Monitoring of vital bio-signs by analysis of speckle patterns in a fabric-integrated multimode optical fiber sensor

Abstract

Continuous noninvasive measurement of vital bio-signs, such as cardiovascular parameters, is an important tool in evaluation of the patient’s physiological condition and health monitoring. Based on new enabling technologies, continuous monitoring of heart and respiration rate, pulse wave velocity and blood pressure have been investigated, advanced and reflected in numerous papers published in recent years. In this paper, we introduce a new technique for noninvasive sensing of vital bio-signs based on a multimode optical fiber sensor that can be integrated into a fabric. The sensor consists of a laser, optical fiber, video camera and computer. Its operation is based on tracking of point-wise intensity variations on speckle patterns caused by interference of the light modes within the fiber subjected to deformation. The paper contains theoretical analysis and experimental validation of the proposed scheme. The main goal is to advance a simple low-cost sensor embedded in a cloth fabric to track changes in the cardiovascular condition of the wearer.

Textile-based fiber optic sensors for health monitoring: A systematic and citation network analysis review

“…Previously, most of the TFOSs were sewn on elastic bands to take measurements on the chest or abdomen. 1,25,27,30,33,36,47 Recently, Massaroni et al. 38 revealed the possibility of using sensing apparel to take full body measurements.…”

“…Previously, most of the TFOSs were sewn on elastic bands to take measurements on the chest or abdomen. 1,25,27,30,33,36,47 Recently, Massaroni et al 38 revealed the possibility of using sensing apparel to take full body measurements. They integrated 12 FBG sensors onto a T-shirt to monitor respiratory movement and evaluate the thoraco-abdominal movement patterns during sporting activities.…”

Recent Progress in Bio‐Integrated Intelligent Sensing System

“…Recently, the needs for monitoring various sensing parameters, including blood pressure, compositions within body fluids, wound temperature, and limb movement, etc., propose many sensing requirements for the bioelectronics. [68][69][70][71][72] For these demands, sensors of BISS need to possess multiple sensing modalities, combining strain sensors, [73][74][75][76] temperature sensors,, [77][78][79] optical elements, [80][81][82][83][84] and other electrochemical types. [85][86][87] The integration of those functions is based on the fact that the ideal sensitive unit in one channel can precisely reflect one specific change of its surrounding environment (sensitivity) without the interference of other modalities (specificity).…”

In Vivo Pulse Wave Measurement Through a Multimode Fiber Diffuse Speckle Analysis System

“…But the intelligent instruments and skillful operators are needed to obtain reliable results. On the other hand, assessment of PWV is also important for daily healthcare monitoring, especially for infants and elderly [7].…”

“…Taking the advantages of flexibility and robustness, fiberbased diffuse optical methods are very popular in clinical applications of deep tissue blood flow measurement. Many systems use multimode (MM) source fiber [7,17] to obtain the contrast information from the diffuse laser speckles and extract blood flow information. Therefore, it is also possible to use MM detection fiber combined with area array camera for diffuse pattern detection [18].…”