We’ve all likely watched an episode of “Star Trek” and admired the level of integration on the sick bay diagnostic bed. With its suite of wireless sensors and flat panel display, even the 1960s imagining of the future blows away the decidedly wired experience of a modern-day ICU stay. But we may be getting closer to [Dr. McCoy]’s experience with this radar-based respiration detector.
[Øyvind]’s build, which takes the origin of the term “breadboard” to heart, is based on a not-inexpensive Xethru module, which appears to be purpose-built for detecting respiration. The extra-thick PC board seems to house the waveguides internally, which is a neat trick but might limit how the module can be deployed. The module requires both a USB interface and level shifter to interface the 2.8V levels of the module to the 5V Arduino Uno. In the video below, [Øyvind]’s prototype simply lights an RGB LED in response to the chest movement it detects, but there’s plenty of potential for development here. We’ve seen a laser-based baby breathing monitor before; perhaps this systems could be used to the same end without the risk of blinding your tyke. Or perhaps better diagnostics for sleep apnea patients than an intrusive night in a sleep study lab.
Clocking in at $249 for the sensor board and USB interface, this build is not exactly for the faint of heart or the light of wallet. But as an off-the-shelf solution to a specific need that also has a fair bit of hacking potential, it may be just the thing for someone. Of course if radar is your thing, you might rather go big and build something that can see through walls.
I hope that thing has some overvoltage protection. I’d hate to make a $750 mistake just by accidentally plugging a wire into the wrong spot on a breadboard.
750$ wtf ????
At $150 (retail) go out and buy a ResMed S+, take out the radar module and connect it to your arduino…
The breathing sensor I built conssited of a stretch resistive sensor made from an ohmic rubber cord around a bungie cord. An inhale separated the coil’s contacting points increasing resistance considerably. This was an easily measured change using an Arduino Uno. The output was to a solenoid which altered the flow from a CPAP upon exhale so the was no resistance (or pressure) to breath against. Positive pressure in/ no pressure out. It worked like a charm but for the inconvenience of wearing the strap and connecting wires. This radar solution though more expensive has my design beat by a mile.
Sounds just like BiPAP, which is basically CPAP with a different pressure setting for exhalation. The BiPAP machine senses the pressure change and alters the airflow accordingly.
Some of the low cost radar motion detectors come without the amplification and filtering circuits. It might be possible to get the respiration out of that one as well.
I mean something like this one: http://www.limpkin.fr/public/HB100/HB100_Microwave_Sensor_Application_Note.pdf
I thought radar can only reflect from metallic surfaces.
Nope, humans are also good reflectors.
Radar reflects best off metallic surfaces, but modern radar systems are sensitive enough to detect even very faint reflections off things like water droplets.
Yes. Case in point they are also used for tank level indication for storage tanks.
There is no “reflect” – only “re-radiate”
If radar can only be used for metal then i guess weather radar is scanning nuts and bolts in the air. lmao….
Wow, your project is amazing i really liked it, i have design Home Made Model of Electronic Bat by Using Arduino Uno but its not a radar i have used sonar a sound wave.
http://www.electronicslovers.com/2017/11/Arduino-Ide-radar-station-Do-it-Yourself-Project.html