System and method to characterize gas transport properties

A method for measurement of transport properties of a gaseous component of a fluid sample, the method comprising:

• obtaining a fluid sample wherein the gaseous component is protected from degradation or reaction and wherein an entrance partial pressure of the gaseous component is calculated or pre-measured;
• conditioning the fluid sample to a predetermined temperature;
• pumping the fluid sample at a pre-selected flow rate through a permeable artificial capillary having a known radius, wherein the artificial capillary is disposed within a gas exchange chamber containing a constant flow of an exchange gas;
• collecting the fluid sample after it has exited the artificial capillary;
• analyzing the fluid sample to determine an exit partial pressure of the gaseous component contained therein;
• and
• calculating a difference between the entrance and exit partial pressures.

A method for analyzing gas transport properties of a solution containing a plurality of solute molecules and having a viscosity, the method comprising:

• obtaining a sample of the solution having an entrance partial pressure of a target gas is calculated or pre-measured;
• pumping the solution sample at a pre-selected flow rate through a permeable artificial capillary having a length and a radius, wherein the artificial capillary is disposed within a gas exchange chamber containing a constant flow of an exchange gas so that the target gas is diffused out or or into the artificial capillary;
• collecting the solution sample after it has exited the artificial capillary;
• analyzing the fluid sample to determine an exit partial pressure of the target gas contained therein;
• calculating a difference between the entrance and exit partial pressures;
• and
• calculating a diffusivity according to the relationship DS = kT y ⁢ ⁢ η a ⁢ r b
• where k is Boltzman's constant, ηa is the viscosity of the solution;
• rb is the radius of the solute molecules;
• ra is the radius of the solute molecules, and y=6 for rb>>ra and y=4 for rb≈ra.

A method for prediction of in vivo blood pressure response to a hemoglobin-based oxgen carrier (HBOC) solution, the method comprising:

• obtaining a sample of the HBOC solution having an entrance partial oxygen pressure that is calculated or pre-measured;
• pumping the HBOC solution sample at a pre-selected flow rate through a permeable artificial capillary having a length and a radius, wherein the artificial capillary is disposed within a gas exchange chamber containing a constant flow of an exchange gas so that oxygen within the HBOC solution is diffused out of the artificial capillary;
• collecting the solution sample after it has exited the artificial capillary;
• analyzing the fluid sample to determine an exit partial oxygen pressure;
• calculating a difference between the entrance and exit partial oxygen pressures;
• and
• calculating a diffusivity according to the relationship D HbO2 = kT y ⁢ ⁢ η a ⁢ r b
• where k is Boltzman's constant, ηa is the viscosity of the solution;
• rb is the radius of the solute molecules;
• ra is the radius of the solute molecules, and y=6 when the solute molecules are hemoglobin and y=4 when the solute molecules are molecular oxygen.

A method for measurement of saturation of a target gas within a solution containing a plurality of solute molecules, the method comprising:

• obtaining a sample of the solution having an entrance partial pressure of a target gas is calculated or pre-measured;
• measuring an entrance optical absorption of the solution sample at a wavelength corresponding to presence of the target gas:
• pumping the solution sample at a pre-selected flow rate through a permeable artificial capillary having a length and a radius so that the solution sample has a known residence time within the artificial capillary, wherein the artificial capillary is disposed within a gas exchange chamber containing a constant flow of an exchange gas so that the target gas is diffused out or or into the artificial capillary;
• measuring an exit optical absorption;
• collecting the solution sample after it has exited the artificial capillary;
• analyzing the fluid sample to determine an exit partial pressure of the target gas contained therein;
• calculating a difference between the entrance and exit partial pressures;
• calculating a difference between the entrance and exit optical absorptions and determining a concentration of solute molecules in the solution;
• and
• determining saturation as a function of the difference in partial pressure, the concentration of solute molecules, and the residence time.