To all the makers out there -
This is a work in progress. We will update it with a complete "How to Make" description as we proceed. If you want to build it with us, please let us know in the comments section.
Evolve is a plug and play platform for Prosthetics and Human Machine Interfaces. Currently developed for a 3D printed Bionic Arm, evolve features an App store so that users can download new features and install it into the arm and a a range of specially designed sensors to know the exact pressure required to hold an object - whether its an apple or a glass bottle and Neural Network for AI based learning.
The current version of evolve was tested to work as a Human Machine Interface, on an inhouse custom built Bionic Hand and on the Inmoov hand (www.inmoov.fr).
The following instructable is written based on how we interfaced EVOLVE to a Bionic Hand
The control input for the bionic hand is a set of EMG sensors and works both as a wired and wireless input. The GUI of the hand gives basic insight into the status of the hand, the apps that are running and features installed. A profile based system and touch input allows the user to select the required functionality for his hand, whether its a key grip to hold a car key or a power grip to hold a ball.
Until now, all the 3D design, hardware development and software coding was done by the same team. We hope to bring a change in this by providing a hardware platform, open source 3D hand model and and app ecosystem. With this, developers working on the 3D model can completely work on it, apps and features can be developed by software developers and hardware teams can develop accessories for the system. This helps to bring down the cost of the system and make it scale able, smarter and easier to work with.
We started working on a bionic hand in 2010, when we first came across a 30,000$ bionic hand video and realized that the number of amputees in need of an affordable version is really high.
Step 1: Power Supply
The motors being used is a combination of MG996R and Each of the motors require around 1 Amp of current and runs on 5V supply. So the basic design consideration is to have a 5 Volt 6 Amp supply powered from a 3.7 Volt 7000 mAH Li-Po battery.
To achieve this, we used a simple boost converter based on XL6009. The demo was done using a 9 Volt dc power adapter and a buck converter.
Step 2: The Sensors
Single Supply EMG sensors were used as the control input. Currently the system is built with specifications that is suitable for both gelled electrodes and reusable electrodes. Its a wireless wearable device that monitors the users muscle signals and transmits a DC averaged value back to Edison via a BLE interface. It also has an option to transmit a partially processed EMG signal after 16 bit ADC conversion (ADS1115).
Step 3: The Brain
When the Intel Edison came to the market, most of our hardware requirements in terms of wireless communication and a powerful processor and memory were immediately satisfied.
The code was done in python script and GUI was built in Node.js. Intel edison sits inside the bionic arm and still gives us the power to have a wireless device interfaced with the hand running python and node.js. With python we were able to develop a system to where we can download new apps and features and gives the user an ability to use/run it as required. This entire system was built from scratch.
Step 4: The Motors
A combination of MG 995 R and 996 R were used. Head on to the HobbyKing website to get more info. about this.
Step 5: The Arm
The acrylic version shown above is our first mock up model.
A detailed assembly instruction of the Inmoov hand can be found in the project website - www.inmoov.fr
Our in house 3D design will be updated shortly.