Abstract: A device and a method for detecting an actuator by sonicating the actuator with sound waves through a sensor. The device is used in particular in a safety application. The sensor and actuator can be moved relative to each other. The sensor includes a sound wave transmitter, a sound wave receiver and a computing unit. The sound wave transmitter is designed to send sound waves in the direction of the actuator. The sound wave receiver, in turn, is designed to pick up the sound waves reflected by the actuator and convert them into an analog signal. The computing unit converts the analog signal into a digital signal and detects the actuator by comparing it with a reference signal.

Abstract: A device includes a sensor and an actuator. The sensor has a receiving circuit with a sensor and a detector, as well as a computer connected to the detector. The sensor cooperates with the actuator to generate a first receiving circuit signal during a normal operation when a switching distance between the sensor and the actuator is undershot. The detector generates a first output signal as a function of the first receiving circuit signal, and to transmit transmits the first output signal to the computer. The receiving circuit includes a signal emulator and a switch-over element. The signal emulator generates a second receiving circuit signal during a test operation. The detector generates a second output signal as a function of the second receiving circuit signal and transmits the second output signal to the computer. The device can repeatedly switch between normal operation and test operation.

Abstract: A device includes a sensor and an actuator. The sensor has a receiving circuit with a sensor and a detector, as well as a computer connected to the detector. The sensor cooperates with the actuator to generate a first receiving circuit signal during a normal operation when a switching distance between the sensor and the actuator is undershot. The detector generates a first output signal as a function of the first receiving circuit signal, and to transmit transmits the first output signal to the computer. The receiving circuit includes a signal emulator and a switch-over element. The signal emulator generates a second receiving circuit signal during a test operation. The detector generates a second output signal as a function of the second receiving circuit signal and transmits the second output signal to the computer. The device can repeatedly switch between normal operation and test operation.

Abstract: A method for the serial transmission of data from a sensor to a safety control device. The sensor has two data processing units which examine and process both the data of the sensor and the request data of the safety control device. The same request data of the safety control device are simultaneously supplied to each data processing unit and the data processing units simultaneously perform a check of the request data after receiving the data. The data processing units operate independently of each other. A sensor unit has a sensor, a safety control device and data processing units. The safety control device is connected to the data processing units via a common serial bus and the data processing units are independent of one another and simultaneously perform the data processing. A system for securing hazardous areas of production facilities with a sensor unit.

Abstract: An apparatus and method for detecting myocardial ischemia in a subject monitors the systemic vascular resistance of the subject and detects the presence of myocardial ischemia when the systemic vascular resistance increases by at least sixty percent over a base line value. Particular apparatus describe providing a measurement corresponding to the systemic vascular resistance of the cardiovascular system. A particular invasive pressure measuring apparatus uses a flexible catheter tube insertable into the artery of the subject and a micro-manometer embedded into the outer face of the wall of the catheter tube. The outer face of the embedded micro-manometer is directly exposed to the blood in an artery and the inner face of the embedded micro-manometer is covered by the inner face of the catheter tube wall.

Abstract: A method and apparatus monitor myocardial ischemic events in various medical applications for providing continuous and contemporaneous information regarding, for example, modifying the amount of medication for a patient, determining response during (PTCA) balloon angioplasty, monitoring the onset of myocardial ischemic events during induction of anesthesia, determining painless myocardial ischemia in a resting patient, and monitoring the onset of myocardial ischemic during stress conditions in a patient. The method and apparatus also provide a calibration method for determining from a Resistive Index and using the resulting transformation for calculating, on a continuing basis, both systemic vascular resistance and cardiac output.

Abstract: In the described method and apparatus for examining a subject's cardiovascular system, a blood-pressure signal having a waveform varying in accordance with the subject's arterial pressure is differentiated to produce a dP/dt signal having a waveform varying in accordance with the rate at which the blood-pressure signal varies. The pressure at the time of the peak dP/dt signal is detected and is divided by the dP/dt signal to produce a measurement corresponding to the systemic vascular resistance. The latter measurement is then multiplied by a resistance factor corresponding to the physical resistance characteristic of the particular cardiovascular system examined. A measurement of the cardiac output may also be produced by subtracting, from the mean arterial pressure of the subject, the subject's central venous pressure and dividing the latter by the systemic vascular resistance.