Abstract: A system and method to extract and measure awareness and a breathing rate information from the cardiac pulse uses plethysmographic and oximeter sensors. The information finds applications in patient monitoring during surgery, intensive care, sleep therapy, and sleep detection in critical operations of airplanes, trucks, automobiles, trains, and in biofeedback therapy.

Abstract: Method for monitoring brain activity. Left and right cardiac pulse signals are detected at bilateral locations on a body for a selected number of cardiac cycles. Computing apparatus computes the standard deviation of the left and right pulse signals for the selected number of cardiac cycles. The standard deviations are normalized on the computing apparatus by dividing the left and right standard deviations by the mean of the left and right pulse signals computed over the selected number of cardiac cycles to produce a left and a right Coefficient of Variation of the pulse signals. A Bilateral Pulse Index is generated from the left and right Coefficients of Variation. The Bilateral Pulse Index relates to brain activity. Cardiac pulse signals from a single location on the body may be utilized in some embodiments.

Abstract: A method of measuring human brain activity includes the steps of simultaneously measuring pulses at two locations on a human subject that each receives blood from a different carotid artery that feeds a respective one of left and right hemispheres of the brain of the human subject, determining pulse characteristics from the measured pulses, and evaluating relative left and right hemisphere activity of the brain of the human subject based on the determined pulse characteristics. The method may use dual photoplethysmograhic blood pulse sensors that measure left and right hemisphere activity by determining pulse amplitude difference and time or phase differences between the earlobes while the subject carries out various mental functions. The data from the sensors are processed to provide a measure of brain function and the mental activity of the subject.

Abstract: A method of measuring human brain activity includes the steps of simultaneously measuring pulses at two locations on a human subject that each receives blood from a different carotid artery that feeds a respective one of left and right hemispheres of the brain of the human subject, determining pulse characteristics from the measured pulses, and evaluating relative left and right hemisphere activity of the brain of the human subject based on the determined pulse characteristics. The method may use dual photoplethysmograhic blood pulse sensors that measure left and right hemisphere activity by determining pulse amplitude difference and time or phase differences between the earlobes while the subject carries out various mental functions. The data from the sensors are processed to provide a measure of brain function and the mental activity of the subject.

Abstract: A scrubber and method for precipitating a sulfide in water which contains hydrogen sulfide or a mercaptan. The scrubber includes a sacrificial first metal anode and a second metal cathode which are in physical and electrical contact and suspended into the water to form an electrolysis cell of the anode, cathode and the water. The second metal is more noble than the first metal. Preferably the anode is iron and the cathode is stainless steel. When so constituted, the anode forms iron oxide which reacts with sulfur from the hydrogen sulfide or the mercaptan to form an iron sulfide precipitate. The anode and cathode may be coplanar and suspended in the water with a free-moving float which facilitates contact of the water with the anode, or may be rods which are tethered and twisted to form a twisted wire pair.