2023-05-12 11:33:00
A research team from the Swiss Federal Institute of Technology has developed a soft robot with sensory legs that can map brain activity inside the human skull. The researchers want to minimize the risk, for example of patients with epilepsy and other neurological disorders, that conventional brain mapping methods entail. The method has so far only been tested on pigs.
Electrocorticography (EKoG) is often used to map epileptogenic brain regions. The procedure is also used when lesions in the brain have to be surgically removed. EKoG is also used in research on applications for the interface between brain and machine. For this purpose, electrodes are conventionally applied to the brain, with considerable risks for the patient. Because the hole to be cut in the skull must be the same size as the sensor surface. Accordingly, only a small area of the cortical surface can be covered with low spatial resolution, the researchers write in the study “Deployment of an electrocorticography system with a soft robotic actuator”which is published in Science Robotics.
Deployable legs
The concept of the soft robot envisages drilling a hole about one square centimeter in the human skull. The approximately 2 cm long robot is introduced into it. Its up to six legs are made of a flexible silicone polymer and are folded together. They spiral around the body, covering an area 4 cm in diameter when fully deployed. Each leg houses electrodes to monitor brain activity and strain sensors to monitor deployment. They return approximately the time when the legs are fully extended.
The legs are initially folded together similar to a sleeve pushed back. Once the robot has been inserted into the skull, they are filled with a liquid and unfold. The unfolding is gentle on the brain because little pressure is exerted.
In the previous prototype, the leg length has not yet reached its final dimension. The researchers assume that it can be extended to 8 to 10 cm. The sensor field created by them would then be correspondingly large. The scientists write that the hole in the skull would not have to be enlarged for this. For removal, the fluid in the legs is drained and the robot is removed from the hole in the skull.
Tests am Mini-Pig
The researchers first tested the robot on a model of a human brain made of plastic and hydrogel. In addition, a miniature pig from Göttingen had to be used for a test procedure. The animal was implanted with a single 15 mm long robotic leg containing the sensors. The electrodes were used to record the mini pig’s brain activity. For this purpose, the animal was electrically stimulated at the snout.
The researchers are certain that the procedure they have developed is a gentle variant of the EKoG and can shorten the time for interventions in the operating room. The researchers set up the start-up Nurosoft Bioelectronics to test the process on humans, to further develop it commercially and to be able to use it.
(olb)
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