Challenge: Use LED google VEP stimulation on patient. Acquire brain neural signal responses from NIHON KOHDEN Neuropack 4 device. Perform real-time signal analysis, automatically detect significant extremes and present them graphically.
Difficulties: Automatic detection of undeterministic signal extremes in noisy environment (uV range). Signal can differ significantly from ideal curve. Perform tests on-sight, during ongoing operation. Use of non standard custom connectivity.
Solution: We use a laptop PC, USB DAQ multifunction board for analog signal acquisition and LabView to create the solution.
Result: During signal recording, interactive graphical analysis is possible in the form of single/multiple signal analysis, real-time event commenting, 4 channel interactive setting of extreme detection time windows. Real-time and average response graph can be presented in clear manner for n (n > 100) signals in the form of shift/stacked plot. Application also performs good/bad signal classification through cross-correlation on average. The program also gives the user an option to review results offline. The solution represents a handy tool to record and review large number of signals. They are now easily managed, arranged and analyzed as real-time or average responses giving the operator valuable feedback on his progress and enabling him to comment his actions.
This project is made for the requirements of the neurosurgical clinic in Ljubljana. The specific of this project is to make a system that is used on brain surgeries live in operation rooms at the Clinical centre. The system is extremely complex, because it includes multiple interconnected systems that enable the surgeon to have insight in brain functioning in real-time.
Insight in this function is done so that the patient, who is anaesthetized, receives special stimulation glasses, which have inbuilt LED diodes that enable light stimulation. Light stimulation influences the brain functioning so that the stimulation glasses send light signals into the patient’s brain, which reacts reflex with production of certain weak electric signals in specific areas of the brain. These signals enforce over the second part of the system with the help of a specialized amplifier of physiologic signals, then they are transferred in the analogue-digital converter, from which they are, via USB interface, transferred into a computer (PC, laptop), which is the station that the surgeon works on. Therefore the surgeon has, during brain surgery, via computer, direct insight into the reflex reactions of different centres in the brain. It controls any unwanted faults during operation (tissue damage etc.).
The system enables a very clear insight (graphical form) of received signals, copying of brain reaction during surgery and further post-operative analysis by the surgeon or other staff of the Clinical centre Ljubljana. The system is very robust and is user friendly due to the sensitivity of the process, which takes place in the operation room. We have deliberately used a very modular system, an analogue-digital card, which enables data transfer via USB interface, so that the data can be transferred on any computer in the operation room.
This is the only system of its kind in the world, and we in Wise Technologies, together with experts at the Clinical centre Ljubljana, plan the production of this system in commercial purposes and also plan presentations of this system at different meetings of neurosurgeons around the world.
On the making of this system we have worked together with the acknowledged surgeon Dr. Roman Bošnjak, who has also taken part in designing the system: from the point of the way of carrying out stimulations to the way of displaying results. Results are displayed and analyzed in accordance with the most recent researches in neurosurgery.