Cerebral vessel deformations generate acoustical bruits due to the disturbance in laminar blood flow. Signals of a characteristic spectral shape are produced by aneurysm, arteriovenous malformation and stenotic narrowing.These acoustical signals are strongly attenuated during propagation through the cranium and become very weak and noisy when outside the skull. A newly designed, highly sensitive accelerometric microphone, a low noise amplifier and a filter unit allow for the detection of very weak (low acoustical level) periodical signals in the 200Hz to 1000Hz span. Signals generated from pathological vessels have peaks in the spectrum at an acoustical level below OdB SPL (Sound Pressure Level). There are also acoustical bruits at much lower levels, which probably owe physiologically originated. Signal control and processing, implemented in the microcomputer software, performs a screening and non-invasive method for early detection of cerebral vessel deformations.

Keywords: Aneurysm, cerebral vessels deformations