Brain Controlled Artificial Legs

2193 Words Aug 25th, 2010 9 Pages

This paper describes a brain controlled robotic leg which is designed to perform the normal operations of a human leg. After implanting this leg in a human, the leg can be controlled with the help of user’s brain signals alone. This leg behaves similar to a normal human leg and it can perform operation like walking, running, climbing stairs etc. The entire system is controlled with the help of advanced microcontrollers and digital signal processors. The signals are taken out from the human brain with the help of electroencephalography technique. The person can perform operations like walking, running etc just by their thought. This system will be very much suitable for those who lost their
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The following figure shows the different types of waves and also the mental state of the per-son. Those waves usually vary from a frequency of 1Hz to 40 HZ. Electrode cap is placed in the scalp of the person. The signals taken out from the human brain will be in the range of mV and µV. Hence they are fed to an amplifier. Then it is sent to a Analog to Digital Converter to convert the analog brain signals in to digital form. Then it is sent to a signal processor where parameter extraction, pattern classification and pattern identification are done. These digital signals are fed as input to microcontroller unit. The last four units (Amplifier, Signal Processor, Analog to Digital Converter and Microcontroller Unit) are placed inside the artificial leg. The output of the microcontroller unit is fed to the driving circuit. Let us see about these blocks in detail.

Electrode Cap: a person wears an electrode cap. These electrode caps contains electrodes which are placed on the skull in an arrangement called 10-20 system, a placement scheme devised by the interna-tional federation of societies of EEG. In most applications 19 electrodes are placed in the scalp. Addi-tional electrodes can be added to the standard set-up when a clinical or research application demands in-creased spatial resolution for a particular area of the brain. High-density arrays (typically via cap or