Blood Pressure Monitor For Under $1

June 20, 2023 by Bryan Cockfield 22 Comments

Medical equipment is not generally known for being inexpensive, with various imaging systems usually weighing in at over a million dollars, and even relatively simpler pieces of technology like digital thermometers, stethoscopes, and pulse oximeters coming in somewhere around $50. As the general pace of technological improvement continues on we expect marginal decreases in costs, but every now and then a revolutionary piece of technology will drop the cost of something like a blood pressure monitor by over an order of magnitude.

Typically a blood pressure monitor involves a cuff that pressurizes against a patient’s arm, and measures the physical pressure of the blood as the heart forces blood through the area restricted by the cuff. But there are some ways to measure blood pressure by proxy, instead of directly. This device, a small piece of plastic with a cost of less than a dollar, attaches to a smartphone near the camera sensor and flashlight. By pressing a finger onto the device, the smartphone uses the flashlight and the camera in tandem to measure subtle changes in the skin, which can be processed in an app to approximate blood pressure.

The developers of this technology note that it’s not a one-to-one substitute for a traditional blood pressure monitor, but it is extremely helpful for those who might not be able to afford a normal monitor and who might otherwise go undiagnosed for high blood pressure. Almost half of adults in the US alone have issues relating to blood pressure, so just getting information at all is the hurdle this device is attempting to overcome. And, we’ll count it as a win any time medical technology becomes more accessible, more inexpensive, or more open-source.

Take A Ride In The Bathysphere

June 13, 2023 by Adam Fabio 5 Comments

[Tom Scott] has traveled the world to see interesting things. So when he’s impressed by a DIY project, we sit up and listen. In this case, he’s visiting the Bathysphere, a project created by a couple of passionate hobbyists in Italy. The project is housed at Explorandia, which based on google translate, sounds like a pretty epic hackerspace.

The Bathysphere project itself is a simulation of a submarine. Sounds simple, but this project is anything but. There are no VR goggles involved. Budding captains who are up for the challenge find themselves inside the cockpit of a mini-submarine. The sub itself is on a DIY motion platform. Strong electric motors move the system causing riders to feel like they are truly underwater. Inside the cockpit, the detail is amazing. All sorts of switches, lights, and greebles make for a realistic experience. An electronic voice provides the ship status, and let’s the crew know of any emergencies. (Spoiler alert — there will be emergencies!)

The real gem is how this simulation operates. A Logitec webcam is mounted on an XY gantry. This camera then is dipped underwater in a small pond. Video from the camera is sent to a large monitor which serves as the sub’s window. It’s all very 1960’s simulator tech, but the effect works. The subtle movements of the simulator platform really make the users feel like they are 20,000 leagues under the sea.

Check out the video after the break for more info!

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A Super-Cheap Turntable Build For Photographic Purposes

June 13, 2023 by Lewin Day 16 Comments

When it comes to photographing products or small items, sometimes it’s useful to get vision from all angles. Shooting a video of an item on a turntable is an ideal way to do this. [ROBO HUB] built a super-cheap turntable for just this purpose.

The build relies upon a regular micro servo to handle rotating the turntable. However, it has been modified from stock to rotate 360 degrees instead of its usual 180 degree range of motion. This is a common hack that allows servos to be used for driving wheels or other rotating mechanisms. In this case, though, any positional feedback is ignored. Instead, the servo is just used as a conveniently-geared motor, with its speed controlled via a potentiometer. A CD covered in paper is used as a turntable, with the electronics and motor assembled in a cardboard base.

It’s a simple hack, and one you can probably put together with the contents of your junk drawer. Combined with a lightbox, it could up your photo and video game significantly. Those skills are super useful when it comes to documenting your projects, after all!

Hackaday Links: June 11, 2023

June 11, 2023 by Dan Maloney 20 Comments

As Tom Nardi mentioned in this week’s podcast, the Northeast US is pretty apocalyptically socked in with smoke from wildfires in Canada. It’s what we here in Idaho call “August,” so we have plenty of sympathy for what they’re going through out there. People are turning to technology to ease their breathing burden, with reports that Tesla drivers are activating the “Bioweapon Defense Mode” of their car’s HVAC system. We had no idea this mode existed, honestly, and it sounds pretty cool — the cabin air system apparently shuts off outside air intake and runs the fan at full speed to keep the cabin under positive pressure, forcing particulates — or, you know, anthrax — to stay outside. We understand there’s a HEPA filter in the mix too, which probably does a nice job of cleaning up the air in the cabin. It’s a clever idea, and hats off to Tesla for including this mode, although perhaps the name is a little silly. Here’s hoping it’s not one of those subscription services that can get turned off at a moment’s notice, though.

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Modern Brownie Camera Talks SD And WiFi

June 11, 2023 by Al Williams 4 Comments

If you’re at all into nostalgic cameras, you’ve certainly seen the old Brownie from Kodak. They were everywhere, and feature an iconic look. [JGJMatt] couldn’t help but notice that you could easily find old ones at a good price, but finding and developing No. 117 film these days can be challenging. But thanks to a little 3D printing, you can install an ESP32 camera inside and wind up with a modern but retro-stylish camera. The new old camera will work with a memory card or send data over WiFi.

The Brownie dates back to 1900 and cost, initially, one dollar. Of course, a dollar back then is worth about $35 now, but still not astronomical. After cleaning up and tuning up an old specimen, it was time to fire up the 3D printer.

There are also mods to the camera to let it accept an M12 lens. There are many lenses of that size you can choose from. There are a few other gotchas, like extending the camera cable, but it looks like you could readily reproduce this project if you wanted one of your very own.

We’ve seen old cameras converted before. Or, you can just start from scratch.

Make Yourself A Megamind With A Hypercentric Camera

June 4, 2023 by Dan Maloney 4 Comments

Sometimes, all it takes to learn something new is a fresh perspective on things. But what’s to be learned from reversing your perspective completely with a hypercentric lens? For one thing, that you can make humans look really, really weird.

To be fair, there’s a lot to the optical story here, which [volzo] goes over in ample detail. The short version of it is that with the right arrangement of optical elements, it’s possible to manipulate the perspective of a photograph for artistic effect, up to the point of reversing the usual diminishment of the apparent size of objects in the scene that are farther away from the camera. Most lenses do their best to keep the perspective of the scene out of this uncanny valley, although the telecentric lenses used in some machine vision systems manipulate the perspective to make identical objects within the scene appear to be the same size regardless of their distance from the camera. A hypercentric lens, on the other hand, turns perspective on its head, making near objects appear smaller than far objects, and comically distorts things like the human face.

[volzo]’s hypercentric camera uses a 700-mm focal length Fresnel lens mounted on a motorized gantry, which precisely positions a camera relative to the lens to get the right effect. A Raspberry Pi controls the gantry, but it’s not strictly needed for the hypercentric effect to work. Lighting is important, though, with a ring of LEDs around the main lens providing even illumination of the scene. The whole setup as well as the weirdly distorted portraits that result are shown in the video below.

If these bizarrely distorted faces look familiar, you might be recalling [Curious Marc]’s head-enlarging wearable.

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AI Camera Imagines A Photo Of What You Point It At

June 2, 2023 by Lewin Day 20 Comments

These days, every phone has a camera, and few of us are ever without one. [Bjørn Karmann] has built an altogether not-camera, though, in the form of the Paragraphica, powered by artificial intelligence.

The Paragraphica doesn’t actually take photographs at all. Instead, it uses GPS to determine the user’s current position. It then feeds the address, time of day, weather, and temperature into a paragraph which serves as a prompt for an AI image generator. It also uses data gathered from various APIs to determine points of interest in the immediate area, and feeds those into the prompt as well. It then generates an artificial image that is intended to bear some resemblance to the prompt, and ideally, the real-world scene. In place of a lens, it bears a 3D printed structure inspired by the star-nosed mole, which feels its way around in lieu of using its eyes.

Three dials on the Paragraphica control its action. The first dial controls the radius of the area which the prompt will gather data about; it’s akin to setting the focal length of the lens. The second dial provides a noise seed value for the AI image generator, and the third dial controls how closely the AI sticks to the generated textual prompt.

The results are impressive, if completely false and generated from scratch. The Paragraphica generates semi-believable photos of a crowded alley, a public park, and a laneway full of parked cars. It’s akin to telling a friend where you are and what you’re seeing over the phone, and having them paint a picture based on that description.

Through their unique abilities and stolen data sets, AI image generators are proving controversial to say the least. As all good art does, Paragraphica explores this and raises new questions of its own.