Optically measuring nerve activity based on an electro-optical detection system

Nerve conduction and activity is a marker of disease and wellness and provides insight into the complex way the nervous system encodes information. We propose an electro-optical detection system and show the recordings from an electrically stimulated in-vitro nerve preparation. The system converts the action potential at the probing position to light intensity before any amplification and detection. Thence the light signal is detected by a photodetector. The new detection system has the ability of isolating the probing point and the amplification circuits, which reduces the electrical interference from the circuit. Moreover, the sampled signal transmitted via optical fibres rather than cables or wires makes it more robust to environmental noise. From the experiment, we demonstrated that the electro-optical detection system is able to detect and amplify the nerve response. By analysing the data, we can distinguish the response from the stimulus artifact and calculate CAP (compound action potential) propagation speed.