Polymer-Based Fiber Optic Sensor for Noninvasive Blood Pressure Monitoring Pratheeksha Srinivasu a , Aditya Sharma a ,Vinayak Ghorapade a ,Hao-Ming Cheng e , Wei-Chih Wang* a,b,c,d a Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu 30013, Taiwan R.O.C; b Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan R.O.C; c Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington 98195, USA; d Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195, USA. e National Yang Ming Chiao Tung University College of Medicine, Taipei, Taiwan ABSTRACT This work presents a novel optical technology for precise sensing of blood pressure waves in response to Oscillo metric movement of arteries. The approach involves the development of a polymer-based fiber-optic sensor, illuminated by an infrared light source, to capture real-time, continuous blood pressure waves non-invasively. The integration of polymer- based optical fibers enhances sensitivity and responsiveness to arterial fluctuations, making this system a promising tool for medical diagnostics and remote patient monitoring. This sensor is a valuable advancement in wearable healthcare devices, offering improved accuracy and reliability over traditional methods. Keywords: Blood pressure (BP), Blood pressure waveforms, Cardiovascular disease, Intensity modulation. 1. INTRODUCTION Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide, accounting for an estimated 17.9 million deaths annually [1]. Among the primary risk factors, hypertension (high blood pressure) is a major contributor to heart attacks, strokes, and kidney diseases, affecting 1.28 billion adults globally, with nearly half of them unaware of their condition [2]. Early detection and continuous monitoring of blood pressure (BP) waveforms are critical for identifying vascular abnormalities, arterial stiffness, and hypertension-related complications, ultimately aiding in early intervention and disease management [3]. However, conventional cuff-based BP monitors suffer from fundamental limitations, including intermittent measurements, patient discomfort, and lack of real-time waveform tracking, making them unsuitable for continuous monitoring and ambulatory healthcare applications [4]. Traditional sphygmomanometers, whether manual (auscultatory) or automated (Oscillo metric), provide only snapshot measurements rather than capturing continuous BP waveforms that can reveal minute variations in pressure dynamics [8]. While widely used in clinical and home settings, these methods fail to provide insights into transient BP fluctuations, pulse wave velocity (PWV), and vascular compliance, which are critical markers for assessing cardiovascular risk. More advanced tonometry techniques, which involve placing a pressure sensor over a superficial artery to continuously record arterial waveforms, offer better diagnostic accuracy but are highly sensitive to sensor placement and require skilled operation, making them impractical for at-home or wearable applications [5]. Similarly, Doppler ultrasound is widely employed for vascular health assessment, allowing clinicians to measure blood flow velocity and arterial occlusions. However, it requires trained personnel, expensive equipment, and specialized clinical settings, making it unsuitable for real-time, non-invasive, and long-term BP monitoring [6]. Although non-invasive techniques such as photo-plethysmography (PPG) and pulse transit time (PTT) monitoring have been explored in wearable devices, their accuracy remains limited due to motion artifacts and dependence on indirect BP estimations [7]. These Soft Mechatronics and Wearable Systems 2025, edited by Ilkwon Oh, Woon-Hong Yeo, Wei Gao, Proc. of SPIE Vol. 13434, 134340B © 2025 SPIE · 0277-786X · doi: 10.1117/12.3051703 Proc. of SPIE Vol. 13434 134340B-1