fMRI (Functional magnetic resonance imaging) is already successfully used with non-responsive patients to learn more about relevant brain activity. However, fMRI has many problems – it is not portable, affordable or accessible for most patients, and completely impractical for frequent use.
One peer-reviewed study showed that over 40% of patients diagnosed as vegetative are reclassified as (at least) minimally conscious when assessed by expert teams. For those reasons, Brain-Computer Interface (BCI) technology using the EEG has been adapted for Disorders of Consciousness (DOC) assessment, creating a much more practical way to measure brain activity, assess disorders of consciousness (DOC) in patients and provide simple communication for some of them.
Coma is characterized by the absence of consciousness.
People with unresponsive wakefulness syndrome (UWS) have emerged from coma. They show periods of eye opening yet remain unresponsive. They may even exhibit reactions to visual stimuli, but still lack cognitive functions.
Patients in a minimally conscious state show limited and transient (but clearly discernible) evidence of some consciousness, but are unable to communicate without mindBEAGLE.
Motor impairment may include the partial or total loss of limb function. This can include muscle weakness, poor stamina, lack of muscle control or paralysis due to neurological conditions such as stroke or multiple sclerosis.
Patients in the locked in state (LIS) often have minor deficits in cognition, but are consciously aware. They have very limited motor control. Communication can be still possible via residual motor functions, e.g. movements of the eyes.
People in completely locked in status (CLIS) have lost all their motor functions, but are usually conscious. Thus, a BCI might be the only means of communication possible for them.
Types of cognitive impairments include dementia, amnesia, or attentional disorders.
The clinical standard tests are based on behavioral observations. This means the patient has to show some voluntary motor responses. Due to the subjective interpretation of these movements, misclassifications could occur. Studies showed that up to 43% of patients diagnosed as UWS are reclassified as (at the least) minimally conscious when assessed by experienced teams.
Parameters like intelligence (nonverbal or general), attention or memory are tested by a wide range of different neuropsychological tests.
The motor skill of patients is measured by motor scales. They are used (for example) after stroke to assess the residual motor functions and further to measure the therapeutic success of stroke rehabilitation.
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The patient is asked to focus on the vibration on a specific body part (e.g. right hand). When the patient is asked a simple YES or NO question, she or he has to focus on the vibrations on the left hand to answer with YES. If the patient wants to answer with NO, she or he has to focus on vibrations on the right hand.
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mindBEAGLE can measure the imagination of an arm or hand movement. In this case, the patient has to imagine the movement in order to answer a question. For example, the movement of the left hand means YES and the movement of the right hand means NO.
Oregon Health & Science
“mindBEAGLE helps us to work with individuals in their home environments to determine if they have measurable evoked potentials.”
FNRS Research Director,
Coma Science Group, GIGA-Ulg and CHU Liège, BE
“mindBEAGLE combines important electro-physiological tests that allow us to search for signs of consciousness after coma. The big advantage of mB is that it is integrated. You can take it to any patients and plug them in and get the results directly. It is still a challenge and it doesn’t work with all the patients. mindBEAGLE is a big help for us to use the paradigms as they are implemented in mB for very challenging patients.”