Medical imaging is one of the very best applications of technology — it allows us to peer inside of the human body without actually performing surgery. It’s non-destructive testing to the extreme, and one of the more interesting projects we’ve seen over the past year uses AC currents and an infinite grid of resistors to image the inside of a living organism. It’s called Spectra and it is the brainchild of [Jean Rintoul]. Her talk at the Hackaday Superconference is all about low cost and open source biomedical imaging.
We’ve seen some interesting medical imaging hacks in the Hackaday Prize over the years. There have been vein finders and even a CT scanner, but when it comes to biomedical imaging, the Spectra project is something different. Right now, it’s just good enough to image organs while they’re still inside your body, and there’s still a lot of potential to do more. Let’s take a closer look a how this works.
The idea behind Spectra is to use AC waves through a medium (a fruit, or a person, or a rat) and use tomographic techniques to image the interior. Specifically, this is called Electrical Impedance Tomography, and you can surprisingly build a small version of this with very, very minimal hardware.
Electrical Impedance Tomography works due to the fact that different tissue types have different resistances. By sending an AC wave (around 10kHz or so) through a body, the inside can be reconstructed. Everything from lung volume measurements to muscle and fat mass to cancers can be detected with this technique. Yes, you’ll still need a tech or an MD to interpret the data, but this is a very inexpensive way to image the human body compared to current technology.
As for why this matters, this is a fantastically cheap way to look inside a body. Preventative care in medicine doesn’t have an affordable imaging solution; if you need an MRI or CT scan, odds are you’re only going to get that when you’re sick. A CT scanner will cost millions of dollars and MRI machines are even more expensive. [Jean]’s prototype electrical tomography setup can be build for well under a thousand dollars — and it looks she even has a crowd funding campaign in the work to get more test hardware out into the world. Making this both open source and low cost makes the technology more accessibility. We hope this ultimately leads to better medical care for everyone, and [Jean] is on the cutting edge of this advancement.