Cheap 3D Printers Make Cheaper(er) Bioprinters

In case you missed it, prices on 3D printers have hit an all time low. The hardware is largely standardized and the software is almost exclusively open source, so it makes sense that eventually somebody was going to start knocking these things out cheap. There are now many 3D printers available for less than $300 USD, and a few are even dipping under the $200 mark. Realistically, this is about as cheap as these machines are ever going to get.

A startup by the name of 3D Cultures has recently started capitalizing on the availability of these inexpensive high-precision three dimensional motion platforms by co-opting an existing consumer 3D printer to deliver their Tissue Scribe bioprinter. Some may call this cheating, but we see it for what it really is: a huge savings in cost and R&D time. Why design your own kinematics when somebody else has already done it for you?

Despite the C-3PO level of disguise that 3D Cultures attempted by putting stickers over the original logo, the donor machine for the Tissue Scribe is very obviously a Monoprice Select Mini, the undisputed king of beginner printers. The big change of course comes from the removal of the extruder and hotend, which has been replaced with an apparatus that can heat and depress a standard syringe.

At the very basic level, bioprinting is performed in the exact same way as normal 3D printing; it’s merely a difference in materials. While 3D printing uses molten plastic, bioprinting is done with organic materials like algae or collagen. In the Tissue Scribe, the traditional 3D printer hotend has been replaced with a syringe full of the organic material to be printed which is slowly pushed down by a NEMA 17 stepper motor and 8mm leadscrew.

The hotend heating element and thermistor that once were used to melt plastic are still here, but now handle warming the metal frame used to hold the syringe. In theory these changes would have only required some tweaks to the firmware calibration to get working. Frankly, it makes perfect sense, and is certainly a much easier to pull off than some of the earlier attempts at homebrew biological printers we’ve seen.

We won’t comment on the Tissue Scribe’s price point of $999 USD except to say that in the field of bioprinters, that’s pocket change. Still, it seems inevitable that somebody will build and document their own bolt-on biological extruder now that 3D Cultures has shown how simple it really is, so they may find themselves undercut in the near future.

If all this talk of hot extruded collagen has got you interested, we’ve seen some excellent resources on the emerging field of bioprinting that will probably be right up your alley.

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Hackaday Prize Entry: Hand Tremor Suppression Wearable Device

It is extremely distressing to watch someone succumb to an uncontrollable hand tremor. Simple tasks become frustrating and impossible, and a person previously capable becomes frail and vulnerable. Worse still are the reactions of other people, in whom the nastiest of prejudices can be unleashed. A tremor can be a debilitating physical condition, but it is not one that changes who the person afflicted with it is.

An entry from [Basian Lesi] in this year’s Hackaday Prize aims to tackle hand tremors, and it takes the form of a wearable device that tries to correct the tremors by applying small electrical stimuli in response to the motion it senses from its built-in accelerometer. At its heart is an ATMega328p microcontroller and an MPU6050 accelerometer chip, and the prototype is shown using a piece of stripboard mounted in a 3D-printed box. It’s still in development and testing, but they have posted a video showing impressive results that you can see below the break, claiming an 85% reduction in tremors.

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Hackaday Prize Entry: Wheelchair User Pressure Relief Indicator System

It is difficult to put yourself as an able-bodied person into the experiences of a person with a physical disability. Able-bodied people are quick with phrases such as “Confined to a wheelchair” with little idea of what that really means, and might be surprised to meet wheelchair users who would point out that far from being a prison their chair might, in fact, be their tool of liberation.

It is also difficult for an able-bodied person to understand some of the physical effects of using a wheelchair. In particular, some wheelchair users with paralysis can suffer from dangerous pressure sores without being aware of them due to their loss of feeling. Such people, therefore, have a regime of exercises designed to relieve the pressure that causes the sores, and these exercises must be completed as often as every half hour. They can be inconvenient and difficult to perform, so in an effort to help people in that position there is a Hackaday Prize entry that provides feedback on how effectively the exercise regime has been performed.

The project puts an array of force-sensitive resistors on the bed of the chair underneath its cushion and monitors them with an Arduino before giving a feedback to the user via a set of LEDs. So far they have created a first prototype, and are awaiting parts and recruiting users for testing a second.

It would be nice to think that this project would have a positive impact on the lives of the people it aims to help. It’s not the first time the Hackaday Prize has ventured into this field, as the 2015 winner demonstrates.

Hackaday Prize Entry: Ebers – Diabetes Care, Step By Step

Diabetes is a disease that, among other things, has significant effects on the feet due to a combination of neuropathy, vascular issues, and other factors. You may have seen special diabetes socks with features like non-elasticated cuffs for better circulation and a lack of seams to prevent the formation of blisters. Taking care of  your feet is essential in diabetes to prevent injury and infection. Ebers is a project that seeks to help in just this area.

Ebers monitors plantar pressure, temperature, and humidity in the sole of the shoe. It then feeds this data back to a smartphone for analysis over Bluetooth. The brain of the project is an Arduino Pro Mini which is tasked with interfacing with the various sensors.

The project relies on 3D printed insoles which fit inside the shoe of the wearer. This is a particularly useful application of 3D printing, as it means the insole can be customised to fit the individual, rather than relying on a smaller selection of pre-sized forms. This has the additional benefit of allowing the insole to be designed to minimise pressure on the foot in the first place, further reducing the likelihood of injury and infection. The pressure sensing is actually built into the insole itself, and can measure pressure at several different areas of the foot.

Overall, it’s a project with huge potential health benefits for those with diabetes. We look forward to seeing where this project goes in future, and how it can bring improvements to the quality of life for people the world over.

Hackaday Prize Entry: OrthoSense, a Smart Knee Brace for Physical Therapy

If you have knee surgery, you can probably count on some physical therapy to go with it. But one thing you might not be able to count on is getting enough attention from your therapist. This was the case with [Vignesh]’s mother, who suffers from osteoarthritis (OA). Her physiotherapist kept a busy schedule and couldn’t see her very often, leaving her to wonder at her rehabilitation progress.

[Vignesh] already had a longstanding interest in bio-engineering and wearables. His mother’s experience led him down a rabbit hole of research about the particulars of OA rehabilitation. He found that less than 35% of patients adhere to the home regimen they were given. While there are a lot of factors at play, the lack of feedback and reinforcement are key components. [Vignesh] sought to develop a simple system for patients and therapists to share information.

The fruit of this labor is Orthosense, an intelligent knee brace system that measures gait angle, joint acoustics, and joint strain.  The user puts on the brace, pairs it with a device, and goes through their therapy routine. Sensors embedded in the brace upload their data to the cloud over Bluetooth.

Joint strain is measured by a narrow strip of conductive fabric running down the length of the knee. As the user does their exercises, the fabric stretches and relaxes, changing resistances all the while. The changes are measured against a Wheatstone bridge voltage divider. The knee’s gait angle is measured with an IMU and is calculated relative to the hip angle—this gives a reference point for the data collected by the strain sensor. An electret mic and a sensitive contact mic built for body sounds picks up all the pops and squeaks emitted by the knee. Analysis of this data provides insight into the condition of the cartilage and bones that make up the joint. As you might imagine, unhealthy cartilage is noisier than healthy cartilage.

[Vignesh]’s prototype is based the tinyTILE because of the onboard IMU, ADC, and Bluetooth. Since all things Curie are being discontinued, the next version will either use something nRF52832 or a BC127 module and a la carte sensors. [Vignesh] envisions a lot for this system, and we are nodding our heads to all of it.

Game Boy Advance Hiding In a Medical Device

It turns out that medical manufacturers also do hacking once in a while. [JanHenrikH] recently tweeted a photo of an ECG-Trigger-Unit that he’d opened up. Inside he found that the LCD screen was that of a Game Boy Advance (GBA) and the reason he could tell was that the screen’s original case was still there, complete with GAME BOY ADVANCE SP written on it.

In the manufacturer’s defense, this device was likely made around the year 2000 when gaming products were some of the best sources for high speed, high quality, small LCDs displays.  This design document for a portable ECG measurement instrument from as recently as 2013 cites reasons for using a GBA as:

  • impressive plotting results,
  • no serious transmission delays, and
  • fine graphics processing capability.

The Verge had even turned up this US patent from 1997 that has the diagnostic medical device be a cartridge for plugging into a Game Boy. At the time, PCs were frequently used for medical displays but this patent cites issues such as the higher cost of PCs, software installation issues, and crashing. However, they talk about the crashing being due to running word processing and spreadsheet software on the same PC, something not likely to happen if the PC is dedicated to bedside monitoring.

But despite all those pros, wouldn’t you feel surprise and alarm when you first glimpse the Game Boy inside the device that’s monitoring your heart? We also have to wonder what licensing these products went through in the countries in which they were used. This particular device was made by German company Medical Imaging Electronics.

Game Boy hacks aren’t limited to the medical industry though. Here on Hackaday, we’ve seen them turned into remote controls for flying drones and we’ve seen Game Boy cartridge emulators that use STM32. Finally, if you’re wondering where you saw [Jan Henrik]’s name before, he was one of the two hackers driving the motorized armchair in a photo in our [Jenny List]’s SHACamp 2017 write-up.

Our thanks to [geonomad] for the tip!

Synthesizing Daraprim to Beat Price Gougers

Drugs are used the world over to treat disease. However, from time to time, the vagaries of market economics, or unscrupulous action, can radically increase the price of otherwise cheap pharmaceuticals far beyond the reach of the average person. This was the case with Pyrimethamine (sold as Daraprim), which is used to treat toxoplasmosis and malaria, among other users. With the price skyrocketing from $13 to $750 a tablet in the US in 2015, [NurdRage] decided to synthesize the drug on their own. (If you missed the background hubbub, search for “Martin Shkreli”.)

The video linked covers the final synthesis, though [NurdRage] has previously covered the synthesis of the required precursor chemicals. Budding chemists may grow excited, but there are significant hurdles to attempting this synthesis yourself. Chemicals involved are carcinogenic, toxic, acidic, or otherwise dangerous, and a fume hood is a necessity if working inside. Outside of this, there are immense risks in homebrewing pharmaceuticals. Performing the synthesis of an important drug is one thing, but to do so at a medical-grade level where the products are safe for human consumption is on an entirely different level.

Overall, [NurdRage] has put out a series of videos that have strong educational value, showing us what really goes into the production of a common pharmaceutical compound. There’s also something to be said about taking the production of life-saving medicines into one’s own hands in the face of prohibitive treatment costs. In a similar vein, perhaps you’ve considered producing your own insulin in an emergency?

[Thanks to jwrm22 for the tip]