Method and apparatus for determining blood oxygen transport

An apparatus for measuring diffusion of oxygen across a red blood cell membrane comprising an oxygen level detector, a gas exchange system, and a red blood cell transport system;

• the red blood cell transport system that transports a fluid containing red blood cells through the gas exchange system and the oxygen level detector, the red blood cell transport system comprising:
• a) a sample receiving system to take in a sample of a red blood cell;
• b) a pump that transports a red blood cell from the sample receiving system to the gas exchange system and the oxygen level detector;
• the gas exchange system that couples to a gas source and exchanges a gas with the fluid containing the red blood cells at a rate faster than the rate at which the gas diffuses across a membrane of the red blood cell, the gas exchange system comprising:
• a) a housing defining a gas inlet, a gas outlet, and a chamber;
• b) a gas permeable tubing at least partially located within the housing for diffusing the gas from the chamber to a red blood cell contained within the gas permeable tubing;
• wherein the gas permeable tubing comprises a lumen effective for containing red blood cells;
• the housing exposing successive sample of red blood cells to the gases without cross-contamination between the samples;
• the oxygen level detector that detects oxygen levels in a red blood cell or in fluid surrounding the red blood cell, the oxygen level detector comprising:
• a) a light source producing light having an absorption free wavelength;
• b) at least one filter;
• c) photopickups to detect the transmission of light at the absorption free wavelength;
• and
• a control system comprising a microprocessor electronically coupled to the oxygen level detector, the gas exchange system, and the red blood cell transport system to operably derive amounts of oxygen levels in a red blood cell, wherein the sample receiving system and the gas exchange system are present in a modular, cartridge-type insert, the cartridge-type insert being configured to be inserted into the apparatus for connection to the pump, the oxygen level detector and the control system, and removed from the apparatus for disposal.

A method for determining a patient's susceptibility to angina, comprising:

• obtaining a blood sample from the patient;
• measuring a rate of oxygen diffusion across a membrane of a red blood cell of the blood sample;
• correlating the measured rate with the susceptibility to angina observed in a control population, or in the patient, at the measured rate;
• and
• correlating the measured rate with residence time of the blood in the heart during stress.

A method for determining a patient's blood oxygen transport, comprising:

• obtaining a blood sample from the patient;
• measuring a rate of oxygen diffusion across a membrane of a red blood cell of the blood sample;
• and
• correlating the measured rate with established levels of blood lipid to determine the patient's relative or absolute blood lipid level;
• and
• further comprising comparing the patient's lipid level to the patient's previous lipid level measured at an earlier time to determine the patient's blood oxygen transport.