Pandya Hardik J, Sheng Jun, Desai Jaydev P
Department of Medicine in the Brigham and Womens Hospital - Harvard Medical School, Boston, MA 02115, USA.
Medical Robotics and Automation Laboratory (RoboMed) in the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
J Microelectromech Syst. 2017 Feb;26(1):264-272. doi: 10.1109/JMEMS.2016.2636018. Epub 2016 Dec 22.
Atrial fibrillation (AFib) is a significant healthcare problem caused by the uneven and rapid discharge of electrical signals from pulmonary veins (PVs). The technique of radiofrequency (RF) ablation can block these abnormal electrical signals by ablating myocardial sleeves inside PVs. Catheter contact force measurement during RF ablation can reduce the rate of AFib recurrence, since it helps to determine effective contact of the catheter with the tissue, thereby resulting in effective power delivery for ablation. This paper presents the development of a three-dimensional (3D) force sensor to provide the real-time measurement of tri-axial catheter contact force. The 3D force sensor consists of a plastic cubic bead and five flexible force sensors. Each flexible force sensor was made of a PEDOT:PSS strain gauge and a PDMS bump on a flexible PDMS substrate. Calibration results show that the fabricated sensor has a linear response in the force range required for RF ablation. To evaluate its working performance, the fabricated sensor was pressed against gelatin tissue by a micromanipulator and also integrated on a catheter tip to test it within deionized water flow. Both experiments simulated the ventricular environment and proved the validity of applying the 3D force sensor in RF ablation.
心房颤动（AFib）是一个严重的医疗问题，由肺静脉（PVs）发出的不均匀且快速的电信号放电引起。射频（RF）消融技术可以通过消融PVs内部的心肌袖套来阻断这些异常电信号。RF消融过程中的导管接触力测量可以降低AFib复发率，因为它有助于确定导管与组织的有效接触，从而实现有效的消融能量传递。本文介绍了一种三维（3D）力传感器的开发，用于实时测量三轴导管接触力。该3D力传感器由一个塑料立方珠和五个柔性力传感器组成。每个柔性力传感器由一个PEDOT:PSS应变片和一个位于柔性PDMS基板上的PDMS凸块制成。校准结果表明，所制造的传感器在RF消融所需的力范围内具有线性响应。为了评估其工作性能，将所制造的传感器通过微操纵器压在明胶组织上，并集成在导管尖端以在去离子水流中进行测试。这两个实验都模拟了心室环境，并证明了在RF消融中应用3D力传感器的有效性。
