Introduction: Co-Ventilator-19

Here I present a ventilator for the islands and any area with a high density of divers. A diving regulator is modified to fit into a chamber that directs air flow to a 22mm exhaust port, and a servo motor that sits above the regulator pushes on the diaphragm of the regulator to meter the flow rate and duration. The servo motor is controlled using an android phone by utilizing the audio port to send a PWM signal to the control board of the servo motor, and is powered by a USB cable that will simultaneously charge the device that creates the signal. On a simple android app a user can select the duration of the diaphragm depression (to adjust amount of delivered air) as well as the amplitude of depression (to adjust flow rate). Alternatively, an audio file can be created and played on repeat to send a similar signal. Air delivered to the SCUBA regulator should be at 50 PSI to enhance the tenability, but 130 PSI air will also work.


Total Cost of all parts ~ $140

· SCUBA Regulator $60 – 150 (or free via donations)

· Ultrasonic humidifier $30

· Servo motor 10 for $17

· headphone cable with mic button $15

· Air pressure gauge $10

· Nuts, bolts, and springs $5

· 3D printed material cost $10

Step 1:

Step 2: DIY Ventilator (all Parts Locally Sourced)


This project is a free Hardware Project.
Open Hardware License and LiabilityDocumentation published describing hardware is licensed under the CERN-OHL-S v2. You may redistribute and modify this documentation under the terms of the CERN-OHL-S v2. ( except otherwise statedFree SoftwarePrograms described/provided/linked in/to this project are free software except otherwise stated. You can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details: are published under Creative Commons Share Alike except otherwise stated.

Everything published about the Hack A vent Open Source Ventilator here is experimental at this stage. This information is intended for researchers at research institutions. It is not targeted at customers. At this time the aim of the information is to find other opinions of how to plan the CSSALT Open Source Ventilator, not to give advice on how to build one. Building an open source ventilator is potentially dangerous. Under no circumstances should anyone actually try to build an open source ventilator based on the information provided on this page without prior consultation of the contact points given in these documents. Under no circumstances should any information on this page be used or tried on human beings without prior written consent of the contact points given in these documents.


Here we present a mechanical ventilator prototype using parts sourced locally. A SCUBA diving regulator is almost a ventilator off-the-shelf since it uses a diaphragm to trigger pressurized air to flow into a breathing chamber which reduces the air to atmospheric allowing the diver to breath from the regulator chamber. If the diaphragm was held open briefly however, the delivered air would be forced into the divers lungs without effort. Using a servo motor to hold the diaphragm open in a controlled manner allows a metered dose of air to be delivered. Furthermore this method of ventilation allows the patient to trigger the mechanism via a push button resting on the diaphragm. A built-in blow off valve on the regulator prevents an over-pressurization event. To tune the pressure delivered to the patient, a spring is placed in line with the blow off valve and a bolt compressing the spring adjusts the peek inspiratory pressure. Air is humidified using an piezo-electric mister to atomize the water in the chamber below the regulator. An Oxygen port is included just above the fogging mechanism that will mix the humidified air with the oxygen.

Step 3: 3D Print All Parts

All 3D printed files are given below.

Briefly, the following parts have been designed

Servo to regulator attachment : This part hold the servo motor and push block to the SCUBA regulator. The regulator is held in place via 4 1/4-20 bolts around the perimeter

Main Body : all airline connections from and to the regulator

PEEP valve : A three piece design utilizes a spring and a bolt to hold a plastic seat against the scuba regulators pressure relief valve. The bolt adjusts the spring tension allowing more or less pressure to actuate the relief valve.

Step 4: Assembly

1)unscrew the cover from the scuba regulator, and cut the tip off of the scuba mouthpiece.

2)assemble the servo cover by placing the servo motor into the housing, and placing the push block into the center with the long end facing downwards. Place the slide arm onto the servo while aligning the pin on the pushblock into the slot of the slide arm.

3) insert the scuba regulator into the housing and tighten all of the four bolts to secure the regulator in place.

4) attach the connection ports body to the mouthpiece of the regulator.

5) assemble the peep valve by placing a spring in between each disk, and sliding the assembly into the housing.

6) place the housing into the blow off valve of the regulator

7) place the cover onto the servo housing

8) place the pressure gauge on the output tube

Step 5: Control

***** I need help from the maker community with skills in android app development *****

The servo motor responds to a button which lies on the diaphragm of the regulator, the button will be connected to the mic terminal of a 3.5 mm headphone jack. When the mic hears a change in signal the servo motor responds by pressing on the diaphragm of the regulator in a controlled manner. The servo motor moves due to a pulse width modulated signal which can be output using the top connector of the 3.5 mm headphone jack.

* the 9 volt batter is temporary and will be replaced with power output from a USB cable which charges the cellphone