The system makes use of the already available hardware in the challenger kit, with some additional items.
Let me list out all the items necessary.
- Raspberry Pi 4
- MAX30102 sensor
- Pimoroni PIM487 Automation HAT
- PIM486 Enviro HAT
- PICO HAT Hacker PCB
- Insulated Copper wires for Anode and cathode linkage to the power supply
- Hot glue
- cylindrical pipe - a small piece
- Wire mesh
- Rubber tube
- O2 suction mask
- RGB LED
- Power Bank
- DC power supply
The blood oxygen level of a person can give an estimation of the oxygen concentration in the body. The MAX30102 sensor attached to the wrist of the person reads the blood oxygen level of the person.
Normal arterial oxygen is approximately 75 to 100 millimeters of mercury (mm Hg). Values under 60 mm Hg usually indicate the need for supplemental oxygen. Normal pulse oximeter readings usually range from 95 to 100 percent.
Values under 90 percent are considered low. Variations in ambient temperature, pressure, and humidity can also cause variation of oxygen levels.
The MAX30102 sensor readings along with the ambient climate (temperature, pressure, humidity) readings from the PIM486 Enviro HAT are monitored in real-time by the Raspberry Pi 4.
Once the readings are evaluated, an automated decision is taken to determine whether there is a sudden requirement for oxygen.
In case of a requirement for oxygen supply, the oxygen supply unit is activated by the relays in PIM487 Automation HAT. The O2 level and associated status will also be displayed on its OLED screen.
The Buzzer and RGB LED which is directly integrated with the Rpi 4 will give various visual and audio warnings based on the O2 level of the person so that more specialized care/help can be obtained if very critical.
The oxygen generator is based on the electrolysis of water. Electrolysis, simply put, is the process where water which is made up of two main constituents of H2O (two parts hydrogen and one part oxygen);
is broken down forcibly with the help of an electric current. Electrolysis results in the release of O2 and H2 out from the water across the two electrodes which are connected to a DC power supply such as 6V, 9V, or 12V;
but with larger current capacity (like those present in portable emergency tube lights.
- Below is the conceptual layout of the module.
- For our system, we will simply take a glass water bottle filled with water.
- 2 stainless steel meshes are fixed on the two open faces of a cylindrical pipe which is small enough to fit inside the bottle.
- Insulated copper wires are soldered to each of these meshes.
- The copper wires are connected to the DC supply via the controller box through the relay in Pimoroni PIM487 Automation HAT, actuated via the Raspberry Pi, based on the sensor readings.
- The controller box houses the Pi assembly, the sensors, actuators, warning RGB LED, and the buzzer.
- The LED will blink GREEN for normal O2 levels, AMBER for reduced O2 levels, and RED for critical O2 levels.
- The buzzer will also sound in the case of a critical O2 level.
- Hot glue can be used to fix the pipe and mesh assembly inside the bottle.
- The generated oxygen and hydrogen will be deposited on the top of the bottle at the anode side.
- If graphite rods are used instead of wire-mesh, a thick rubber/plastic or similar partition can be provided at the top half of the bottle so that gaseous O2 can be easily obtained without mixing with gaseous H2.
- A rubber tube connected to the top part of the bottle can channel the generated O2 to the O2 suction mask to be worn by the person or out to the ambient environment for O2 refilling.
- The Rpi and sensors will be separately powered by a suitable power bank of an adequate 5V 2A power bank.