Methods and systems are disclosed for controlling an exhaust gas recirculation valve in an engine by determining errors in exhaust backpressure estimates and adapting EGR flow estimations based on these errors to meet target EGR dilutions in the engine. An alarm is configured to emit a signal when the cutting blade moves relative to the blade channel. The aperture is selectively openable and returnably resilient. The modem comprises an antenna coupled to an upconverterdownconverter. A diaphragm valve is fluidically connected to the pump in parallel circuit with the regulating piston assembly to provide an alternative bypass mechanism as a backup for the electrical solenoid valve. The implantable device generates potential signals modulated with digitally encoded data by operating a current source to cause corresponding electrical potentials that can be sensed at the skin surface by the external data logging device.