Catheter-mounted smart hydrogel ultrasound resonators for intravenous analyte monitoring

Abstract

Continuous monitoring of drug concentrations in blood plasma can be beneficial to guide individualized drug administration. High interpatient variability in required dosage and a small therapeutic window of certain drugs, such as anesthetic medications, can cause risks and challenges in accurate dosing during administration. In this work, we present a sensing platform concept using a smart hydrogel micro resonator sheet with medical ultrasound readout that is integrated on the top of a catheter. This concept is validated invitro using glucose as an easy to access and handle target analyte. In the case of continuous glucose measurement, our novel catheter-mounted sensing platform allows the detection of glucose concentrations in the range of 0 mM to 12 mM. While these experiments use a well-known glucose-sensitive smart hydrogel for proof-of-principle experiments, this new sensing platform is intended to provide the basis for continuous monitoring of various intravenously applied medications. Selectivity to different drugs, e.g., fentanyl, can be accomplished by developing a corresponding smart hydrogel composition. Clinical Relevance-Many intravenous medications, especially anesthetics, show considerable pharmacokinetic intersubject variability. Continuous monitoring of intravenous analyte concentrations would enable individualizing the administration of these drugs to the specific patient.

Smart Hydrogel Swelling State Detection Based on a Power-Transfer Transduction Principle

“…The transduction relies on the swelling state dependence of the sheet’s resonance frequency where a reduction of the observed reflected wave intensity occurs. This concept has already been demonstrated in in vivo test cases for glucose sensing , and furthermore been suggested for integration into a catheter …”

“…This concept has already been demonstrated in in vivo test cases for glucose sensing 46 , 47 and furthermore been suggested for integration into a catheter. 48 …”

“…This concept has already been demonstrated in in vivo test cases for glucose sensing 46,47 and furthermore been suggested for integration into a catheter. 48 Transduction concepts that only use the electrical properties of the hydrogel are rare and mainly rely on conductometric measurements based on interdigitated electrodes (IDEs). Thereby, the hydrogel is placed on top of the IDE and its swelling/shrinking changes the conductivity within the IDE, resulting in a change of impedance or output voltage.…”