Polymer Optical Fiber Plantar Pressure Sensors: Design and Validation

Abstract

The proper measurement of plantar pressure during gait is critical for the clinical diagnosis of foot problems. Force platforms and wearable devices have been developed to study gait patterns during walking or running. However, these devices are often expensive, cumbersome, or have boundary constraints that limit the participant’s motions. Recent advancements in the quality of plastic optical fiber (POF) have made it possible to manufacture a low-cost bend sensor with a novel design for use in plantar pressure monitoring. An intensity-based POF bend sensor is not only lightweight, non-invasive, and easy to construct, but it also produces a signal that requires almost no processing. In this work, we have designed, fabricated, and characterized a novel intensity POF sensor to detect the force applied by the human foot and measure the gait pattern. The sensors were put through a series of dynamic and static tests to determine their measurement range, sensitivity, and linearity, and their response was compared to that of two different commercial force sensors, including piezo resistive sensors and a clinical force platform. The results suggest that this novel POF bend sensor can be used in a wide range of applications, given its low cost and non-invasive nature. Feedback walking monitoring for ulcer prevention or sports performance could be just one of those applications.

Multifunctional Integration of Optical Fibers and Nanomaterials for Aircraft Systems

“…In another configuration for optical fiber pressure sensors, the diaphragm positioned along the optical fiber enables the development of diaphragm-embedded OFS based on intensity variation [ 97 ], interferometers [ 98 ], and FBGs [ 99 ]. Due to larger dimensions of the diaphragm in this configuration, the fabrication tolerances are smaller (when compared with the diaphragm on the tip of optical fibers) and the multiplexing capabilities are favorable, since many diaphragms can be employed along the optical fiber [ 100 ].…”

“…To that extent, not only the diaphragm properties are important on the sensors’ performance, but also the optical fiber mechanical properties, since the sensor is based on the strain transmitted to the optical fiber. Thus, the use of POFs generally leads to higher sensitivity and resolution in the pressure sensors, due to their lower Young’s modulus (when compared with conventional silica optical fibers) [ 99 ].…”

Research progress of the plantar pressure monitoring system for gait analysis

“…光纤传感器 主要由3个部件组成 [50] : 产生光的光源、作为光束行进 通道的光纤和接收衰减光束的光电探测器. Safarloo等 人 [51] 使用塑料光纤(plastic optical fibre, POF)制造了一 种低成本足底压力传感器. 该传感器使用总直径为 2 mm的HFBR-R/EXXYYYZ POF光纤, 切割到所需长 度后, 连接到电路, 通过电路将光耦合到光纤中, 监测 输出光强度, 随着时间推移记录数据.…”