IEEE Sensors Journal最新文献

{"title":"An Underscreen Fingerprint Sensor for Measurement of PPG and Blood Pressure Estimation","authors":"Duc Huy Nguyen;Paul C.-P. Chao;Duc Thang Ngo;Sheng-Chieh Huang;Yen-Tang Huang;Mei-Lien Huang;Yan-Liang Chen;Teng-Wei Huang","doi":"10.1109/JSEN.2025.3541447","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3541447","url":null,"abstract":"A fingerprint sensor array of pixels with photodiodes for sensing and thin-film transistors (TFTs) as switches were developed for the first time together with new algorithms to estimate blood pressure (BP) based on quality photoplethysmography (PPG) sensed from this array device. Toward obtaining PPG in high quality, i.e., low noise, the pixels in the sensor array for underscreen fingerprint sensing in mobile devices are designed capable of being operated in a different mode, connected in parallel to output larger current signals than the original mode of fingerprint sensing, for better signal-to-noise ratio (SNR) of sensed PPGs. The sensed PPG is next preprocessed by being filtered to remove noise, normalized, resampled, and so on, followed by a quality check engineered to assess further the sensed PPG in real time by a built deep-learning (DL) model, a 1-D convolutional neural network (1D-CNN) with long short-term memory (LSTM). The model is intended to disqualify the PPGs contaminated by ambient light interference and motion artifacts. Data were collected from 88 subjects, including 52 men and 36 women, by measuring PPG signals from a fingerprint sensor, with systolic BP (SBP) ranging from 90 to 150 mmHg and diastolic BP (DBP) from 50 to 85 mmHg. An OMRON HEM-7127 device was used to obtain reference BPs. In the results, an accuracy of 97.13% for distinguishing between qualified and unqualified PPGs has been achieved by the aforementioned 1D-CNN trained by ground truths, precollected PPGs judged and labeled into two groups, qualified and unqualified PPGs. Next, only the qualified PPGs are fed to another DL model built for estimating BP, in a structure of 1D-CNN with three consecutive sections of convolution, batch normalization, and max pooling. This BP model is next optimized to a structure and parameters to achieve the best-combined estimation of SBP and DBP. The results show accuracy with 1.31 mean absolute error (MAE) <inline-formula> <tex-math>$pm ~1.34$ </tex-math></inline-formula> standard deviation (SD) for SBP and 4.11 (MAE) <inline-formula> <tex-math>$pm ~3.32$ </tex-math></inline-formula> (SD) for DBP, favorable as compared to all the prior arts using an image sensor to estimate BPs.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"10964-10976"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Hemodynamic Changes in Deeper Dermal Vasculature During Cold-Induced Vasoconstriction and Vasodilation Using a Laser Speckle-Based Optical Flowmetry Method","authors":"Tristan Wen Jie Choo;Ghayathri Balasundaram;Yi Qi;Ruochong Zhang;Songhua Zheng;Renzhe Bi;Malini Olivo","doi":"10.1109/JSEN.2025.3542539","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3542539","url":null,"abstract":"While the Lewis hunting reaction has been studied for decades, little remains known about the hemodynamic changes which occur in the deeper dermal arteries and arterioles during its alternating phases of cold-induced vasoconstriction (CIVC) and cold-induced vasodilation (CIVD). Here, we present an integrated sensor that simultaneously measures blood flow speed and fingertip temperature to study this relatively unknown physiology. Using diffuse speckle pulsatile flowmetry (DSPF), a laser speckle-based optical flowmetry method which measures blood flow speed from relatively deeper vasculature (up to around 15 mm depth), we show that the sensor was able to detect the changes in five morphological features within arterial blood flow speed waveforms—average blood flow speed, amplitude, time to peak, 50% pulse width, and area under the curve. In a pilot study with 14 subjects, a decrease in the value of all five features was observed during CIVC (significant for three features), whereas a subsequent significant increase in all five features was observed during CIVD. This study provides further insight into the Lewis hunting reaction and demonstrates the feasibility of our sensor in monitoring the physiological response to cold environments. It will potentially contribute to the diagnosis and prevention of cold-related pathologies such as hypothermia and Raynaud’s syndrome.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"11935-11943"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel Multipurpose Fuel Sensor for Efficient Estimation of Fuel-Level, Dual-Axis Inclination, and Two-Component Fuel Composition","authors":"Narayanan P. P.;Sreenath Vijayakumar","doi":"10.1109/JSEN.2025.3542559","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3542559","url":null,"abstract":"Modern automotive technologies necessitate monitoring of a wide variety of physical parameters, such as fuel level, dual-axis vehicle inclination, and fuel composition. Traditionally, this is achieved through the incorporation of numerous sensors, resulting in increased complexity, expense, and bulkiness. This article proposes a novel solution by designing a single capacitive-based sensor system capable of simultaneously monitoring fuel level, dual-axis vehicle inclination, and fuel mixture composition. In contrast to current fuel sensing architectures, the proposed sensor eliminates the need for movable parts and is immune to fuel type. This makes it compatible with any gasoline-powered combustion engine automobiles. The proposed sensor incorporates a dual-axis inclination measurement, which is essential for accurate level measurement, and ensuring vehicle safety. In addition, due to the current availability of a wide variety of fuel mixtures in the market, knowledge of fuel composition is critical in any vehicle for optimizing engine performance. Implementation of all these features through a single sensor eliminates the requirement for supplementary components, resulting in a reduction in both hardware implementation expenses and system complexity. This is the first of its kind such a single sensing scheme is reported. The prototype sensor demonstrates high linearity of 0.43% and 0.88% for level and inclination measurements, respectively. The sensor prototype was also tested with ethanol-petrol fuel mixtures and exhibits a worst case linearity error of 2.43% for concentrations ranging from E0-petrol to E100-petrol. The developed sensor promises a feasible and economically efficient solution for integration into contemporary automobiles.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"12109-12118"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Compact Differential Microwave Fluid Sensor for Permittivity Measurement of Ethanol–Water Solution","authors":"Aref Rasoulzadeh;Changiz Ghobadi;Javad Nourinia","doi":"10.1109/JSEN.2025.3542217","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3542217","url":null,"abstract":"In this article, a novel approach is proposed to address sensors’ significant challenges by introducing a portable planar microstrip sensor based on a dual-bandpass filter (BPF). This sensor is designed specifically for permittivity measurement of water-ethanol solution and offers high sensitivity, low cost, and reusability while minimizing the environmental unwanted effects. The proposed sensor consists of a microstrip line structure with two crescent arms as host, and an innovative sensing area is coupled to it. The sensing mechanism relies on the manipulation of the transmission resonance frequency. Notably, this configuration exhibits two transmission poles (TPs) in the transmission coefficients at specific frequencies, namely, 1.6 and 4.48 GHz. The second TP is particularly sensitive to changes in ethanol concentration (EC) and ambient variations too. On the other hand, the first TP remains unaffected by variations in the sample under test (SUT). To validate the effectiveness of the proposed sensor, a prototype was fabricated on RO4003C dielectric substrate, and subjected to rigorous testing using various ECs in deionized water. The prototype sensor boasts high sensitivity and compact size of <inline-formula> <tex-math>$8times 7.2times 0.508$ </tex-math></inline-formula> mm, which is advantageous for practical applications where space constraints are a concern.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"11024-11032"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damage Source Localization in Concrete Slabs Based on Acoustic Emission and Machine Learning","authors":"Wei Fu;Ruohua Zhou;Yan Gao;Ziye Guo;Qiuyu Yu","doi":"10.1109/JSEN.2025.3541721","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3541721","url":null,"abstract":"Acoustic emission (AE) technology faces challenges in concrete structures due to anisotropy and heterogeneity, causing wave velocity variations, reflection, refraction, and localization inaccuracies. To overcome these limitations, this study introduces a novel damage source localization approach that integrates AE technology with machine learning (ML) models. The proposed method utilizes a sensor array to capture AE signals, accurately determining their arrival times using the Akaike information criterion (AIC). Subsequently, the time difference of arrival (TDOA) between sensors is computed as input features for the model. For linear localization, a linear regression (LR) model establishes a direct relationship between TDOA and damage locations. For planar localization, lightweight models based on deep neural networks (DNNs), 1-D convolutional neural networks (1D-CNNs), and long short-term memory (LSTM) networks are developed to balance computational efficiency and localization accuracy. Additionally, a fine-tuning strategy is implemented to adjust the models with a minimal amount of new data, enhancing their adaptability to the diverse characteristics of different concrete slabs. Compared to conventional localization techniques and recent deep learning-based methods, the proposed approach demonstrates significant advancements in adaptability, computational efficiency, and localization accuracy. These improvements highlight its superior generalization capabilities and potential for practical applications.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"11622-11635"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Low-Cost and High-Stability Demodulation Method for Photothermal Spectroscopy Gas Detection in Power Transformer","authors":"Houxian Du;Xunbo Gao;Daiyuan Yang;Ruize Tong;Yukun Wang;Guoming Ma","doi":"10.1109/JSEN.2025.3542318","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3542318","url":null,"abstract":"Dissolved gas analysis is a critical component of transformer defect diagnosis. Oil-dissolved gas sensing based on fiber-optic photothermal spectroscopy was proposed for it is immune to electromagnetic interference. Traditional methods apply sinusoidal modulation to the pump light wavelength. However, sinusoidal phase noise is also generated in the absence of gas due to the laser absorption by fiber splice points, flanges, and other components. This noise makes it difficult to further lower the detection limit. In this article, a pump light frequency modulation method combining a sine wave with a sawtooth wave was introduced. The gas concentration was determined by detecting the amplitude of the second harmonic wave, which addressed the aforementioned issues. However, these systems are highly sensitive to temperature, vibrations, and other factors, leading to poor stability. In addition, the industry application is limited by the high cost of the demodulation system. Thus, this article proposed an acetylene sensing topology based on heterodyne interference and Mach-Zehnder interferometric structure. The sensing phase signal was modulated by a 100-MHz modulation, achieved by introducing an acousto-optic modulator (AOM) into the reference arm, which reduced low-frequency noise interference. Then, a low-cost demodulation method was also proposed based on mixing and down conversion. This method lowered the carrier frequency from 100 MHz to 100 kHz, reducing demodulation costs by about 91%. The proposed photothermal spectroscopy gas detection system achieved a detection limit of 0.256 ppm for acetylene.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"11092-11101"},"PeriodicalIF":4.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chip-Scale Resonant Optical Gyroscope With Near Earth-Rate Sensitivity","authors":"Adele N. Zawada;Warren Jin;Nathan Abrams;Avi Feshali;Mario Paniccia;Michel J. F. Digonnet","doi":"10.1109/JSEN.2025.3540400","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3540400","url":null,"abstract":"This article reports progress toward developing a passive chip-scale resonant optical gyroscope with a measured noise approaching tactical-grade specification. The gyroscope consists of a ring resonator fabricated with an ultra-low-loss silicon-nitride (SiN) waveguide tightly wound in a spiral with a length of 1.2 m, an average radius of 6.1 mm, and a Q factor of 60 million. We previously reported an earlier version of this spiral gyro with a measured noise and drift of 210°/h/<inline-formula> <tex-math>$surd $ </tex-math></inline-formula>Hz and 4000°/h, respectively. The noise was reduced by one order of magnitude by interrogating the gyro with a more coherent source, which simultaneously decreased the two dominant noise sources (laser-frequency noise and backscattering noise). Improvements made to the experimental setup, including the optimization of the modulation frequencies and the placement of some optical components, further reduced the noise by a factor of more than 2. Additionally, the drift was improved by more than one order of magnitude when several of the mechanical fiber connectors, which contribute to polarization-coupling drift, were replaced with polarization-maintaining splices. The measured noise of this improved spiral gyro is 6.7°/h/<inline-formula> <tex-math>$surd $ </tex-math></inline-formula>Hz, which is among the lowest reported values for a resonator with this footprint, and less than a factor of 3 from meeting the tactical-grade angular random walk (ARW) requirement. The measured drift is 250°/h. The next-generation SiN gyroscope will be designed specifically to further improve the drift by reducing the component and connector count. This work demonstrates that a miniature CMOS-compatible optical gyroscope with tactical-grade specifications is within reach.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"10949-10956"},"PeriodicalIF":4.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Scalable Textile Strain Sensor Matrix: Design, Implementation, and Application Exploration","authors":"Chenhui Zhang;Zhen Liang;Fangting Xie;Xiaohui Cai","doi":"10.1109/JSEN.2025.3542226","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3542226","url":null,"abstract":"The measurement of biomechanical loads is important for various applications, such as healthcare, sports, and human–computer interaction (HCI). To obtain a detailed view of the biomechanical loads, it is necessary to monitor the strain distribution on the body surface which is perpendicular to the pressure. The current strain sensing methods lack scalability and comfort for body-scaled usage. We design a fully textile strain sensor matrix that can be realized based solely on off-the-shelf materials and textile industry machines. The novel matrix design reduces the wiring scale to the square root of the sensor unit scale, enabling a practical, portable, and wearable deployment of strain distribution sensing. We created a matrix with 256 sensing points and explored its applications in both environmental and wearable scenarios. The results prove the necessity of measuring strain distribution that the 3-D biomechanical loads shall be obtained in detail. The data from the on-body applications also show good performance in human posture classification, motion monitoring, and environmental condition recognition.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"11924-11934"},"PeriodicalIF":4.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IoT-Based System Using IMU Sensor Fusion for Knee Telerehabilitation Monitoring","authors":"Mohamed El Fezazi;Abdelouahad Achmamad;Atman Jbari;Abdelilah Jilbab","doi":"10.1109/JSEN.2025.3542261","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3542261","url":null,"abstract":"High costs and clinical limitations restrict access to rehabilitation services, especially in low- and middle-income countries. There is a growing need for affordable, home-based solutions that enable continuous remote monitoring of patient rehabilitation progress. This work proposes an Internet of Thing (IoT)-based system for knee movement monitoring during telerehabilitation. The system comprises wearable inertial measurement units (IMUs) integrated into an IoT architecture. This architecture leverages edge and cloud computing to facilitate remote monitoring and real-time feedback. A sensor fusion algorithm was implemented on the edge to estimate knee joint angle, and a cloud-based application was developed to extract kinematic parameters and assess rehabilitation outcomes. The system was implemented using system-on-chip (SoC) technology, allowing embedded signal processing and wireless communication in a compact and low-power design. Three experimental validation tests were conducted: One hardware test evaluating the performance of the proposed sensor fusion algorithm; goniometer-based static test assessing the impact of environmental interference on system accuracy; dynamic test involving rehabilitation exercises to validate system performance against a gold-standard video-based system in the home context. The results demonstrated that the proposed algorithm achieved an optimal trade-off between accuracy, computational efficiency, and resilience to magnetic distortions. The system showed acceptable accuracy, with an average root mean square error (RMSE) ranging from 3.08° to 6.43° across all exercises. These results are consistent with the current state of the art, highlighting the system’s potential for objective and remote monitoring of knee movement in home-based rehabilitation.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"11906-11914"},"PeriodicalIF":4.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of an Inductive Torque Sensor for Robotic Applications","authors":"Ji-Hun Meng;Seo-Hyun Kim;Jae-Bok Song","doi":"10.1109/JSEN.2025.3541215","DOIUrl":"https://doi.org/10.1109/JSEN.2025.3541215","url":null,"abstract":"Collaborative robots enhance work efficiency through human-interaction functionalities, such as collision detection and direct teaching. These functionalities are often achieved by equipping each rotary joint of the robot with torque sensors, which improves workspace safety and convenience. However, commercial strain gauge-based torque sensors are often unsuitable for collaborative robots due to their high cost and incompatible form factors. Moreover, various forces applied to the robot’s joints induce crosstalk errors in the torque sensors, which degrades the overall performance. Previous studies have addressed crosstalk errors by employing complex processing methods or mechanisms that induce structural deformation in specific directions. Although these approaches effectively decrease crosstalk error, they often increase the size or cost of torque sensors, which limits their applicability to robots. This study proposes a novel torque sensor based on the inductive sensing technology, characterized by high-torque measurement performance and a simplified manufacturing process. The proposed torque sensor estimates the torque by measuring the inductance of a rectangular coil implemented on a printed circuit board (PCB). The coil is designed to exhibit minimal inductance change under crosstalk conditions to minimize crosstalk errors. The developed torque sensor has a diameter of 90 mm and a thickness of 13 mm. The performance of the proposed sensor was evaluated in calibration and torque measurement experiments. Comparative studies with a commercial force/torque sensor (FTS) and crosstalk error measurements demonstrated the feasibility of the proposed torque sensor for use in collaborative robots.","PeriodicalId":447,"journal":{"name":"IEEE Sensors Journal","volume":"25 7","pages":"10749-10757"},"PeriodicalIF":4.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}