IEEE Open Journal of Instrumentation and Measurement最新文献

{"title":"Real-Time Vision-Based Bending Angle Estimation in a Soft Robotic Actuator Using Gaussian Processes and Kalman Filtering","authors":"Narges Ghobadi;Tony Szturm;Nariman Sepehri","doi":"10.1109/OJIM.2026.3670516","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3670516","url":null,"abstract":"Accurate estimation of finger bending angles is essential in rehabilitation, as it enables precise assessment of a patient’s joint motion and recovery progress. Soft robotic devices can leverage this information to provide adaptive and safe assistance, facilitating effective and personalized therapy sessions. In this article, a soft pneumatic actuator designed for the index finger is utilized to assist finger movements during rehabilitation. Because the actuator’s bending behavior depends on the internal pressure, a Gaussian process (GP) is employed to learn the nonlinear relationship between pressure and bending angle. The unscented Kalman filter (UKF) then fuses these GP-based predictions with vision-based keypoint measurements using a red, green, blue-depth (RGBD) camera to achieve robust and low-latency angle estimation for real-time control. A lightweight detection model is developed that identifies visual keypoints on the actuator’s surface with 98% precision, from which bending angles are derived. The system achieves an average frame capture time of 18.26 ms and a processing time of 13.20 ms, resulting in a total delay of 31.46 ms per frame. Quantitative evaluation demonstrates that the proposed GP–UKF fusion achieves root-mean-square error (RMSE) values of 2.32° metacarpophalangeal (MCP) and 2.64° proximal interphalangeal (PIP), improving accuracy compared to camera-only estimation (4.24°, 4.80°) and providing comparable performance to GP-only predictions (2.61°, 1.31°) while maintaining an average uncertainty of ±2.48° within the 95% confidence interval (CI). UKF effectively reduces visual jitter, correcting keypoint shifts of up to ±5 pixels and ensuring smooth angle trajectories even under noisy or partially occluded conditions. Unlike previous fusion approaches that relied solely on deterministic estimates, the proposed GP–UKF framework explicitly incorporates and propagates uncertainty from the pressure–angle model that enables reliable and interpretable real-time estimation for soft actuators under occlusion. Experimental validation on a soft actuator designed for rehabilitation demonstrates that the proposed GP–UKF fusion framework enables stable and reliable real-time angle estimation using only a camera and without requiring additional hardware sensors. The proposed system offers strong potential for adaptive, safe, and patient-tailored rehabilitation systems.","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"1-18"},"PeriodicalIF":1.5,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11426797","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147440671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2025 Index IEEE Open Journal of Instrumentation and Measurement","authors":"","doi":"10.1109/OJIM.2026.3660504","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3660504","url":null,"abstract":"","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"4 ","pages":"1-19"},"PeriodicalIF":1.5,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11371758","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146175701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OJIM 2025 Reviewer List","authors":"","doi":"10.1109/OJIM.2026.3654828","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3654828","url":null,"abstract":"","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"1-5"},"PeriodicalIF":1.5,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11363666","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Analysis of Electrode Configurations for Estimating Respiratory Effort From Diaphragmatic Electromyography","authors":"Gabriela M. Grońska;Elisabetta Peri;Xi Long;Sebastiaan Overeem;Johannes P. van Dijk;Massimo Mischi","doi":"10.1109/OJIM.2026.3709410","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3709410","url":null,"abstract":"Accurate estimation of respiratory effort is essential for obstructive sleep apnea (OSA) assessment. The current gold standard is esophageal pressure (Pes); however, its intrusiveness makes it unsuitable for routine use. Surface diaphragmatic electromyography (dEMG) provides a promising nonintrusive alternative, although optimal electrode placement and signal processing strategies remain unclear. This study evaluated dEMG channel configurations in data from ten OSA patients. Four electrodes were used to obtain monopolar and bipolar configurations, from which previously validated features were extracted. A random forest (RF) regression model with ten-fold nested cross-validation was employed to assess each configuration’s performance in estimating respiratory effort, using the area under the curve (AUC) of Pes as the reference. Feature-importance scores from the regression model were used to assess both the channel configurations and their individual features. Bipolar configurations outperformed monopolar ones, achieving median correlations with the reference of 0.71 and 0.62, respectively, (p < 0.05). Among the bipolar channel configurations, the anterior one (BF: L2-R2) performed best (p < 0.008). Waveform length (WL), slope sign change, and AUC achieved the highest importance score when estimating respiratory effort from dEMG. These results emphasize the relevance of appropriate dEMG channel configuration and time-domain features for supporting dEMG as a valid alternative for respiratory effort assessment.","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"4000209-4000209"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11594116","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148507866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RSconv: A Shape-Adaptive Learnable Affine Convolution Mode for Robust UAV Tracking in Infrared Scene","authors":"Dakai Sun;Qian Jiang;Wangming Lan;Shiwei Wang;Xin Jin","doi":"10.1109/OJIM.2026.3723491","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3723491","url":null,"abstract":"Using visual sensors is a common and low-cost strategy for implementing anti-uncrewed aerial vehicle (UAV) tasks. In UAV object tracking tasks, the frequent changes in flight attitude and object shape pose significant challenges for feature extraction. Traditional convolutional forms possess only translation invariance, making them sensitive to rotation and deformation, which easily affects feature extraction, common factors in UAV tracking scenarios. To address this issue, we propose RSconv (rotation-angle and scale-factor learnable convolution), a novel convolutional mechanism that endows convolution kernels with rotation and scale adaptability. In particular, RSconv performs affine convolution using learnable rotation and scale parameters that are optimized during training, enabling the kernel to adapt to local geometric variations of the target. By introducing learnable parameters s and <inline-formula> <tex-math>$theta $ </tex-math></inline-formula> into the convolution kernel, RSconv learns to adjust the kernel parameters through affine transformation (rotation and scaling) before performing convolution. This enables adaptive feature extraction for UAV targets with varying shapes. At the same time, this does not require adding any additional modules. This design allows the convolution operation to achieve enhanced robustness to rotation and scale variations, significantly improving the robustness of tracking models against UAV pose variations. Experimental results demonstrate that on the anti-UAV dataset, using our designed tracker SiamDfc, which already outperforms other trackers, and considering that trackers struggle to extract effective features in the complex anti-UAV410 dataset, our designed SiamDcn outperforms most mainstream convolutional neural network (CNN)- and Transformer-based trackers. These results validate that RSconv achieves translation, rotation, and scale invariance, thereby providing stronger tracking robustness under diverse UAV flight attitudes and target deformations. The code is publicly available at <uri>https://github.com/jinxinhuo/RSConv</uri>","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"5000410-5000410"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11655233","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148836726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analyzing Calibration Sensitivity in Markerless Tracking Systems","authors":"Vanessa Yelós Tellagorry;Ariel E. Stassi;Germán Pequera;Martín Arévalo;Carlo M. Biancardi","doi":"10.1109/OJIM.2026.3723540","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3723540","url":null,"abstract":"Motion capture (MOCAP) techniques based on markers have been used worldwide in the gait analysis field for years. Despite their accuracy, this is a costly method that needs specialized equipment and personnel. That is the reason why, nowadays, new low-cost methods such as markerless techniques based on human pose estimation (HPE) have been developed and progressively adopted for this purpose. The calibration stage in MOCAP systems is an important procedure that clearly impacts on the system performance. However, it is not fully validated how the results are affected by variations in the calibration procedures. This work proposes to evaluate two different spatial configurations of the acquisition devices modifying their height (H1, highest and H2, lowest) and different calibration procedures (intrinsics and extrinsics parameters) in a markerless system based on four smartphones iPhone SE. To evaluate the impact of intrinsics parameters, the distance between calibration pattern and camera (DPC); and the number of acquired frames (#frames) were modified. Three different calibration patterns (extrinsics calibration fitting) were evaluated to quantify the effect on markerless system performance. The final results of the trajectory of the markers were compared to the gold standard method, eight VICON Bonita cameras, data which was captured simultaneously. Comparisons were realized considering two metrics widely used in bibliography (MPJPE and PCK). The results show that H1 configuration performs slightly better than H2. Regarding extrinsic calibration, patterns that consider a volume more than a surface are better for both configurations. About the intrinsic calibration, the best performance is given by the minimum DPC with Pattern 2, with a negligible influence of #frames. Respecting PCK performance for different thresholds, the results are worse for H2 than for H1 in most of the markers. Comparing both methods, the most affected direction is the transversal while the vertical and anteroposterior show similar performances.","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"5000507-5000507"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11656823","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Evolution of Reliability Methods for Nondestructive Evaluation (NDE): From Probability of Detection (POD) Conception to Contemporary Practices","authors":"Christine Knott;Jennifer Brown;John C. Aldrin;Christine Schubert Kabban","doi":"10.1109/OJIM.2026.3731334","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3731334","url":null,"abstract":"Nondestructive evaluation (NDE) methods are powerful tools for detecting and characterizing flaws in structural components, but their reliability must be evaluated before they can be used in critical applications. For more than 50 years, probabilistic and statistical methods have been used effectively to estimate reliability by describing an NDE system’s probability of detection (POD) for flaws of realistic sizes. The POD methods used by the United States Air Force (USAF) and National Aeronautics and Space Administration (NASA), like Hit/Miss, signal-response (<inline-formula> <tex-math>$hat {a}$ </tex-math></inline-formula> versus <inline-formula> <tex-math>$a$ </tex-math></inline-formula>), and point-estimate method (PEM, a.k.a. 29/29), have evolved, alongside newer approaches like the limited sample POD (LS-POD) method and model-assisted POD (MAPOD). This article reviews the history of each POD method, describes the statistical methods currently used by the USAF and NASA, and describes when it is appropriate to use each method. Although this article focuses on the accepted methods, it also addresses the challenges and limitations of the methods, in hopes of inspiring new avenues of research for assessing the reliability of NDE systems.","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"6000417-6000417"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11682967","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149033616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Response Degradation in Low-Cost Electrochemical NH3 Sensors After Barn Exposure","authors":"Michael Kazda;Stefan Linke;Marc Frank","doi":"10.1109/OJIM.2026.3736146","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3736146","url":null,"abstract":"Low-cost electrochemical ammonia (NH3) sensors are increasingly considered for emission monitoring in naturally ventilated livestock buildings, where their low cost enables spatially distributed measurements. While sensor accuracy and long-term stability have been widely investigated, comparatively little is known about how cumulative field exposure affects dynamic response under practical conditions. This study examined the relationship between cumulative NH3 field exposure and sensor response time using two independent field campaigns followed by standardized 0–10-ppm NH3 laboratory step-response measurements with a Fourier transform infrared spectrometer (FTIR) as a reference. In the second campaign, the same sensors were characterized before and after deployment to reduce the influence of initial sensor-to-sensor variability. An exploratory single co-location case study further assessed whether the laboratory-observed degradation was reflected under practical operating conditions. Both laboratory campaigns showed increasing <inline-formula> <tex-math>$T_{50}$ </tex-math></inline-formula> response times with increasing cumulative exposure, with highly exposed sensors reaching response times in the minute range. The field comparison indicated increasing attenuation of rapid concentration changes by the low-cost sensor relative to an industrial-grade comparison system, whereas slower variations were represented more similarly. These results show that cumulative field exposure is associated with degradation of the dynamic response of low-cost electrochemical NH3 sensors. Dynamic response should therefore be evaluated alongside accuracy and long-term stability when assessing such sensors for emission measurements in naturally ventilated livestock buildings.","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"9500209-9500209"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11704691","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature Compensation in Loop and Patch FSS Strain Sensors: Analysis and Experimental Validation","authors":"Swathi Muthyala Ramesh;Kristen M. Donnell","doi":"10.1109/OJIM.2025.3650259","DOIUrl":"https://doi.org/10.1109/OJIM.2025.3650259","url":null,"abstract":"Frequency selective surfaces (FSSs) are arrays of conductive elements or apertures that exhibit frequency-dependent reflection and transmission properties. Their electromagnetic response is influenced by geometry and environmental conditions, making them attractive for wireless strain-sensing applications. However, temperature variations can produce frequency shifts similar to those caused by strain, reducing measurement accuracy. This work investigates the effects of intrinsic temperature compensation on two common FSS unit cell geometries—loop and patch—through comprehensive simulation analysis. The results show that loop-based cells offer superior thermal stability, while patch-based cells provide greater strain sensitivity, illustrating the tradeoff between thermal robustness and mechanical responsiveness. A patch-type FSS strain sensor was designed, fabricated, and characterized under varying temperature and strain. The sensor achieves a strain sensitivity of ~150 MHz per 1%<inline-formula> <tex-math>${varepsilon }_{l}$ </tex-math></inline-formula>, while temperature-induced drift is limited to ~12 MHz over a 200°C range, confirming the effectiveness of the intrinsic compensation strategy. The results provide valuable insights for optimizing FSS-based sensor design in structural health monitoring applications and balancing thermal stability with mechanical sensitivity to ensure reliable performance in thermally dynamic environments.","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"1-13"},"PeriodicalIF":1.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11321304","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AI-Driven Measurements: Opportunities, Uncertainties, and Sustainable Future Perspectives","authors":"Leopoldo Angrisani","doi":"10.1109/OJIM.2026.3709385","DOIUrl":"https://doi.org/10.1109/OJIM.2026.3709385","url":null,"abstract":"Artificial intelligence (AI) is increasingly adopted to support measurement processes in cases where conventional methodologies are unavailable, impractical, or inadequate for the intended application. However, the use of AI in measurements raises several fundamental issues. Among these, first, AI-based inference cannot be regarded as part of a measurement process unless it is formulated within a rigorous metrological framework, so that its results can be considered metrologically trustworthy. In this respect, the conceptual framework established by the Joint Committee for Guides in Metrology (JCGM) represents a key enabling element: it provides the principles needed to interpret AI-driven data processing not merely as a prediction tool, but as part of a measurement process aimed at estimating a measurand under defined conditions and with associated uncertainty. Second, the development and deployment of AI within measurement processes require computational resources that translate into energy consumption and associated emissions, making environmental sustainability a potentially relevant concern in the design of measuring systems. This article offers a positioning perspective on these issues, arguing that the central question is not the use of AI in measurements as such, but the conditions under which it can be incorporated into a measurement process in a rigorous, trustworthy, and sustainable manner. In this respect, the JCGM framework provides the conceptual basis for interpreting AI-driven inference as part of a measurement process directed to the estimation of a defined measurand with associated uncertainty, while also supporting a more structured assessment of the tradeoffs between metrological performance and environmental sustainability.","PeriodicalId":100630,"journal":{"name":"IEEE Open Journal of Instrumentation and Measurement","volume":"5 ","pages":"2500204-2500204"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11594108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148508036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}