Abstract: A pressure sensor for detecting a pulse wave, a digital conversion unit for converting a pressure signal from the pressure sensor into a digital signal, and a fourth derivative filter having an adjustable frequency characteristic for obtaining a fourth derivative wave of an original waveform based on the digital signal generated by the conversion by the digital conversion unit are provided. Local extrema of the fourth derivative wave in a section of the pulse wave corresponding to one beat are calculated. Based on the calculated local extrema, an early systolic component and a late systolic component are calculated.

Abstract: A tissue treatment apparatus includes a bandage that is transparent to, or transmissive of, energy in a predetermined range of the infrared (IR) portion of the electromagnetic spectrum. The bandage includes a layer that acts as a bandpass filter, permitting IR radiation in the range of wavelengths between 3 and 30 &mgr;m to pass through the bandage to tissue against which the bandage is disposed. A heater is used to generate heat, including IR radiation, and an attachment device retains the heater over or on the bandpass bandage layer. The bandage and heater together have a low profile so as to be convenient for a patient, and are flexible so as to conform to the shape of a wound and to contours of the skin near the wound. The bandage is provided with an adhesive pattern for maintaining moisture at the wound site. The heater may maintain a normothermic condition at subdermal regions of the wound treatment area.

Abstract: The present invention provides an indirect calorimeter for measuring the metabolic rate of a subject. The calorimeter includes a respiratory calorimeter configured to be supported in contact with the subject so as to pass inhaled and exhaled gases as the subject breathes. A flow pathway is operable to receive and pass inhaled and exhaled gases. A first end of the flow pathway is in fluid communication with the respiratory connector and a second end is in fluid communication with a source and sink for respiratory gases. A flow meter generates electrical signals as a function of the instantaneous flow volume of inhaled and exhaled gases passing through the flow pathway. A component gas concentration sensor generates electrical signals as a function of the instantaneous fraction of a predetermined component gas in the exhaled gases as the gases pass through the flow pathway.

Abstract: A system for measuring a blood parameter, such as pH, pCO.sub.2 or pO.sub.2, comprises an optical probe with an optical fiber and an invasive blood sensor. Light emitted by a light-emitting diode (1) is irradiated into an optical fiber (2). The system compensates for variations in the luminous efficiency of the LED (1) in that either a fraction of the light is fed directly to a photodetector (22), or in that the forward voltage of the LED is measured, and in that the signal received from the sensor is either normalized, or in that the LED drive current is adjusted accordingly.