Abstract: A method and apparatus for ascertaining the cerebral state of a patient. The method/apparatus may find use in ascertaining the depth of anesthesia of the patient. In one embodiment, the entropy of the patient's EEG signal data is determined as an indication of the cerebral state. A frequency domain power spectrum quantity is obtained from the patient's EMG signal data. The latter quantity can be updated more frequently than the EEG entropy due to its higher frequency. The EEG entropy indication and the EMG power spectrum indication can be combined into a composite indicator that provides an immediate indication of changes in the cerebral state of the patient. In another embodiment, the frequency range over which the entropy of the biopotential signal from the patient is determined is broadened to encompass both EEG signal data and EMG signal data and the entropy so determined used as an indication of the patient's cerebral state.

Abstract: A method and apparatus for ascertaining the cerebral state of a patient. The method/apparatus may find use in ascertaining the depth of anesthesia of the patient. In one embodiment, the entropy of the patient's EEG signal data is determined as an indication of the cerebral state. A frequency domain power spectrum quantity is obtained from the patient's EMG signal data. The latter quantity can be updated more frequently than the EEG entropy due to its higher frequency. The EEG entropy indication and the EMG power spectrum indication can be combined into a composite indicator that provides an immediate indication of changes in the cerebral state of the patient. In another embodiment, the frequency range over which the entropy of the biopotential signal from the patient is determined is broadened to encompass both EEG signal data and EMG signal data and the entropy so determined used as an indication of the patient's cerebral state.

Abstract: A method and apparatus for ascertaining the cerebral state of a patient. The method/apparatus may find use in ascertaining the depth of anesthesia of the patient. In one embodiment, the entropy of the patient's EEG signal data is determined as an indication of the cerebral state. A frequency domain power spectrum quantity is obtained from the patient's EMG signal data. The latter quantity can be updated more frequently than the EEG entropy due to its higher frequency. The EEG entropy indication and the EMG power spectrum indication can be combined into a composite indicator that provides an immediate indication of changes in the cerebral state of the patient. In another embodiment, the frequency range over which the entropy of the biopotential signal from the patient is determined is broadened to encompass both EEG signal data and EMG signal data and the entropy so determined used as an indication of the patient's cerebral state.

Abstract: A method and apparatus for ascertaining the cerebral state of a patient. The method/apparatus may find use in ascertaining the depth of anesthesia of the patient. In one embodiment, the entropy of the patient's EEG signal data is determined as an indication of the cerebral state. A frequency domain power spectrum quantity is obtained from the patient's EMG signal data. The latter quantity can be updated more frequently than the EEG entropy due to its higher frequency. The EEG entropy indication and the EMG power spectrum indication can be combined into a composite indicator that provides an immediate indication of changes in the cerebral state of the patient. In another embodiment, the frequency range over which the entropy of the biopotential signal from the patient is determined is broadened to encompass both EEG signal data and EMG signal data and the entropy so determined used as an indication of the patient's cerebral state.

Abstract: The invention relates to an apparatus and a method for analyzing a compound to be drawn from a patient's organ. The apparatus comprises a sampling element having a wall which a compound to be analyzed is capable of penetrating. The apparatus also includes a pressure-difference producing element which, through the action of a pressure-difference, is capable of delivering a sample along a tube extending from the sampling element. The apparatus also includes an analyzer capable of performing an analysis on a sample drawn from the sampling element. The analyzer is in flow communication with the sampling element by way of the tube. According to the method, a mixture consisting of a medium and a compound drawn from the organ is delivered to the analyzer for a subsequent analysis, and at least some of the mixture is returned from the analyzer back to the sampling element.

Abstract: The invention relates to an automatic identification method for the cuff of a sphygmomanometer. When changing the pressure in a cuff (6 or 19) or in a space in flow communication therewith, the pressure change occurring in this space is monitored at two spaced-apart measuring points by means of one or a plurality of pressure-sensing means (12 and/or 9) and the pressure signals obtained from these two measuring points are compared to each other and, on the basis of the conducted comparison, the different cuff types are distinguished from each other as the measured pressure difference indicates a cuff type presently in use.

Abstract: The invention relates to a gas detector for measuring one or more hydrocarbons or some other gas having its infrared absorption spectrum partially or entirely overlapping with water and, in addition, carbon dioxide and/or nitrogen oxide. The gas detector comprises a radiation source (1), a measuring chamber (3), a reference chamber (4), the electromagnetic radiation coming from the radiation source passing through said chambers, and a radiation detector (5). A beam passing from radiation source (1) both to measuring chamber (3) and to reference chamber (4) and from these chambers further to detector (5) travels in a space (14) which is provided with both a carbon-dioxide removing material (11) and a water-removing material (12). The invention relates also to a method for absorbing the carbon dioxide contained in said gas detector space (14) or in a part of this space into a carbon-dioxide removing material (11) and for absorbing the water into a water-removing material (12).

Abstract: An apparatus and method for the identification of one or more anesthetic or other gases included in the respiratory air of a patient, said identification being effected within the infrared range 3-4 .mu.m. The appratus comprises a radiation source (4), a chamber (1) for receiving therein a gas or gases to be examined, an optical filter (7) for passing the radiation exiting the chamber therethrough, an optical focusing device (12) through or via which the incoming radiation travels, a radiation detector (10) and a measuring processor (19) which performs the measuring and identification. The transmission band of the optical filter (7) or a combination of successive filters is within a range of 1.5%-0.4% of the mean transmission wavelength and the ray arriving at filter (7) has an angle of incidence between 10.degree.-60.degree., the measuring effected within this range being performed at more than two angles.

Abstract: The invention relates to an identification method for the cuff of a non-invasive automatic sphygmomanometer and to a flow restriction means for moderating the rate of pressure increase or decrease or both. Such a flow restriction means, which is fitted e.g. in a separate adapter (4), is useful particularly in connection with small-sized cuffs (6) intended for newborn babies. On the other hand, when using larger, such as adult cuffs, it is preferably to omit a flow restriction means completely. Identification is based on the fact that, when using a flow restriction means, either the increase of pressure downstream of a flow restriction means or the decrease of pressure upstream of a flow restriction means occurs slowly after the pumping is finished. If there is no flow restriction means at all, there will be no pressure change after the pumping is finished. Through the intermediary of a pressure sensing element (9), a control element (10) detects the size of a cuff.