Biomedical Engineering Reference
user to perform easy and fast coil positioning with the robotized TMS system.
Furthermore, the current gravity compensated force/torque readings are sent to the
TMS control software via an extended robot server. In this way, the TMS control
software uses the forces for contact pressure control to place the coil on the
patient's head and to maintain the optimal contact pressure.
Direct head tracking is in principle feasible for robotized TMS. It will further
increase the system's safety and comfort. A head marker, which might cause safety
concerns, is not required in this approach. Furthermore, it allows for automatic
head registration which is a comfort plus for the operator. Currently, the resolution
and/or scanning and processing time of direct tracking devices are too poor for
precise head tracking. However, with advanced technologies it will be possible in
the near future.
In conclusion, we have now developed a safe and clinically applicable robot-
ized system for Transcranial Magnetic Stimulation. The developed FTA sensor
with the optimized Force-Torque (FT) control is now available as an extension to
SmartMove TM , called TouchSense [ 1 ], for the clinical market.
10.2 Outlook and Future Work
With the system's presented current state of development, the robotized TMS
system can be easily deployed for experimental, clinical or therapeutic applica-
tions of TMS. As shown in Part I, robotized TMS outperforms hand-held TMS in
terms of accuracy and precision. Therefore, we encourage the researchers and
TMS users to frequently use the robotized TMS system to systematically inves-
tigate TMS and its functionality. In this way, advanced treatment strategies using
repetitive Transcranial Magnetic Stimulation (rTMS) for neurological or psychi-
atric diseases could be established.
From an engineering point of view, there are some aspects that might be worthy
for further developments:
10.2.1 Fully Automated TMS
With the presented further development of robotized TMS, we are on the way
towards fully automated TMS. When combining robotized TMS with surface
electrode recordings and the TMS stimulator, an automated hot-spot search
including Motor Threshold MT estimation is imaginable. Based on the Motor
Evoked Potential (MEP) amplitudes, the hot-spot can be estimated in an automated
manner. The contact pressure control will assure an optimal coil to scalp distance.
Once, the hot-spot is estimated, the robot will automatically reposition the coil at
the hot-spot and estimate the MT. Current MT estimation algorithms could easily