Medical Graphics Corporation

Other

Michael G Snow

Yu Chen

C Peter Howard

Jeffrey M Snow

Steven D James

John A Norlien

A Gerrit Crawford

Robert J Fallat

Sung-peng Hsu

William R Tyler

Bernhard H Kaeferlein

Jeffrey G Thieret

Peter C Howard

A method of calibrating a metabolic analyzer incorporating an oxygen analyzer and a NDIR carbon dioxide analyzer in the field that does not require the use of gas cylinders containing gases of known concentration is described. In calibrating the COdetector, at the time of factory setup, the detector output for a gas of a known concentration is measured and stored in the memory of the metabolic analyzer's microprocessor, as is the detector output voltage when the IR source is dimmed by a known percentage. Subsequently, in the field, COlevels in ambient air and cell pressure are measured at two different flow rates through the sample chamber and the IR source is again dimmed by the same percentage as had been used at the time of factory setup. Based upon the resulting readings, both the zeroing and span adjustment factors can be computed.

Gasless calibration in metabolic gas analyzers

A device for directly measuring a person's respiratory exchange ratio (RER) utilizes a Zn-air battery cell and a constant current load circuit as an Opump capable of drawing oxygen from expired air. A thermistor located in the flow path forms a leg of a bridge circuit whose output is proportional to oxygen concentration in the expired air and, therefore, to oxygen uptake. The thermistor flowmeter circuit utilizes the thermal conductivity differences between Oand COto provide a measure at the relative ratio of the two gases present.

Respiratory exchange ratio sensor

A rectangular sheet of flexible and resilient material such as plastic with notches at the midpoint of its sides. The size of the sheet and notches allow the insert to be placed into and located by a cell of a chain link fence. Notches fit around the wire crossovers of the chain link fence and locate the insert at the mid-plane of the fence. The corners of the insert extend into adjoining cells. Adjoining inserts overlap to provide complete visual privacy. The tile-like nature of the inserts allows great flexibility in arrangements and colors to provide visual privacy, decoration, words, logos, or signage.

Tile type fencing insert

A method for prescribing an exercise regimen for a particular subject to either maximize cardiovascular performance or to lose weight involves the use of a microprocessor-based cardiopulmonary exercise system to measure oxygen uptake and carbon dioxide production on a breath-by-breath basis. These measured quantities are used to calculate energy expenditure and a subject's respiratory exchange ratio from which a fat metabolization curve can be plotted. By examining the length of a plateau in the curve where the fat substrate utilization is maximized, and noting the average heart rate in this zone, a target heart rate for optimal weight loss is arrived at. If the goal of the exercise is cardiovascular improvement, the anaerobic threshold can readily be determined as the midpoint between maximal fat utilization and the maximum acceleration towards the point where the respiratory exchange ratio becomes equal to 1 or the fat metabolism goes to 0. By noting the average heart rate at the anaerobic threshold, a target heart rate for optimizing cardiovascular fitness may be arrived at.

Method for detecting anaerobic threshold and prescribing a training zone to maximize fat utilization or improved cardiovascular fitness

A portable apparatus for measuring the thoracic lung volume of a patient without enclosing the patient in a sealed chamber, comprising first and second impedance belts, a flow meter, shutter and a microprocessor-based controller. The flow meter includes pressure transducers for measuring the change in volume and pressure as the patient respires therethrough. The change in thoracic cage volume of the patient's lungs is directly correlated with the change of impedance in the belts. The thoracic lung volume is then determined from a measured barometric pressure, the measured change in pressure and the measured volume change in the thoracic cage volume utilizing a correction factor to determine the thoracic cage volume.

Boxless measurement of thoracic gas volume

A flow meter system having a disposable mouthpiece including symmetrically disposed pitot tubes for measuring the velocity of the respiratory gases flowing through the mouthpiece and an electronic module including sensitive pressure transducers coupled to the mouthpiece and operative over a wide dynamic range provides input signals to a signal processing network for converting the pressure readings to flow information useful in cardiopulmonary performance analyzing equipment.

Flow meter system

A pulmonary diagnostic apparatus includes a personal computer including a memory for storing expected values, each representing a predicted normal level for a pulmonary function. A parameter limit file stores abnormality limits, each related to one of the expected values. A configuration file contains a plurality of degree of severity labels and numerical breakpoints between severity degrees. Finally, a statement data file contains a plurality of textual statements concerning lung functions and diseases or conditions. The three files are operatively associated with the computer. Lung function measuring equipment also is connected to the computer, whereby measured values are compared with the expected values. Based on the comparison, the computer generates an output identifying certain measured values as abnormal, and the degree of abnormality. Also, appropriate statements from the statement data file are generated as output, based upon the comparison. By selectively editing the parameter limit, configuration and statement files, the operator can cause the computer to generate an output corresponding to the operator's preferred analytical approach and syntax.

Growing community of inventors

White Bear Lake, MN, United States of America

Michael G Snow