Whether you are trying to drop some fat or build some muscle, it’s important to track progress. It’s easy enough to track your weight, but weight doesn’t tell the whole story. You might be burning fat but also building muscle, which can make it appear as though you aren’t losing weight at all. A more useful number is body fat percentage. Students from Cornell have developed their own version of an electrical body fat analyzer to help track body fat percentage.
Fat free body mass contains mostly water, whereas fat contains very little water. This means that if you were to pass an electrical current through a body, the overall bioelectrical impedance will vary depending on how much fat or water there is. This isn’t a perfect system, but it can give a rough approximation in a relatively easy way.
The students’ system places an electrode on one hand and another on the opposite foot. This provides the longest electrical path possible in the human body to allow for the most accurate measurement possible. An ATMega1284P is used to generate a 50kHz square wave signal. This signal is opto-isolated for user safety. Another stage of the circuit then uses this source signal to generate a 10ua current source at 50kHz. This is passed through a human body and fed back to the microcontroller for analysis.
The voltage reading is sent to a MATLAB script via serial. The user must also enter in their weight and age. The MATLAB script uses these numbers combined with the voltage reading to estimate the body fat percentage. In order to calibrate the system, the students measured the body fat of 12 of their peers using body fat calipers. They admit that their sample size is too small. All of the sample subjects are about 21 years old and have a similar body fat percentage. This means that their system is currently very accurate for people in this range, but likely less accurate for anyone else. Continue reading “DIY Electrical Body Fat Analyzer”
Thermal imaging cameras are the new hotness when it comes building DIY tools that are much less expensive than their commercial counterparts. [Mike Harrison] built a very high-resolution version from Flir’s Lepton module, but an IR temperature sensor and a servo can also create a decent image. [AKA] played around with some of these thermal imaging modules, but found them a little hard to interface. Panasonic’s Grid-EYE module, however is reasonably cheap as far as thermal imaging devices go, and can be read over an I2C bus.
[AKA]’s entry for the Hackaday Prize, the GRID-EYE Thermal Camera is one of two Prize entries that survived the great culling and made it into the quarterfinalist round. [AKA] was kind enough to sit down and do a short little interview/bio with us, available below.
Continue reading “THP Hacker Bio: AKA”
I met up with [Kenji Larsen] at HOPE X last weekend, and I’m fairly certain he was the coolest person at a conference full of really cool people. Talking to him for a little bit, you get a sense of what it would be like to speak with [Buckmister Fuller], [Tesla], or any of the other ‘underappreciated, but not by people in the know’ minds scattered about history. I’ll just let his answers to our hacker bio questions demonstrate that.
[Kenji]’s project for The Hackaday Prize is the Reactron Overdrive. It’s not just one board he’s building here, but an entire suite of sensors, interfaces, and nodes that form a complete human to machines – note the plural ‘machines’ – interface. When you consider that no one knows what the Internet of Things actually is, and that [Kenji] is working on IoT 3.0, you get a sense that there’s really something here. Also, his project log has a Tron Recognizer in it. That has to count for something, right?
Continue reading “THP Hacker Bio: Kenji Larsen”
Remote sensing applications that make sense and cents? (sorry, couldn’t help ourselves) That’s what [hackersbench], aka [John Schuch], aka [@JohnS_AZ] is working on as his entry for The Hackaday Prize.
He received a multi-thousand-dollar water bill after having an underground pipe break and leak without knowing it. His idea will help you notice problems like this sooner. But if you actually have a way to capture data about your own water use you also have a tool to help encourage less wasteful water use habits. We wanted to learn more about the hacker who is working on this project. [John’s] answers to our slate of questions are after the break.
Continue reading “THP Hacker Bio: hackersbench”
Have you ever wanted to build a robot arm, or even a full robot, but were put off by the daunting task of making all of those articulations work? Moti could make that a lot easier. The project seeks to produce smart servo motors which can connect and communicate in many different ways. It’s a great idea, so we wanted to know more about the hacker behind the project. After the jump you’ll find [nsted’s] answers to our slate of question for this week’s Hacker Bio.
Continue reading “THP Hacker Bio: nsted”
[David Cook] has been on the front page with gnarly hacks many times. We’re happy to present his Hackaday Projects profile as this week’s Hacker Bio.
His entry for The Hackaday Prize is something of a one-wireless-pair-to-rule-them approach to connected devices which he calls LoFi. We were delighted by his first demo video which is exactly what we envisioned for preliminary entries; [David] explains the concept and how he plans to implement it using a few visual aids to drive the point home.
Join us after the break to find out more about [David]. Oh, if you’re wondering about the times he’s been featured on Hackaday, check out his capacitor/coin cell swap which is one of our favorites.
Continue reading “THP Hacker Bio: David Cook”
[Drew Endy]’s Programming DNA talk was by far the most interesting talk we saw at Chaos Communication Congress. No, DNA doesn’t have much to do with computers, but he points out that hacking principles can be applied just the same. Right now engineers are reversing genetic code and compiling building blocks for creating completely arbitrary organisms. This talk was designed to bootstrap the hacking community so that we can start using and contributing standard biological parts to an open source collection of genetic functions.
You should definitely watch the video to get a good idea of where biohacking is at today. You can find a higher quality version of the video in the archives.