Local Glucose Tolerance Test Needle With Measurement and Administration Flow Channels

ABSTRACT Assessment of impaired insulin secretion and insulin resistance is critical to determining the type of diabetes and planning optimal management and preventive strategies in clinical practice. To measure insulin resistance, a minimally invasive needle with measurement and administration flow channels for local glucose tolerance tests was fabricated. The administration flow channel has a hole on the tip end of the flow channel. The microperfusion flow channel starts from the root side of the needle, turns around at the needle‐tip end, and returns back to the root side of the needle. It has a perforated membrane on the surface of the area placed in the skin when inserted. Glucose is administrated through the flow channel, and glucose concentration of the skin is measured by microperfusion before and after administration. When the perfusate is perfused into the microperfusion flow channel, since the glucose concentration of the skin is higher than the perfusate, glucose contained in the skin's interstitial fluid moves into the flow channel through the perforated membrane by concentration diffusion, and the glucose can be collected. The needle's administration and glucose‐collecting functions were evaluated in the skin of mice.