Biomedical Engineering Hack Chat

Join us on Wednesday, February 7 at noon Pacific for the Biomedical Engineering Hack Chat with Nyeli Kratz!

Although medical doctors and engineers generally work in completely different domains, there’s a fair amount of overlap between the disciplines. At the end of the day, they both solve problems, and while doctors clearly focus on the biological aspects of disease, there just might come a point where the problem has to be addressed with engineering principles. From the intricate design of an artificial hip to the electrical interface between an amputee’s nervous system and a prosthetic limb, biomedical engineers can make a tremendous contribution to positive patient outcomes.

join-hack-chatNyeli Kratz, a recent biomedical engineering grad, has worked on quite a few engineering solutions to diseases. Many of her projects, like this stand-up mobility aid or a wheelchair attachment that lets a tetraplegic father interact with his newborn child, seem aimed at making it easier for patients to interact with the world. She’ll stop by the Hack Chat to talk about these projects in particular as well as what the engineer brings to the table when it’s time to design hardware that heals.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, February 7 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Fail Of The Week: PCB LED Cube Fails Successfully

Remember LED cubes? We sure do — they were all the rage for a while, and then it seemed like everyone just sort of lost interest in them. There are probably a lot of reasons for that, not least of which is likely the amount of work it takes to put one together from discrete LEDs and separate pieces of wire. Could there be a better way?

Of course there could, and [Sasa Karanovic] thought he had it all figured out with this PCB-based LED cube. At first glance, it seems to make perfect sense; after all, weren’t PCBs invented to take the place of all that pesky point-to-point wiring in the early days of electronics? The boards [Sasa] designed are pretty cool, actually. They’ve each got room for 16 addressable WS2812 LEDs in 5 mm packages, with every possible bit of substrate removed to block the minimum amount of light. That left very little room for traces on the 2-mm-wide arms, so the PCBs had to have four layers, which raised eyebrows at the PCB house when [Sasa] submitted the design.

Such an airy and open design obviously has the potential for mechanical issues, which [Sasa] addressed by adding pads at three corners of each board; a vertical PCB connects to each LED board to provide mechanical support and distribute signals to the LEDs. The cube seems solid enough as a result, and even when handled the LED boards don’t really flop around too much. See the cube in action in the video below.

What’s nice about this design is the perfect spacing between the LEDs in all three dimensions, and the way everything lines up nice and straight. That would be really hard to do with wire, even for the most practiced of circuit sculptors. [Sasa] seems to agree, but still deems the build a failure because the PCBs block too much of the view. We suppose he’s got a point, and we’re not sure how well this would scale to an 8×8 cube. We’re not sure how we’d feel about paying for PCBs that are mostly air either, but as failures go, this one still manages to be pretty successful. Continue reading “Fail Of The Week: PCB LED Cube Fails Successfully”

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Hackaday Links: February 4, 2024

Things may not have gone as planned last week for the flying cellphone on Mars, but just because Ingenuity‘s flying career is over doesn’t mean there’s no more work to do. NASA announced this week that it’s going to try a series of “wiggle” maneuvers on Ingenuity‘s rotors, in an attempt to get a better look at the damage to the blade tips and possibly get some clues as to what went wrong. The conjecture at the moment seems to be that a large area of relatively featureless terrain confused the navigation system, which uses down-facing cameras to track terrain features. If the navigation program couldn’t get a bead on exactly how far above the ground it was, it’s possible the copter came in too hard and caused the rotor tips to dig into the regolith. There seems to be some photographic suggestion of that, with what looks like divots in the ground about where you’d expect the rotor tips to dig in, and even scraps of material that look out of place and seem to be about the same color as the rotor blades. All this remains to be seen, of course, and we’re sure that NASA and JPL are poring over all available data to piece together what happened. As much as we hate to say goodbye to Ingenuity, we eagerly await the post-mortem.

Continue reading “Hackaday Links: February 4, 2024”

Tricky 3D Printed Joinery Problem? Give Heat Staking A Try

When you just can’t 3D print something as a monolithic part, you’re going to have to join pieces together. In such cases, most of us instinctively include threaded inserts or nut slots in the design, or even reach for a tube of CA glue. But perhaps you should be thinking more along the lines of heat-staking your printed parts together.

Although you might not be familiar with the term, if you’ve looked inside anything made out of plastic, chances are good you’ve seen a heat-staked joint. As [Richard Sewell] explains, a heat-staked joint is nothing more than the classic mortise-and-tenon made from plastic where the tenon stands proud of the joint face so it can be softened with heat. The tenon spreads out so the joint can’t be pulled apart. A variant on the theme includes a mortise with a generous chamfer so the melted tenon can spread out, providing not only extra resistance to pull-out be also a more flush surface.

To melt the joint, [Richard] simply uses a soldering iron and a little pressure. To spread out both the heat and the force a bit, he uses the barrel of the iron rather than a tip, although we could see a broad chisel tip being used for smaller joints. Either way, a layer of Kapton tape helps keep the iron from getting gunked up with melted plastic. [Richard] lists a host of advantages for this kind of plastic joinery, including eliminating the need for additional hardware. But we think the best feature of this joint is that by avoiding monolithic prints, each aspect of a part can have its layer lines optimized.

While it probably isn’t applicable everywhere, heat-staking looks like a technique to keep in mind. We’d love to see [Stefan] over at CNC Kitchen do some of his testing magic on these joints, like he did for threaded inserts.

Hackaday Podcast Episode 255: Balloon On The Moon, Nanotech Goblets, And USB All The Way

This week, Dan joined Elliot for a review of the best and brightest hacks of the week in Episode 0xFF, which both of us found unreasonably exciting; it’s a little like the base-2 equivalent of watching the odometer flip over to 99,999. If you know, you know. We had quite a bumper crop of coolness this week, which strangely included two artifacts from ancient Rome: a nanotech goblet of colloidal gold and silver, and a perplexing dodecahedron that ends up having a very prosaic explanation — probably. We talked about a weird antenna that also defies easy description, saw a mouse turned into the world’s worst camera, and learned how 3D-printed signs are a whole lot easier than neon, and not half bad looking either. As always, we found time to talk about space, like the legacy of Ingenuity and whatever became of inflatable space habitats. Back on Earth, there’s DIY flux, shorts that walk you up the mountain, and more about USB-C than you could ever want to know.

And don’t forget that to celebrate Episode 256 next week, we’ll be doing a special AMA segment where we’ll get all the regular podcast crew together to answer your questions about life, the universe, and everything. If you’ve got a burning question for Elliot, Tom, Kristina, Al, or Dan, put it down in the comment section and we’ll do our best to extinguish it.

 

Grab a copy for yourself if you want to listen offline.

Continue reading “Hackaday Podcast Episode 255: Balloon On The Moon, Nanotech Goblets, And USB All The Way”

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Hackaday Links: January 28, 2024

From the “No good deed goes unpunished” files, this week came news of a German programmer who probably wishes he had selected better clients. According to Heise Online (English translation), a freelance programmer — referred to only as “defendant” in the article — was retained by a company to look into a database problem in their system. His investigation revealed that the customer’s database was being filled with log messages from a third-party service called Modern Solution GmbH & Co. KG. over a MySQL connection to a remote server. Assuming this connection was dedicated for his client’s use, the programmer looked at the executable used to make the connection with a text editor, which revealed a password in plain text. Upon connecting to the remote database, he found that it not only contained data for all of Modern Solution’s customers, but also data for all the end users of their customers.

Realizing he’d unintentionally wandered into verboten territory, the programmer immediately backed out and contacted Modern Solutions. They quickly fixed the issue, and then just as quickly reported him to the police. Their “investigation” revealed that the programmer had “decompiled” the executable to obtain the password, in violation of German law. The judge agreed, stating that merely looking at and using the password constituted a criminal offense, regardless of intent and despite the fact that Modern Solution had provided the password to the programmer’s client when they sold them the software. The upshot of all of this nonsense? A €3,000 fine for the programmer, if the verdict stands on appeal. It could have been worse, though; German law allows for up to three years in prison for such offenses.

Continue reading “Hackaday Links: January 28, 2024”

Reviving A Sensorless X-Ray Cabinet With Analog Film

In the same way that a doctor often needs to take a non-destructive look inside a patient to diagnose a problem, those who seek to reverse engineer electronic systems can greatly benefit from the power of X-ray vision. The trouble is that X-ray cabinets designed for electronics are hideously expensive, even on the secondary market. Unless, of course, their sensors are kaput, in which case they’re not of much use. Or are they?

[Aleksandar Nikolic] and [Travis Goodspeed] strongly disagree, to the point that they dedicated a lot of work documenting how they capture X-ray images on plain old analog film. Of course, this is nothing new — [Wilhelm Konrad Roentgen] showed that photographic emulsions are sensitive to “X-light” all the way back in the 1890s, and film was the de facto image sensor for radiography up until the turn of this century. But CMOS sensors have muscled their way into film’s turf, to the point where traditional silver nitrate emulsions and wet processing of radiographic films, clinical and otherwise, are nearly things of the past. Continue reading “Reviving A Sensorless X-Ray Cabinet With Analog Film”