New Intelligence Report
New Intelligence Report
Editor: Yuanzi
【New Intelligence Introduction】Foreign experts teach you how to make a low-cost open source ventilator by yourself. You only need to buy a mask, tube, and some necessary parts online, connect it to an Arduino development board, and you can DIY a ventilator that can save lives in critical times! Meanwhile, hospitals in Italy’s hardest-hit areas have successfully rescued 10 critical patients using 3D printed ventilator valves. “New Intelligence is urgently hiring chief writers, editors, operations managers, and account managers. Add HR WeChat (Dr-wly) or scan the QR code at the end of the article for details.”
Report: Doomsday Shelter, Ventilators Exhausted!
As COVID-19 begins to explode globally, medical resources have suddenly become tight. If one day the most valuable medical device for pneumonia patients—ventilators—runs out during hospitalization, what should we do? Foreign DIY experts say don’t worry, I will teach you how to make a low-cost ventilator by yourself, which might save lives in critical moments!
Warning/Disclaimer: Please proceed under the guidance or supervision of a professional. We do not recommend taking action without appropriate medical knowledge. Think twice before acting! The author also requests that a professional pulmonologist verify the effectiveness of the entire ventilator.
Several issues that still need to be resolved
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A pulmonologist, the kind that gives professional advice. After all, this involves life and death. -
Testing with a simple air pump to achieve the same pressure control. -
Can we detect the breathing cycle just by observing the motor current? Adding a pressure sensor might complicate the construction, but using a simple current sensing resistor is much easier. -
Develop a better solution to address the interface diameter issue. The current solution will require a lot of tape to generate enough pressure. -
Some parts the author has may not be easy to buy. -
A solution to prevent the system from becoming unsafe during power outages is needed. The author admits to not being very knowledgeable about this and hopes to receive suggestions.
Materials Needed for DIY Ventilator
Continuous Positive Airway Pressure (CPAP) devices are commonly used by individuals to treat sleep apnea, so they are relatively easy to purchase. The author uses a product from Respironics REMStar, priced under $20.
Arduino-compatible Nano/Clone can control motor speed, breathing cycles, and handle user inputs. Just download the Arduino IDE to program the microcontroller software.
Brushless DC motor electronic speed controller, with a current of at least 10A.
Buttons or switches for input control. The code cycles through 5 pressure levels, then double-click to switch between CPAP and BiPAP/Fixed PEEP modes.
12v DC power supply capable of handling at least 5A of current. The fan operates well, and the breathing cycle will cause a voltage drop, which can restart the Arduino if the power supply is not strong enough.
Tubes and masks. CPAP masks are easy to buy.
Optional built-in 12v backup battery.
Making a Fan
This is a complete system with a mask, tubing, pump, 12v battery, and switch. It is strongly recommended to use a DC power supply, as the battery can only last about 3-4 hours. Wearing a mask when the battery is dead may lead to dangerous carbon dioxide buildup.
Below is a close-up of the fan. It is just a BLDC motor driving the fan, accompanied by a small ESC and Arduino (technically a Teensy2.0++, but the code has now been changed to Arduino Nano). It has a 3D printed conical hose adapter on top.
You can program the microcontroller software using the Arduino IDE. The software will go through a brief initialization process to configure the ESC, then start from the lowest CPAP setting. You can cycle through pressure levels using the switch, then double-click to cycle between operating modes.
Below is a schematic of the electronics.
Making a Mask/Oral Appliance
The author uses the Resmed AirFit F20 mask. If you don’t have a mask on hand, you can also use an oral appliance like the one in the picture below.
After using enough tape, the difference isn’t significant. You also need some elastic bands to secure the mask to the mouth. The seal should not be too tight; leave a little gap for carbon dioxide to escape, so it doesn’t accumulate in the tube.
Buyer’s show:
Italian Hospital Manufactures Valves for Critical Resuscitation Equipment via 3D Printing
Due to the severe epidemic in Italy, the consumption of medical resources has surged. A hospital in northern Italy urgently needed valves for critical resuscitation equipment, but supplies were short. Therefore, FabLab in Milan utilized 3D printing technology to quickly produce a large number of valves in a short time, alleviating the urgent needs of the Brescia hospital located in the epidemic-stricken area, allowing 10 patients to use ventilators in a timely manner.
