Abstract:
Objective To investigate the distribution characteristics and potential impact factors of oxygen concentration in capillaries and tissues by using a three-dimensional capillary-tissue model for determination of oxygen transportation within biological tissues,thereby offering theoretical ground for complete quantilied calibration of implantable glucose sensor.Methods Elemental and complicated capillary-tissue models were constructed for simulation of oxygen transportation within capillaries by adopting equations for convection and diffusion control that incorporated with intracapillary free oxygen and hemoglobin-bonded oxygen,and for simulation of oxygen transportation within tissues by adopting equations tor diffusion.Results Oxygen concentration appeared to decline along with the blood flow,as suggested by elemental and complicated capillary-tissue models.The distance of oxygen transportation in muscle tissues was approximately 40 μm during static state.Increased tissue maximal oxygen consumption,reduced oxygen diffusion cocfficicnt,declined mean blood flow and decreased capillary inlet oxygen partial pressure were all responsible for lowered oxygen concentration within the tissues under steady state.Conclusion Simulation results of oxygen transportation are in tune with empirical data or observed phenomenon upon our successful construction of three-dimensional capillary-tissue model.