Abstract: An underwater transducer system reproduces high-fidelity audio signals underwater, and detects and monitors low levels of sound activity, both adjacent to a body of water such as a swimming pool, and in the water. The system includes an underwater housing for a diaphragm that directly contacts the water, a coil assembly movable within the housing and rigidly connected to the center of the diaphragm by a tubular member of the coil assembly engaging a cylindrical boss portion of the diaphragm. The housing can be suspended by an elongated cord member from a wall coping, or mounted within a wall fixture structure. The system can have a source of illumination, a conduit from the source terminating in the housing on the coil axis proximate the diaphragm, and an optical element sealingly protrudes the diaphragm for transmitting light-amplified illumination into the water.

Abstract: An underwater transducer system reproduces high-fidelity audio signals underwater, and detects and monitors low levels of sound activity, both adjacent to a body of water such as a swimming pool, and in the water. The system includes an underwater housing for a diaphragm that directly contacts the water, a coil assembly movable within the housing and rigidly connected to the center of the diaphragm by a tubular member of the coil assembly engaging a cylindrical boss portion of the diaphragm. The housing can be suspended by an elongated cord member from a wall coping, or mounted within a wall fixture structure. The system can have a source of illumination, a conduit from the source terminating in the housing on the coil axis proximate the diaphragm, and an optical element sealingly protrudes the diaphragm for transmitting light-amplified illumination into the water.

Abstract: A tibia-referenced system for objectively testing the integrity of the anterior and posterior cruciate ligaments of the knee with passive drawer, active drawer, and end point tests. Two simplified forms of the invention embody an elongated reference arm with a distal end pad that is fulcrumed against a distal region on the tibia and a proximal reference pad that rests on either the tibial tubricle or patellar bone structure, while a displacement indicator rod slidably mounted on the arm carries another proximal reference pad that rests on the other of these two bone structures adjacent the knee joint.