Abstract: A mass spectrometer includes an ion source for ionizing a sample substance to provide an ion current of predetermined beam width and energy. A mass filter includes a plurality of drift tubes wherein succeeding drift tubes are of increasing length separated by gaps that increase in length. The ion current is supplied to the mass filter along with an alternating current electrical signal in a manner so that particles having a predetermined mass receive a predetermined maximum energy increase while traversing the mass filter and so that particles not having the predetermined mass do not receive the maximum energy increase. A detector is provided to create an energy barrier whereby only particles that receive the maximum energy increase will have sufficient to completely traverse the barrier. Particles which traverse the barrier are detected thereby to determine the amount of particles having a predetermined mass that were contained in the sample substance.

Abstract: An apparatus and method for detecting patient inspiration is provided. It includes means for providing a baseline level for the patient's respiration signal and for establishing a trigger level representative of inspiration. When the respiration signal crosses the trigger level for selected crossovers inspiration trigger signals are generated. Most importantly means are provided for automatically detecting shifts in the baseline level and for re-establishing the trigger level for the shifted waveform. In the preferred embodiment the apparatus is capable of detecting a baseline shift in about one cycle of the respiration waveform.The apparatus and method further provides for an inspiration detector with adjustable detection characteristics to accommodate both adult and neonate patients.

Abstract: Apparatus for displaying first and second information signals includes detection circuitry for detecting the first and second signals to be displayed as well as detecting the occurrence of a predetermined phenomenon with respect to the first information signal. The first and second information signals are processed in conjunction with a timing signal to provide a display signal, wherein the display signal is adapted to be displayed using known display circuitry. Detection of the predetermined phenomenon provides an interrupt to the processing of the information signals such that the occurrence of the predetermined phenomenon can be recorded, in time correlation with the occurrence of the first and second information signals. The information signals are thereafter processed so that the ocurrence of the predetermined phenomenon can be displayed in time correlation with either the first or second information signal.

Abstract: A respiration monitor for measuring the variations of the thorax impedance of a patient due to respiration is described. The monitor includes circuitry for suppressing the indication of unwanted signals caused by cardio-vascular activity of the patient. The circuitry receives trigger signals immediately following the QRS complex of the patient's ECG waveform. If a certain negative-going slope is detected in the thorax impedance waveform following the QRS complex, it is counted as a cardio-vascular artifact and not respiration activity. After a predetermined number of cardio-vascular artifact are detected and counted, the respiration monitor is disabled so that this cardio-vascular activity will not reset an apnea counter.