132results about How to "High false positive rate" patented technology

An alarm processor suppresses alarms when a physiological parameter is below a predetermined value but recovering toward a normal range.

A parallel alarm processor has a threshold detector, a pattern extractor, a predetermined reference pattern, a first alarm and a second alarm. The threshold detector has a first output responsive to relatively long duration oxygen desaturations. The pattern extractor has a second output responsive to relatively short duration oxygen desaturations. The predetermined reference pattern is indicative of a series of intermittent oxygen desaturations. A first alarm is triggered when the first output crosses a lower limit threshold. A second alarm is triggered when the second output matches the predetermined reference pattern. In an embodiment, an integrator inputs smoothed oxygen saturation measurements to the threshold detector, and a predictor inputs predictive oxygen saturation measurements to the pattern extractor.

A method and apparatus for inspecting the surface of articles, such as chips and wafers, for defects, includes a first phase of optically examining the complete surface of the article inspected at a relatively high speed and with a relatively low spatial resolution, and a second phase of optically examining with a relatively high spatial resolution only the suspected locations for the presence or absence of a defect therein.

A system to detect subsurface activity. The system employs vibration sensor pairs, with each sensor pair having a shallow sensor and a deep sensor. Outputs of the sensors of a pair are processed together and events are detected based on the relative values detected by the sensors of the pair. When signal energy departs from a detected background level, the relative amplitude and frequency content of vibrations measured at the shallow and deep sensors may be compared. The comparison may be performed, at least in part, using a classifier that discriminates between subsurface activity and surface to activity. The outputs of sensor pairs may be aggregated to make a determination of whether subsurface activity exists and / or its location. Aggregation may involve comparing the outputs of the same sensor pair at multiple time intervals or may involve comparing the outputs of arrayed sensor pairs.

There is provided a personal fall detection system comprising a sensor module that is suitable for attachment to a user, the sensor module comprising an accelerometer for measuring accelerations acting on the sensor module; and a processor for analyzing the measured accelerations to determine if the sensor module has suffered an impact, and for estimating a vertical displacement of the sensor module during a time period immediately before the impact; wherein the processor estimates the vertical displacement of the sensor module by twice integrating the measurements from the accelerometer.

A computer / computer network security alert management system aggregates information from multiple intrusion detectors. Utilizing reports from multiple intrusion detectors reduces the high false alarm rate experienced by individual detectors while also improving detection of coordinated attacks involving a series of seemingly harmless operations. An internal representation of a protected enclave is utilized, and intrusion detection system (IDS) information is correlated to accurately prioritize alerts. In one embodiment, the system is capable of utilizing data from most existing IDS products, with flexibility to add further IDS products.

The invention discloses a synthetic aperture radar (SAR) image change detection difference chart generation method based on contourlet transform. A realization process mainly comprises the following steps of: firstly, constructing a logarithmic ratio image and a mean ratio image on two SAR images which are preprocessed and obtained at different time and in a same region; generating corresponding Contourlet coefficients by Contourlet transform processing; respectively calculating the coefficients of the two images in a high-frequency mode and a low-frequency mode according to different fusion rules; performing inverse Contourlet transform on the fused Contourlet coefficients to generate a change difference chart. The different characteristics of high frequency and low frequency are respectively extracted by the mean ratio image and the logarithmic ratio image, and complementation information of the source images is fully utilized by the image fusion based on the Contourlet transform, so that the SAR image change detection can have a better result, the detection error ratio is low, the image noise is inhibited, and the analysis precision is improved. Compared with other difference chart generation methods, the method disclosed by the invention is high in noise inhibition and good in edge maintenance, and can reserve change information to the maximum extent.

An apparatus carried by an unmanned vehicle to provide passive sensing and facilitate avoiding airborne aerial obstacles is provided. The apparatus can include at least one, but typically multiple optical systems installed, for example, in the nose of the aerial vehicle to passively sense and determine a range, direction, and velocity of the airborne obstacles to allow the aerial vehicle to avoid the airborne obstacles. The typical optical system includes at least one focal plane array or other imaging device configured to receive a wide field of view and at least one focal plane array or other imaging device configured to receive a steerable narrow field of view within the wide field of view to allow concentrated determination of the range, direction, and / or velocity of obstacles detected by the wide field of view imaging devices.

There is provided a personal fall detection system comprising a sensor module that is suitable for attachment to a user, the sensor module comprising an accelerometer for measuring accelerations acting on the sensor module; and a processor for analyzing the measured accelerations to determine if the sensor module has suffered an impact, and for estimating a vertical displacement of the sensor module during a time period immediately before the impact; wherein the processor estimates the vertical displacement of the sensor module by twice integrating the measurements from the accelerometer.

Detecting and identifying ions using surface enhanced Raman spectroscopy (SERS) and an ion separation pre-filter, such as an ion spectrometer, are provided. The combination of an ion separator as a pre-filter for SERS provides a highly sensitive detector with very low false alarm rates. Target ions from an ionized sample are identified and separated by the ion separator. The target ions are steered and deposited onto a SERS substrate for Raman spectroscopic analysis with an optical probe. The Raman spectrum is compared with reference spectra and the composition of the sample is identified. The ion current from the target ions can also be measured, preferably concurrently with the Raman spectrum measurement. Types of ion separators include a differential ion mobility spectrometer, an ion mobility spectrometer, or a mass spectrometer.