Christian Buess

Bio: Christian Buess is an academic researcher from École Polytechnique Fédérale de Lausanne. The author has contributed to research in topics: Ultrasonic sensor & Ultrasonic flow meter. The author has an hindex of 5, co-authored 8 publications receiving 98 citations.

Apparatus for measuring the parameters of respiratory gases

Abstract: The invention relates to an apparatus for measuring the parameters of respiratory gases comprising a respiratory tube, ultrasonic sensors and pre-amplifier electronic circuitry arranged in a separate housing. In order to prevent dangerous cross infections between patients following repeated utilization of the such measuring apparatus the ultrasonic sensors are permanently integrated in the respiratory tube so that they constitute a single part therewith and in that at least the respiratory tube together with the integrated ultrasonic sensors is designed in the form of an interchangeable part for use once only.

Design and Construction of a Pulsed Ultrasonic Air Flowmeter

Abstract: The construction and specific function of a new ultrasonic flowmeter are described. The mean velocity of the respiratory air flow is calculated by measuring the transit times of short ultrasonic pulse-trains simultaneously transmitted upstream and downstream at a 650 Hz rate. The flowmeter system consists of a control unit and a separate flowhead. The former includes the power supplies, a controlling microprocessor, most of the signal processing circuitry, and three analog outputs for flow, volume, and temperature, respectively. The flowhead contains the respiratory tube with a constant circular cross section (length 90 mm, diameter 20 mm, dead space 35 cm3), a fast temperature sensor, two electronic circuits for processing of flow and temperature data, and a sound transmission channel with two capacitive ultrasonic wide-band transducers. This respiratory air flowmeter is extremely fast (response time 1-2 ms) and accurate, with low noise (below 9ml/s), with a wide flow range (bidirectional from 0 to 9 l/s) and with a linear frequency response up to 70 Hz.

Method for non-cooperative lung function diagnosis using ultrasound

Abstract: A method and device are provided for measuring state of lung function of a patient using ultrasonic flow and molar mass measurement. Flow and molar mass signals are recorded during tidal breathing without requiring patient cooperation. Statistical analysis of the recorded data in combination with anthropometirc data and/or data form a questionnaire can be used to diagnose various pulmonary ailments or diseases.

Vorrichtung zur Messung von Atemgasparametern

Abstract: Die Erfindung betrifft eine Vorrichtung zur Messung von Atemgasparametern mit einem Atemrohr, Ultraschallsensoren und einer in einem separaten Gehause angeordneten Vorverstarkerelektonik. Um gefahrliche Kreuzinfektionen zwischen den Patienten bei Mehrfachverwendung der Mesvorrichtung zu verhindern, sind die Ultraschallsensoren in dem Atemrohr fest integriert, so das sie mit diesem ein einstuckiges Teil bilden, wobei zumindest das Atemrohr mit den integrierten Ultraschallsensoren als austauschbares Teil zur einmaligen Verwendung ausgebildet ist.

Device for measuring respiratory gas parameters

Abstract: The invention relates to a device for measuring respiratory gas parameters, with a breathing tube, ultrasound sensors and pre-amplifier electronics located in a separate housing. In order to avoid dangerous cross-infections between patients on multiple use of the measuring device, the ultrasound sensors are firmly integrated in the breathing tube, so that they form an integral part with the latter. At least the breathing tube with the integrated ultrasound sensors is designed as an exchangeable part for single use.

Physiological monitor and associated computation, display and communication unit

Abstract: A personal digital assistant (PDA) (10) stores data from physiological monitors (12) so that the data can be used in various software applications. In different embodiments the physiological monitor (12) can include data storage or have memory modules that are accepted by accessory slots (48 and 50).

Integrated calorie management system

Abstract: An improved health management system for a person is disclosed, in which the person's resting metabolic rate (RMR) is determined at intervals using an indirect calorimeter. RMR values are used in setting and revising goals in, for example, a weight control program. The effects of a weight control program on RMR can hence be compensated for, which enables an improved weight control program to be developed. In one embodiment, the person is provided with a portable electronic device, for use as a caloric intake calculator, caloric expenditure calculator, and caloric balance calculator.

Interactive physiological monitoring system

Abstract: Systems and methods relating to physiological monitoring of a person including a monitor module (74), and interactive display (76), and a portable computing device (70) including a remote control unit.

Metabolic calorimeter employing respiratory gas analysis

Abstract: An indirect calorimeter for measuring the metabolic rate of a subject includes a respiratory connector configured to be supported in contact with the subject so as to pass inhaled and exhaled gases as the subject breathes, a flow pathway, and a hygiene barrier positioned to block a predetermined pathogen from the exhaled gases. The indirect calorimeter also includes a flow pathway having a first end in fluid communication with the respiratory connector and a second end in fluid communication with a source and sink for respiratory gases. The flow pathway includes a flow tube through which the inhaled and exhaled gases pass, an outer housing surrounding the flow tube, and a chamber disposed between the flow tube and the first end. The indirect calorimeter also includes a flow meter configured to generate electrical signals as a function of the instantaneous flow volume of inhaled and exhaled gases passing through the flow pathway, and a component gas concentration sensor operable to generate electrical signals as a function of the instantaneous fraction of a predetermined component gas in the exhaled gases as the gases pass through the flow pathway. The indirect calorimeter further includes a computation unit operable to receive the electrical signals from the flow meter and the concentration sensor and operative to calculate at least one respiratory parameter for the subject as the subject breathes through the calorimeter.

Weight control method using physical activity based parameters

Abstract: A method of assisting a person to achieve a weight control goal comprises determining a resting energy expenditure for the person using an indirect calorimeter, and converting the resting energy expenditure of the person into a number of resting points. The activity level of the person can be monitored or estimated, and converted into a number of activity points. The sum of activity points and resting points can be compared with the number of diet points consumed by the person, wherein the diet points are calculated based on calorie content and other nutritional values. The balance of these weight control points can be presented to a person, so as to assist the person succeed in a weight control program.