Abstract: Systems, devices, and techniques for establishing communication between two medical devices are described. In one example, an implantable medical device comprises communication circuitry, therapy delivery circuitry, and processing circuitry configured to initiate a communication window during which the implantable second medical device is capable of receiving the information related to a cardiac event detected by a first medical device, the communication window being one of a plurality of communication windows defined by a communication schedule that corresponds to a transmission schedule in which the first medical device is configured to transmit the information, control the communication circuitry to receive, from the first medical device, the information related to the cardiac event that is indicative of a timing of the cardiac event with respect to a timing of the communication window, schedule and control delivery of a therapy according to the information related to the cardiac event.

Abstract: A system and method of determining a physiological state of a ruminant animal by monitoring the pH and temperature of the animal's stomach. A battery-less, single unit sensor and transmitter is placed within the rumen or reticulum of the animal. pH and temperature measurements are taken and transmitted along with the animal identification code to a wireless receiver. The physiological state of the animal is determined using the mathematically analyzed pH and temperatures.

Abstract: A nonlinear shock absorber is disclosed. The device has a housing filled with hydraulic fluid and contains a relatively heavy mass or piston supported by a helical coil. The helical coils disposed and shaped so as to provide a nonlinear resistance to a shock applied to the housing. During shock absorption fluid flows contra to the piston movement with a corresponding elongation of the helical coil spring causing the coil spring to engage an inner wall of the housing to provide for frictional dampening.