Abstract: Disclosed is a mattress control method, comprising the steps of obtaining biometric information of a user, outputting vibration based on a sound source according to a comparison result between the biometric information and a threshold value, and transmitting at least one of the biometric information, the threshold value, and mattress control information to an external controller, wherein the biometric information includes at least immobility state duration information as sub-information, the threshold value includes at least an immobility state duration threshold value, and the vibration is output when the immobility state duration information exceeds the immobility state duration threshold value, and is output based on external control information when the external control information is received from the external controller.

Abstract: A mattress combined with a sound vibration module and air fibers, and an operating method therefor. An air mattress to which air fibers are applied comprises a sound vibration module comprising a speaker, a tactile transducer, a controller, and an amplifier, the sound vibration module being manipulated to generate low-frequency vibration through the conversion of an input sound source into vibration or sound after being amplified, and at the same time emit same as sound. While sound vibration stimuli are applied to the skin through the sound vibration module, contact pressure is distributed on the air mattress to which air fibers are applied, and a static pressure state can be maintained as a fluctuating pressure state. Moreover, the effect of improving muscle strength by healing of muscle cells, blood flow improvement, and low-frequency vibration can be realized through vibration stimulation, to thereby stably prevent the occurrence of bedsore.

Abstract: An apparatus for measuring phase and amplitude jitter and simultaneously and audibly counting and monitoring transient excursions of two linear bar-chart type readouts calibrated in degrees and modulation percents and which are capable of displaying jitter measurements. The transient excursions in the form of phase hits, gain hits, drop outs and impulse noise are simultaneously counted in parallel registers and means are provided for visually indicating the cumulative real time count total of each register in numerical display. The method of evaluating parameters affecting voiceband data transmission includes simultaneously displaying phase and amplitude jitter components onto linear bar-chart displays and separately deriving the information for each of said displays and providing continuous and sequential illumination on each display encompassing the range of fluctuations from the jitter detectors.