Brain stimulation is now being used successfully to combat diseases such as Parkinson's (lat. Parkinson scriptor morbus), chronic depression, pain and tinnitus. By making neurostimulators smaller and more energy efficient, they can be used more effectively and for a wider range of brain and nervous disorders. Marijn van Dongen, the scientist of Delft University of Technology (TUDelft), made a prototype of a chip that enables this kind of neurostimulation to be used. Brain stimulation is successfully used today to combat neurological diseases and there is evidence that brain stimulation may also be successful in the treatment of many more brain disorders, such as epilepsy, addictions, migraine and dementia. Many existing neurostimulators, however, have a limited energy efficiency, making a large battery necessary. This in turn increases the size of the whole neurostimulator, making it impossible to locate the implant where it is actually needed. Subcutaneous wires often connect the neurostimulator in the chest with the electrodes in the brain.
This is why a new method of neurostimulation has been researched at TU Delft: high-frequency (HF) neurostimulation. The effectiveness of this HF stimulation has been demonstrated in simulations and with in-vitro measurements (in collaboration with the Department of Neuroscience at the Erasmus Medical Centre). Not only does HF stimulation have the same effect on tissue as classical stimulation, but it can also be more energy efficient. This means that the battery can be smaller and fewer space-consuming components are needed.
According to Marijn van Dongen, in his research, they focused on new stimulation patterns that can be generated efficiently. Instead of a constant current, scientists stimulate the brain with a series of high-frequency pulses of current. These kinds of pulses can be generated in an energy efficient way thanks to the principle of a switched-mode power supply. Scientists have designed an energy-efficient neurostimulator chip that is up to 200% more energy efficient than its conventional counterparts. This means that future neurostimulators can be made smaller and as a result can be used for a greater range of brain and nervous disorders. Moreover, these pulses can activate different targets simultaneously, increasing the efficiency of the neurostimulation.
A prototype chip has been developed which can be used with this form of neurostimulation. The method has also been successfully verified in collaboration with neuroscientists at Erasmus University Medical Centre, the University of Texas at Dallas (US) and the University of Otago (New Zealand).