Non-invasive analyte sensing system and method

A non-invasive transcutaneous blood gas sensing system for determining a concentration of at least one arterial blood gas (“arterial blood gas concentration”) in a mammal based on rates of diffusion prior to reaching equilibrium (“initial rates of diffusion”), comprising:

• a diffusion chamber adapted to receive a mammalian appendage;
• a measurement chamber pneumatically coupled to the diffusion chamber, thereby adapted to receive at least a portion of one or more arterial blood gases from the diffusion chamber when the one or more arterial blood gases diffuse transcutaneously from the mammalian appendage into the diffusion chamber;
• at least one optical chemical sensor positioned in the measurement chamber that is adapted to chemically interact and/or physically react with a respective arterial blood gas;
• at least one optoelectronic component positioned outside the measurement chamber for remotely detecting the chemical interaction and/or the physical interaction of the at least one optical chemical sensor;
• and
• a controller for determining initial rates of diffusion of the at least one arterial blood gas being measured into the diffusion chamber based on signals received from the at least one optoelectronic component, wherein the controller determines the arterial blood gas concentration based on the determined initial rates of diffusion.

A non-invasive transcutaneous blood gas sensing system for determining a concentration of at least one arterial blood gas (“arterial blood gas concetration”) in a mammal based on rates of diffusion prior to reaching equilibrium (“initial rates of diffusion”), comprising:

• a combined diffusion and measurement chamber comprising at least one gas permeable surface adapted to allow transcutaneous diffusion of one or more arterial blood gases from a mammal when the gas permeable surface is in contact with the mammal;
• at least one optical chemical sensor positioned in the combined diffusion and measurement chamber that is adapted to chemically interact and/or physically react with a respective arterial blood gas;
• and
• an optoelectronic system positioned outside the combined diffusion and measurement chamber for remotely detecting the chemical interaction and/or the physical interaction of the at least one optical chemical sensor;
• and
• a controller for determining initial rates of diffusion of the at least one arterial blood gas being measured into the combined diffusion and measurement chamber based on signals received from the at least one optoelectronic system, wherein the controller determines the arterial blood gas concentration based on the determined initial rates of diffusion.

A method of measuring at least one analyte that is contained in an object that is at least partially permeable to the at least one analyte, comprising the steps of:

• inserting at least a portion of the object that contains the at least one analyte into a diffusion chamber that is pneumatically coupled to a measurement chamber that contains at least one analyte sensor, wherein the pneumatically coupled diffusion and measurement chambers form a circulation loop;
• opening the circulation loop to flush the diffusion chamber with nitrogen until the at least one analyte sensor outputs a predetermined baseline reading;
• closing the circulation loop and circulating nitrogen continuously around the circulation loop;
• determining a change in the at least one analyte partial pressure in the measurement chamber as a function of time;
• and
• determining a concentration of the at least one analyte in the object based on changes in the at least one analyte partial pressure in the measurement chamber prior to the at least one analyte partial pressure in the measurement chamber reaching an equilibrium state.

A method of measuring at least one analyte that is contained in an object that is at least partially permeable to the at least one analyte, comprising the steps of:

• providing a combined diffusion and measurement chamber that contains at least one analyte sensor and that comprises a diffusion surface that is at least partially permeable to the at least one analyte;
• flushing the combined diffusion and measurement chamber with nitrogen until the at least one analyte sensor outputs a predetermined baseline reading;
• isolating the combined diffusion and measurement chamber from its surrounding atmosphere;
• placing the diffusion surface in physical contact with a surface of the object;
• determining a change in the at least one analyte partial pressure in the combined diffusion and measurement chamber as a function of time;
• and
• determining a concentration of the at least one analyte in the object based on changes in the at least one analyte partial pressure in the measurement chamber prior to the at least one analyte partial pressure in the measurement chamber reaching an equilibrium state.