Bluetooth Headphones For Hearing Aids

hearing

Cyborgs walk among us, but for the time being, it’s really only people with glasses, contact lenses, the occasional hearing aid and the infrequent prosthesis. As with all technology, these devices can be expanded into something they were not originally designed to do – in [Gertlex]‘ case, the superpower of listening to music through his hearing aids. he gets a few strange looks from wearing a Bluetooth headset around his neck, but the power to turn his hearing aids ito what are effectively in-ear monitors is a great application of modified electronics.

[Gertlex] began with a Bluetooth headset, his hearing aid, a few resistors, some wire, a 3.5mm audio connector, and an absurdly expensive DAI cable. The DAI cable – Direct Audio Input – is a pseudo-standardized feature on many hearing aids. as its name implies, it allows the wearer of a hearing aid to pipe audio directly into their ear.

By cutting up one of these $50+ DAI cables, [Gertlex] was able to construct a DAI to 3.5mm adapter cable. From there, it was simply a matter of installing a 3.5mm socket on a Bluetooth headset.

It’s a brilliant build, with the most expensive component being the DAI connector itself. [Gertlex] has a few ideas for making these connectors himself – they’re really only three pins and some plastic – and we’re hoping he gets around to that soon.

 

Android Based Wireless ECG

ECG

The title of [Nuclearrambo's] post says it all, “Android based wireless ECG monitoring (Temperature sensor and glucometer included).” Wow! What a project!

The project is built around the HC-06 bluetooth module and the Stellaris LaunchPad from TI, an inexpensive ARM developer kit. Building an ECG is a great way to learn about instrumentation amplifiers, a type of differential amplifier used for its extremely high common mode rejection ratio (CMRR). Please be sure to keep in mind that there are a myriad of safety issues and regulation concerns for medical device, and there is no doubt that an ECG is considered a medical device. Sadly, [Nuclearrambo's] post does not include all of the code and design files you need to build the system, which is understandable considering this is a medical device. That being said, he provides a lot of information about building high-quality ECG instrumentation and the web interface.

It would be great if [Nuclearrambo] could post the Android application code and Stellaris LaunchPad code. Even with these omissions, this post is still worth reading. Designing medical devices requires a lot of know-how, but who knows, maybe your next project can save your life!

A Webcam Based Posture Sensor

Webcam based posture sensor

Even for hobby projects, iteration is very important. It allows us to improve upon and fine-tune our existing designs making them even better. [Max] wrote in to tell us about his latest posture sensor, this time, built around a webcam.

We covered [Max's] first posture sensor back in February, which utilized an ultrasonic distance sensor to determine if you had correct posture (or not). Having spent time with this sensor and having received lots of feedback, he decided to scrap the idea of using an ultrasonic distance sensor altogether. It simply had too many issues: issues with mounting the sensor on different chairs, constantly hearing the clicking of the sensor, and more.  After being inspired by a very similar blog post to his original that mounted the sensor on a computer monitor, [Max] was back to work. This time, rather than using an ultrasonic distance sensor, he decided to use a webcam. Armed with Processing and OpenCV, he greatly improved upon the first version of his posture sensor. All of his code is provided on his website, be sure to check it out and give it a whirl!

Iteration leads to many improvements and it is an integral part of both hacking and engineering. What projects have you redesigned or rebuild? Let us know!

3D Printed Splint Saves Baby’s Life

3D-printed-breathing-device-2a

Here’s another heartwarming story about how 3D printers are continuing to make a real difference in the medical world. [Garrett] is just a baby whose bronchi collapse when breathing — he’s been on a ventilator for most of his life – Until now.

[Scott Hollister] is a professor of Biomedical Engineering and Mechanical Engineering, as well as being an associate professor of surgery at the University of Michigan. Between him and [Doctor Glen Green], an associate professor of Pediatric Otolaryngology, they have created a bioresorbable device that could save little [Garrett's] life.

By taking CT scans of [Garrett's] bronchi and trachea, they were able to create a 3D model and design a “splint” to help support the bronchi from collapsing during normal breathing. If all goes well, within 3 years, the splint will dissolve in his body and he will be able to breath normally for good. The material in question is a biopolymer called polycaprolactone, which they were actually granted emergency clearance from the FDA to use for [Garrett]. They used an EOS SLS based 3D printer.

The surgery was successful, and [Garrett] is now on the road to recovery. Stick around for a few videos showing of the printing process and surgery.

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Sniffing pH Sensor RF Signals for Feedback Re: Your Esophagus

For about a week [Justin] had a wireless acidity level sensor in his esophagus and a pager-looking RF receiver in his pocket. So he naturally decided to use an RTL-SDR dongle to sniff the signals coming out of him. As most of our Hackaday readers know, these cheap RTL2382U-based DVB-T receivers are very handy when it comes to listening to anything between 50MHz and 1800MHz. [Justin] actually did a great job at listing all the things these receivers can be used for (aircraft traffic monitoring, weather images download, electric meter reading, pacemaker monitoring…).

After some Googling he managed to find his Bravo pH sensor user’s guide and therefore discovered its main frequency and modulation scheme (433.92MHz / ASK). [Justin] then used gqrx and Audacity to manually decode the packets before writing a browser-based tool which uses an audio file. Finally, a few additional hours of thinking allowed him to extract his dear esophagus’ pH value.

MRRF: 3D Bioprinting

bioprint

There were a few keynotes at this year’s Midwest RepRap festival, and somewhat surprisingly most of the talks weren’t given by the people responsible for designing your favorite printer. One of the most interesting talks was given by [Jordan Miller], [Andy Ta], and [Steve Kelly] about the use of RepRap and other 3D printing technologies in biotechnology and tissue engineering. Yep, in 50 years when you need a vital organ printed, this is where it’ll come from.

[Jordan] got his start with tissue engineering and 3D printing with his work in printing three-dimensional sugar lattices that could be embedded in a culture medium and then dissolved. The holes left over from the sugar became the vasculature and capillaries that feed a cell culture. The astonishing success of his project and the maker culture prompted him and others to start the Advanced Manufacturing Research Institute to bring young makers into the scientific community. It’s a program hosted by Rice University and has seen an amazing amount of success in both research and getting makers into scientific pursuits.

One of these young makers is [Andy Ta]. An economics major, [Andy] first heard of the maker and RepRap community a few years ago and bought a MakerBot Cupcake. This was a terrible printer, but it did get him involved in the community, hosting build workshops, and looking into 3D printing build around DLP-cured UV resin. At AMRI, [Andy] started looking at the properties of UV-cured resin, figuring out the right type of light, resin, and exposure to create a cured resin with the right properties for printing cell colonies. You can check out [Andy]‘s latest work on his webzone.

[Steve Kelly] has also done some work at AMRI, but instead of the usual RepRap or DLP projector-based printers, he did work with shooting cell cultures out of an ink jet print head. His initial experiments involved simply refilling an ink jet cartridge with a bacterial colony and discovering the cells actually survived the process of being heated and shot out of a nozzle at high speed. Most ink jets printers don’t actually lay out different colors on a precise grid, making it unusable for growing cell cultures. [Steve] solved this problem with an inkjet controller shield attached to a RepRap. All of [Steve]‘s work is documented on his Github.

It’s all awesome work, and the beginnings of both bioengineering based on 3D printers, and an amazing example of what amateur scientists and professional makers can do when they put their heads together. Video link below.

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Taste-O-Vision Is Now A Thing

taste

Not satisfied with late 1950s concepts of Smell-O-Vision [Nimesha]  has created something extraordinary: A digital taste sensor, capable of representing taste with a little bit of heat, electricity, and an Arduino

The device purportedly works by via thermal and electrical stimulation of the tongue using silver electrodes. According to this video, different tastes are created with different currents and temperatures. For example, a sour taste is produced on the electrodes by varying the current from 60uA to 180uA and increasing the temperature up to 30 degrees C. Mint is produced by simply decreasing the temperature from 22C to 19C.

The control electronics include an Arduino, a motor controller, and a heat sink attached to one of the silver electrodes. Communication is done through USB, and of course there’s a mobile app for it, more specifically a protocol called Taste Over IP. This allows anyone to send a taste to anyone with one of these devices.

Videos below, and before you laugh, we’d really like to try one of these out.

Thanks [Jess] for the tip.

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