Emergency low cost ventilator
Channel: Share your knowledge for better world
Date: 02/07/2020

Asslamualaikum everyone,my name is Borhan Uddin.In this pendamic covid-19 situation so many Bangladeshi corona effected people are suffering for breating problem.So, the absence of main ventilator this emergency low cost ventilator can be used for emergency breathing  and save human life. To be clear, this is not a substitute for a real ventilator. This is mandatory ventilation only; the lack of a breath trigger is probably its biggest weakness. It's one step above prolonged hand-bagging.Till now It is not authorized by any Bangladesh government authority.This piece of equipment is constructed from wood, PVC, common fasteners, and easily sourced motor/electrical parts, and it can be built using only hand tools.  As built, it can supply a tidal vol:500 ml,minute vol:7.65 LPM,Oxegen-20 percent, I:E ratio1:2.7,PIP-35.3cmH2O,MAP-7.6cmH2O,IPP-32.4cmH2O and fits easily into typical airway circuits. It requires a source of electricity (100-240V AC or 12V car battery) and oxygen, as well as a PEEP valve and microbial filter for ideal operation. This is intended to be used in disaster and/or low-resource environments, and then only as a replacement for long-term manual bagging.
The design first established a doctor in U.S.A and named his machine Macgyvilator disaster ventilator Mk2.Some modification I made in MK2 and increase the tidal volume and decrease the operation noise.

Parts list for the emergency low cost ventilator ,inspired from Macgyvilator disaster ventilator, Mk2

AMBU  Bag
You can find  AMBU bag from below websites or other medical equipment website or BMA market dhaka
http://www.tajbd.com/surgical/114-ambu-bag.html
https://www.clickbd.com/bangladesh/2689760-ambu-bag.html
Flexible Hose pipe
You can find  flexible hose pipe from below website or other medical equipment website or BMA market dhaka
https://bmabazar.com/shop-2/medical-equipment/ventilator/cpap-bipap-psg/flexible-hose-pipe-connect-with-cpap-breathing-cpap-mask-apparatus/
Breathing Filter
You can find  flexible hose pipe from below website or other medical equipment website or BMA market dhaka
https://bmabazar.com/shop-2/accessories-others/for-artificial-nasal-composite-filter-hme-wet-heat-exchanger-anesthetic-gas-filter/
Wood
● Plywood, ⅜-½” is fine, any grade - need 2’length x 1.5’width x 1’’height section for each base
●  Motor  rotating arm, one piece 16’’ x 2’’ x ‘1’’(can use anything similarly shaped, but keep it stiff and thin and light)
● Motor support stand one piece 2’ x 4’’ x 2’’ for each stand
● Motor Regulator support stand one piece 1’ x 4’’ x 2’’
● AMBU bag support one piece  4’’ x4’’ x 2”
● PVC pipe support 2 pieces 4’’ x4’’ x 2”PVC
● ¾” PVC pipe - need 32’’ lengths, these are often available pre-cut
● ¾” PVC pipe –need 2 pieces 8’’ length for attach to main pipe 
● T-fitting one piece for ¾” PVC - should fit snugly over the tubing above
Fasteners and small bits
● Wood screws, 2” (a bunch)
● Bolts, 5/16” (one per build)
● Nuts, 5/16” (up to six per build)
● Fender washer, 5/16””
● Skateboard bearings (or rollerblade bearings or fidget spinner bearings) - need 2-3 for each build
● Machine screws, 10/24, 2” (four per build)
● Lock washers, washers, and wingnuts for machine screws
● Screw-in hooks
● Spring
● Seal tape
● Small wood screws to mount flange to rotating arm (usually 4)
● Velcro, ¾” 
● Foam
Motors, electronics, and accessories
● 12V, 10A power supply that takes 220V AC (or whatever your particular region’s wall power is). You can find from this website or any other electonics website or nawabpur dhaka electronics market: 
https://www.rcproductbd.com/product/ac-dc-12v-10a-switching-power-supply/
● 12V high torque, low RPM motor (need 50-100 RPM max, even 20 RPM is helpful, I’ve used torque ratings of 25KGF.CM--90kgf.cm ). You can find from this website or any other electonics website or nawabpur dhaka electronics market
https://bdspeedytech.com/index.php?route=product/product&path=16&product_id=3205. 
Whatever you choose to use should be stress tested for at least 24 hours at max settings. Torque is typically the limiting factor, and motor failure (for me) has come from overheating (does not smell good). garage door opener motors can also work.
● Flange for above motor (usually adjust the motor shaft diameter with flange) & you can make one from workshop. 
● Mounting plate for motor. you can make one from sheet metal from workshop.
● 12V PWM module (most of these take a voltage range, just make sure 12V is in that range). You can find from this website or any other electonics website or nawabpur dhaka electronics market
https://www.electronics.com.bd/dc-motor-speed-governor-pwm-controller-10a-50v-1000uf-large-capacitor?search=PWM, 
but there are plenty of equivalents. Just be sure it covers 12V in its voltage range and can take 10A. 
● Wire, 14-16 ga, stranded copper from electronics shop.
If you have questions, please feel free to email me at borhanuac@gmail.com I’ll do my best to keep up with the messages.