A Method for Measuring the Volume of Transdermally Extracted Interstitial Fluid by a Three-Electrode Skin Resistance Sensor

Abstract

It is difficult to accurately measure the volume of transdermally extracted interstitial fluid (ISF), which is important for improving blood glucose prediction accuracy. Skin resistance, which is a good indicator of skin permeability, can be used to determine the volume of extracted ISF. However, it is a challenge to realize in vivo longitudinal skin resistance measurements of microareas. In this study, a three-electrode sensor was presented for measuring single-point skin resistance in vivo, and a method for determining the volume of transdermally extracted ISF using this sensor was proposed. Skin resistance was measured under static and dynamic conditions. The correlation between the skin resistance and the permeation rate of transdermally extracted ISF was proven. The volume of transdermally extracted ISF was determined using skin resistance. Factors affecting the volume prediction accuracy of transdermally extracted ISF were discussed. This method is expected to improve the accuracy of blood glucose prediction, and is of great significance for the clinical application of minimally invasive blood glucose measurement.

Sampling Dermal Interstitial Fluid Using Microneedles: A Review of Recent Developments in Sampling Methods and Microneedle‐Based Biosensors

“…The longitudinal skin resistance of the ultrasonic area on the skin develops vertical micropores and good permeability, but it is also difficult to measure the longitudinal skin resistance precisely. [ 61 ] Thus, the application of this technique has been very limited, and further studies are required for successful and repeated extraction of ISF. Generally, almost no pain is associated with this method, but the patient may experience slight heating of the skin during the process.…”

A thermal activated and differential self-calibrated flexible epidermal biomicrofluidic device for wearable accurate blood glucose monitoring

“…Normal skin impedance was proven to be an important indicator of skin permeability (19). Therefore, normal skin impedance experiments were conducted firstly to verify the possibility of the proposed thermal activation method by a noninvasive three-electrode measurement method (20). The measurement method, setup, and data are shown in figs.…”

A Flexible Interdigital Electrode Used in Skin Penetration Promotion and Evaluation with Electroporation and Reverse Iontophoresis Synergistically

“…Under low frequency conditions (100 Hz~1000 Hz), skin impedance can better reflect its penetration. The smaller the impedance of skin becomes, the greater the penetration of skin becomes [ 11 , 12 , 13 ]. Traditionally, skin permeability evaluation, which is realized by impedance detected at a certain frequency based on macro-electrode, has the disadvantages of large measurement error, low sensitivity, and difficulty in integration [ 14 , 15 ].…”