Transducers

传感器
  • 文章类型: Journal Article
    随着时间的推移,颅骨超声的质量有所改善,随着先进的技术导致更高的分辨率,更快的图像处理,数字显示,和备份。然而,一些脑部病变可能仍然难以表征:因为更高的频率导致更大的空间分辨率,另外的换能器的使用可以克服这些限制中的一些。甚高频换能器(18-5MHz)目前用于小部件和肺部超声。在这里,我们报告了第一个病例系列,比较了早产儿颅骨超声的极高频探头(18-5MHz)和标准微凸探头(8-5MHz)。在这个系列中,我们在13例妊娠≤32周的早产儿(9例脑部异常,4例正常)中,比较了使用微凸换能器(8~5MHz)和使用甚高频(18~5MHz)线性阵列换能器获得的头颅超声图像.同时使用甚高频线性换能器和标准中频微凸换能器进行超声检查。我们还将超声检查结果与足月矫正年龄时获得的脑MRI图像进行了比较。使用非常高频(18-5MHz)换能器获得的超声图像显示出高质量和准确性。值得注意的是,尽管它们的频率更高,而且预期的渗透能力有限,早产儿的大脑大小足够小,所以大脑结构靠近传感器,允许完整的评估。结论:我们建议在妊娠≤32周的早产儿中,常规使用极高频线性探头作为颅骨超声的补充扫描方式。什么是已知的:•早产儿的脑部病变可能通过常规的颅骨超声扫描保持不充分定义。•更高频率的探头提供更好的空间分辨率,但具有较窄的勘探范围和有限的穿透能力。新增内容:•在妊娠≤32周的婴儿中,将非常高频的探头与标准的中频探头进行了比较。•由于早产儿的头骨尺寸较小,新的甚高频传感器允许一个完整和准确的评估。
    The quality of cranial ultrasound has improved over time, with advancing technology leading to higher resolution, faster image processing, digital display, and back-up. However, some brain lesions may remain difficult to characterize: since higher frequencies result in greater spatial resolution, the use of additional transducers may overcome some of these limitations. The very high-frequency transducers (18-5 MHz) are currently employed for small parts and lung ultrasound. Here we report the first case series comparing the very high-frequency probes (18-5 MHz) with standard micro-convex probes (8-5 MHz) for cranial ultrasound in preterm infants. In this case series, we compared cranial ultrasound images obtained with a micro-convex transducer (8-5 MHz) and those obtained with a very high-frequency (18-5 MHz) linear array transducer in 13 preterm infants ≤ 32 weeks gestation (9 with cerebral abnormalities and 4 with normal findings). Ultrasound examinations using the very high-frequency linear transducer and the standard medium-frequency micro-convex transducer were performed simultaneously. We also compared ultrasound findings with brain MRI images obtained at term corrected age. Ultrasound images obtained with the very high-frequency (18-5 MHz) transducer showed high quality and accuracy. Notably, despite their higher frequency and expected limited penetration capacity, brain size is small enough in preterm infants, so that brain structures are close to the transducer, allowing for complete evaluation.    Conclusion: We propose the routine use of very high-frequency linear probes as a complementary scanning modality for cranial ultrasound in preterm infants ≤ 32 weeks gestation. What is Known: • Brain lesions in preterm infants may remain insufficiently defined through conventional cranial ultrasound scan. • Higher frequency probes  offer better spatial resolution but have a narrower filed of exploration and limited penetration capacity. What is New: • Very high-frequency probes were compared with standard medium-frequency probes for cranial ultrasound in infants  ≤ 32 weeks\' gestation. • Thanks to the smaller skull size of preterm infants, the new very high-frequency transducers allowed a complete and accurate evaluation.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Case Reports
    2019年新型冠状病毒(COVID-19)的传播引起了全球大流行。疾病迅速蔓延,研究表明,COVID-19可以诱发长期的心脏损伤。COVID-19可导致指示急性心脏损伤的心脏生物标志物升高,利用超声心动图的研究表明,这些患者也有机械功能障碍,尤其是在观察等容时,收缩压,和心脏周期的舒张部分。这项研究的目的是提供两个关于COVID-19阳性患者的案例研究,这些患者在急性期每天都进行心脏机械功能评估,以表明这些患者的心脏功能发生了改变,发生的损害可能每天都在变化。参与者1在收缩期显示心功能受损,舒张时间,等容时间,和计算的心脏性能指标(HPI),这些损伤甚至在症状发作后23天仍持续。此外,参与者1显示收缩期延长,持续时间长于舒张期,提示肺动脉压升高。参与者2显示收缩期减少,因此,HPI在症状发作后3天内增加,这些变化在第4天后恢复正常。这些结果表明,每天观察心脏功能可以提供关于心脏功能障碍发生的总体机制的详细信息,并且COVID-19可以以独特的模式引起心脏损害,因此可以逐例进行研究,感染期间的日常工作。这可以使我们朝着更加个性化的心血管医学治疗迈进。
    The spread of the novel coronavirus 2019 (COVID-19) has caused a global pandemic. The disease has spread rapidly, and research shows that COVID-19 can induce long-lasting cardiac damage. COVID-19 can result in elevated cardiac biomarkers indicative of acute cardiac injury, and research utilizing echocardiography has shown that there is mechanical dysfunction in these patients as well, especially when observing the isovolumic, systolic, and diastolic portions of the cardiac cycle. The purpose of this study was to present two case studies on COVID-19 positive patients who had their cardiac mechanical function assessed every day during the acute period to show that cardiac function in these patients was altered, and the damage occurring can change from day-to-day. Participant 1 showed compromised cardiac function in the systolic time, diastolic time, isovolumic time, and the calculated heart performance index (HPI), and these impairments were sustained even 23 days post-symptom onset. Furthermore, Participant 1 showed prolonged systolic periods that lasted longer than the diastolic periods, indicative of elevated pulmonary artery pressure. Participant 2 showed decreases in systole and consequently, increases in HPI during the 3 days post-symptom onset, and these changes returned to normal after day 4. These results showed that daily observation of cardiac function can provide detailed information about the overall mechanism by which cardiac dysfunction is occurring and that COVID-19 can induce cardiac damage in unique patterns and thus can be studied on a case-by-case basis, day-to-day during infection. This could allow us to move toward more personalized cardiovascular medical treatment.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Case Reports
    背景:二尖瓣旁囊肿是一种罕见的肩痛原因。线性超声换能器通常用于肌肉骨骼评估和干预。然而,当目标结构位于深处并被骨屏障阻挡时,线性换能器的使用受到限制,与骨旁神经节囊肿一样。
    目的:本病例报告旨在描述使用凸换能器对评估和超声引导下肩峰下二尖瓣旁囊肿的干预的有益作用。
    方法:两名在物理医学和康复门诊就诊的患者抱怨肩部运动时剧烈疼痛。使用线性换能器的超声扫描检测到肩袖病变。尽管对肩袖病变进行了治疗干预,但由于持续疼痛,因此进行了肩部磁共振成像。并证实了二尖瓣旁囊肿。尽管线性阵列换能器无法可视化囊性病变,但只能进行肩胛骨上神经阻滞和关节内注射,使用凸阵列换能器改善了我们使用超声引导抽吸和囊内注射治疗的囊性病变的可视化。检查视觉模拟量表和肩痛残疾指数,以评估各干预措施的治疗效果。囊内注射与抽吸和关节内注射显示疼痛评分的轻度至中度改善。
    结论:在与肩部运动相关的疼痛中,尤其是疼痛,尽管有适当的治疗肩袖病变,超声诊断关节旁神经节囊肿使用凸换能器将提高诊断价值和干预的准确性。
    BACKGROUND: Paralabral cysts are a rare cause of shoulder pain. Linear ultrasound transducers are often used for musculoskeletal evaluation and intervention. However, the use of linear transducer is limited when the target structure is located deep and blocked by bony barriers, as is the case of paralabral ganglion cysts.
    OBJECTIVE: This case report aims to describe a beneficial role of using a convex transducer on the evaluation and ultrasonography-guided intervention of paralabral cysts below the acromion.
    METHODS: Two patients visiting the outpatient clinic of Physical Medicine and Rehabilitation complained of severe pain during shoulder movement. Ultrasound scans with linear transducer detected rotator cuff lesions. Shoulder magnetic resonance imaging was done because of the persistent pain despite therapeutic interventions for the rotator cuff lesion, and confirmed paralabral cysts. Although a linear array transducer could not visualize the cystic lesion but could only perform suprascapular nerve block and intra-articular injection, the use of a convex array transducer improved the visualization of the cystic lesion which we treated using ultrasound-guided aspiration and intra-cystic injection. Visual analog scale and Shoulder Pain and Disability Index were checked to assess the treatment effect of each intervention. The intra-cystic injection with aspiration and intra-articular injection showed minimal to moderate improvement of pain score.
    CONCLUSIONS: In pain related to shoulder movement, especially pain that continues despite appropriate treatment for rotator cuff lesions, ultrasound diagnosis of paralabral ganglion cysts using convex transducers will improve the diagnostic value and accuracy of intervention.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Letter
    暂无摘要。
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    目的:在慢性淋巴细胞白血病(CLL)中,某些特殊miRs的表达缺失或失调会破坏恶性细胞的凋亡;因此miR的表达可以增强细胞增殖,疾病进展和降低患者生存率。
    结果:30名CLL患者和20名健康人参与了研究。提取RNA以评估miR-125,miR-223,BCL-2和信号转导和转录激活因子3(STAT3)基因的表达;进行定量实时PCR(Q-RT-PCR)。与对照组相比,患者的MiR-125a和miR-223表达降低(P值:0.001)。BCL-2和STAT3是这两种miR的靶基因,显示表达增加,患者与对照组相比(P值:0.001和P值:0.64)。miR-125a和BCl-2表达与WBC计数之间存在显著的反向关系。重要的是,miR-223表达与患者吸烟相关(P值:0.007)。此外,基于与白细胞计数和血红蛋白(Hb)浓度的负相关,这些miR可能通过控制白细胞(WBC)的产生而具有调节作用.最后,miR-223可用作CLL患者的预后因子;miR-125a可用于评估基于与BCl-2的反向链接的治疗方法。
    OBJECTIVE: In chronic lymphocytic leukemia (CLL), lack of expression or dysregulation of some special miRs disrupts apoptosis of malignant cells; thereby miR expression can enhance cell proliferation, disease progression and decrease patient survival.
    RESULTS: 30 CLL patients and 20 healthy individuals participated in the study. RNA was extracted to evaluate the expression of miR-125, miR-223, BCL-2 and signal transducer and transcription 3 activator (STAT3) genes; quantitative Real Time- PCR (Q-RT-PCR) was performed. MiR-125a and miR-223 expression decreased in the patients compared to the control group (P-Value:0.001). BCL-2 and STAT3 which are the target genes of these two miRs, showed increased expression, in the patients compared to the control subjects (P-Value: 0.001 and P-Value: 0.64 respectively). A significant reverse relationship was found between miR-125a and BCl-2 expression and WBC count. Significantly, miR-223 expression was associated with smoking in patients (P-Value: 0.007). Also, these miRs may have regulatory effects by controlling white blood cell (WBC) production based on the inverse correlation with WBC count and hemoglobin (Hb) concentration. Finally, miR-223 can be used as a prognostic factor in CLL patients; miR-125a may be useful for evaluating the therapeutic approaches based on the inverse link with BCl-2.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

  • 文章类型: Case Reports
    严重急性呼吸系统综合症新型冠状病毒-2大流行给医疗保健提供带来了一系列新的挑战。可植入心脏设备上的远程监测生理传感器可以深入了解心力衰竭人群中呼吸困难的鉴别诊断。我们报告了传感器偏差的独特模式,该模式似乎特别发生在严重的急性呼吸道综合症新型冠状病毒2感染中。
    The severe acute respiratory syndrome novel coronavirus-2 pandemic has established a new set of challenges to health care delivery. Remotely monitored physiologic sensors on implantable cardiac devices can provide insight into the differential diagnosis of dyspnea in the heart failure population. We report on a unique pattern of sensor deviations that seem to occur specifically with severe acute respiratory syndrome novel coronavirus-2 infection.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

  • 文章类型: Journal Article
    Iran has experienced a severe drought during the past two decades. Increasing water demand and decreasing available water resources have led the country to critical conflicts, particularly in shared watersheds. In these basins, the precise measurement of releasing water from upstream to downstream can be a key data for resolving water conflicts. The Iranian Ministry of Energy (MOE) makes the streamflow measurements through regional water administrative offices, mainly using the classical rating curve (RC) method. The documented measurements of runoff by adjacent offices usually present different estimations of the water resources, due to high uncertainties of the RC approach. Fluvial acoustic tomography (FAT) is a reliable technology for continuously monitoring streamflow, which can be implemented to solve this problem of shared basins. In this study, FAT is applied to the Zayanderud basin, an Iranian shared watershed and its results are compared with the RC methods. The main terms of FAT streamflow measurement uncertainty are velocity resolution component, and the selected flow angle between the stream direction and acoustic transmission path. Therefore, a new equation is proposed to carefully choose accurate angles for different river widths to decrease FAT measurement error in this paper. The obtained results show that the measured streamflow by FAT and RC are 9.89 m3/s and 10.3 m3/s, respectively, and the largest possible error of FAT is less than 15%.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    OBJECTIVE: In the Multisensor Chronic Evaluation in Ambulatory Heart Failure Patients study, a novel algorithm for heart failure (HF) monitoring was implemented. The HeartLogic (Boston Scientific) index combines data from multiple implantable cardioverter defibrillator (ICD)-based sensors and has proved to be a sensitive and timely predictor of impending HF decompensation. The remote monitoring of HF patients by means of HeartLogic has never been described in clinical practice. We report post-implantation data collected from sensors, the combined index, and their association with clinical events during follow-up in a group of patients who received a HeartLogic-enabled device in clinical practice.
    RESULTS: Patients with ICD and cardiac resynchronization therapy ICD were remotely monitored. In December 2017, the HeartLogic feature was activated on the remote monitoring platform, and multiple ICD-based sensor data collected since device implantation were made available: HeartLogic index, heart rate, heart sounds, thoracic impedance, respiration, and activity. Their association with clinical events was retrospectively analysed. Data from 58 patients were analysed. During a mean follow-up of 5 ± 3 months, the HeartLogic index crossed the threshold value (set by default to 16) 24 times (over 24 person-years, 0.99 alerts/patient-year) in 16 patients. HeartLogic alerts preceded five HF hospitalizations and five unplanned in-office visits for HF. Symptoms or signs of HF were also reported at the time of five scheduled visits. The median early warning time and the time spent in alert were longer in the case of hospitalizations than in the case of minor events of clinical deterioration of HF. HeartLogic contributing sensors detected changes in heart sound amplitude (increased third sound and decreased first sound) in all cases of alerts. Patients with HeartLogic alerts during the observation period had higher New York Heart Association class (P = 0.025) and lower ejection fraction (P = 0.016) at the time of activation.
    CONCLUSIONS: Our retrospective analysis indicates that the HeartLogic algorithm might be useful to detect gradual worsening of HF and to stratify risk of HF decompensation.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

  • 文章类型: Journal Article
    Despite having notable advantages over established machine learning methods for time series analysis, reservoir computing methods, such as echo state networks (ESNs), have yet to be widely used for practical data mining applications. In this paper, we address this deficit with a case study that demonstrates how ESNs can be trained to predict disease labels when stimulated with movement data. Since there has been relatively little prior research into using ESNs for classification, we also consider a number of different approaches for realising input-output mappings. Our results show that ESNs can carry out effective classification and are competitive with existing approaches that have significantly longer training times, in addition to performing similarly with models employing conventional feature extraction strategies that require expert domain knowledge. This suggests that ESNs may prove beneficial in situations where predictive models must be trained rapidly and without the benefit of domain knowledge, for example on high-dimensional data produced by wearable medical technologies. This application area is emphasized with a case study of Parkinson\'s disease patients who have been recorded by wearable sensors while performing basic movement tasks.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    本研究的目的是测试一种想法,并描述一种新颖的方法的概念,该方法检测与超声设备中水平不均匀性有关的缺陷。该方法基于对直接从临床工作流程收集的超声图像的分析。从数据库中回顾性地收集了来自两个供应商的三个超声扫描仪的总共31000张图像。开发了一种算法并将其应用于图像,150次,用于检测图像表面部分的系统暗区。将结果与换能器的电测量(FirstCall)进行比较,在已知换能器有缺陷的时候执行。该算法对长时间在不同时间点获取的图像进行了类似的水平不均匀性检测。结果表明,与有缺陷的换能器的可用电测量结果具有良好的主观视觉一致性,指示临床图像用于早期和自动检测有缺陷的换能器的潜在用途,作为质量控制的补充。
    The purpose of the present study was to test an idea of and describe a concept of a novel method of detecting defects related to horizontal nonuniformities in ultrasound equipment. The method is based on the analysis of ultrasound images collected directly from the clinical workflow. In total over 31000 images from three ultrasound scanners from two vendors were collected retrospectively from a database. An algorithm was developed and applied to the images, 150 at a time, for detection of systematic dark regions in the superficial part of the images. The result was compared with electrical measurements (FirstCall) of the transducers, performed at times when the transducers were known to be defective. The algorithm made similar detection of horizontal nonuniformities for images acquired at different time points over long periods of time. The results showed good subjective visual agreement with the available electrical measurements of the defective transducers, indicating a potential use of clinical images for early and automatic detection of defective transducers, as a complement to quality control.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

公众号