Portable MRI Machine Comes To The Patient

May 8, 2020 by 41 Comments

To say that the process of installing a magnetic resonance imager in a hospital is a complex task is a serious understatement. Once the approval of regulators is obtained, a process that could take years, architects and engineers have to figure out where the massive machine can be installed. An MRI suite requires a sizable electrical service to be installed, reinforced floors to handle the massive weight of the magnet, and special shielding in the walls and ceiling. And once the millions have been spent and the whole thing is up and running, there are ongoing safety concerns when working around a gigantic magnet that can suck ferromagnetic objects into it at any time.

MRI studies can reveal details of diseases and injuries that no other imaging modality can match, which justifies the massive capital investments hospitals make to obtain them. But what if MRI scanners could be miniaturized? Is there something inherent in the technology that makes them so massive and so expensive that many institutions are priced out of the market? Or has technology advanced far enough that a truly portable MRI?

It turns out that yes, an inexpensive MRI scanner is not only possible, but can be made portable enough to wheel into a patient care room. It’s not without compromise, but such a device could make a huge impact on diagnostic medicine and extend MRI technologies into places far beyond the traditional hospital setting.

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Hackaday Podcast 066: The Audio Overdub Episode; Tape Loop Scratcher, Typewriter Simulator, And Relay Adder

May 8, 2020 by 3 Comments

Hackaday editors Elliot Williams and Mike Szczys stomp through a forest full of highly evolved hardware hacks. This week seems particularly plump with audio-related projects, like the thwack-tackular soldenoid typewriter simulator. But it’s the tape-loop scratcher that steals our hearts; an instrument that’s kind of two-turntables-and-a-microphone meets melloman. We hear the clicks of 10-bit numbers falling into place in a delightful adder, and follow it up with the beeps and sweeps of a smartphone-based metal detector.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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A Microcontroller Display With A Classic Twist

May 8, 2020 by 18 Comments

In a fit of lock-down-induced boredom, [Peter Z] has turned his smartphone into an LCD screen (simulation) via an Android app (German language, Google Translate link), so that a mobile device can be plugged into your favourite microcontroller and the classic HD44780 LCD look can be replicated on its screen.

It doesn’t speak standard HD44780, but rather a custom UART serial protocol, so if you’re looking for something to replace a busted LCD, this isn’t your bag. But if you are looking for a large UART terminal for debugging, with a nice aesthetic, you win.

We’d guess that a serial-to-Bluetooth converter could also be made to function, with a bit of work. The protocol is trivial too, meaning that almost any microcontroller could make use of it. All the code as well as the APK is available from the forum linked above, and there is a YouTube video of it in operation below.

The number one complaint in the comments is going to be that this doesn’t emulate a HD44780, so if that’s really what you want, read this deep-dive into the HD44780 and get hacking.

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This Week In Security: Psychic Paper, Spilled Salt, And Malicious Captchas

May 8, 2020 by 10 Comments

Apple recently patched a security problem, and fixed the Psychic Paper 0-day. This was a frankly slightly embarrasing flaw that [Siguza] discovered in how iOS processed XML data in an application’s code signature that allowed him access to any entitlement on the iOS system, including running outside a sandbox.

Entitlements on iOS are a set of permissions that an application can request. These entitlements range from the aforementioned com.apple.private.security.no-container to platform-application, which tells the system that this is an official Apple application. As one would expect, Apple controls entitlements with a firm grip, and only allows certain entitlements on apps hosted on their official store. Even developer-signed apps are extremely limited, with only two entitlements allowed.

This system works via an XML list document that is part of the signed application. XML is a relative of HTML, but with a stricter set of rules. What [Siguza] discovered is that iOS contains 4 different XML parsers, and they deal with malformed XML slightly differently. The kicker is that one of those parsers does the security check, while a different parser is used for that actual permission implementation. Is it possible that this mismatch could contain a vulnerability? Of course there is.
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Fail Of The Week: Bright Idea For LED Signs Goes Bad

May 8, 2020 by 43 Comments

Typically when we select a project for “Fail to the Week” honors, it’s because something went wrong with the technology of the project. But the tech of [Leo Fernekes]’ innovative LED sign system was never the problem; it was the realities of scaling up to production as well as the broken patent process that put a nail in this promising project’s coffin, which [Leo] sums up succinctly as “The Inventor’s Paradox” in the video below.

The idea [Leo] had a few years back was pretty smart. He noticed that there was no middle ground between cheap, pre-made LED signs and expensive programmable signboards, so he sought to fill the gap. The result was an ingenious “LED pin”, a tiny module with an RGB LED and a microcontroller along with a small number of support components. The big idea is that each pin would store its own part of a display-wide animation in flash memory. Each pin has two terminals that connect to metal cladding on either side of the board they attach to. These two conductors supply not only power but synchronization for all the pins with a low-frequency square wave. [Leo]’s method for programming the animations — using a light sensor on each pin to receive signals from a video projector — is perhaps even more ingenious than the pins themselves.

[Leo]’s idea seemed destined for greatness, but alas, the cruel realities of scaling up struck hard. Each prototype pin had a low part count, but to be manufactured economically, the entire BOM would have to be reduced to almost nothing. That means an ASIC, but the time and expense involved in tooling up for that were too much to bear. [Leo] has nothing good to say about the patent game, either, which his business partners in this venture insisted on playing. There’s plenty of detail in the video, but he sums it up with a pithy proclamation: “Patents suck.”

Watching this video, it’s hard not to feel sorry for [Leo] for all the time he spent getting the tech right only to have no feasible way to get a return on that investment. It’s a sobering tale for those of us who fancy ourselves to be inventors, and a cautionary tale about the perils of participating in a patent system that clearly operates for the benefit of the corporations rather than the solo inventor. It’s not impossible to win at this game, as our own [Bob Baddeley] shows us, but it is easy to fail.

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No Corners Were Cut On This Arduino Circle Cutter

May 8, 2020 by 9 Comments

Hackers always have their eye out for a good deal, so when [Gadget Reboot] saw a good price on square stickers he had to pull the trigger. There was just one problem: his logo is a circle. He could have rectified the problem with a pair of scissors on a lazy afternoon, but we think building an elaborate circle cutting machine was a much better use of his time.

But this project isn’t just for the Giotto wannabes. Even if you don’t find yourself in need of an infinite supply of perfect paper circles, the video after the break provides an excellent case study in getting stepper motors to do your bidding; whatever that might be. [Gadget Reboot] walks the viewer through the design and construction of a dual stepper motor controller that could be used for a multitude of tasks.

With an onboard Arduino Pro Micro, OLED display, and rotary encoder, this controller just needs some custom software to make your CNC dreams come true. [Gadget Reboot] is even using low-cost optical endstops in this build, which are a great non-contact way of making sure your machine doesn’t go out of bounds. That’s particularly important when the machine happens to be wielding a razor blade.

If you’re a thoroughly modern hardware hacker who prefers using a web browser to twiddling knobs, then perhaps you’d be interested in the WiFi enabled stepper motor controller we covered recently.

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Making Art With Keycap Bots

May 7, 2020 by 9 Comments

Robots come in all shapes and sizes, from remote landers on distant planets to assembly arms working hard in auto plants. Of course, the definition is broad and can contain more frivolous entities, too. [smdavee]’s watercoloring ‘bots may not be particularly complex or sentient, but they’re a fun creative build.

The design is akin to that of the BristleBot, with a pager vibration motor allowing the ‘bot to wobble about on unsteady feet. In this case, a keyboard cap is used, with cottontips inserted in the base to act as legs. These are then dipped in watercolor paints, and the attached motor is then switched on to vibrate the ‘bot around the page.

It’s an easy build, and one that would be particularly well-suited to teaching young children basic electronic concepts. Plus, there’s the added fun of getting to make a mess with watercolors, too. If you’ve got a fun art robot hiding away in your garage, be sure to let us know. Video after the break.

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