In one aspect, a method of detecting ischemia within the brain of a patient.
The
method includes assigning a first value to a first signal generated by a tissue
on the right-hand side of the body and assigning a second value to a second signal
generated by a tissue on the left-hand side of the body. The method also includes
comparing the first value and the second value. The difference between the first
value and the second value indicates that ischemia is present within the patient's brain.