Siemens Elema Ab

Siemens Aktiengesellschaft

Christer Str&ouml;m

G&ouml;ran Cewers

Johan Bennarsten

G&ouml;ran Rydin

A ventilator for connection to a patient to provide assisted breathing, has a gas flow generator, a pressure meter, a flow meter and a control unit, which determines a gas pressure, on the basis of a pre-set tidal volume for the patient and measurement signals from the pressure meter and flow meter, for each breath and which regulates the gas flow generator so that it generates the determined gas pressure. An improved breathing mode, better tailored to the patient, is achieved by the control unit also determining the gas pressure to be generated by the gas flow generator on the basis of mechanical resistances and a variable corresponding to the aggregate effect of the resistance and elastance of the lungs.

Ventilator operable in a compensated volume support mode

In a method for assessing pulmonary stress, a flow of respiratory gas is supplied to the lungs of a subject, an ensuing pressure is measured in relation to time and the pressure-time relationship is analyzed. In this analysis, the profile of the pressure-time relationship is determined. In summary, the profile is straight when no stress is present, is convex when there is a risk for over-distension, and is concave when alveolar units are opened up. Implemented in a breathing apparatus the method can be used to assist an operator in diagnostic and therapeutic considerations in relation to a patient.

Method for assessing pulmonary stress and breathing apparatus employing the method

In a method and arrangement for evaluating effective flow resistance of a patient breathing circuit connected to a mechanical breathing assist device, a flow controller is operable to temporarily introduce an occlusion to the gas flow within the breathing circuit at a time after the end of an inspiration phase of a breathing cycle provided by the breathing assist device. A sensor unit has a flow sensor for measuring gas flow within the circuit and a pressure sensor for measuring gas pressures within the circuit. An evaluating unit receives measurements from the sensor unit, to determine for a measured gas flow a value of a pressure drop within the breathing circuit after the introduction of the occlusion, and establishes a relationship between the calculated pressure drop and the measured gas flow, such as based on the known Blasius formula.

Method and arrangement for evaluating effective flow resistance of patient breathing circuit

A device for the supply of a gas from a respirator/anaesthesia device to a bedridden patient has at least one gas tube and a connecting interface, which can be connected to the patient, and an adjustable holding device for the gas tube and for the connecting interface. In order to prevent leaks, injury to the patient or damages to the gas tubes when the patient moves or changes position, the device is provided with at least one sensor and the holding device is provided with control arrangement for controlling its movements. The sensor detects movement of the patient is connected via the connecting interface, and a signal generated by the sensor and supplied to the control arrangement which, dependent thereon, controls the holding device such that its movements and therefore the movements of the connecting interface automatically follow the movements of the patient.

Device for the supply of a gas from a respirator/anaesthesia device to a bedridden patient

In a method and apparatus for determining at least one parameter related to a patient's spontaneous attempts at inspiration and/or the patient's respiratory effort in attempts at spontaneous inspiration, a pressure gradient is determined in relation to a known apparatus pressure and time, the pressure gradient being generated by the patient at inspiration, a residual positive pressure in the patient's lungs is determined and an output signal is generated. The output signal can represent determined parameters as well as other related calculated results. The pressure gradient can be extrapolated against residual positive pressure, and both a delay for respiratory assistance and true inspiratory effort can be determined.

Method for determining a parameter related to spontaneous breathing efforts by a subject, and breathing-assist apparatus operating in accordance with the method

Growing community of inventors

Piteå, Sweden

Christer Ström

Growing community of inventors

Piteå, Sweden

Christer Str&ouml;m

Christer Ström