Southwest Research Institute

Colin Electronics Co., Ltd.

Nippon Colin Co., Ltd.

Bruce C Mather

Dennis J Wenzel

Dean C Winter

Harry H Peel, Iii

William C Fox

David S McFalls, Ii

Douglas L Michalsky

A monitoring system for providing an accurate indication of a patient's respiration rate. The system is effective in eliminating or significantly reducing the effects of heart sounds and ambient noise. The system comprises means for obtaining a first signal waveform containing components corresponding to the patient's breath sounds, as well as components corresponding to heart sounds and ambient noise. The signal is passed through a digital bandpass filter having a passband selected to remove heart sounds and ambient noise to produce a second waveform. From the second waveform the total energy is computed of a portion of the signal within a moving window of predetermined length. The resulting energy envelope signal is smoothed and then high-pass filtered by removing the average DC value of the signal over a predetermined preceding time interval. Respiration is detected by identifying significant, positive-going zero crossings of the resulting signal through a band about zero. The zero-band threshold used to obtain this waveform can be controlled by the operator or pre-set for a particular sensitivity.

Respiration rate monitor

An improved method and apparatus for classifying and quantifying lacquer and carbon deposits on internal combustion engine pistons. In the preferred embodiment of the invention, a piston is mounted on a rotating means and is rotated to expose the entire surface of the piston to a video imaging system. The piston is illuminated with indirect lighting in order to minimize reflections and to enhance the contrast of the video image. The video imaging system is comprised of a video camera which employs a charged coupled device (CCD) sensor and data storage for storing digital video produced by the camera. A microprocessor is operable to control operation of the camera and to process the stored data according to an algorithm to classify the video image into one of six categories.

Optical inspection of lacquer and carbon deposits

A method for determining the pulse rate of a person. The method of the present invention is implemented in two phases. The first phase involes the determination of pulse intervals and the second phase provides an indication of the pulse rate based on the data produced during the first phase. The first phase is implemented by an algorithm which produces a pulse distribution profile from an array of pulses obtained from an appropriate transducer. In the second phase of the measurement, the distribution is searched to locate the region of maximum density. The pulse rate within the maximally dense region are then averaged to determine pulse rate. The pulse rate detection method of the present invention eliminates a significant number of erroneous pulse signals before calculation of pulse rate, thus providing a more accurate indication of the true pulse rate. The processing algorithm used in the preferred embodiment is based on an integer distribution the measurement can be obtained with a minimum amount of system memory and processor time.

Method and apparatus for determining pulse rate

Growing community of inventors

San Antonio, TX, United States of America

Bruce C Mather