- 标题
- 摘要
- 关键词
- 实验方案
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Stereo vision system for human motion analysis in a rehabilitation context
摘要： The present demographic trends point to an increase in aged population and chronic diseases which symptoms can be alleviated through rehabilitation. The applicability of passive 3D reconstruction for motion tracking in a rehabilitation context was explored using a stereo camera. The camera was used to acquire depth and color information from which the 3D position of prede?ned joints was recovered based on: kinematic relationships, anthropometrically feasible lengths and temporal consistency. Finally, a set of quantitative measures were extracted to evaluate the performed rehabilitation exercises. Validation study using data provided by a marker based as ground-truth revealed that our proposal achieved errors within the range of state-of-the-art active markerless systems and visual evaluations done by physical therapists. The obtained results are promising and demonstrate that the developed methodology allows the analysis of human motion for a rehabilitation purpose.
关键词： stereo vision,biomedical engineering,Rehabilitation,human motion tracking
更新于2025-09-23 15:21:21
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A Fully Integrated 11.2 mm2 a-IGZO EMG Front-end Circuit on Flexible Substrate Achieving up to 41dB SNR and 29MΩ Input Impedance
摘要： A biopotential front-end circuit is designed and fabricated using a-IGZO TFTs on flexible plastic substrate. Its input chopper provides both noise reduction and Frequency Division Multiplexing among multiple front-ends in an array. Measurements of the front-end at chopping frequencies from 5 to 8 kHz show a gain in the range of 24.9 - 23.1 dB, bandwidth of 5.4 to 5.2 kHz, input noise in the EMG band ranging from 125 μVRM S to 31.4 μVRM S, and an input impedance of 29.6 to 23 M ?. At different chopping frequencies, the SNR in the EMG band is respectively 29, 32.3, 38, 41 dB, enough to monitor Muscle Fibre Conduction velocity. This is achieved in a total area of 11.2 mm2 and with 1.3 mW power consumption. In-vivo recordings of EMG from the forearm of a person using the fabricated front-end and standard gel electrodes have been performed. The measurements show EMG bursts with a maximum amplitude of 1.6 mV, which is within the physiological range for this muscle. The proposed circuit achieves an 8.9X reduction in size compared to previous front-ends fabricated on flexible foil for EMG applications, enabling a spatial resolution in the order of a few millimetres, with great benefit for the diagnosis of neuromuscular disorders.
关键词： IGZO,EMG,flexible electronics,Biomedical circuits,EHG
更新于2025-09-23 15:21:21
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Eco-friendly highly sensitive transducers based on a new KNN-NTK-FM lead-free piezoelectric ceramic for high-frequency biomedical ultrasonic imaging applications
摘要： High-frequency ultrasonic imaging with improved spatial resolution has gained increasing attention in the field of biomedical imaging. Sensitivity of transducers plays a pivotal role in determining ultrasonic image quality. Conventional ultrasonic transducers are mostly made from lead-based piezoelectric materials that may be harmful to the human body and the environment. In this study, a new (K,Na)NbO3-KTiNbO5-BaZrO3-Fe2O3-MgO (KNN-NTK-FM) lead-free piezoelectric ceramic was utilized in developing eco-friendly transducers for high-frequency biomedical ultrasonic imaging applications. A needle transducer with a small active aperture size of 0.45 × 0.55 mm2 was designed and evaluated. The transducer exhibits great performance with a high center frequency (52.6 MHz), a good electromechanical coupling (keff ~ 0.45), a large bandwidth (64.4% at -6 dB), and a very low two-way insertion loss (10.1 dB). Such high sensitivity is superior to those transducers based on other lead-free piezoelectric materials and can even be comparable to the lead-based ones. Imaging performance of the KNN-NTK-FM needle transducer was analyzed by imaging a wire phantom and an agar tissue-mimicking phantom. Imaging capabilities of the transducer were further demonstrated by ex vivo imaging studies on a porcine eyeball and a rabbit aorta. The results suggest that the KNN-NTK-FM piezoceramic has many attractive properties over other lead-free piezoelectric materials in developing eco-friendly highly sensitive transducers for high-frequency biomedical ultrasonic imaging applications.
关键词： lead-free piezoelectric ceramic,Biomedical ultrasonic imaging,high-frequency ultrasonic transducer,eco-friendly
更新于2025-09-23 15:21:21
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Colloidal CdSe Nanocrystals as a Material for Optoelectronics and Biomedical Imaging
摘要： Cadmium selenide nanocrystals were prepared in water phase chemistry technique with gelatin, polivinil alcohol, lactose, triton-100 acting as capping agent. Structures were characterized using scanning electron microscopy (SEM), visible absorption and photoluminescence spectroscopies. Influence of component concentrations and technological parameters on nanocrystals average size and properties was studied
关键词： photoluminescence,optical,selenide,optoelectronics,biomedical imaging,cadmium,nanocrystals,absorption
更新于2025-09-23 15:21:21
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High-contrast, fast chemical imaging by coherent Raman scattering using a self-synchronized two-colour fibre laser
摘要： Coherent Raman scattering (CRS) microscopy is widely recognized as a powerful tool for tackling biomedical problems based on its chemically specific label-free contrast, high spatial and spectral resolution, and high sensitivity. However, the clinical translation of CRS imaging technologies has long been hindered by traditional solid-state lasers with environmentally sensitive operations and large footprints. Ultrafast fibre lasers can potentially overcome these shortcomings but have not yet been fully exploited for CRS imaging, as previous implementations have suffered from high intensity noise, a narrow tuning range and low power, resulting in low image qualities and slow imaging speeds. Here, we present a novel high-power self-synchronized two-colour pulsed fibre laser that achieves excellent performance in terms of intensity stability (improved by 50 dB), timing jitter (24.3 fs), average power fluctuation (<0.5%), modulation depth (>20 dB) and pulse width variation (<1.8%) over an extended wavenumber range (2700–3550 cm?1). The versatility of the laser source enables, for the first time, high-contrast, fast CRS imaging without complicated noise reduction via balanced detection schemes. These capabilities are demonstrated in this work by imaging a wide range of species such as living human cells and mouse arterial tissues and performing multimodal nonlinear imaging of mouse tail, kidney and brain tissue sections by utilizing second-harmonic generation and two-photon excited fluorescence, which provides multiple optical contrast mechanisms simultaneously and maximizes the gathered information content for biological visualization and medical diagnosis. This work also establishes a general scenario for remodelling existing lasers into synchronized two-colour lasers and thus promotes a wider popularization and application of CRS imaging technologies.
关键词： Coherent Raman scattering,CRS microscopy,biomedical imaging,fibre laser,nonlinear optical imaging
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 19th International Conference on Nanotechnology (IEEE-NANO) - Macao (2019.7.22-2019.7.26)] 2019 IEEE 19th International Conference on Nanotechnology (IEEE-NANO) - Fiber-optic laser-ultrasound transducer using carbon nanoparticles for intravascular sonothrombolysis
摘要： This paper relates to a genuine wrist pulse oximeter, which is a noninvasive medical device that can measure the pulse rate and oxygen saturation level in a person’s blood. The device is novel due to its innovative design. It is a new type of re?ective oximeter, which has a concave structure for housing the optical source and sensor. The neo-re?ective sensor module of the device is designed to send the sensor data to a nearby intelligent mobile phone using wireless data transmission. The pulse oximeter has been developed and calibrated, and the calibration curve was analyzed. The innovative design of this pulse oximeter would enable the user to wear the low-cost device on one wrist continuously throughout the day, without the inconvenience of a conventional ?nger pulse oximeter.
关键词： wrist oximeter,Biomedical sensor,blood oxygen saturation,re?ective oximetry,pulse oximetry
更新于2025-09-23 15:21:01
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Anti-Biofouling Properties of Femtosecond Laser-Induced Submicron Topographies on Elastomeric Surfaces
摘要： Anti-bacterial coatings are often employed to elastomer surfaces to inhibit bacterial attachment. However, such approaches could lead to increased antibiotic resistance. Surface micro/nano texturing is gaining significant attention recently, as it is a passive approach to reduce bacterial adhesion to surfaces. To this end, this work aims to assess the anti-biofouling functionality of femtosecond laser-induced sub-micron topographies on biomedical elastomer surfaces. Femtosecond laser processing was employed to produce two types of topographies on stainless steel substrates. The first one was highly regular and single scale sub-micron laser-induced periodic surface structures (LIPSS) while the second one was multi-scale structures (MS) containing both sub-micron and micron-scale features. Subsequently, these topographies were replicated on Polydimethylsiloxane (PDMS) and Polyurethane (PU) elastomers to evaluate their bacterial retention characteristics. The sub-micron textured PDMS and PU surfaces exhibited long term hydrophobic durability up to 100 hours under the immersed conditions. Both LIPSS and MS topographies on PDMS and PU elastomeric surfaces were shown to substantially reduce (> 89%) the adhesion of gram-negative Escherichia coli bacteria. At the same time, the anti-biofouling performance of LIPSS and MS topographies was found to be comparable with that of lubricant-impregnated surfaces. The influence of physical defects on textured surfaces on the adhesion behaviour of bacteria was also elucidated. The results presented here are significant because the polymeric biomedical components that can be produced by replication cost-effectively, while their biocompatibility can be improved through femtosecond surface modification of the respective replication masters.
关键词： anti-biofouling,polyurethane,biomedical elastomers,PDMS,femtosecond,lubricant-impregnated surfaces,laser induced periodic surface structures
更新于2025-09-23 15:21:01
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Low-Power Optical Sensor for Traffic Detection
摘要： 4-D-computed tomography (4DCT) provides not only a new dimension of patient-specific information for radiation therapy planning and treatment, but also a challenging scale of data volume to process and analyze. Manual analysis using existing 3-D tools is unable to keep up with vastly increased 4-D data volume, automated processing and analysis are thus needed to process 4DCT data effectively and efficiently. In this paper, we applied ideas and algorithms from image/signal processing, computer vision, and machine learning to 4DCT lung data so that lungs can be reliably segmented in a fully automated manner, lung features can be visualized and measured on the fly via user interactions, and data quality classifications can be computed in a robust manner. Comparisons of our results with an established treatment planning system and calculation by experts demonstrated negligible discrepancies (within ±2%) for volume assessment but one to two orders of magnitude performance enhancement. An empirical Fourier-analysis-based quality measure-delivered performances closely emulating human experts. Three machine learners are inspected to justify the viability of machine learning techniques used to robustly identify data quality of 4DCT images in the scalable manner. The resultant system provides a toolkit that speeds up 4-D tasks in the clinic and facilitates clinical research to improve current clinical practice.
关键词： classification algorithms,machine learning algorithms,image analysis,Biomedical image processing,data visualization,computed tomography,morphological operations
更新于2025-09-23 15:21:01
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Quantum entangled photon emitting diodes based on GaAs quantum dots on (111)A: Robustness against increasing temperature
摘要： This paper relates to a genuine wrist pulse oximeter, which is a noninvasive medical device that can measure the pulse rate and oxygen saturation level in a person’s blood. The device is novel due to its innovative design. It is a new type of re?ective oximeter, which has a concave structure for housing the optical source and sensor. The neo-re?ective sensor module of the device is designed to send the sensor data to a nearby intelligent mobile phone using wireless data transmission. The pulse oximeter has been developed and calibrated, and the calibration curve was analyzed. The innovative design of this pulse oximeter would enable the user to wear the low-cost device on one wrist continuously throughout the day, without the inconvenience of a conventional ?nger pulse oximeter.
关键词： blood oxygen saturation,re?ective oximetry,wrist oximeter,Biomedical sensor,pulse oximetry
更新于2025-09-23 15:21:01
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Highly Linear and Stable Flexible Temperature Sensors Based on Lasera??Induced Carbonization of Polyimide Substrates for Personal Mobile Monitoring
摘要： Wearable on-skin electronic devices that can monitor temperature in real time are of significant interest for personalized mobile health monitoring. Here, a flexible temperature sensor directly patterned by laser-induced carbonization on Kapton polyimide films integrated with flexible printed circuit boards is reported. The proposed sensor design possessing high resistance values exhibits high-linear and stable response to temperatures when integrated with flexible printed circuit boards (FPCBs) to enable continuous monitoring. The anisotropic conductive film bonding technique is used to obtain the stable real-time monitoring data under various complex environments. The sensor integration with a wearable patch based FPCB establishes conformal contacts with human skin and allows wireless sensing capabilities smoothly in real time. This kind of approach can enable multifunctional sensors to be directly laser patterned on FPCBs without any additional interfacing.
关键词： real-time monitoring,FPCB,laser-induced carbonization,temperature sensors,biomedical devices
更新于2025-09-23 15:21:01