Other

Thornhill Scientific Inc.

David Preiss

Joseph A Fisher

Alex Vesely

Steve Iscoe

Eitan Prisman

Ron Somogyi

Takafumi Azami

Tehilla Adams

Dan Nayot

Takafumi Asami

Eltan Prisman

A method of identifying alveolar ventilation (V) in a subject, the method comprising: (1) using a breathing circuit which, at exhalation, keeps exhaled gas separate from inhaled gas and at inhalation, when a first gas set (FGS) flow is less than the subject's minute ventilation (V), results in a subject inhaling FGS first and then a second gas set (SGS), for the balance of inhalation; (2) setting the FGS flow at a rate greater that V; (3) measuring an end tidal COconcentration at a steady state; (4) progressively lowering the FGS flow until a time equal to a recirculation time of COin the subject; and (5) deriving Vas the rate of FGS flow at the intersection between an average PETCOin a steady state and a line fit to the PETCOvalues after the rise in PETCOvalues begins until the recirculation time.

Method of measuring cardiac related parameters non-invasively via the lung during spontaneous and controlled ventilation

A breathing circuit for sequential gas delivery of a first gas set (FGS) and a second gas set (SGS) employs an arrangement of conduits and active or passive valves to prevent mixing of the FGS and SGS including a valve triggered by depletion of FGS that makes the SGS available for inspiration after the FGS is depleted.

Breathing circuits to facilitate the measurement of cardiac output during controlled and spontaneous ventilation

An apparatus to measure cardiac output (Q) and other parameters such as alveolar ventilation (VA), minute COelimination from the lung (VCO), minute oxygen consumption (VO), oxygenated mixed venous partial pressure of CO, (PvCO-oxy), true mixed venous partial pressure of CO(PvCO), PaCO, mixed venous oxygen saturation (SvO), pulmonary shunt, and anatomical dead space, consisting of: a) a breathing circuit with characteristics that: i. on exhalation, exhaled gas is kept substantially separate from inhaled gas; ii. on inhalation, when Vis greater than FGS flow, the subject inhales FGS first and then inhales a gas that is substantially SGS, for the balance of inhalation; b) gas sensor means for monitoring gas concentrations at the patient-circuit interface c) a first gas set (FGS), and a second gas set (SGS), said second gas set which may comprise previously exhaled gases or exogenous gases or both d) a gas flow control means for controlling the rate of FGS flow into the breathing circuit e) means to identify phase of breathing, said means may consist of pressure sensors or analysis of signal generated by gas sensors or other means known to those skilled in the art; f) machine intelligence consisting of a computer or logic circuit capable of controlling the gas flow control means, receiving the output of the gas sensor means and means to identify phase of breathing, and performing the calculations for measuring cardiac output and other parameters as outlined in the disclosure.

A method of calculating the flux of any gas (x) in a CBC circuit for a ventilated or a spontaneous breathing subject, for example said gas(x) being; a) an anesthetic such as but limited to; i)NO; ii) sevoflurane; iii) isoflurane; iv) halothane; v) desflurame; or the like b) Oxygen; c) Carbon dioxide; or the like utilizing the following relationships; Flux of gas(x)=SGF (F&#x2212;F) wherein SGF=Source of gas flow into the breathing circuit (CBC circuit) in liters/minute as read from the gas flow meter as set by the anesthesiologist; F=Fractional concentration of gas X in the source gas (which is set by the anesthesiologist); F=Fractional concentration of gas X in the end expired gas as determined by a portable gas analyzer, or the like.

Method for continuous measurement of flux of gases in the lungs during breathing

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Thornhill, Canada

David Preiss