Printable Portable Mask Gives You The Numbers On Your Workout

January 16, 2022 by Dan Maloney 7 Comments

We’re currently in the midst of New Year’s Resolutions season, which means an abundance of spanking new treadmills and exercise bikes. And one thing becomes quickly obvious while using those machines: the instruments on them are, at best, only approximately useful for measuring things like your pulse rate, and in the case of estimating the calories burned by your workout, are sometimes wildly optimistic.

If precision quantification of your workout is your goal, you’ll need to monitor your “VO₂max”, a task for which this portable, printable mask is specifically designed. This is [Robert Werner]’s second stab at a design that senses both pressure differential and O₂ concentration to calculate the maximum rate of oxygen usage during exercise. This one uses a commercially available respirator, of the kind used for painting or pesticide application, as the foundation for the build. The respirator’s filter elements are removed from the inlets to provide free flow of air into the mask, while a 3D printed venturi tube is fitted to its exhaust port. The tube houses the pressure and O₂ sensors, as well as a LiPo battery pack and an ESP32. The microcontroller infers the volume of exhaled air from the pressure difference, measures its O₂ content, and calculates the VO₂ max, which is sent via Bluetooth to a smartphone running an exercise tracking app like Zwift or Strava.

[Robert] reports that his $100 instrument compares quite well to VO₂ max measurements taken with a $10,000 physiology lab setup, which is pretty impressive. The nice thing about the design of this mask is how portable it is, and how you can take your exercise routine out into the world — especially handy if your fancy exercise bike gets bricked.

Zinc Fever: A Look At The Risks Of Working With Hot Metal

April 12, 2021 by Dan Maloney 69 Comments

For as raucous as things can get in the comments section of Hackaday articles, we really love the give and take that happens there. Our readers have an astonishing breadth of backgrounds and experiences, and the fact that everyone so readily shares those experiences and the strongly held opinions that they engender is what makes this community so strong and so useful.

But with so many opinions and experiences being shared, it’s sometimes hard to cut through to the essential truth of an issue. This is particularly true where health and safety are at issue, a topic where it’s easy to get bogged down by an accumulation of anecdotes that mask the underlying biology. Case in point: I recently covered a shop-built tool cabinet build and made an off-hand remark about the inadvisability of welding zinc-plated drawer slides, having heard about the dangers of inhaling zinc fumes once upon a time. That led to a discussion in the comments section on both sides of the issue that left the risks of zinc-fume inhalation somewhat unclear.

To correct this, I decided to take a close look at the risks involved with welding and working zinc. As a welding wannabe, I’m keenly interested in anything that helps me not die in the shop, and as a biology geek, I’m also fascinated by the molecular mechanisms of diseases. I’ll explore both of these topics as we look at the dreaded “zinc fever” and how to avoid it.

Continue reading “Zinc Fever: A Look At The Risks Of Working With Hot Metal” →

Hybrid Respirator Uses Repurposed Filters

December 5, 2020 by Lewin Day 15 Comments

With the coronavirus raging worldwide, 2020 has seen major shortages of personal protective equipment impact healthcare workers and individuals alike. This has led many to improvise their own solutions. One of the more complete offerings we’ve seen is this hybrid respirator build from [Ben Howard].

[Ben’s] build goes above and beyond the usual craft project masks. It uses a laser-cut chipboard frame to fit three HEPA filters, originally designed for the Roomba robotic vacuum cleaner. Two are used for exhalation, while one is used for inhalation. A small blower fan is installed with the intake filter, to provide mild positive pressure when breathing in. The assembly is wrapped up in fabric, using layers of spandex, fleece, and ripstop nylon to provide the best possible seal against the wearer’s face.

It’s a build that should appeal to those who want to breathe cleaner air and also protect others from exhaled particles that can spread respiratory viruses. We’ve seen all kind of masks hit the scene this year; the graphene-impregnated variety is one of the more interesting designs. Still, one can hope that future years lead to less reliance on such measures!

Ventilators 101: What They Do And How They Work

March 25, 2020 by Bob Baddeley 88 Comments

Treating the most serious cases of COVID-19 calls for the use of ventilators. We’ve all heard this, and also that there is a shortage of these devices. But there is not one single type of ventilator, and that type of machine is not the only option when it comes to assisted breathing being used in treatment. Information is power and having better grasp on this topic will help us all better understand the situation.

We recently wrote about a Facebook group focused on open source ventilators and other technology that could assist in the COVID-19 pandemic. There was an outpouring of support, and while the community is great when it comes to building things, it’s clear we all need more information about the problems doctors are currently dealing with, and how existing equipment was designed to address them.

It’s a long and complicated topic, though, so go get what’s left of your quarantine snacks and let’s dig in.

Continue reading “Ventilators 101: What They Do And How They Work” →

3D Printed Parts Keep Respirators Operational During COVID-19 Epidemic

March 16, 2020 by Lewin Day 71 Comments

COVID-19 can seem like a paper tiger, when looking at bare mortality rates. The far greater problem is the increase in fatalities as health systems are stretched to the limit. With thousands of patients presenting all at once, hospitals quickly run out of beds and resources and suddenly, normally survivable conditions become life threatening. One Italian hospital found themselves in such a position, running out of valves for a critical respirator device needed to save their patients. Supplies were running out – but additive manufacturing was able to save the day.

The original part, left, with its 3D-printed replacement.

While the article uses the term “reanimation device”, it’s clear we’re talking about respirators here, necessary to keep patients alive during respiratory distress. The valve in question is a plastic part, one which likely needs to be changed over when the device is used with each individual patient to provide a sterile flow of air. After the alarm was raised by Nunzia Vallini, a local journalist, a ring around of the 3D printing community led to a machine being sent down to the hospital and the parts being reproduced. Once proven to work, things were stepped up, with another company stepping in to produce the parts in quantity with a high-quality laser fusion printer.

It’s a great example of 3D printers being used to produce actual useful parts, and of the community coming together to do vital lifesaving work. We’ve seen the technology come in clutch in the medical field before, too. Stay safe out there, and live to hack another day.

Thanks to [Jarno Burger], [LuigiBrotha], and [Michael Hartmann] for the tips!

Ultimate Medical Hackathon: How Fast Can We Design And Deploy An Open Source Ventilator?

March 12, 2020 by Gerrit Coetzee 898 Comments

[Gui Cavalcanti], whose name you might recognize from MegaBots, got on a call with a medical professional in San Francisco and talked about respirators. The question being, can we design and deploy an open source version in time to help people?

Unnerving reports from Italy show that when the virus hits the susceptible population groups the device that becomes the decider between life and death is a ventilator. Unfortunately they are in short supply.

The problem gets tricky when it comes to what kind of respirator is needed CPAP, BIPAP, or Hi-Flo oxygen NIV are all out. These systems aerosolize the virus making it almost guaranteed that anyone around them will get infected.

What we need is a Nasal cannula-based NIV. This system humidifies air, mixes it with oxygen and then pushes a constant stream of it into people’s lungs. If we can design a simple and working system we can give those plans to factories around the globe and get these things made. If the factories fail us, let’s also have a version people can make at home.

If you aren’t sure if a ventilator is something you can work on there are other problems. Can you make algorithms to determine if a person needs a ventilator. Can we recycle n95 masks? Can we make n95 masks at home? Workers also require a negative pressure tent for housing patients. This will be especially useful if we need to build treatment facilities in gyms or office spaces. Lastly if you’re a medical professional, can you train people how to help?

Let’s beat this thing. The ultimate medical hackathon begins.

How Many Puffs Does It Take To Kill An E-Cigarette?

January 10, 2015 by Rick Osgood 20 Comments

Most of us have probably heard the old Tootsie Pop slogan, “How many licks does it take to get to the center of a Tootsie Pop?” [E-Smoker2014] had a similar question about his e-cigarettes. These devices are sometimes advertised with the number of puffs they are good for. [E-Smoker2014] had purchased an e-cigarette on a trip to Belgium that advertised 500 puffs. After a bit of use, he started to suspect that he wasn’t getting the advertised number of puffs in before the battery would die. Rather than just accept that the world may never know for sure, he decided to test it out himself.

There aren’t many details on this build, but you can tell what’s going on from the video below. [E-Smoke2014r] built a machine to artificially puff on an e-cigarette. The e-cigarette is hooked up to what appears to be vinyl tubing. This tubing then attaches to a T-splitter. One end of the splitter is hooked up to a DIY actuator valve that can open or close the port. The other end of the splitter is hooked up to more tubing, which in turn is attached to a plastic cylinder placed in a container of water.

To simulate breathing, the computer first opens the relief valve in the splitter. It then mechanically lowers the plastic container into the bowl of water, pushing out a bunch of air in the process. The valve closes, and the computer then raises the plastic container out of the water. This action creates suction that draws air in through the e-cigarette like a normal user would do with their lungs. The computer increases the puff count and then repeats the process, expelling any vapor out of the relief valve.

The results of the test indicated that [E-Smoker] could only get 59 puffs out of this particular e-cigarette before draining the battery. Not even close to the advertised 500 puffs. Maybe he should consider building his own e-cigarette vaporizer? Continue reading “How Many Puffs Does It Take To Kill An E-Cigarette?” →