Introduction to Paper Presentation on Brain Controlled Artificial Legs :
Brain controlled artificial legs is designed to perform normal operations of human leg. After artificial leg is implanted into human body, it can be controlled with the help of user’s brain signals alone. It can behave similar to normal human leg and can perform operations like walking, running, climbing stairs, cycling, hopping etc. The controlling is done with the help of micro controllers and digital signal processors. The signal from human brain is taken out with the help of electroencephalography technique. This system is much suitable for those who lost their legs in accidents and it is much more feasible in the real time environment.
The communication is required between human brain and an external device this is called as Brain-computer interface (BCI), which provides a direct pathway for communication. The activity produced in brain is displayed in the form of brainwaves, these brainwaves range from most activity to least activity.
- If brain is awake and very much engaged in mental activities then it produces beta waves. Beta waves are of low amplitude, and fastest of other different waves with a frequency of 15 to 40 cycles a second. Beta brainwaves indicate brain is alert and working.
- If brain is not awake then it produces alpha brainwaves, which are slow and higher in amplitude, and their frequency is from 9 to 14 cycles per second. Alpha brainwaves indicate relaxed status.
- Theta brainwaves consist of greater amplitude and slower frequency; it ranges between 5 to 8 cycles per second. When human brain switches from busy work to idle status and starts daydreaming often produces theta brainwaves. Theta brainwaves indicate drowsy or id eating.
- Next comes the delta brainwaves, which are of greatest amplitude and slowest frequency. It ranges between 1.5 – 4 cycles/second. Delta brainwaves will never run down to zero, since zero indicates brain is dead. But deep sleep results in lowest frequency range between 2 – 3 cycles/second. Delta brainwaves indicate sleeping, dreaming, deep dreamless sleep.
For each signal produced in the micro controller memory, the artificial leg is pre-programmed to do a specific operation. The produced signal should match with the actual signal from user’s brain.
A small sized lithium-ion batteries supply power to the artificial legs and they need to be charged once a day. These batteries have very high charge density, so that they can store a lot of energy.
Thus brain controlled artificial legs involves ease of construction, and less cost is needed. Users can have full control over their artificial leg, and they are semi-automatic. This requires a simple control unit.
Download Paper Presentation on Brain Controlled Artificial Legs .