Significance Respiration is an important physiological process maintaining human homeostasis, and its parameters such as frequency and rhythm are important indicators for evaluating vital signs. Traditional respiratory monitoring relies on devices such as polysomnography (PSG) and pulmonary function analyzers, which suffer from drawbacks including the bulkiness of PSG that interfered with sleep and the complexity of operation of pulmonary function analyzers, making them difficult to meet the requirements of convenient and real-time monitoring. With the development of flexible electronic technology, respiratory monitoring devices transform from "rigid" to "wearable". Among them, fabric-based wearable respiratory monitoring systems are directly adhered to the human body surface, realizing continuous real-time collection of respiratory parameters without interfering with normal physiological activities. While reducing monitoring costs, they also promote the shift of health management models towards "prevention-oriented". Based on this, this paper reviewed the research progress on respiratory monitoring sensing mechanisms and wearable sensing monitoring fabrics in the fields of medical health and sports management, providing references for the further development and application of wearable respiratory sensing monitoring fabrics.

Progress Wearable respiratory sensing monitoring fabrics captured physical and chemical changes during respiration through flexible sensing units, which were converted into quantifiable parameters through signal conditioning and data analysis. According to this, their sensing mechanisms were classified into four categories: electrical, optical, thermal, and mechanical. Among them, electrical sensing was fast responsive and highly integrated, which was further divided into impedance sensing (highlighting visualization and real-time performance but with low spatial resolution and insufficient algorithm generalization ability) and piezoresistive sensing (good flexibility and low cost but weak ability to capture micro-deformations and prone to signal drift). Optical sensing possessed the ability of anti-electromagnetic interference and high safety, with mature application of fiber optic sensors but limited sensitivity and obvious photoelectric loss. Thermal sensing was convenient and low-power with multi-dimensional monitoring capability but slow response and susceptible to environmental temperature interference. Mechanical sensing could measure respiratory depth accurately, including respiratory inductance plethysmography (strong binding sensation) and piezoelectric sensing (piezoelectric materials were prone to fatigue attenuation). In terms of research applications, the medical health field focused on high-precision monitoring needs. The developed fabric electrode vest achieved real-time monitoring of respiration in patients with chronic obstructive pulmonary disease. Triboelectric fiber arrays exhibited improved washability. The design of multi-fiber Bragg gratings (FBG) and multi-conductive sensors has reduced the impact of posture on precision. The double-layer capacitor bending angle sensor achieved high-precision monitoring under low pressure, but they generally faced problems such as poor posture sensitivity, poor washability, signal drift, and relatively high cost. The sports management field focused on the coordinated monitoring of respiration and gait. The timeliness and anti-interference ability of monitoring were improved by integrating the micro-control unit (MCU) modules with the inertial measurement unit (IMU) and optimizing capacitance digital converters. The 3D open-type fabric exhibited improved monitoring stability during exercise, but it had defects such as baseline drift, single-channel susceptibility to interference from strenuous exercise, and complex structure. In short, sensor array optimization and algorithm fusion significantly improved monitoring accuracy and anti-interference ability, but common defects were insufficient comfort, poor long-term stability, and individual calibration differences.

Conclusions Fabric-based wearable respiratory monitoring technology has shown broad application prospects in the fields of medical health and sports management due to its flexible adherence and continuous real-time monitoring characteristics. Through employing methods such as sensor array optimization and algorithm fusion, its monitoring performance has been effectively improved, but it is still limited by key issues such as insufficient comfort, poor long-term stability, and individual calibration differences. Future research should focus on the optimization of materials and processes, with the emphasis on improving the stability of flexible sensitive materials. At the same time, future research should promote the in-depth integration of multi-modal sensing and intelligent algorithms, reduce the impact of single technology defects on monitoring accuracy, and ultimately achieve accurate adaptation to complex application scenarios, further expanding application value in clinical medicine and health management.