Abstract: A system for enhancing patient compliance with a predetermined breathing pattern during inspiration measurements utilizes patient feedback based on inspiration flow. The measured inspiration flow is displayed on a first display and a target inspiration flow is displayed on a second display, preferably, disposed adjacent to the first display to facilitate visual comparison. The patient is instructed to breathe in a manner that causes the measured inspiration flow display to match, or follow the target inspiration flow display.

Abstract: A medical testing system includes telemetry features whereby physiological data collected by a collection device at a medical facility is transmitted to a remote processing center for analysis by a trained analyst to provide a test result. In one embodiment, the collection device is a heart rate monitor capable of collecting data with which heart rate variability can be assessed. The heart rate monitor includes a display on which is displayed a waveform showing the breathing performance of the patient during data collection along with standards against which to compare the waveform in order to determine the extent to which the patient followed a predetermined breathing regimen during data collection. The operator of the monitor can use the performance waveform to assess how well the test was taken (i.e., how well the patient complied with the prescribed breathing regimen) and can accept or reject the physiological data accordingly.

Abstract: A disposable differential pressure pneumotachometer includes an inlet chamber having an air inlet, an outlet chamber having an air outlet, and a resistive element disposed between the inlet and outlet chambers. Air flow across the resistive element results in a pressure gradient which is measured to provide air flow rate. According to one aspect of the invention, the pressure port through which the static pressure in the inlet chamber is sensed is disposed in the outlet chamber. According to a further aspect of the invention, the resistive element comprises a bacterial filter material. Also described is a pneumotachometer in which at least one pressure port is covered with a bacterial filter material.

Abstract: A system for enhancing patient compliance with a predetermined breathing pattern during inspiration measurements utilizes patient feedback based on inspiration flow. The measured inspiration flow is displayed on a first display and a target inspiration flow is display on a second display, preferably, disposed adjacent to the first display to facilitate visual comparison. The patient is instructed to breathe in manner that causes the measured inspiration flow display to match, or flow the target inspiration flow display.

Abstract: Methods and apparatus for providing a single, accurate indicator of a patient's autonomic nervous system function are described. The indicator is a combination of results of a plurality of different autonomic nervous system tests performed on the patient and referenced to a cross-sectional population. In one embodiment, the results of the different autonomic nervous system tests are referenced to a limited age group of the cross-sectional population. A method according to the invention includes generating a mathematical expression for each of the autonomic nervous system tests as a function of physiological data of the cross-sectional population, inserting measured physiological data of the patient into the mathematical expressions to compute output values for each of the tests, and combining the output values to provide the autonomic function indicator.

Abstract: Apparatus and methods for determining the precise times of occurrence of R-waves in an ECG signal of a patient. Samples of the patient's ECG signal are accumulated and an ECG window comprising a predetermined number of the samples is defined. In accordance with one embodiment of the invention, the patient's blood pressure signal is processed to detect systoles and the ECG window has a predetermined time relationship to detected systoles. In accordance with an alternative embodiment, the ECG signal is first processed to approximate the times of occurrence of R-waves and the ECG window is defined to have a predetermined time relationship to the approximated R-wave times. ECG signal samples within the ECG window are processed to determine a maximum and the time of occurrence of the maximum is stored as the time of an R-wave event.

Abstract: A system for measuring a patient's inspiration volume and for enhancing patient compliance with a predetermined breathing pattern during inspiration volume measurements. A flexible conductive loop adapted for being wrapped around, and conforming to the patient's chest is coupled to an amplifier circuit including a signal generator and an exclusive-OR gate. The signal generator generates a square-wave signal for coupling to a first terminal of the conductive loop and the exclusive-OR gate is responsive to the applied square-wave signal and to a signal at the second terminal of the loop for measuring the delay between the signals. The output signal of the amplifier circuit is indicative of the inductance of the loop, which varies with the patient's inspiration volume. The measured inspiration volume is displayed on a first display and a target inspiration volume is displayed on a second display, preferably, disposed adjacent to the first display.

Abstract: Apparatus and methods for determining the precise times of occurrence of R-waves in an ECG signal of a patient. Samples of the patient's ECG signal are accumulated and an ECG window comprising a predetermined number of the samples is defined. In accordance with one embodiment of the invention, the patient's blood pressure signal is processed to detect systoles and the ECG window has a predetermined time relationship to detected systoles. In accordance with an alternative embodiment, the ECG signal is first processed to approximate the times of occurrence of R-waves and the ECG window is defined to have a predetermined time relationship to the approximated R-wave times. ECG signal samples within the ECG window are processed to determine a maximum and the time of occurrence of the maximum is stored as the time of an R-wave event.