Abstract: A non-invasive method, and an apparatus, for determining heart-related parameters in patients. The method and apparatus determine pulse pressure, time constant of the arterial system, systolic and diastolic pressure, peripheral resistance, cardiac output and mean arterial blood pressure.

Abstract: The invention relates to a method and apparatus for determining the magnitude of heart-related parameters in a patient. In accordance with the invention, blood volume variation of a peripheral part of the body of a patient, which variation is cyclic in nature, is detected to provide a signal representative of the blood volume. The maximum amplitude, minimum amplitude of the signal at maximum slope, the time interval between the maximum and minimum amplitudes and the instantaneous cyclic repetition rate (period) of the signal are measured, and the parameters are calculated in accordance with appropriate formulae.

Abstract: The invention relates to a non-invasive oximetry process for determining the value of oxygen saturation of the blood of a subject. In some ear oximetry processes, light at two or more frequencies is transmitted through the ear lobe or pinna of the ear of a subject, and the intensity of the transmitted light is measured on the other side of the ear lobe. These processes are affected by such variables as depth of blood in the ear lobe or pinna and differences in the total hemoglobin concentration in the blood. Applicant has discovered that inaccuracies caused by these variables can be eliminated or greatly reduced by taking the derivative of the intensity of the transmitted light, and processing the values of these derivatives in association with a set of predetermined pseudo coefficients by applying these to newly developed relationships disclosed in the specification. The result of such processing yields the value of oxygen saturation of the blood of the subject.

Abstract: The invention relates to a method and apparatus for continuously monitoring systolic blood pressure of a subject. The instrument includes a light transducer for detecting variations in light intensity corresponding to variations in blood volume of tissue of the subject under the transducer and for converting the changes in light intensity to changes in voltage. In one embodiment, a heater is provided to dilate the tissue under the transducer. The voltage signals are differentiated with respect to time, and the differentiated signal is sampled once every heart beat of the subject at the beginning of diastole, or at the maximum value of the differentiated signal sampled during diastole, to produce a sampled voltage signal. To this sampled voltage signal is added a voltage representative of a steady pressure, and the sum is a voltage representative of systolic pressure.

Abstract: Alert apparatus worn by a driver includes a motion responsive switch including a pendant wiper associated with a plurality of closely spaced contacts surrounded by an auxiliary contact. A plurality of resistors of different values are respectively coupled to different ones of the contacts for randomly placing different ones of the resistors in a circuit for charging a selected capacitor coupled to the wiper. An amplifier and switching circuit energizes an alarm when the capacitor is charged to a predetermined level and the auxiliary contact is coupled to the capacitor to enable its discharge as the wiper is accellerated against the auxiliary contact in response to deliberate shaking movement by the operator.

Abstract: A non-invasive method, and an apparatus, for determining heart-related parameters in patients. The method and apparatus determine pulse pressure, time constant of the arterial system, systolic and diastolic pressure, peripheral resistance, cardiac output and mean arterial blood pressure.