-
1Gather all the tools and resources
There are several better guides out there to setup an electronics lab, in this section I am just highlighting some things you'll definitely need to create your own low cost BioAmp sensor at home. You'll need some basic tools and electronics components as listed below. You can choose to start building your BioAmp on a BreadBoard but it's highly recommended to transfer it to a perf (copper dot) board. I highly recommend you to get:
- Assorted component box for
- 1% precision resistors
- 5% general resistors
- Ceramic disc capacitors
- Electrolytic capacitors
- General purpose op-amps
- Light Emitting Diodes (LEDs)
- Electronics lab tools like:
- Soldering Iron
- Solder wire
- Wire strippers and nippers
- Different size tweezers
- Additionally you can get
- Arduino UNO/Nano
- Full size BreadBoard
- Perf (copper dot) board
- Hobby servo motor
- Jumper cables
- Connection wires
The things listed above should already be in an electronics hobbyist lab setup. If you are very new to the field and even slightly interested in electronics It's highly recommended to get these basic tools and components to start your electronics journey.
- Assorted component box for
-
2HCI and BCI Design Overview
Our nervous system is divided into,
- Central nervous system (Brain & Spinal cord)
- Peripheral nervous system
- Somatic nervous system (Voluntary muscle movement & reflex actions)
- Autonomic nervous system (Heart rate, blood pressure, respiration...)
When we say we are designing a Brain Computer interface we are actually targeting the Central nervous system and when we say we are creating a Human Computer Interface we are actually targeting the Somatic nervous system. A highly simplified HCI & BCI design doc is presented below that shows how we go from signals emerging inside body to recording them using electronics and then using it to manipulate or control things on a computer.
The six part HCI/BCI design flow contains:
- BioPhysiological signals originating from our body (ECG, EMG, EOG, and EEG)
- Initial RF low pass filter to remove high frequency background noise
- Instrumentation amplifier for high quality signal conditioning
- Band Pass Filter (BPF) to aplify signals from a specific frequency band only
- Analog to Digital Converter (ADC) to digitize the analog signals into zeros & ones.
- Computer to record, visualize and interpret the signals
-
3Overview of BioAmp Design
-
4How to choose a good Quad OpAmp?
To create a BioAmp that performs good for your specific requirement you can choose any low cost Quad OpAmp. Below image shows all the characteristics that are desirable to get the best results from a lab grown BioAmp sensor. Although not up to the mark you can choose to use LM324 through hole IC on a breadboard or perfboard to create your first BioAmp for EMG recording.
-
5Instrumentation amplifier design
-
6Bandpass filter design
To create a good BioAmp hardware you need on-board signal filtering so that we get clean signal. To design a bandpass filter you can learn complex equations or use any online calculator like this. Below are the different biopotential signals frequency coverage and amplitude list so that you can design your own bandpass filter,
- EEG is a uV signal of 0.5 to 40Hz
- EMG is a mV signal of 40 - 2000Hz
- EOG is a mV signal of 0.5 - 10Hz
- ECG is a mV signal of 0.5Hz to 45Hz
Below schematic diagram shows the Muscle BioAmp BisCute design and all the parts required to build it can be procured for about $1 depending on your location. You can try out building it on a breadboard with LM324, 1% precision resistors and other passive components as per the schematic diagram below. -
7Listening to your BioPotential signals
-
8Connecting sesnor to MCU
-
9Making HCI & BCI projects
Electroencephalography (EEG)
Recording brainwaves (EEG) using BioAmp EXG Pill
Electromyography (EMG)
Bionic Claw game controlled by muscles
Electrocardiography (ECG)
Heartbeat-activated RGB Led controller
Electrooculography (EOG)
Clicking photos by blinking your eyes
Drowsiness Detector
Discussions
Become a Hackaday.io Member
Create an account to leave a comment. Already have an account? Log In.