Patent No. 3892227 System for stimulation and recording of neurophysiologic data

 

Patent No. 3892227  System for stimulation and recording of neurophysiologic data (Coursin, Jul 1, 1975)

Abstract

Standardized stimuli of visual, auditory and somatosensory nature are precisely structured and recorded by central computer facilities on a cassette magnetic tape with these standardized recordings of electronic control signals and instructions played back by a field technician at a remote station. The electrophysiologic responses are recorded directly on a second cassette system by the remote station for later evaluation at the central computer facilities through equipment to make the information compatible with input to a computer.

 

Notes:

System for stimulation and recording of neurophysiologic data. Filed March 1973, granted July 1975. First paragraph under background of the invention, first sentence states that using EEGs and stimuli correlated together to collect evoked potential data was done in the 1950s. The patent is for remote gathering of EEG data in response to stimuli and sending said data to a central facility for processing by a computer. It uses a lot of the same procedures listed in later patents for gathering evoked potential data. Leave out the magnetic tape and put in electromagnetic transmissions and add the remote neural monitoring and it is an early brain to computer to brain device using specific evoked potentials and other brainwave data (artifacts). It also suggests that someone could be attacked locally and the data transmitted back to a central facility until enough information was gathered to attack them from the central facility. Or even that the attacks could be done locally with a central facility controlling them (this would require a slight additional time frame for the receiving and retransmitting of the brainwave data). This patent also lists a paper on a study done in Japan that was written in 1968 about this type of experiment (the experiment as mentioned in the patent). It also says that these type of experiments were performed on infants. And also that a lot of this experimentation was done in so-called Third World countries and that the findings of the experiment was made available to interested organizations.

 

FIELD OF THE INVENTION

The present invention relates to an apparatus for presenting appropriate stimuli to subjects at a remote location and recording of their electrophysiological responses with least transfer of equipment to the remote testing area.

BACKGROUND OF THE INVENTION

In the 1950's, Dr. David Baird Coursin, one of the present inventors, established a research project using electrophysiological techniques (electroencephalography and auditory evoked response) to study the process of maturation of the brain in human infants. As part of this research, he studied a number of infants who were experiencing convulsive seizures, behavioral change, and some evidence of mental retardation. These subjects were eventually found to be receiving a diet of infant formula in which the amount of vitamin B6 was reduced to a borderline deficient level. This marginal single nutrient deficiency altered the activity of a number of brain enzyme systems resulting in the clinical picture just described.

Using biochemical, electrophysiological, and clinical techniques, Dr. Coursin was able to demonstrate conclusively the relationship of the borderline deficiency of this single nutrient to the neurochemical changes that caused derangements in the patient's neurophysiology (electroencephalograph and auditory evoked response) and the appearance of abnormalities in performance. This triad of interaction has become one of the classical demonstrations of the interrelationship of neurochemistry with neurophysiology and clinical behavior.

As a result of these discoveries, extensive studies were undertaken using electrophysiological techniques (resting electroencephalograph and evoked response EEG) to monitor the effects of neurochemical change. Research in a number of laboratories has clearly shown that this approach is valuable in linking the neurochemical states of the brain to the individual's clinical capability and performance.

In the course of studying these problems, Dr. Coursin extended his concept of the effect of single nutrient deficiency to include the broader scope of general malnutrition. His studies took him to Central America for the purpose of evaluating mental development in populations at nutritional risk. There he found supporting evidence of this concept in impoverished situations in which the deficiency of single and/or multiple nutrients along with deprived psycho-social conditions impaired the normal development of clinical capability and performance in children.

Other workers have recognized the importance of electrophysiological studies in man and have used the standard paper tracing electroencephalograph as part of their research studies in several underdeveloped areas of the world. Their findings routinely have shown the subject's electroencephalogram to be abnormal in the malnourished state and to improve toward normal with dietary therapy. However, there have been no long-term follow-up studies of these findings, nor have there been any in which the more recent computer techniques for analysis of electrophysiological data have been used.

A single exception to this situation has been one study in Sendai, Japan, in which photic evoked response and frequency analysis were undertaken in a well nourished population of children and compared with one in a malnourished population in the mountainous areas of that country. Publication of this data by Dr. Arakawa and his staff along with Dr. Coursin (Arakawa, T., Mizuno, T., Chiba, F., Sakai, K., Watanable, S., Tamura, T., Tatsumi, S. and Coursin, D. B. "Frequency Analysis of Electroencephalograms and Latency of Photically Induced Average Evoked Responses in Children with Ariboflavinosis," Tohoku J. Exp. Med., 94 327, 1968) represents the only study of its kind in the literature. Furthermore, the technical difficulties in moving the appropriate complex, expensive equipment to the site of the malnourished populations and the difficulties in obtaining tracings preclude other studies of this nature from being readily undertaken.

Several international meetings have reaffirmed the tremendous need for further research in this area, for development of appropriate equipment, and for standardization of techniques that would permit comparisons of findings from different parts of the world. It is well established that the normal process of mental growth and development is reflected in the maturation of the electroencephalogram; that various states including malnutrition cause abnormalities both in the tracing per se as well as in their maturational sequence; and that the success of therapy can be detected by the improvement of these tracings.

At present, there are an estimated 400,000,000 children exposed to nutritional risk throughout the world. They range from severely malnourished youngsters that represent some 3 to 4 percent of the total to mild and moderate degrees of severity that comprise the remainder. Depending upon the time of onset, severity, type and duration of malnutrition, the mental development of these individuals may be impaired to the degree of reducing their eventual performance potential by some 10 to 20 percent. Under these circumstances, malnutrition becomes of major critical importance to the eventual capability of the individual, his capacity to contribute to the well-being of himself, family, community, and nation. As such, this problem is presently recognized as one of major consequence throughout the world.

Unfortunately, the multidiscipline nutrition research projects in this country and abroad do not have the necessary expensive apparatus at hand, nor the specially trained personnel to operate these projects. Furthermore, the environmental conditions within which studies would have to be undertaken could often render the recording apparatus unstable and the results questionable.

Conversely, major medical facilities that do have the appropriate equipment and personnel are routinely located in major centers in affluent areas that are far removed from malnourished populations in which studies of this nature could be undertaken. It has been against this background that the present inventors have endeavored to develop a means for bringing the electrophysiologic techniques to the field and acquiring electrophysiologic data in a manner which would not require the transfer to the field locus of massive electronic equipment or highly skilled electronics personnel.

SUMMARY OF THE INVENTION

The system of the present invention was designed to provide an economical and convenient means of data acquisition, control and storage in a field installation where more complex electronic equipment is not available.

The functions of the system of the present invention are accomplished by providing a convenient means of presenting timed, visual, acoustic and somatosensory (sensory pathways associated with the striated skeletonal musculature of body and limbs) stimuli to a test subject; integrating the control of the stimuli generators used in the test; recording two channels of the electrophysiologic data and three channels of behavioral events on magnetic tape; and providing a means of displaying time code information onto a strip chart recorder.

The present invention includes a program cassette unit which is used to control the presentation of stimuli and to provide a serial time code for use in strip chart recording.

It is, accordingly, an object of the present invention to overcome the deficiencies of the prior art, such as indicated above.

It is another object of the invention to obtain an evoked response EEG in the field at a remote locus without complex equipment.

It is another object of the present invention to allow data acquired in the field to be subjected to the most sophisticated analysis for obtaining an assessment of the individual's electrophysiological status. This information is then to be transmitted to the nutrition research organization that would correlate it with other information obtained from multidiscipline studies of food composition, dietary intake, medical status, sociology, psychology, biochemistry, anthropometry, behavioral performance responses, etc.

Basically, the invention comprises a system involving the production of a programmed tape with voice comment, stimulus pulses, and acoustical stimulus, with time code pulses on a second channel, playing this tape through a main control unit to stimulus generators and an electroencephalograph unit with vocal instructions to a field technician and coding of the evoked responses onto another tape for transport to a computer center where this second tape is played and the information prepared for use in a computer.

A strip chart from the EEG unit is coordinated with this information at the computer center.

The invention also comprises the combination of apparatus used to perform the steps in the stated method.