SNAP: watching the brain during exercise
The Bochum team at SNAP GmbH can read from the brain when a muscle has had enough exercise. The effectiveness of a course of physiotherapy is usually assessed by the visible progress of the patient. However, by chance the researchers at SNAP in Bochum have discovered an entirely new approach.
The researchers at the test station of the BioMedizinZentrum in Bochum normally search for patterns in the brain that match up with certain motion sequences. Test persons walk through a virtual obstacle course on a treadmill whilst their brain activity is measured. The test station serves as a tool for manufacturers for developing artificial limbs that are controlled by the patient’s thoughts. But the team led by Professor Weigelt went one step further and measured the brain activity of test persons being moved in special rehabilitation equipment at the AMBULANTICUM® in Herdecke. The Lokomat® moves the legs in a natural walking pattern, helping the patient to learn normal movement sequences again. The measurements were taken to test SNAP’s mobile measurement methodology and technology in a variety of movement situations.
Using electroencephalography (EEG) on the test persons, Professor Weigelt was able to establish when exhaustion levels were reached: “To measure brain activity we use the ´sleep index´ (spectral frequency index or SFx), a method also used by anaesthetists. This is a ratio between certain readings that varies between individuals and tells us how alert or exhausted a person is. An anaesthetist refers to the SFx before the surgeon can begin to operate. It is useful in rehabilitation therapy because it informs the therapist when the patient is exhausted and the therapy should stop,” explains Weigelt. Normally it is up to the therapist to estimate the ideal duration of training for each individual patient: whether it is still having an anabolic effect or whether it is too much. EEG provides a helpful new tool. This method, classified as a neurofeedback procedure, has not been applied in this form before.
SNAP CEO Uwe Seidel adds, “A physical movement carried out externally by the Lokomat® simultaneously has a positive effect on the SFx. This observation could lead to further fields of application.” One likely use would be to monitor activation by movement, for example during motor function training in stroke patients. However, further studies using test volunteers are needed.