Open Autoclave: a Humanitarian Maker Project

Why did I make this project?

I read a World Health Organization report that said 3 billion people in the world live in rural areas without reliable electricity and that, because of this, they often cannot get access to surgical care. The reason is that medical instrument sterilizers are usually too expensive and use too much electricity to work in these areas. I realized that I could use my RepRap building skills to design and build an autoclave that operates on 12VDC and is controlled by an Arduino. This means that it is inexpensive and can also run off grid from a vehicle or a solar panel. I wanted to promote this project to people who can build/test/deploy it in the field. Most of all, I want to promote the idea that we makers have skills that apply to solving real world problems, and can actually save lives.

What is the Open Autoclave?

The Open Autoclave uses low cost 12 volt cartridge heaters usually found in DIY 3D printers. These heaters can save lives.

This article presents an open source and freely published book that shows a method for making a practical off-grid autoclave. The autoclave in this book is designed to run on 12 volt power from the cigarette lighter port of any motor vehicle. It can also run on an 80 watt solar panel. The book is designed to let makers, medical workers, and motivated individuals construct one such device for around $250 USD from easy-to-order commodity parts.

Build it! Test it! Use it!

It is my sincerest hope that this book will capture the imagination of a new generation of makers: A growing group of makers ready to apply their Arduino-superpowers to help their fellow person. These goodness-minded collaborative creators can be aptly called Humanitarian Makers. Perhaps this project will inspire you to be part of the Humanitarian Maker Movement.

Step 1: Overview of the Project

I made a PDF document that lays out all the steps to this project. I recommend you just download it and print it out. It's not a hard project, I just went a little overboard on the details in the instructions. I wanted it to be doable even for people with little to no prior technical experience.

There are some other files attached to this build, including the Arduino software, electronic schematics, parts lists, and diagrams for assembly.

If you are interested in more about the author or about this project, check out my blog at Idea Propulsion Systems.

This is the table of contents for the PDF book associated with this build on Instructables:

Chapter 1 - Setup

1.1 Set up your workspace 5

1.2 Tools 5

1.3 Parts and supplies 6

Chapter 2 - Build the autoclave oven

2.1 Insulated pot 16

2.2 Base tray 19

2.3 Heater rack 21

Chapter 3 - Build the electronic controller

3.1 Drill holes in the electronics box 25

3.2 Install the components 30

3.3 Finish the wiring 39

Chapter 4 - Set up the controller computer

4.1 Install the Arduino software 47

4.2 Download the Open Autoclave software 49

4.3 Upload the software to the microcontroller 51

Chapter 5 - Test the autoclave system

5.1 Run a full cycle 55

5.2 Download and graph the data 59

5.3 Using biological indicator strips 62

5.4 Troubleshooting 63

5.5 Using the autoclave, no computer 65

Chapter 6 - Resources

6.1 Change the temp and time settings 68

6.2 Volt-ohm meter 69

6.3 Anti-static mat 70

6.4 Pin connector crimper 71

6.5 Full electrical schematic 72

6.6 Diagram of autoclave system 73

6.7 Template for drilling electrical box lid 74

6.8 Template for drilling electrical box 75

6.9 Placement of components in electrical box 76

6.10 Ideas for improvements 77

6.11 Powering Open Autoclave with Solar 78

Step 2: Download the Full PDF Instruction Book

The attached PDF book is a free download published into the Creative Commons by author David Hartkop under a CC-BY license.

You are free to:
Share, copy and redistribute the material in any medium or format. Adapt, remix, transform, and build upon the material for any purpose, even commercially. The licensor cannot revoke these freedoms as long as you follow the license terms.

Under the following terms: Attribution:

You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. No additional restrictions: You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

Hartkop, David T.
Open Autoclave: Create an open-source off-grid medical instrument sterilizer
ISBN: 978-1729731949

181226_OpenAutoclaveBookDownload.pdf
Download

Step 3: Download the Arduino Software

The Open Autoclave can be made with or without a microcontroller. If you choose to do the full build, there is an Arduino Uno R3 microcontroller that acts as a timer and a thermostat, and also does data logging for each sterilization cycle. The software for the Arduino can has been included with this step for you to download.

Along with the software are some schematics and diagrams, temperature logs and charts that will help you along the way to building and using the Open Autoclave.