Abstract: A method and apparatus for detection of coronary artery disease. The apparatus records and analyzes that portion of the phonocardiogram lying between about 100 to 600 Hz. An electrocardiogram is also recorded and examined in order to pinpoint the diastolic window of PCG data. This window of data is subject to autocorrelation analysis and spectral analysis, resulting in a partial correlation coefficient index and a power density index. A linear combination of these two indices results in a Cardiac Screening Index which is indicative of the presence or absence of coronary artery disease.

Abstract: A method and apparatus for collecting measurements on the surface of the earth in a form which can be processed to obtain enhanced resolution of subsurface resistivity anomalies in the earth's geologic structure. The system of the preferred embodiment utilizes many separately acquired voltage and current measurements on the earth's surface in a superposition analysis to "synthesize" the condition whereby the many separate measurements are acquired simultaneously to give useful advantages in improved depth of investigation commonly known as focused resistivity measurements.

Abstract: For use in logging a borehole through various formations of the earth, the preferred and illustrated embodiment of an RF transmitter system including antenna placed in the sonde is disclosed. The embodiment sets forth a pair of dipole antennas mounted in a closed chamber on a central support. The chamber is in a cylindrical housing filled with a high dielectric material. The antennas are bowtie dipoles which are fed with separately time delayed pulses (preferably having waveforms of only one cycle) so that the relative time delay between the two antenna inputs and the propagation velocity in the high dielectric medium results in reinforcing addition of the radiated wave in the forward direction and destructive cancellation in the reverse direction to provide a directional azimuthal radiation pattern. The housing is rotated at a slow rate to enable pulses to be transmitted in various directions to map the formations near the borehole.