- April 11, 2020 at 13:50 #105409Davide SherKeymaster
This ventilator is not intended as a replacement for high-end ventilators. It is, instead, just intended to replace the hand of a medical person using a manual ventilator (Ambu-bag / Bag Valve Mask) with an automated hand.
Important note: Ventilators are a class II medical device. This means that you would need to go through a regulatory approval process before it can be used. It would have to be designed and manufactured to a quality standard and taken through clinical trials before getting approval from the FDA or equivalent regulatory body in your country. This design is NOT approved! It is only intended to give people ideas for other emergency ventilator applications.
Note, also, that because our additive manufacturing lab is currently on lock-down because of COVID-19, we have not been able to physically test this design yet. This is why we are making the design open-source to all so that others can print it, test it and improve it. As soon as we are able to build and test our own we will, no doubt, be improving it, and will then make all the new files available here.
At best, this type of ventilator could only be used as a controlled mechanical ventilation system (CMV). This type ventilation does not allow any synchronization with the patient’s own breathing and is only allowed when patients are deeply unconscious and paralyzed. It could, potentially, also be used to transport patients needing ventilation from one place to another, thus freeing up the hands of medical person that might, otherwise, have to ventilate the patient with an Ambu-bag.
In its most basic configuration, it just uses an off-the-shelf PWM motor speed controller, and a simple relay circuit to change motor direction when a micro-switch is triggered at the opening and closing of the fingers (IE: it mimics at what speed the medical persons hand is opened and closed around the bladder). If latching relays are used, the ventilator can be made to work without even needing a micro-controller or any coding.
In a more advanced configuration, we use an Arduino Uno as the micro-controller to control the ventilator. To add more functionality we use a simple current sensing circuit to control the volume/tidal flow of the ventilator (IE: mimic how far the hand closes on the bladder when the medical person closes and opens their hand). And a simple bit of timing code controls how many breaths per minute are required (IE: the frequency at which the medical person closes and opens their hand).
If you come up with any further improvements, please email them to us at firstname.lastname@example.org and we’ll update the downloadable files on the site.
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