Patent Document ID: 8838226
Application ID: 12628568
Patent Flag: 1

Claim One:
1. A method of determining electroencephalogram (EEG) signal quality in a device for quantifying brain or cortical activity as a function of depth of sedation or anesthesia comprising steps of: a. anesthetizing or sedating a subject; b. monitoring the subject with a brain having a left hemisphere and a right hemisphere under anesthesia or sedation device for quantifying brain or cortical activity as a function of depth of sedation or anesthesia, the device with at least two measurement electrodes, and at least one reference electrode, the at least two measurement electrodes comprising at least one electroencephalogram (EEG) electrode, having a signal, positioned to monitor left hemisphere brain or cortical activity and at least one EEG electrode, having a signal, positioned to monitor right hemisphere brain or cortical activity of the subject's brain, the reference electrode comprising at least one EEG electrode, each electrode providing an EEG analog signal which is subsequently converted to a digital signal; c. measuring the brain or cortical activity of both the subject's left and right brain hemispheres essentially simultaneously over a period of time part of the period of time over which the subject is under sedation or anesthesia; d. calculating based in part on the digital signals with the processor at least one numerical quantitative electroencephalogram (QEEG) time-series index corresponding to the brain or cortical activity as a function of depth of anesthesia or sedation of each of the left and right hemispheres of the subject's brain over the period of time part of the period of time over which the subject is under sedation or anesthesia; e. displaying the at least two numerical time-series indices, with at least one numerical time-series index corresponding to the brain or cortical activity of each of the left and the right hemispheres over the period of time, part of the period of time over which the subject is under sedation or anesthesia, on a monitor simultaneously; f. comparing the numerical time-series indices of each hemisphere's cortical or brain activity as a function of depth of anesthesia or sedation; and g. determining, based at least in part on differences between the at least two numerical QEEG time-series indices corresponding to the brain or cortical activity as a function of depth of anesthesia or sedation, whether the signal of at least one of the EEG electrodes has poor quality.