Abstract: A movement and sound monitor and stimulator which is particularly useful for preventing death in human infants from sudden infant death syndrome is disclosed. The movement and sound monitor and stimulator has a base member which may be a fluid-filled sensing pad for supporting the infant or other animate object which is being monitored and a transducer positioned for detecting movement or acoustic activity (e.g., heartbeat, breathing) of the object on the base member to provide an output signal in response to forces applied thereto which are generated by such movement. A circuit is connected to monitor the output signal from the transducer and activates a stimulator which is operable to provide movement to the base member to stimulate movement in the object when output from the transducer to the circuit corresponds to no movement from the object. The transducer may be a pressure transducer in fluid communication with the fluid interior of the sensing pad.

Abstract: A sonar sensor comprising a substantially non-corrodible housing and a fluidic gainblock disposed therein. In addition, one or more fluid-filled laminar proportional amplifiers are arranged either in series or in parallel and contained within the fluidic gainblock. Means are provided to produce a jet within each laminar proportional amplifier, which is then modulated by incoming acoustic signals. The pressure caused by diverting the jet from its equilibrium path is proportional to, but greater than, the incoming acoustic signal. Hydrophones are used to convert the amplified acoustic signal into an electrical signal. In one embodiment, the fluidic gainblock is free-flooded and open to the liquid environment in which it is used, obviating the need for pressure equalization. In another embodiment, the fluidic gainblock is provided with filtering means for prevent the accumulation of sediment within the cavities making up the laminar proportional amplifiers.