Abstract:
The invention relates to paramagnetic analyzer for measurement of oxygen contents of gas mixtures. The analyzer comprises electromagnet in a closed cavity controlled with chopped DC-current, sample and reference gas conduits entering the cavity and magnet core and common exit conduit. Gases are led to magnetic field in the gap between magnet poles through holes (13) and (14) drilled into the magnet core so that pedestals (15 and 16) in the gap guide gas flows to collide to be mixed. The mixed gas flows freely out from the gap to the surrounding cavity space (1).
Abstract:
The invention relates to a mechanism for determining the depth of sleep of a subject. In order to obtain information about the continuum of the depth of sleep in a user-friendly way without a need for high computational power, EEG signal data is obtained from a subject, REM sleep periods of the subject are detected, and a measure indicative of irregularity in the EEG signal data is derived. Based on the measure and the detected REM sleep periods, a sleep depth index and state information are produced, where the index is indicative of the depth of sleep of the subject and the state information indicates whether or not the EEG signal data is obtained during a REM sleep period. The detection of the REM periods may be based on a bioimpedance measured from EEG electrodes simultaneously with the EEG measurement or on EOG signal data measured from the subject.
Abstract:
An apparatus for monitoring a respiratory gas flow, comprising a gas collector unit (8), which separates an ambient gas space from that remaining inside the gas collector unit and in which a patient respires the gas contained in said gas collector unit. A conduit (7) flows a respiratory gas from one or more gas sources (1) into the gas collector unit (8) to be respired by a patient, and a conduit (14) delivers a respiratory gas, which at least partially contains a gas exhaled by a patient, from the gas collector unit (8) to a measuring device (13) for examination. The pressure difference between a gas space protected by the gas collected unit and a gas space existing outside it is indicated by a pressure-difference detecting element (17). A method for monitoring a respiratory gas flow compares the pressure of a respiratory gas existing inside the gas collector unit (8) with that prevailing outside the gas collector unit and adjust gas flows accordingly.
Abstract:
A unitary, multi-electrode biopotential signal sensor is formed of injection molded plastic. A plurality of electrode areas containing spikes are defined in a base member of the sensor. The remaining areas of the base member are formed to have a greater flexibility than the electrode areas, as by being thinner or being perforated. The spikes and electrode areas of the base member are coated with a conductor layer to form the electrodes. Conductors on the base member lead to connectors to provide biopotential signals from the electrodes.
Abstract:
An electrode for acquiring bioelectrical signals employs an array of spikes that penetrate the viable epidermis layer of the skin of a patient. The spikes may be conductive to provide the bioelectrical signal. Or, the spikes may extend through a conductive layer that provides the bioelectrical signal. The signal obtained from the patient may be amplified using an amplifier and battery circuit present on the electrode body. The electrode may be used with or without conductive paste or gel.
Abstract:
An apparatus and method for determining the intratracheal pressure of a patient intubated with an endotracheal tube. An infusion conduit has a first end at the proximal end of the endotracheal tube and a second end proximate to the distal end of the endotracheal tube. The first end of the infusion conduit is connectable to a pressure sensing unit. A fluid source flows a gaseous or liquid fluid through the infusion conduit to maintain the patency of the infusion conduit from the first end to the second end and to allow the pressure obtained at the second end of the infusion conduit to be used to determine the intratracheal pressure of the subject.
Abstract:
The invention relates to a device intended for monitoring the carbon dioxide output, oxygen consumption and respiration quotient of a patient connected to a respirator. The device comprises O.sub.2 (15) and CO.sub.2 (14) analyzers, a mixing chamber (6), a constant flow fan (8), a gas collector hose (2) and magnetic valves (10-13). The carbon dioxide output and oxygen consumption are directly calculated from the carbon dioxide content of gas mixed with constant air flow from said mixing chamber, from the carbon dioxide and oxygen contents of the gas in said mixing chamber, and from the oxygen content of the gas delivered into a patient by said respirator.
Abstract:
Method and arrangement for obtaining diagnostic information of a patient, the method comprising the steps of carrying out heart rate measurements of the patient at least during two sleep stages before the operation to obtain preoperative heart rate data, carrying out measurements containing information related to the different stages of sleep that are synchronized with the heart rate measurements to obtain preoperative sleep stage data, and calculating a dynamic heart rate variability measures by utilizing non-linear analysis from heart rate data obtained and enabling comparison of the heart rate variability measure between at least two different stages of the sleep state.
Abstract:
A method and system for combining active and passive neuromonitoring methods to measure biopotential signals in sedated ICU patients over the entire range of sedation from fully alert to the suppression of EEG. The system utilizes an integrated sensor that includes a sound generator and a plurality of EEG electrodes on a single, lightweight disposable component. The method of the present invention utilizes a control unit for switching between active and passive monitoring methods, depending upon the level of sedation. The control unit displays the results of active monitoring during levels of consciousness and light sedation and displays the results of passive monitoring during levels of deep sedation.
Abstract:
A method and apparatus for delivering respiratory gases to a patient maintains a mixture of gases stable and minimizes the effects of ambient air leakage. Some of the gases supplied to a gas collection unit in which the patient's head is placed are by-passed to a buffer space that partially surrounds the gas collection unit. The volume of the buffer space stabilizes the mixture and outflow from the buffer space minimizes ambient air leakage into the gas collection unit. Gases from the gas collection unit are supplied to a measuring unit for analyzing the gas respired by the patient.