Over the last 20 years, over 20 such patents for clinical neurobiological computing methods arising from BRL research have been assigned by our faculty members to NYU. Many of those patented have been licensed to biomedical computer system manufacturers by NYU. Using only QEEG measurements, BRL staff members successfully developed and patented a method to enable an automatic instrument to quantify and monitor the depth of anesthesia, during induction and maintenance of the loss of consciousness during surgery, independent of the particular substances used for induction or hypnosis. That method was licensed by NYU to a biomedical instrument manufacturer and incorporated in an FDA-approved instrument. Drs. John and Prichep subsequently published a general neurophysiological theory of anesthesia which is the first such theory since 1904.
Fetal Brain Monitor
The Fetal Brain Monitor (FBM) is an instrument intended to monitor the functional state of the brain stem of a fetus while it is the mother’s uterus, by analyzing electrical activity recorded from the surface of the abdomen of the mother. This electrical activity includes potentials generated from various sources within the body of the mother, including intra-uterine activity generated in the central nervous system of a fetus. Such fetal brain activity is voltage oscillations reflecting neural transactions in the fetal brain. These transactions consist of the electroencephalogram, or EEG, produced spontaneously by rhythmic interactions among masses of neurons in different brain structures but can also include activity induced in neuroanatomical pathways reflecting the processing of sensory information, known as “evoked potentials”, or EPs.
During gestation, the fetus develops an array of specialized neural receptors for each sensory modality. These receptors, together with the neuroanatomical systems that mediate the processing of information in each of these modalities, become functional at various times during the period of gestation well before birth. In the newborn infant, the functional adequacy of each system can be evaluated by stimulation of the corresponding receptors by appropriate stimulus generators. The sensory EP’s elicited by such stimulation consist of oscillations of voltages that can be recorded from the scalp.
These oscillatory potentials arise from synchronized activation of large populations of neurons that comprise way stations along bundles of fibers in the pathway of the nervous system. These connect the receptor surfaces to sequential way stations in the information processing systems at ascending levels in the brain, in the brainstem, the thalamus and the cerebral cortex. The neuroanatomy of each of the various sensory pathways has been very well established.
As volleys of nerve impulses arising from stimulation of the receptors propagate along these pathways, the way stations are sequentially activated. For this reason, the waveshape of the EP produced by activation of a neural pathway is an oscillation with a series of peaks. The time between presentation of the stimulus and a given peak in the EP, the “peak latency”, represents the arrival of information at each way station and depends upon the transmission speed in the corresponding pathway. This transmission velocity depends upon the level of maturation of the pathway, the extent of myelination of the nerve fibers, and the availability of neurotransmitters. Thus, the latencies of the successive peaks in an EP depend upon a variety of metabolic, neurochemical and physiological factors and provide an overview of the functional status of multiple brain regions and processes. For these reasons, EP examinations have been found valuable for a wide variety of clinical purposes. Using complex signal processing of the recorded responses, the ability to record the fetal brainstem from the mother's abdomen has now been demonstrated in women who are between 29 weeks and fullter of pregnancy. Clinical data acquisition continues on this important device.
Handheld Instruments for the Evaluation of Brain Function
Though a licensing agreement between NYUSOM/Brain Research Laboratories and a BioMedical Instrument manufacturer (BrainScope, Inc.), patented technology for quantitative analysis of the spontanous (EEG) and evoked (ERP) electrical activity of brain is being implemented in handheld (PDA like) devices. These devices perform automatic acquisition, analysis and interpretation of brain electrical activity relevant to a number of applications, such as in the Emergency Room (ER) for altered states of consciousness, and evaluation of patients for dementia or Attention Deficit Hyperactivity Disorder (ADHD). Currently a data acquisition study is underway in the ERs at Bellevue Hospital Center and several other ERs across the country. Such devices are intended to bring state-of-the-art evaluation tools which are non-invasive, inexpensive and easy to use, to the hands of the clinicians.