Recording/Sensing Neurotechnology for Medical Applications

Recording/Sensing Neurotechnology for Medical Applications

To better diagnose and treat medical conditions it is often helpful to access and measure the state of the brain and the nervous system. For the case of neural recording, there are different types of signals that can be measured and that have been identified as viable proxies of brain and nervous system activity: namely, electric and chemical signals. These measurements can be used for diagnosis and to inform treatment efficacy. The surface electroencephalogram (EEG) can be used to measure the electrical activity of the brain by placing electrodes on the surface of the scalp. The changes in the electric potential measured by the electrodes can provide information about which areas of the brain are activated by an external stimulus. For instance, EEG is used to test the auditory system of newborns. While the baby is asleep, simple sounds are played and clinicians look at the EEG recordings to see if the brain receives the signals from the auditory sensory system, responding with characteristic electrical waves, called evoked potentials. In other applications, the mental state of a participant being recorded can be inferred from analyzing the frequencies of the electrical waves generated by their brain, which changes according to the participant’s level of attention, drowsiness, relaxation, etc.

Imaging techniques can be used to measure biochemical cerebral activity, for instance, active brain areas show an increased level of local blood oxygenation that can be measured with  magnetic resonance imaging (MRI). MRI can be used, for example, to check the brain damage after a stroke. The impaired brain areas appear as dark or light spots that do not look like the normal brain tissue.

EEG and MRI are two examples of non-invasive techniques that are commonly used to record neural activity, but many others are available and are mainly used for diagnostic purposes. Each technology has its application according to the temporal and spatial resolution needed.

Recording/Sensing Medical Neurotechnologies

Table 1.1 Examples of Existing and Anticipated Recording/Sensing Medical Neurotechnologies