavelengths that are on the right spots on the curve as well as what wavelengths of LED are actually available and affordable (only a new nm difference can mean a $1 LED or a $100LED due to the material in the LED that emits the light). This is not an easy problem to solve, other than blasting more light in, but you then run into concerns over heating the skin (absorbing IR light means conversion into heat) as well as power consumption and safety (too intense and you run the risk of eye damage if some fool stares into the back of the watch with the LEDs on. Not an easy fix.

The Beer-Lambert law is pretty much the attenuation due to the imaginary part of the complex (real plus imaginary parts) index of refraction of the material (in this case the human tissue). The real part controlling the change in phase as the light propagates and so the angle of refraction. For a given material the index of refraction will have peaks and valleys in it described empirically by the Sellmeier equation. Basically the engineer would have to find a frequency of light where the imaginary part of the index of refraction isn’t significantly effected by the melanin in the skin. But as you mentioned whether or not it is economically practical depends on the availability of LEDs in that range. Bandgaps of LEDs can be tuned using structures like quantum wells though.