Progress,
in public.

Repairing our 3D printer

We have found some models on NIH 3D that would make good phantoms, specifically we have decided to model the Radius bone to measure bio impedance testing. (link to 3d model: here), an image has also been attached for reference. However while testing our 3d printer's leveling and filament dispencement, a part known to be a weakness of the Ender 3 v2 snapped in half, we have ordered the replacement part on and should continue with the phantom creation the following week.

Beginning Experimenting With Hardware

We have recieved our hardware from Analog Digital this past week and have begun setting up the software necessarry to begin testing. The last couple of weeks have been slow as I recently had surgery on my right hand and have been recovering. Our first goal is to understand the bundled software with the analog digital hardware, specifically analog devices SensorPal. We also want to begin experiemnting with phantoms as soon as possible, this means 3d printing a mock bone and placing it in a saline control tube to simulate a bone surrounded by blood. We will begin building researching electrode sensors to use for the phantom model.

Commiting to Alternative Hardware

Yesterday EIT-tek has committed and ordered our choice of hardware. We have decieded to go with AN-1557 stack from analog digital. The following hardware is a major improvement and a more specialized stack for bio-impedance imaging. Analog digital has specific drivers for analyzing these signals, if you are interested in the hardware we will be using, click here. Compared to the Red Pitaya this hardware stack produces greater noise at 100dB compared to 80dB, effectivly a 100 times better result than the Red Pitaya, (db scales logarithmically). The total cost of this hardware was about 600 dollars, we should recieve this stack within the coming week. Additionally we plan on creating an analog mux in the frontend to allow us to create multiple channels of electrodes. More to come.

Researching Alternative Hardware

After our previous meeting with a researcher in the electrical impedance tomography field, we have had a lot to think about, I went into this project thinking the EIT-KIT from MIT was going to be the solution our imaging problems. However after doing further research we have decieded to move forward with the Red Pitaya board for further testing. This device (specifically the Red-Pitaya STEMlab 125-14) offers us more customizable hardware, and higher dB readings than that of the EIT-KIT. Though subsituting size for strength, we believe it can still be a portable, accessible, and cost effective imaging tool. Additionally this specific hardware has been referenced in multiple EIT papers. Though we will consult with professionals we believe this is the path EIT-tek will be heading.

Meeting with Veteran Electrical Impedance Imaging Researcher

Today EIT-tek met with a veteran electrical impedance tomography researcher to discuss the direction of our project and the realistic goals EIT-tek can achieve. This call taught us a lot, instead of utilizing the HHT (Hilbert Huang Transform) an algorithm that is particularly useful for analyzing signals whose spectral content changes in time. This algorithm provides an instantaneous frequency, which is already a known value in Electrical Impedance Imaging. Additionally we learned that in order to generate a good image you need a very high dB value. We will now be looking into a EIT/EIM hybrid approach which has been used in a clinical setting to assess changes in muscle architecture, specifically by reading the fluid buildup represented by edema.

Launching the public build log.

Going public with progress. The goal: treat this like a wet-lab notebook anyone can read. Trainers, clinicians, and investors shouldn't have to wait for a pitch deck to see what we're working on — they should be able to watch the prototype take shape, week by week.

Next up: finishing the 2D pyEIT mesh, filing the provisional patent, and running the first Hilbert-Huang pass on a clean reference signal to baseline the denoising before we touch the phantom.