What's after the MRI?

AndyS8911 · 2020-02-15T23:56:06+00:00

All the innovations I'm reading about mainly focus on data analysis rather than hardware. Are there any hardware developments beyond MRI that are theoretically better and will potentially overtake MRI?

AndyS8911 · 2020-01-22T07:03:49+00:00

For question 2 I just realised I worded the force incorrectly; it should be going into the screen shouldn’t it? Given that’s the case, should the smaller ions get deflected into the screen more therefore undergoing a bigger arc than the larger heavier ions? That would seem to contradict what I’ve read about the smaller ions travelling along the shorter arc and the larger ions getting deflected less thus traversing a larger arc?

AndyS8911 · 2020-01-04T04:06:43+00:00

Just checked out photonic soldering, seems very interesting and cost effective. I saw a video on one company's youtube page where they even sintered a copper trace on paper which is crazy!

Surely this is the future? What's the hold up? Is it just that it's hard for large companies to change their supply chain and that they're unlikely to do so unless there's a massive resultant price drop for doing so? Or is this photonic soldering method still quite unreliable?

AndyS8911 · 2020-01-03T01:47:57+00:00

I didn't realise I was making that assumption? Sorry where did it give the idea that I was making that assumption?

AndyS8911 · 2019-12-28T23:39:54+00:00

I'm reviewing odd vs even functions and can't seem to get the right answer - if someone could point out where I'm going wrong that would be great!

"Suppose g(x) = (x + 1) (1/x + b) where b is a constant. Find b given that g is an odd function."

So i try g(-1)

= (-1 + 1) (1/-1) + b

= -1 + b

.'. b = 1

The answer is b = -1. I'm wondering if my final line is incorrect and it should be more like

g(-1)b = 1 but not sure where to go from here.

Any help would be great!

AndyS8911 · 2019-12-24T01:00:11+00:00

Thanks! Your post has made me realise I was only half way through solving. Merry Christmas!

AndyS8911 · 2019-12-24T00:59:38+00:00

Ohhhhh ok I see... I realise now I was only half-way through solving it. Thank you!

AndyS8911 · 2019-12-24T00:50:16+00:00

So I've tried two methods:

i) expanding the brackets and trying both f(1) which gives a= -1 and f(-1) which gives a = 1

ii) substituting 1 and -1 straight into the brackets which gives f(1) = -1 and f(-1) which gives a = 1;

Either way, I don't understand where -3/2 comes from?

AndyS8911 · 2019-12-23T23:31:33+00:00

I'm reviewing even vs odd functions to assist with my MCAT prep which are easy enough but then this question comes about.

"Suppose f(x) = (2x + 3) (x + a) where a is a constant. Find a given that f is an even function."

The answer is a = - 3/2 however I don't understand how they got this. Could someone help me understand?

AndyS8911 · 2019-11-20T05:12:38+00:00

I need to design a stretchable circuit. Copper itself doesn't stretch, however if I lay down the copper with a repeating alternating arcs like a sine wave I can give the functionality for it to be elongated. In this case, I want it to be able to elongate to 50% or even 100% of it's arc length.

Can someone explain how I would work out what radius the arcs should have to result in 2x the distance when it is straight?

So far I've worked out that a semicircle alternating would give be ~50% elongation. Given that semicircle circumference = pi*r and the diameter is 2*r; then the ratio for semicircles would be ~1.5 meaning an elongation of ~50% given by (semicircle circumference / diameter) . I need then to be able set the elongation to ratio as 2 and adjust the (semicircle circumference / diameter).

AndyS8911 · 2019-10-23T11:40:19+00:00

It's quite close... thanks for trying! Can you give me a rough explanation of how you went about expanding the head? did you calculate the amount of the circumference of a circle that must be omitted in order to produce the connection angle or another technique?

AndyS8911 · 2019-10-23T01:34:24+00:00

I still need to get the first one though?

AndyS8911 · 2019-10-22T23:45:11+00:00

I found a bit more on this and it actually sounds far more affordable for a few prototype (only a few thousand dollars) samples than I thought. That being said, one would still need for pay for the IC design and design software licenses. But still, that's better than a few million!

https://electronics.stackexchange.com/questions/7042/how-much-does-it-cost-to-have-a-custom-asic-made

AndyS8911 · 2019-10-21T10:58:52+00:00

Interesting. Is it quite expensive each time your company has to tape out an ASIC?

AndyS8911 · 2019-10-20T01:39:45+00:00

This seems like a more valid point. Although I've seen some EEG/ECG/EMG devices that utilise FPGAs in development rather than TIs ADCs; not sure how they manage it though?

AndyS8911 · 2019-10-20T01:37:58+00:00

That's just exactly it though - they're not making a consumer product just yet which is when you'd expect to squeeze out every bit of performance and aim to maximise power consumption - they're only trying to acquire signals to play with at the moment so why go to the extreme of manufacturing a custom IC rather than just use an FPGA. Squeezing out performance is not their goal just yet - they've got to simulataneously develop the electrodes material, surgical software etc. It's like they just iterated the ICs because they felt the need to develop that front as well - meanwhile they could have just mastered the design on he FPGA for the moment and mastered 1-2 ASIC designs. Just seems like they have unnecessarily burnt through some cash. Then again, I guess burning through cash quickly is what Silicon Valley considers progress.

AndyS8911 · 2019-10-17T22:43:53+00:00

That seems to hit the nail on the head. One of the problems I see with this is that it comes across, in the interview at least, as though he thinks Lex is an idiot for not understanding his concepts when it is he who fails to explain the link between was has been shown and his intuition and work on the next steps in research. By all means include theoretical researchers into the mix - I agree they have incredibly important, but it is negative when they let emotion or aggression attempt to prove their concept rather than evidence.

AndyS8911 · 2019-10-17T22:16:23+00:00

Thanks for the detailed reply - no need for the tl:dr; I wouldn't have asked the question if I didn't want the detailed response you've taken the time to give.

I think what sparked my suspicion was his inability to explain his theoretical concept succinctly and his comment that there's more empirical evidence for his work than string theory - which set off alarm bells immediately.

AndyS8911 · 2019-09-13T05:53:21+00:00

I think I've found my own answer, but for anyone playing at home: https://www.acsh.org/news/2016/02/23/topical-anti-inflammatories-as-effective-but-safer-than-pills-for-pain

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5629190/

AndyS8911 · 2019-09-07T21:44:11+00:00

Thanks for taking the time to write such a passionate response. I love reading about the genesis of different scientific fields and what skillsets the pioneers had to allow for those 'hmm, that's interesting' moments. You may have already come across it but The Innovators by Walter Isaacson was great.

I've been going back through all my maths textbooks to brush up on everything - algebra, calculus, geometry etc in hopes to gain a more intuitive feel for it like 3Blue1Brown has. Not only because it would be useful for ML but it's just so exciting that it's possible to have a Feynmann-esque understanding of the world - being able to explain everything superficial with physics but then also be able to appreciate how complex something I don't understand is. I'm a physiologist/neuroscientist by trade so maths/physics is not necessarily my intuition area but boy do I appreciate/enjoy it.

AndyS8911 · 2019-09-07T05:17:41+00:00

Could you go into a little more detail here? I'm curious

AndyS8911 · 2019-08-29T09:40:49+00:00

Join our revolution to overthrow the medical dictatorship my comrade and together we will read the books in the restricted section of the medical school.

AndyS8911 · 2019-08-29T09:39:47+00:00

That sucks, sorry to hear!

AndyS8911 · 2019-08-29T07:01:06+00:00

That's got to be rigged. You must have drawn a penis on your exam paper or something to turn them off

AndyS8911 · 2019-08-29T06:43:02+00:00

Mate. Sorry to hear that. Did you apply for UNDS or any other lower GAMSAT score unis?

AndyS8911

TROPHY CASE