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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - Simulation of Photoacoustic Imaging of Red Blood Cell Aggregation Using a Numerical Model of Pulsatile Blood Flow
摘要： Photocatalytic imaging of blood flow using a pulsed laser diode of semiconductor blood flow aggregation and oxygenation saturation (sO2) estimation. During blood flow aggregation, the oxygen saturation of the blood flow is affected by the interaction between red blood cell (RBC) aggregation and the oxygen saturation (sO2) [1-7]. The mechanism of the aggregation is not yet fully understood. To date, two models, namely the bridging and depletion models, are proposed for explaining the kinetics of RBC aggregation [20-21]. Using the proposed models, new efforts have been published to investigate the kinetics of RBC aggregation [22-24]. In this paper, a simple particle motion model in two-dimensional (2D) space was introduced to understand the photothermal imaging of blood flow aggregation from the flow model. The flow model consisted of 125 elements spaced at 10 μm center-to-center, yielding a lateral length of 22.0 mm. The incident laser fluence was less than 10 mJ/cm2, below the safety limit by the American National Standards Institute (ANSI) for these wavelengths. The photothermal power (PTP) was computed from the flow model at each time step, and the simulated PTP was compared to the measured PTP in vivo. From the comparison, the kinetics of RBC aggregation was studied.
关键词： blood flow,aggregation,photocatalytic imaging,photothermal power,kinetics,red blood cell,oxygenation saturation
更新于2025-09-23 15:23:52
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Head-to-head comparison of the diagnostic performances of Rubidium-PET and SPECT with CZT camera for the detection of myocardial ischemia in a population of women and overweight individuals
摘要： Background. The aim of this study was to compare the diagnostic performances for the detection of myocardial ischemia of 82-Rb-PET-MPS and 99m-Tc-SPECT-MPS in overweight individuals and women. Methods and Results. Men with BMI ≥ 25 and women referred for MPS were considered for inclusion. All individuals underwent 99m-Tc-SPECT-MPS with CZT cameras and 82-Rb-PET-MPS in 3D-mode. Individuals with at least one positive MPS were referred for coronary angiography (CA) with FFR measurements. A criterion for positivity was a composite endpoint including significant stenosis on CA or, in the absence of CA, the occurrence of acute coronary event during the following year. 313 patients (46% women) with mean BMI of 31.8 ± 6.5 were included. Sensitivity for the detection of myocardial ischemia was higher with 82-Rb-PET-MPS compared with 99m-Tc-SPECT-MPS (85% vs. 57%, P < .05); specificity was equally high with both imaging techniques (93% vs. 94%, P > .05). 82-Rb-PET allowed for a more accurate detection of patients with a high-risk coronary artery disease (HR-CAD) than 99m-Tc-SPECT-MPS (AUC = 0.86 vs. 0.75, respectively; P = .04). Conclusions. In women and overweight individuals, 82-Rb-PET-MPS provides higher sensitivity for the detection of myocardial ischemia than 99m-Tc-SPECT-MPS thanks to a better image quality and an improved detection of HR-CAD.
关键词： CZT camera,MPI,Diagnostic and prognostic application,PET,Myocardial blood flow,SPECT,82-Rubidium,CAD
更新于2025-09-23 15:23:52
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A new self-made digital slide scanner and microscope for imaging and quantification of fluorescent microspheres
摘要： Objective: A low-cost microscope slide scanner was constructed for the purpose of digital imaging of newborn piglet brain tissue and to quantify fluorescent microspheres in tissue. Methods: Using a standard digital single-lens reflex (DSLR) camera, fluorescent imaging of newborn piglet brain tissue was performed. A computer algorithm available for download was created to detect fluorescent microspheres in the brain tissue slides and to calculate regional cerebral blood flow (rCBF). The precision of the algorithm was tested by comparing with manual counting of the fluorescent microspheres. Finally, bright-field imaging was tested by adding light diffuser film. Results: Cost of the slide scanner was a fraction of the cost of a commercial slide scanner. The slide scanner was able to image a large number of tissue slides in a semiautomatic manner and provided a large field of view (FOV) of 101 mm2 combined with a resolution of 2.9 μm. The mean difference (SD) between manual and automatic counts was in absolute numbers 0.32 (1.5) microspheres ranging from -5 to 5 microspheres per slide. The relative total difference between automatic and manual counts was -3.1%. Conclusions: A slide scanner was constructed and an automatic algorithm to detect fluorescent microspheres in tissue was developed and validated and showed an acceptable difference to “gold standard” manual counting. The slide scanner can be regarded as a low-cost alternative for researchers when digital slide imaging and quantification of fluorescent microspheres are needed.
关键词： Slide scanner,Fluorescence,Bright-field,Microspheres,Microscopy,Cerebral blood flow
更新于2025-09-23 15:23:52
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Ocular blood flow by laser speckle flowgraphy to detect cerebral ischemia during carotid endarterectomy
摘要： Laser speckle flowgraphy (LSFG) is a noninvasive technique that can measure relative blood flow velocity in the optic fundus contributed by the ophthalmic artery, the main first branch originating from the internal carotid artery (ICA). The aim of this study was to assess the feasibility of ocular blood flow measurement by LSFG to detect ischemic stress due to carotid clamping during carotid endarterectomy (CEA). Nineteen patients undergoing CEA with ocular blood flow measurement by LSFG and intraoperative monitoring (IOM) were prospectively enrolled between August 2016 and March 2019. The mean blur rate (MBR) of ocular blood flow by LSFG, representing relative blood flow of the branch of the retinal artery originating from the optic nerve head, was compared between before and after carotid clamping during CEA. The correlation between the reduction ratio of MBR and the regional saturation oxygen (rSO2) index by near infrared spectroscopy was investigated. Ocular blood flow measurement by LSFG could not be performed in one patient with a severe cataract. In the other 18 patients, LSFG could be performed in all 106 sessions during surgery. The MBR reduction ratio between before and after carotid clamping ranged from ? 12 to 100%. The MBR reduction ratio was positively correlated with the rSO2 index (r = 0.694, 95% confidence interval: 0.336–0.877, p = 0.001). The MBR reduction ratio of ocular blood flow by LSFG after carotid clamping was significantly correlated with the rSO2 index. The ocular blood flow by LSFG could be considered an adjunct modality for evaluating cerebral ischemic tolerance during CEA.
关键词： Ocular blood flow,Laser speckle flowgraphy,Cerebral blood flow,Carotid endarterectomy
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 21st Electronics Packaging Technology Conference (EPTC) - Singapore, Singapore (2019.12.4-2019.12.6)] 2019 IEEE 21st Electronics Packaging Technology Conference (EPTC) - A Process Study of Laser Patterning of Different Conductive Layers for Printed Electronics
摘要： Stress-induced psychological and somatic diseases are virtually endemic nowadays. Written self-report anxiety measures are available; however, these indices tend to be time consuming to acquire. For medical patients, completing written reports can be burdensome if they are weak, in pain, or in acute anxiety states. Consequently, simple and fast non-invasive methods for assessing stress response from neurophysiological data are essential. In this paper, we report on a study that makes predictions of the state-trait anxiety inventory (STAI) index from oxyhemoglobin and deoxyhemoglobin concentration changes of the prefrontal cortex using a two-channel portable near-infrared spectroscopy device. Predictions are achieved by constructing machine learning algorithms within a Bayesian framework with nonlinear basis function together with Markov Chain Monte Carlo implementation. In this paper, prediction experiments were performed against four different data sets, i.e., two comprising young subjects, and the remaining two comprising elderly subjects. The number of subjects in each data set varied between 17 and 20 and each subject participated only once. They were not asked to perform any task; instead, they were at rest. The root mean square errors for the four groups were 6.20, 6.62, 4.50, and 6.38, respectively. There appeared to be no significant distinctions of prediction accuracies between age groups and since the STAI are defined between 20 and 80, the predictions appeared reasonably accurate. The results indicate potential applications to practical situations such as stress management and medical practice.
关键词： blood oxygenation,prevention medicine,Anxiety index,neuronal activity,regional cerebral blood flow,translational engineering,near infrared spectroscopy,health and safety,prediction methods,oxyhemoglobin
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE International Electron Devices Meeting (IEDM) - San Francisco, CA, USA (2019.12.7-2019.12.11)] 2019 IEEE International Electron Devices Meeting (IEDM) - Silicon nitride waveguide coupled 67+ GHz Ge photodiode for non-SOI PIC and ePIC platforms
摘要： As a major application domain of vascular ultrasound, the carotid artery has long been the subject of anthropomorphic phantom design. It is nevertheless not trivial to develop walled carotid phantoms that are compatible for use in integrative imaging of carotid wall motion and flow dynamics. In this paper, we present a novel phantom design protocol that can enable efficient fabrication of walled carotid bifurcation phantoms with: 1) high acoustic compatibility; 2) artery-like vessel elasticity; and 3) stenotic narrowing feature. Our protocol first involved direct fabrication of the vessel core and an outer mold using computer-aided design tools and 3-D printing technology; these built parts were then used to construct an elastic vessel tube through investment casting of a polyvinyl alcohol containing mixture, and an agar-gelatin tissue mimicking slab was formed around the vessel tube. For demonstration, we applied our protocol to develop a set of healthy and stenosed (25%, 50%, and 75%) carotid bifurcation phantoms. Plane wave imaging experiments were performed on these phantoms using an ultrasound scanner with channel-level configurability. Results show that the wall motion dynamics of our phantoms agreed with pulse wave propagation in an elastic vessel (pulse wave velocity of 4.67 ± 0.71 m/s measured at the common carotid artery), and their flow dynamics matched the expected ones in healthy and stenosed bifurcation (recirculation and flow jet formation observed). Integrative imaging of vessel wall motion and blood flow dynamics in our phantoms was also demonstrated, from which we observed fluid-structure interaction differences between healthy and diseased bifurcation phantoms. These findings show that the walled bifurcation phantoms developed with our new protocol are useful in vascular imaging studies that individually or jointly assess wall motion and flow dynamics.
关键词： carotid bifurcation phantom,vessel wall motion,integrative imaging,Blood flow dynamics
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE Eurasia Conference on IOT, Communication and Engineering (ECICE) - Yunlin, Taiwan (2019.10.3-2019.10.6)] 2019 IEEE Eurasia Conference on IOT, Communication and Engineering (ECICE) - Mobile Phone Audio Combined with Self-Made Laser Light Transmission Frequency Wireless Actuated Electromagnetic Lock
摘要： Caloric vestibular stimulation (CVS) to elicit the vestibulo-ocular reflex has long been used in clinical settings to aid in the diagnosis of balance disorders and to confirm the absence of brainstem function. While a number of studies have hinted at the potential therapeutic applications of CVS, the limitations of existing devices have frustrated that potential. Current CVS irrigators use water or air during short-duration applications; however, this approach is not tenable for longer duration therapeutic protocols or home use. Here, we describe a solid-state CVS device we developed in order to address these limitations. This device delivers tightly controlled time-varying thermal waveforms, which can be programmed through an external control unit. It contains several safety features, which limit patients to the prescribed waveform and prevent the potential for temperature extremes. In this paper, we provide evidence that CVS treatment with time-varying, but not constant temperature waveforms, elicits changes in cerebral blood flow physiology consistent with the neuromodulation of brainstem centers, and we present results from a small pilot study, which demonstrate that the CVS can safely and feasibly be used longitudinally in the home setting to treat episodic migraine. Together, these results indicate that this solid-state CVS device may be a viable tool for non-invasive neuromodulation.
关键词： Caloric vestibular stimulation,brainstem,migraine,cerebral blood flow,neuromodulation
更新于2025-09-19 17:13:59
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Adjunctive effects of laser therapy on somatosensory function and vasomotor regulation of periodontal tissues in patients with periodontitisa?? A randomized controlled clinical trial
摘要： Background: The purpose of this prospective study was to compare the changes in periodontal somatosensory function and microcirculation in patients with periodontitis following initial treatment with scaling and root planing (SRP) with or without adjuvant laser therapy. Methods: Twenty-four patients suffering from periodontitis were recruited and randomly allocated into a split-mouth design to either SRP combined laser therapy side (test side) or SRP only side (control side). All treatments were performed by the same investigator at a single visit. Laser Doppler Flowmetry (LDF) and Quantitative Sensory Testing (QST) were performed at baseline (W0), 1 week (1W), 2 weeks (2W), and 4 weeks (4W) after treatment on both sides of the attached gingiva of the maxillary lateral incisor. Clinical examination including pocket probing depth (PPD) and bleeding on probing (BOP) was performed at W0, 2W, and 4W on both sides. Data were analyzed with two-way analysis of variance (ANOVA). Results: The PPD and BOP significantly improved after treatment (P <0.001). The LDF values were significantly decreased on both sides at all follow-up time points (P <0.001), temperature was increased only on the test side (P =0.017) whereas there was no significant change on the control side (P=0.792). Significantly less sensitivity was observed for all QST parameters (P <0.030) except for warmth detection after treatment. Conclusion: Adjunctive use of laser therapy did not provide any significant clinically advantage or additional effects on the recovery of periodontal somatosensory function or gingival microcirculation in the present study.
关键词： Quantitative sensory testing,periodontal somatosensory function,inflammation,Nd:YAG laser,blood flow
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Transparent WO <sub/>x</sub> window layers for silicon based heterojunction solar cells
摘要： As a major application domain of vascular ultrasound, the carotid artery has long been the subject of anthropomorphic phantom design. It is nevertheless not trivial to develop walled carotid phantoms that are compatible for use in integrative imaging of carotid wall motion and flow dynamics. In this paper, we present a novel phantom design protocol that can enable efficient fabrication of walled carotid bifurcation phantoms with: 1) high acoustic compatibility; 2) artery-like vessel elasticity; and 3) stenotic narrowing feature. Our protocol first involved direct fabrication of the vessel core and an outer mold using computer-aided design tools and 3-D printing technology; these built parts were then used to construct an elastic vessel tube through investment casting of a polyvinyl alcohol containing mixture, and an agar-gelatin tissue mimicking slab was formed around the vessel tube. For demonstration, we applied our protocol to develop a set of healthy and stenosed (25%, 50%, and 75%) carotid bifurcation phantoms. Plane wave imaging experiments were performed on these phantoms using an ultrasound scanner with channel-level configurability. Results show that the wall motion dynamics of our phantoms agreed with pulse wave propagation in an elastic vessel (pulse wave velocity of 4.67 ± 0.71 m/s measured at the common carotid artery), and their flow dynamics matched the expected ones in healthy and stenosed bifurcation (recirculation and flow jet formation observed). Integrative imaging of vessel wall motion and blood flow dynamics in our phantoms was also demonstrated, from which we observed fluid-structure interaction differences between healthy and diseased bifurcation phantoms. These findings show that the walled bifurcation phantoms developed with our new protocol are useful in vascular imaging studies that individually or jointly assess wall motion and flow dynamics.
关键词： carotid bifurcation phantom,vessel wall motion,integrative imaging,Blood flow dynamics
更新于2025-09-19 17:13:59
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Dilated residual learning with skip connections for real-time denoising of laser speckle imaging of blood flow in a log-transformed domain
摘要： Laser speckle contrast imaging (LSCI) is a wide-field and noncontact imaging technology for mapping blood flow. Although the denoising method based on block-matching and filtering three-dimensional (BM3D) was proposed to improve its signal-to-noise ratio (SNR) significantly, the processing time makes it difficult to realize real-time denoising. Furthermore, it is still difficult to obtain an acceptable level of SNR with a few raw speckle images given the presence of significant noise and artifacts. A feed-forward denoising convolutional neural network (DnCNN) achieves state-of-the-art performance in denoising nature images and is efficiently accelerated by GPU. However, it performs poorly in learning with original speckle contrast images of LSCI owing to the inhomogeneous noise distribution. Therefore, we propose training DnCNN for LSCI in a log-transformed domain to improve training accuracy and it achieves an improvement of 5.13 dB in the peak signal-to-noise ratio (PSNR). To decrease the inference time and improve denoising performance, we further propose a dilated deep residual learning network with skip connections (DRSNet). The image-quality evaluations of DRSNet with five raw speckle images outperform that of spatially average denoising with 20 raw speckle images. DRSNet takes 35 ms (i.e., 28 frames per second) for denoising a blood flow image with 486 × 648 pixels on an NVIDIA 1070 GPU, which is approximately 2.5 times faster than DnCNN. In the test sets, DRSNet also improves 0.15 dB in the PSNR than that of DnCNN. The proposed network shows good potential in real-time monitoring of blood flow for biomedical applications.
关键词： Blood flow,convolutional neural network (CNN),laser speckle contrast imaging (LSCI),dilated convolution,skip connection
更新于2025-09-16 10:30:52