Method and apparatus for non-invasively measuring blood flow and for acquiring and processing an ECG signal

An apparatus for acquiring and processing an electro-physiological signal, said apparatus comprising

• an ECG arrangement having at least two electrodes for measuring a potential difference between at least two points on a surface of the body near a blood vessel and for producing a potential signal, the signal being an electro-physiological ECG signal overlaid with interference signals due to the magnetic field, and
• means for ascertaining a component of the potential signal curve which is produced on the basis of the Hall effect by the movement of charge carriers in the vessel.

A non-invasive method for operating an electro-physiological instrument and for evaluating an electro-physiological signal acquired from a body exposed to a magnetic field by measuring potential differences between at least two points on a body surface near a blood vessel, the potential being overlaid with interference signals due to the magnetic field, said method comprising steps of

• determining a component of the signal curve which is caused by the Hall effect on charge carriers in blood flowing in the blood vessel and subsequently
• deriving from the component of the signal curve which is caused by the Hall effect a value which is characteristic of the flow of blood in a vessel.