Abstract: The present invention uses a personal computer 180 with an A/D converter 184 and a hard disk drive 182 to record the electroencephalographic (EEG) activity of a subject 192 during a commercial and to record event related potentials (ERP) during commercial evaluation sequences subsequent to the commercial. The EEG is analyzed by a signal processing computer 205 for alpha and beta frequency amplitude content to determine attention cognition of the commercial. Different commercials for the same product are compared using overall attention and cognition ratings. The ERP is analyzed to determine the amplitude and latency of the ERPs potentials produced by stimulus events in the evaluation sequences. The ERPs are filtered and the peak amplitudes and latency measured. The amplitude and/or latency determines the understanding of the commercial, the value of the product, the intent to buy the product and the memory of the product. By computing overall results for each commercial different commercials can be compared.

Abstract: An automated visual testing system is disclosed which presents an alternating steady state visual stimulus to a patient through an optical system that modifies the stimulus image. As the image changes, the patient produces evoked potentials that change. The evoked potentials are detected by a product detector which produces the amplitude of the evoked potentials. The product detector includes filters which isolate the patient's evoked potentials, a modulator which detects the response using the stimulus source frequency and a demodulator that determines the amplitude of the response. The product detector detects the level of the steady state evoked potential signals even in the presence of substantial background noise and extraneous electroencephalograhic signals. These detectors can be used to monitor the evoked potential produced by visual, aural or somatic steady state stimuli.

Abstract: A self-preparing electrode includes a conductive conical disk and a nonconductive plastic abrading brush removably interfitted through an aperture in the disk. The brush extends axially through the disk cavity to an abrading end of the brush disposed beyond the cavity at the large diameter end of the disk. The brush also extends axially through and beyong the aperture of the disk to a fused end of the brush which holds the strands or bristles of the brush together. An apparatus which fabricates the brush and assembles it to an electrode disk uses a pair of pressure roller to feed multiple strands from supply spools mounted in a supply rack, through input and output tubular orifices, to and through the aperture of the disk. A shuttle positions a fusing anvil in contact with the leading ends of the strands extending through the disk aperture for fusing them into a connecting bead.

Abstract: An automated visual testing system is disclosed which presents an alternating steady state visual stimulus to a patient through an optical system that modifies the stimulus image. As the image changes, the patient produces evoked potentials that change. The evoked potentials are detected by a product detector which produces the amplitude of the evoked potentials. The amplitude is monitored through an analog to digital converter by a supervisor computer. The supervisor computer produces patient response curves from which it diagnoses visual system malfunction and/or prescribes correction. A control processor controls a stimulus generator to produce the image and an optical system, that includes polarizers, an astigmatism test slit or a cylindrical lens, a zoom lens system and a variable focal length test lens, transmits the image to the patient. The steady state visual potential stimulus generator is a device by which a rapidly complementing or flashing pattern can be presented to the patient.

Abstract: A personal monitor (10, 100, 200) for work and heat stress has a heart beat sensor (12) producing output electrical signals indicating a user's heart beats. A memory (127) stores heart beat information corresponding to the heart beat signals produced over predetermined time intervals. A microprocess (126) is connected to receive the heart beat information from the memory (127). The microprocessor (126) analyzes the heart beat information incrementally over the predetermined time intervals under program control to obtain a physiological demand during the predetermined time intervals and compares the obtained physiological demand against a stored physiological demand limit. Light emitting diodes (208) and a sound producing diaphragm (186) provide indications to the user when the stored physiological demand limit has been exceeded. The microprocessor (126) controls operation of the LEDs (208) and the diaphragm (186).

Abstract: An automated visual testing system is disclosed which presents an alternating steady state visual stimulus to a patient through an optical system that modifies the stimulus image. As the image changes, the patient produces evoked potentials that change. The evoked potentials are detected by a product detector which produces the amplitude of the evoked potentials. The amplitude is monitored through an analog to digital converter by a supervisor computer. The supervisor computer produces patient response curves from which it diagnoses visual system malfunction and/or prescribes correction. A control processor controls a stimulus generator to produce the image and an optical system, that includes polarizers, an astigmatism test slit or a cylindrical lense, a zoom lense system and a variable focal length test lense, transmits the image to the patient. The steady state visual potential stimulus generator is a device by which a rapidly complementing or flashing pattern can be presented to the patient.

Abstract: The present invention includes an adjustable head set held in place on the back of a patient's head when the patient leans back against a chair head rest. The head set includes self-preparing disposable monitors that provide good contact with the patient's head without prior skin preparation. The monitors include a conductive tube containing conductive wires, the tips of which form a planar cushion surface for contacting thr patient's head through a caratinaceous layer of skin. The monitors are held in adjustable holders that allow the contact force to be adjusted. The adjustable holders are mounted in holder slots of head set springs where the slots also allow adjustment of the placement of the monitors. The springs can include hinges for rotatably adjusting placement of the monitors. The disposable monitors are filled with an electrolyte solution using a disposable applicator including a puncturable film, punctured by a monitor when the electrolyte solution is being applied.

Abstract: An electroencephalographic (EEG) cap for a human head for use in an evoked potential autorefractometry system which includes an adjustable headband having relatively rigid straps crossing over EEG measurement regions. Inserted through the straps are self-preparing electrodes which are connected to shielded cables. The self-preparing electrodes penetrate a dead skin layer without causing bleeding during positioning of the cap and do not require a previously prepared electrode positioning site. An electrolyte solution can be applied to the electrodes and the regions for measurement after the cap is in position by an electrolyte solution pump system. The entire cap can be shielded by a metal shield dome and held in place by a chin strap.

Abstract: The present invention includes an adjustable head set held in place on the back of a patient's head when the patient leans back against a chair head rest. The head set includes self-preparing disposable monitors that provide good contact with the patient's head without prior skin preparation. The monitors include a conductive tube containing conductive wires, the tips of which form a planar cushion surface for contacting the patient's head through a caratinaceous layer of skin. The monitors are held in adjustable holders that allow the contact force to be adjusted. The adjustable holders are mounted in holder slots of head set springs where the slots also allow adjustment of the placement of the monitors. The springs can include hinges for rotatably adjusting placement of the monitors. The disposable monitors are filled with an electrolyte solution using a disposable applicator including a puncturable film, punctured by a monitor when the electrolyte solution is being applied.

Abstract: An evoked potential autorefractometry system includes a computer driving an alternating checkerboard mirror stimulus to project a stimulus pattern directly to a patient through a continuously variable focus lens controlled by the computer and which maintains a constant image size on the patient's retina. The evoked potentials produced by the patient are amplified, asychronously filtered both in an analog and digital fashion to allow peak to peak detection of the evoked potentials to determine amplitude. The digital filter includes a 255 point running sum. The peak to peak amplitudes are asychronously digitally filtered using a 16 point running sum to produce an amplitude measure of the evoked potentials. The lens is swept rapidly from one extreme of focus to the other extreme in relatively large steps to determine the area in which the peak amplitude occurs.

Abstract: A low noise EEG probe wiring system that substantially eliminates noise picked up by the loop enclosed by the cables of the wiring system, electrostatic and magnetic noise, and noise due to triboelectric effects. The low noise EEG probe wiring system comprises a pair of coaxial cables each including a central connector, a graphite coated insulating layer positioned around the central conductor, a first braid shield positioned around the graphite coated insulating layer and along the length of the coaxial cable, and a first insulator layer positioned around the first braid shield and along the length of the coaxial cables.

Abstract: A low noise, high gain differential amplifier suitable for EEG amplification is constructed in a shielded metal enclosure, preferably on a ground plane circuit board. The amplifier is battery powered to eliminate all possibility of noise from the power system. The amplifier utilizes a pair of operational amplifiers to provide high input impedance for each of two input signals. A differential amplifier generates an internal signal which is filtered and amplified by a pair of bandpass amplifiers and overlapping low pass and high pass amplifiers.

Abstract: A self-preparing electrode, suitable for EEG mapping, includes a metallic cylinder separated by a dielectric cylinder from a socket for a probe assembly. The probe assembly is preferably a tulip probe removably held by the socket which is connectable to an inner conductor of a coaxial cable. The metallic cylinder includes a cavity into which the tip of the tulip probe is partially depressed when the probe assembly and shell are placed on the skin of a patient. The tip of the tulip probe has multiple points which penetrate the dead skin layer and make electrical contact with the blood-rich skin layer of the patient. The electrode is held in place by straps attached to the shell of the electrode.

Abstract: A self-preparing subkeratinous probe for electroencephalographic measurement includes a spring body which applies a penetrating force to a plow which parts hair and scrapes through a dead keratinous layer of skin to a bloodrich epidermis layer while the probe is being positioned on the head without causing bleeding. The plow includes tabs which form a gap for parting the hair and scraping the skin. The probe also includes an electrolyte tube which can be used to apply electrolyte solution to the skin and plow after it is positioned.

Abstract: A phase locked loop stepper motor controlled light chopper for providing a specific pattern reversal rate. The stepper motor controlled light chopper includes a phase comparator for comparing the phase of a reference signal to the phase of a comparison signal; a RC low pass filter for filtering the output of the phase comparator; a voltage controlled oscillator having a frequency varying in response to the output of the RC filter. The chopper also includes a binary counter for generating count signals responsive to the frequency of the voltage controlled oscillator; a divide by 10 circuit counting one of the outputs of the binary counter and providing the comparison signal. The light chopper also includes a memory circuit for storing an eight state four bit gray code for driving a four phase stepper motor as a chopper wheel in a specified pattern mounted on a drive shaft.