To address the challenges of capturing micro-strains in detecting esophageal motility disorders and the limitations of existing high-resolution manometry and functional intraluminal imaging probes in directly measuring esophageal tissue electrical impedance, this study proposes a novel flexible balloon sensor structure that integrates a piezoelectric film assembly with a distributed impedance electrode array. Using the electrical analysis module in the finite element analysis (FEA) software, simulations of the forward problem for esophageal impedance detection were conducted to optimize the excitation source parameters, and a physical prototype was fabricated. Under a relative excitation mode with a voltage sensitivity of 2.059%, the voltage output characteristics of the impedance electrode array were analyzed during linear changes in the balloon filling volume. Based on the performance variation of the piezoelectric film assembly, 80% was selected as the optimal filling volume. Force-electric coupling tests were conducted on the balloon sensor using a pressure testing platform, revealing that both the piezoelectric film assembly inside the balloon and the impedance electrodes outside the balloon exhibited significant load differentiation characteristics as the force application point shifted. In summary, this balloon sensor facilitates the localization of force application while simultaneously analyzing esophageal tissue properties, offering a novel diagnostic approach and objective tool for esophageal disease detection.
Esophagus/physiology* ; Electric Impedance ; Humans ; Finite Element Analysis ; Manometry/methods* ; Electrodes ; Esophageal Motility Disorders/physiopathology* ; Equipment Design

Objective To investigate the mechanical characteristics and voltage output changes of microcatheter sensors during cyclic blood flow,and explore the feasibility of designing microcatheter sensors which can monitor pressure information and stenosis lesion information.Methods A two-way fluid-solid coupling model was constructed to perform finite element numerical simulation of the interaction between the microcatheter sensor and blood,the mechanical characteristics of the sensor in the longitudinal and circumferential directions in each key frame was analyzed,and the differences in mechanical characteristics of the sensor in healthy and stenotic vessels were compared;a PVDF force-electricity simulation model was constructed,and mechanical signals on the sensor were imported to analyze the sensor's voltage output in two scenarios.Results The longitudinal and circumferential outputs of the sensors in healthy vessels were relatively even in magnitude,with a ratio close to 1.In vessels with stenotic lesions,the longitudinal outputs of the sensors yielded significant differences,with ratios ranging from 0.3 to 0.6,and abnormal distributions in circumferential stenotic regions,with the ratio of the stenosis-direction component to the average value much larger than 1.Force-electric simulation further revealed that the sensors could convert mechanical signals into electrical signals and output them.The force-electric simulation further revealed that the sensor could convert the mechanical signal into an electrical signal and output it,and its output values ranged from 8.01 mV to 225.2 mV.Conclusions There was a significant difference in mechanical characteristics of the sensor between healthy vessels and vessels with stenotic lesions,the location and direction of stenotic lesions could be obtained by analyzing the output of the sensors,while the PVDF sensor could convert these mechanical characteristics into electrical signals which were easier to be processed.This study provides a theoretical reference for the development and application of the novel microcatheter sensors.

Objective To investigate the mechanical characteristics and voltage output changes of microcatheter sensors during cyclic blood flow,and explore the feasibility of designing microcatheter sensors which can monitor pressure information and stenosis lesion information.Methods A two-way fluid-solid coupling model was constructed to perform finite element numerical simulation of the interaction between the microcatheter sensor and blood,the mechanical characteristics of the sensor in the longitudinal and circumferential directions in each key frame was analyzed,and the differences in mechanical characteristics of the sensor in healthy and stenotic vessels were compared;a PVDF force-electricity simulation model was constructed,and mechanical signals on the sensor were imported to analyze the sensor's voltage output in two scenarios.Results The longitudinal and circumferential outputs of the sensors in healthy vessels were relatively even in magnitude,with a ratio close to 1.In vessels with stenotic lesions,the longitudinal outputs of the sensors yielded significant differences,with ratios ranging from 0.3 to 0.6,and abnormal distributions in circumferential stenotic regions,with the ratio of the stenosis-direction component to the average value much larger than 1.Force-electric simulation further revealed that the sensors could convert mechanical signals into electrical signals and output them.The force-electric simulation further revealed that the sensor could convert the mechanical signal into an electrical signal and output it,and its output values ranged from 8.01 mV to 225.2 mV.Conclusions There was a significant difference in mechanical characteristics of the sensor between healthy vessels and vessels with stenotic lesions,the location and direction of stenotic lesions could be obtained by analyzing the output of the sensors,while the PVDF sensor could convert these mechanical characteristics into electrical signals which were easier to be processed.This study provides a theoretical reference for the development and application of the novel microcatheter sensors.