A mixed analog and digital integrated circuit with features which are especially useful for application as a front end for physiological signal instrumentation such as electrocardiographs, electromyographs, and electroencephalographs. The integrated circuit has 5 signal channels, each with analog amplification...http://www.google.fr/patents/US5467090?utm_source=gb-gplus-shareBrevet US5467090 - Serial processing circuits with serial chaining
