System for measuring blood oxygen levels
AssigneeAlliance Pharmaceutical Corp.
InventorsNicholas S. Faithfull, Glenn Rhoades
Life of this patent
Estimating the term…
Abstract
A system and software is described for calculating, in real-time, the mixed venous partial pressure of oxygen in a patient. The system uses a computer, an arterial pressure line and a blood chemistry monitor to assist a physician with an on-line system for accurately determining when to give a patient a blood transfusion or otherwise alter the clinical management of that patient.
Claims16
A method for determining mixed venous blood oxygen tension (PvO.sub.2) of a patient in real-time, comprising the steps of:
- storing constant values corresponding to blood volume, oxygen solubility in plasma and oxygen content of a desired unit of saturated oxyhemoglobin of a patient into a first computer memory;
- measuring cardiac output values (CO) of a patient in real-time, wherein said cardiac output values are saved to a second computer memory;
- storing a value corresponding to whole body oxygen consumption (VO.sub.2) of said patient into a third computer memory;
- determining arterial oxygen content (CaO.sub.2) of said patient using numerical values corresponding to hemoglobin concentration, arterial tension of oxygen (PaO.sub.2), arterial tension of carbon dioxide (CO.sub.2), arterial pH and body temperature wherein said values are obtained contemporaneously with said measurement of cardiac output levels;
- and
- calculating the mixed venous blood oxygen tension (PvO.sub.2) of a patient in real-time.
An apparatus for determining mixed venous blood oxygen tension (PvO.sub.2) of a patient in real-time, comprising:
- a first computer memory for storing constant values corresponding to blood volume, oxygen solubility in plasma and oxygen content of a desired unit of saturated oxyhemoglobin;
- an input that measures cardiac output values (CO) of a patient in real-time, wherein said cardiac output values are saved in a second computer memory;
- first instructions for storing a value corresponding to whole body oxygen consumption (VO.sub.2) of said patient into a third computer memory;
- second instructions for obtaining arterial oxygen content (CaO.sub.2) of said patient using values corresponding to hemoglobin concentration, arterial tension of oxygen (PaO.sub.2), arterial tension of carbon dioxide (CO.sub.2), arterial pH and body temperature wherein said values are obtained contemporaneously with said continuous measurement of the cardiac output levels;
- and
- third instructions in said memory for calculating the mixed venous blood oxygen tension (PvO.sub.2) of a patient in real-time.
Dependencies are inferred from the claim text.