Wearable Thin-Film Piezoelectric Sensor System for Continuous Lung Function Monitoring

Background

Respiratory health monitoring is critical for managing diseases such as COPD, asthma and emerging conditions like COVID-19. Early detection of changes in lung function, including variations in breathing rate and volume, can inform timely clinical interventions and reduce hospitalizations. Traditional approaches such as spirometry, chest auscultation and impedance pneumography are confined to clinical settings, provide only sporadic snapshots, and require trained personnel. There is a growing demand for unobtrusive, long-term monitoring solutions capable of capturing continuous, high-fidelity respiratory data outside the hospital, enabling remote patient management and personalized care pathways.

Existing wearable and portable respiratory sensors face several limitations that hinder continuous, long-duration monitoring. Bulkiness and rigid form factors cause discomfort and limit adherence, while noise sensitivity and motion artifacts degrade signal quality during daily activities. Many devices rely on periodic calibration, short battery life or single-modality measurement, preventing rich multiparameter assessment. Acoustic and accelerometer-based sensors often lack the sensitivity to detect subtle chest wall deformations and low-amplitude breathing sounds, leading to inaccurate estimates of lung volume and rate. High production costs and scalability challenges further restrict widespread adoption in home-care settings.

Technology

An elastic thin-film sensor adhered to the lower rib cage integrates a printed multilayer stack—including a thin-film piezoelectric layer sandwiched between micro-electrode layers on an adaptable substrate—to capture chest-wall acoustic vibrations and convert them into electrical signals. Real-time signal analysis yields lung volume, respiration rate, and capacity metrics, which are wirelessly streamed to a smartphone app for continuous monitoring over periods exceeding two weeks. Inkjet printing enables rapid prototyping and fine-tuning of electrode geometries, while roll-to-roll thin-film fabrication provides a scalable, low-cost manufacturing route. The flexible, ultrathin design conforms to body contours, supporting comfortable, long-term wear without compromising signal fidelity.

This approach outperforms traditional rigid microphone-based devices by delivering higher acoustic sensitivity in a smaller, thinner form factor that conforms seamlessly to the chest wall. The multimodal architecture can be extended to integrate additional sensing modalities—such as strain and capacitive sensors—for comprehensive health monitoring. Compared to bulkier alternatives, the low-weight, skin-like sensor enables continuous, daily wear while maintaining signal fidelity. Scalable roll-to-roll manufacturing and inkjet-enabled customization reduce production costs and accelerate development, distinguishing this solution as a versatile platform for next-generation respiratory diagnostics.

Benefits

• High-sensitivity detection of chest-wall acoustic vibrations for accurate monitoring of lung volume, respiration rate, and capacity
• Flexible, ultra-thin form factor allowing comfortable, conformal wear on the lower rib cage for continuous use over 14+ days
• Wireless real-time data transmission to a smartphone app for remote monitoring, early intervention, and rapid clinical response
• Rapid, low-cost, scalable manufacturing enabled by inkjet printing and roll-to-roll thin‐film fabrication
• Expandable platform supporting additional sensing modalities (e.g., strain, capacitive) for multiparameter health monitoring
• Generation of large-scale respiratory datasets to support disease prediction, personalized care, and big-data health analytics

Applications

• Home respiratory health monitoring
• Chronic disease lung function tracking
• Hospital patient respiration monitoring
• Telemedicine lung function assessment
• Clinical trial respiratory data collection

Additional info

An elastic thin‐film patch adheres to the lower rib cage, hosting a printed multilayer stack—a piezoelectric film sandwiched between inkjet‐printed microelectrodes on an elastic substrate—that transduces chest-wall acoustic vibrations into electrical signals. Data representing lung volume, respiration rate and capacity are wirelessly streamed to a smartphone app for continuous monitoring beyond two weeks. Roll-to-roll fabrication ensures low-cost scalability, while flexible design offers enhanced sensitivity and multiparameter expansion.