An Improved Tool for Spinal Cord Monitoring

CLASSIFICATION OF SOMATOSENSORY EVOKED POTENTIAL WAVEFORMS

Dr HU Yong, Prof LUK Dip Kei, Keith
Department of Orthopaedics and Traumatology

US Patent No. 8,498,697 granted on July 30, 2013

CN Patent No. ZL201080049651.X granted on December 17, 2014

Somatosensory-evoked potentials (SEPs) tests are performed to determine the electrical responses in the brain when the hands or limbs are touched or stimulated by a small electric pulse. SEPs can be used to monitor the function of somatosensory afferent pathways during surgery for preventing possible surgical injury. However, SEP responses are embedded in a high level of electrical noise caused by background electrical activity and other non-cortical artifacts. It is challenging to obtain a reliable estimation of single-trial SEP responses.

The newly granted patent greatly improves the signal quality, reproducibility, and reliability of automatic spinal cord monitoring. By using both the frequency and temporal property of SEP responses, it can classify collected data samples for the purpose of removing noisy sweeps and produce a clean waveform for monitoring and diagnostics. The neurosurgeon can visually and accurately trace the situation of the patient during surgical treatment.

Compared to the conventional approach, this invention shows high reproducibility between successive measurements and therefore the measurements will become more accurate. In addition, it shortens the time required to monitor patients since only as few as one-tenth the number of stimuli are needed to measure the nerve conductivity per site. This in turn means a shorter anaesthetic for patients and so the secondary risk is also reduced.