PC in MRI (was "OT/field coil?")

[PRR]

an MRI guy  --shooter

Shooter - You may enjoy this story.

But it DID destroy the data

At this small rural hospital, when IT staffers decommission old PCs, they're careful to destroy all the data on the hard drives, says an IT pilot fish there.

"Having no access to a regular disk-wipe system, we would always take the hard drive out of the PC and into the room with the magnetic resonance imaging machine," fish says.

"An MRI machine is primarily a huge electromagnet, so simply walking into the room with the drive would scramble the bits."

But one day, a relatively new PC tech can't get the case off an old PC to remove the hard drive. "He thought that if taking the hard drive near the MRI would clean it, then surely taking the entire computer in there would serve the same purpose," says fish.

So the tech loads the PC onto a cart and heads for Radiology, where he enlists the help of the MRI tech in rolling the cart into the room.

"Bad idea," fish says. "The PC was just sitting on top of the cart, and when they got to within 10 feet of the MRI machine's aperture, the PC started to slide.

"It picked up speed, then literally flew off the cart, crashing into the opening where a patient would lie during an exam."

There are gouges in the MRI machine. The legs of the cart have been smashed. The PC's case looks like a crumpled fender. And the stunned PC and MRI techs are just glad they weren't in the way when PC and cart took off.

"We tried to get the PC out of the magnet without turning off the MRI, because turning it off and back on and recalibrating it would take three days and cost a bundle," fish says.

"We wrapped it with duct tape, tied three thick ropes to it, then enlisted 12 large men from maintenance to try to pull it out."

No luck. When they pull, the PC floats in the opening, but they can't drag it out.

"Yes, we had to turn the MRI off," says fish. "It took three days and support folks from the vendor had to be flown in to restart it. Luckily we were insured for loss of business.

"And we bought a disk-wipe system."

Shark Tank -- InfoWorld

[shooter]

 
Oh the things I've pulled out!
I once took out a steel O2 tank that a Doctor grabbed because his wife, the patient, was breathing hard!  It smashed the plastic façade, broke her shoulder, n stuck.  I used old climbing gear, ropes, webbing n carabineers, and a 1TON come-a-long.  I was able to tension and get the tank, "suspended", while they got her out.

The worst was a floor buffer!, sockets, lighters, wheelchair, bobbey pins, pens.............

 the biggest PITA were metal shavings brought in by guys that grind metal, it's in their cloths, then gets sucked into cracks n crevices, as you pulse the magnetic field, they "dance", causing white pixel artifacts that can take days to isolate and fix! 

new procedures were finally implemented universally to keep those projectiles from ever getting close.

[PRR]

Very early article on MRI. 1958. Not doing precision mapping; only reading water-content of a small vial of corn syrup.

https://www.americanradiohistory.com/Archive-Electronics/50s/Electronics-1958-02-28.pdf
16MB PDF file, around page 53 of the PDF.

Magnetic Resonance Determines Moisture
The absorption of radio-frequency energy by the nucleus of a hydrogen atom
placed in a constant magnetic field is the principle used to measure the moisture
content in hygroscopic solids. Nondestructive analysis of raw materials
and end products can be conducted by nontechnical personnel, is accurate
within 0.2 percent and may take as little as 30 seconds to make
By THOMAS F. CONWAY and ROBERT J. SMITH, Corn Products Refining Co., Chicago, Ill.

[shooter]

 
I was just thinking of my MRI days!, Told my wife; working on my camper in the cold was like doing a cryo-fill in January!
Was also thinking of the gradient amps, basically crown DC300's modified.  used 6 amps as master/slave for the 3 main axes. inside a 40cm sphere we would shim the magnetic field so Fo was 63.8-ish mhz +/- 2hz at the course pass, then induce dc current in the gradients to bring that down to +/- .2hz
In the early days that took 2 days and 2 techs, by the time I was out you could nail it on a GE system in 4-6hrs, and 12hrs on a Philips.

My favorite story glancing, was GM self driving car, "auto driving system allows driver to light cigarette while making a sweeping loop"    Hell, we did that WITHOUT self driving features 

thanks PRR

[shooter]

I made it through the lite reading 
what strikes me, they had all the "logic" figured out by '58, flipflops, mutivibrators, realtime clocks, OR, AND....
BUT they were just getting to core memory, early transistors, still working tube logic 

I thought the hardware woulda came then the logic guys asking what can we do with this 

It's truly amazing how devolved we've become

thanks again

[PRR]

The logic existed on paper long before the hardware was practical. Babbage struggled to make hardware for mechanical calculations.

[shooter]

Babbage

WOW!
read the wiki highlights and my head is spinning.  We do stand on the shoulders of giants

thanks for the history, I'm finally old enough to enjoy it 

[DummyLoad]

The logic existed on paper long before the hardware was practical. Babbage struggled to make hardware for mechanical calculations.

https://www.history.com/news/10-things-you-may-not-know-about-ada-lovelace

and she wrote the first theoretical program based on babbage's works.


--pete

[sluckey]

Any kin to Linda?

[PRR]

Back to MRI.....

Here's a couple idiots with an MRI machine in the garage!

https://www.roadandtrack.com/car-culture/a25674/this-wrench-costs-100-times-more-than-yours/

They throw a stapler in and it goes crazy. They tie a (plain steel) wrench to a scale and find 500 pounds pull. They then try an office chair, 2,000 pounds pull and not even in the main field!

Side note: VARIAN, the name on the MRI, is the outfit which absorbed much tube technology including the H+K transmitter tubes that some guys here were working in Champ SE fashion.

[shooter]

still got a few titanium tools, useless as actual tools 
doing it long enough you learned which steel tools you could "get away with" in the field.  The biggest problem, you'd have a screwdriver in the back pocket, walk up and WHAM, upside the head 

one interesting thing, once you had a steel tool (smallish, nothing bigger than #2 Philips) inside the bore, the "sweetspot",(magnetic iso-center), had very little pull, move it the wrong way and get a wrist snap from hell!! 

as complex as the systems were, the primary fails were almost always mechanical, big mechanical required bringing the magnet off field ~~ 3hr process down then up, burning ~~ 50-100L of helium, then at least an hour running cal's.  So changing a table drive motor (1.5hrs), was an 8hr day, well night, you never got to take a system down if you could keep it limping til the patients were done