Abstract: A threat detection and response system including at least one sound sensor configured to sense sound within a detection zone and transmit sound data corresponding to the sensed sound. A system gateway including a processor configured to receive the sound data, analyze the sound data to detect a vocal phrase within the sensed sound, determine that the detected vocal phase corresponds to a pre-defined vocal phrase associated with a threat, and communicate an existence of the threat to a recipient device.

Abstract: A threat detection system includes a processor configured to receive a stream of audio data from one or more sensors positioned in or around a space monitored by the threat detection system; extract a portion of the stream of audio data; determine a signal characteristic of the portion of the stream of audio data; after determining that that a portion of the stream is compatible with a first machine learning model, determine a first confidence score for an existence of a threat in the space using the first machine learning model; determine a second confidence score by providing the portion of the stream of audio data, the signal characteristic, and the first confidence score to a second machine learning model; detect the existence of the threat based on based first and/or second confidence scores; and communicate the existence of the threat to a recipient device.

Abstract: A threat detection system includes a processor configured to receive a stream of audio data from one or more sensors positioned in or around a space monitored by the threat detection system; extract a portion of the stream of audio data; determine a signal characteristic of the portion of the stream of audio data; after determining that that a portion of the stream is compatible with a first machine learning model, determine a first confidence score for an existence of a threat in the space using the first machine learning model; determine a second confidence score by providing the portion of the stream of audio data, the signal characteristic, and the first confidence score to a second machine learning model; detect the existence of the threat based on based first and/or second confidence scores; and communicate the existence of the threat to a recipient device.

Abstract: Clock synchronization, including: receiving a first message at an uncorrected unit with a propagation delay time, wherein a transmission time of the first message is recorded by a corrected unit; recording an arrival time of the first message by the uncorrected unit; transmitting a second message from the uncorrected unit to the corrected unit after a pre-determined delay, receiving a third message at the uncorrected unit, wherein the third message includes a propagation delay time and the transmission time of the first message recorded by the corrected unit; calculating a clock offset between the corrected unit and the uncorrected unit using the propagation delay time and the transmission time of the first message recorded by the corrected unit; and applying the clock offset to synchronize a clock of the uncorrected unit to a clock of the corrected unit.

Abstract: A motion sensor applicable to medical procedures includes a source of light with a wavelength bandwidth and an optical detector. A first optical coupler terminates in a first probe tip and couples the light into the first probe tip. A second optical coupler terminates in a second probe tip and directs onto the detector scattered light returning through the second probe tip. A presentation device outputs a signal that indicates motion in a target volume of a sample in a vicinity of the probe tips based on a Doppler shift of the scattered light. The volume depends on coherence distance determined by the bandwidth. In variations, the first and second tips are the same tip, a multimode fiber is included, the bandwidth is between 0.1% and 5% of a center wavelength, or the presentation device is a speaker, or some combination.

Abstract: A motion sensor applicable to medical procedures includes a source of light with a wavelength bandwidth and an optical detector. A first optical coupler terminates in a first probe tip and couples the light into the first probe tip. A second optical coupler terminates in a second probe tip and directs onto the detector scattered light returning through the second probe tip. A presentation device outputs a signal that indicates motion in a target volume of a sample in a vicinity of the probe tips based on a Doppler shift of the scattered light. The volume depends on coherence distance determined by the bandwidth. In variations, the first and second tips are the same tip, a multimode fiber is included, the bandwidth is between 0.1% and 5% of a center wavelength, or the presentation device is a speaker, or some combination.