Abstract: A method and apparatus by which deceases are identified uses computer analysis of sound signals that are picked up from various locations on the chest walls of a subject by a modified stethoscope. The modification includes a small microphone in one of the hoses of the stethoscope. Signals from the microphone are input to a computer such as a personal computer or PC for processing. The computer extracts from these signals features which are dominant for particular diseases. A classifier classifies these features, determines if the lungs are diseased, and identifies the disease.

Abstract: A method and apparatus by which lung deceases are identified uses computer analysis of sound signals that are picked up from various locations on the chest walls of a subject by a modified stethoscope. The modification includes a small microphone in one of the hoses of the stethoscope. Signals from the microphone are input to a computer such as a personal computer or PC for processing. The computer extracts from these signals features which are dominant for particular lung diseases. A classifier classifies these features, determines if the lungs are diseased, and identifies the disease.

Abstract: A method and apparatus by which lung deceases are identified uses computer analysis of sound signals that are picked up from various locations on the chest walls of a subject by a modified stethoscope. The modification includes a small microphone in one of the hoses of the stethoscope. Signals from the microphone are input to a computer such as a personal computer or PC for processing. The computer extracts from these signals features which are dominant for particular lung diseases. A classifier classifies these features, determines if the lungs are diseased, and identifies the disease.

Abstract: A method of reconstructing a damaged sequence of symbols where some symbols are missing is provided in which statistical parameters of the sequence are used with confidence windowing techniques to quickly and efficiently reconstruct the damaged sequence to its original form. Confidence windowing techniques are provided that are equivalent to generalized hidden semi-Markov models but which are more easily used to determine the most likely missing symbol at a given point in the damaged sequence being reconstructed. The method can be used to reconstruct communications consisting of speech, music, digital transmission symbols and others having a bounded symbol set which can be described by statistical behaviors in the symbol stream.

Abstract: A method of reconstructing a damaged sequence of symbols where some symbols are missing is provided in which statistical parameters of the sequence are used with confidence windowing techniques to quickly and efficiently reconstruct the damaged sequence to its original form. Confidence windowing techniques are provided that are equivalent to generalized hidden semi-Markov models but which are more easily used to determine the most likely missing symbol at a given point in the damaged sequence being reconstructed. The method can be used to reconstruct communications consisting of speech, music, digital transmission symbols and others having a bounded symbol set which can be described by statistical behaviors in the symbol stream.

Abstract: An apparatus and process for determining the existence and location of a leak in a vessel such as a container or an above ground or underground pipe, comprises a plurality of remote acoustic transmission sensor units distributed along the pipe and each containing equipment for analyzing acoustic signals from the pipe. The equipment includes a mechanism for identifying acoustic features of the acoustic signals which distinguish the acoustic signals of a leak from ambient acoustic signals. A control unit is connected to each of the remote units and includes additional equipment for further analyzing the signals to determine the proximity of the signal to a particular remote unit and, using the amplitude of the signal and the transmission characteristics of the pipe, determining the location of the leak.

Abstract: A device monitors a pressurized vessel to detect small leaks, ruptures and hard hits on the vessel. Transducers are attached to the vessel and transmit acoustic signals which are processed to extract frequency spectra which contain dominant resonant frequency peaks, if the vessel contains a small leak. If multiple frequency component of the spectra shift to a lower frequency suddenly and stay at the lower frequency, this indicated the presence of a larger leak or rupture. A hard hit on the vessel, for example by machinery, is detected by a shift in the transient response of harmonics in the acoustic signal.

Abstract: An apparatus and process for determining the existence and location of a leak in an underground pipe, comprises a plurality of remote acoustic transmission sensor units distributed along the pipe and each containing equipment for analyzing acoustic signals from the pipe. The equipment includes a mechanism for identifying acoustic features of the acoustic signals which distinguish the acoustic signals of a leak from ambient acoustic signals. A control unit is connected to each of the remote units and includes additional equipment for further analyzing the signals to determine the proximity of the signal to a particular remote unit and, using the amplitude of the signal and the transmission characteristics of the pipe, determining the location of the leak.

Abstract: A method of diagnosing arterial stenosis from a received Doppler shifted acoustic signal from an artery during multiple heartbeats, each having systolic and diastolic phases uses pattern recognition techniques that are applied to the signal to determine the presence of turbulence during the diastolic phases which indicates stenosis. This is advantageously done by comparing the systolic and diastolic phases as part of the pattern recognition technique, large differences being indicative of a healthy artery and smaller differences being indicative of stenosis.