Abstract: The disclosure teaches an electronic apparatus for stimulating the muscles of a patient by disposing electrodes on the outer surface of the patient in the vicinity of the muscles. The stimulating wave consists of a composite signal comprising bursts of a sine wave, having a frequency greater than 500 Hz, and preferably in the range of 2000-3000 Hz, modulated by a signal at a frequency less than 500 Hz, and preferably in the range of 40-60 Hz. The bursts are applied for 2-20 second periods separated by 2-50 second rest intervals. The apparatus includes safety circuits which sense the current to the electrodes and turn off the stimulating waves on detection of a no load or overload condition. The apparatus also includes a power amplifier with a gain control and a switch associated with the gain control such that, if, at the beginning of any treatment, the gain control is not set to zero, stimulating waves will not be applied.

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.