穿戴式随行监护系统心电信号质量评价研究

穿戴式生理参数监测技术是一种新型的生理监护技术,代表未来监护技术的发展方向,但该类技术应用于临床尚有许多问题亟待解决。本文针对自主研发的穿戴式随行监护系统(SensEcho-5B)的心电信号质量评价问题开展了探索性研究。首先基于模板匹配法开发出一种心电信号质量评价算法,用于心电信号的自动、定量评价,在100名受试者(15名健康人和85名心血管疾病患者)随机抽取的100 h心电信号数据集上进行了算法性能测试。在此基础上使用SensEcho-5B与心电Holter同步采集了30名受试者(7名健康人和23名心血管疾病患者)的24 h心电数据,使用心电信号质量评价算法对两个系统同步记录的心电信号质量进行评价。算法性能测试结果:敏感度为100%,特异度为99.51%,准确率为99.99%。30名受试者的对照试验结果:SensEcho-5B所检测到的心电信号,信号质量较差时间的中位数(Q1,Q3)为8.93(0.84,32.53)min,Holter所检测到的心电信号,信号质量较差时间的中位数(Q1,Q3)为14.75(4.39,35.98)min(秩和检验P=0.133)。研究结果表明,本文提出的心电信号质量评价算法能够对穿戴式随行监护系统的心电信号质量进行有效评价;随行监护系统SensEcho-5B与对照Holter相比,心电信号质量相当。后续研究将进一步在真实临床环境中采集大样本量的随行监护生理数据,并对心电信号质量进行分析和评价,从而使监护系统的性能得到持续优化。     

基于IPPG非接触式生理参数测量算法的研究

介绍了基于成像式光电容积描记技术(imaging photoplethysmography,IPPG)的非接触式人体生理参数测量算法的研究工作。在自主研发的IPPG非接触生理参数测量仪中运用IPPG的新原理。运用视频图像处理的新方法,基于视频信号检测经过人体组织和血液吸收后的反射光强不同,从得到的脉搏波中计算出心率、呼吸频率及血氧饱和度。实现了人体生理参数无创连续非接触测量的新技术。经过实验验证与对比分析,本系统取得了较好的测量效果。在未来家庭健康医疗发展的场景下,具有很大的应用价值。     

不同运动速率下心率检测算法效果评估

心脑血管疾病对人类健康的威胁日益严重,实时心率的检测与过快心率预警愈加重要。但现有的穿戴式心电研究及心率检测算法,主要应用于临床数据及静息状态数据,针对运动状态的相关研究并不全面。使用穿戴式心电衣与惯性导航仪器相结合的方式,选取5名志愿者进行实验,获取共433段实时数据,以手动标注结果为真值,对速度与心率进行相关性分析。同时,将实验数据以1.5 m/s为分界点分块,选取如下5种QRS检测算法,原始Pan & Tompkins算法、Hamilton & Tompkins算法、JQRS算法、Sixth-power算法、DOM算法,分别进行在低速与高速区间上的心率检测,对检测误差进行对比。结果表明,速度和心率存在正相关关系,5种算法中,DOM算法的心率检测准确率最高,适宜于穿戴式运动心电相关领域应用,Sixth-power算法检测结果最差。     

基于可穿戴设备量化分析急性心衰患者夜间呼吸模式的探索性研究

急性心力衰竭（AHF）患者常伴呼吸困难,对患者的呼吸模式进行监测和量化分析可为病情和预后评估提供参考信息。本文纳入39例AHF患者和24例健康受试者,采用可穿戴设备收集其夜间胸腹呼吸信号,并量化分析两组人群夜间呼吸模式的差异。与健康组相比,AHF组的呼吸率（BR）均值更高[（21.03±3.84）次/分vs.(15.95±3.08)次/分,P <0.001],相对浅快呼吸指数变异系数更大[70.96%(54.34%～104.28)%vs. 58.48%(45.34%～65.95)%,P=0.005],腹呼吸贡献比变异系数更大[（22.52±7.14）%vs.(17.10±6.83)%,P=0.004],呼吸率样本熵更小（0.67±0.37 vs. 1.01±0.29,P <0.001）;此外,吸气（TI）和呼气（TE）时间均值更短、变异系数更大,劳累呼吸指数变异系数更大,庞加莱图SD1、SD2更大,以上指标的两组间差异均有统计学意义。使用Logistic回归校准发现TI均值降低是AHF的危险因素。BR均值区分两组人群的能力最强,曲线下面积（AUC）为0.846。结果表明呼吸...     

一种可穿戴式心电图动态监护系统

介绍一种基于柔性电极可穿戴心电监护系统的软硬件设计方案,主要解决现阶段心电监护系统中存在的高成本、高耗能、心电图信号连续性差等问题。同时在电极设计上采用银纤维布料的方法,消除一次性AgCl/Ag湿电极在可穿戴心电系统中无法长期佩戴的弊端。经志愿者测试验证分析,系统有着较高的稳定性和实用性,对可穿戴心电监护体系的发展有实际应用推广价值。     

新型传感技术在睡眠呼吸障碍家庭监护的前沿研究进展EI北大核心CSCD

睡眠呼吸障碍(SRBD)是一种睡眠疾病,其患病率高、并发症多,但病情不易察觉,严重危害人体健康。目前,家用SRBD监测设备是领域内的研究热点之一,以提高患者对病情的认识和关注。本文针对SRBD的家庭监护领域,横向对比了近年来的前沿研究成果,旨在全面分析各类技术的优势和局限性,并指明未来研究方向和商业化方向。根据系统设计,可以将新型家用SRBD监护设备划分为可穿戴型和无约束型两类。两类设备各有优劣,可穿戴设备相对简单、便携,但舒适度和续航性能有待提升;而无约束设备则更隐蔽、舒适,但分析算法较为复杂。目前,领域内的研究主要集中在系统设计和性能测试上,但算法优化和临床试验的工作仍有待推进。本文可以帮助科研人员快速而全面地把握领域内的科研进展,从而拓宽科研思路,寻求未来研究的突破点和创新点。此外,本文也归纳了现有的商业化睡眠监护产品,并展望新型家用SRBD监护设备的商业潜力,力图推动科研成果的转化落地。     

一种基于可穿戴设备和智能手机的呼吸监测系统

目的呼吸运动是人体重要的生理活动之一,呼吸频率的变化能反映人体生理状况的好坏,因此呼吸频率的监测对于健康监护具有重要意义。方法本研究设计一种基于可穿戴设备和智能手机的呼吸监测系统。可穿戴式设备的主控芯片采用低功耗蓝牙芯片nrf52832,利用加速度传感器MPU6050采集人体呼吸运动的加速度信号,利用低功耗蓝牙方式与智能手机进行通信;智能手机端软件能够实时接收可穿戴式设备发送的呼吸运动数据,利用后台运行的呼吸检测算法计算出呼吸频率等相关参数,并绘制出呼吸运动波形。此外,智能手机可以对接收到的呼吸运动数据进行存储,可对用户的呼吸活动进行长期的分析研究。结果(1)穿戴式设备工作电流11mA,广播电流12mA,待机电流10mA,工作电压3.3V,功率约为33mW;(2)呼吸检测的准确率在95%以上;(3)智能手机界面能够实时显示呼吸运动的加速度波形和呼吸频率。结论该系统具有方便佩戴、功耗低和呼吸检测准确性高等优点,能够适用于家庭等场所进行呼吸监护,满足人们对日常健康监护的需求。     

引导呼吸下的呼吸性窦性心律不齐的研究

研究渐进性引导呼吸对呼吸性窦性心率不齐(RSA)的影响。对15名健康成年男性采集引导呼吸率依次为【14次/min—12.5次/min—11次/min—9.5次/min—8次/min—7次/min】状态下的同步心电、呼吸信号,采用提取RSA时、频特征参数的方法来研究渐变性呼吸率对RSA的影响。计算结果显示:表征RSA强度的三个特征参数总体上随着呼吸率的逐渐降低均呈现出增大的变化趋势。RSA代表着呼吸系统对心血管系统的反射调控,此实验结果表明,随着呼吸率的降低,呼吸系统对心血管系统的反射调控作用逐渐增加,提示可通过改变呼吸模式来改善心血管系统的功能。     

帕金森病冻结步态的实时监测系统

目的由于帕金森病冻结步态的突发性,临床上对其进行评估存在一定困难,为此本文研究了一种用于实时监测冻结步态的系统。方法该系统由可穿戴设备和配套的APP两部分构成,其中设备通过惯性传感器和超声波传感器采集患者腿部运动的加速度和抬脚高度数据,并传输至APP软件中,通过软件中的冻结步态识别模型进行分析。系统为构建冻结步态识别模型,首先通过实验采集12位患者的运动数据,然后经过信号预处理、特征提取和机器学习算法训练出模型,最后通过对数据集采用十折交叉验证来评估模型的准确度和精确度。结果系统对冻结步态的识别准确率可达98.6%,精确率达97.2%。结论该系统能够实时监测帕金森病患者日常生活中的冻结步态发作情况,为医生的诊疗提供定量、可靠的参考依据。     

Stressing the accuracy: Wrist‐worn wearable sensor validation over different conditions

Wearable sensors are promising instruments for conducting both laboratory and ambulatory research in psychophysiology. However, scholars should be aware of their measurement error and the conditions in which accuracy is achieved. This study aimed to assess the accuracy of a wearable sensor designed for research purposes, the E4 wristband (Empatica, Milan, Italy), in measuring heart rate (HR), heart rate variability (HRV), and skin conductance (SC) over five laboratory conditions widely used in stress reactivity research (seated rest, paced breathing, orthostatic, Stroop, speech task) and two ecological conditions (slow walking, keyboard typing). Forty healthy participants concurrently wore the wristband and two gold standard measurement systems (i.e., electrocardiography and finger SC sensor). The wristband accuracy was determined by evaluating the signal quality and the correlations with and the Bland‐Altman plots against gold standard‐derived measurements. Moreover, exploratory analyses were performed to assess predictors of measurement error. Mean HR measures showed the best accuracy over all conditions. HRV measures showed satisfactory accuracy in seated rest, paced breathing, and recovery conditions but not in dynamic conditions, including speaking. Accuracy was diminished by wrist movements, cognitive and emotional stress, nonstationarity, and larger wrist circumferences. Wrist SC measures showed neither correlation nor visual resemblance with finger SC signal, suggesting that the two sites may reflect different phenomena. Future studies are needed to assess the responsivity of wrist SC to emotional and cognitive stress. Limitations and implications for laboratory and ambulatory research are discussed.     

Low latency breathing frequency detection and monitoring on a personal computer

We demonstrate a low latency respiratory/breathing frequency detection system that is fast (<5?ms), easy to operate, requires no batteries or external power supply and operates fully via computer-standard USB connection. Exercises in controlling ones breathing frequency, usually referred to as paced-breathing exercises, have shown positive effects in treating pulmonary diseases, cardiovascular diseases and stress/anxiety-related disorders. We developed a breathing frequency detection system which uses two pairs of microphones to detect exhalation activity, eliminate noise from the environment and stream the recording data via USB connection to a personal computer. It showed 97.1% reliability (10 subjects) when monitoring breathing activity in non-guided free breathing and 100% reliability (10 subjects) when monitoring breathing activity during interactive paced-breathing exercises. We also evaluated the breathing frequency detection systems noise elimination functionality which showed a reduction of 84.2 dB for stationary (white noise) and a reduction of 79.3 dB for non-stationary (hands clapping) noise.     

Validity of heart rate measurements by the Garmin Forerunner 225 at different walking intensities

The accuracy of wrist worn heart rate monitors based on photoplethysmography (PPG) is not fully clinically accepted. Therefore, we aimed to validate heart rate measurements of a commercially available PPG heart rate monitor, i.e. the Garmin Forerunner^® 225. Twelve healthy volunteers (six women; mean age: 28 years) performed a treadmill protocol consisting of: five minutes sitting, five minutes standing, 10 minutes walking at 4 km/h, 10 minutes walking at a gradient of 5% and intensity of 4–6 metabolic equivalents (METs), 10 minutes walking at a gradient of 8% and intensity of seven METs or more. Walking speeds were individually determined. Walking bouts were separated by a standardised five minute rest period. Heart rate was measured as the average of the last three minutes standing and of each walking bout. A three lead patch-based electrocardiogram (ECG; Zensor^®) was used as criterion method. Statistical analyses included Pearson’s correlation (r), paired t-tests, root mean squared error (RMSE) and Bland?Altman plots. The mean values per three minutes of every condition did not differ significantly between the Garmin Forerunner^® 225 and the Zensor^®. RMSE was 3.01 beats per minute (bpm) or 2.89%. The Bland–Altman bias was 1.57 bpm. Limits of agreement (LoA) were wide, ranging from 32.53 to 29.40 bpm. However, Pearson’s r ranged from 0.650 to 0.868 suggesting moderate to strong validity. Generally, mean heart rates, r values, RMSE and the Bland–Altman bias indicated good overall agreement in this sample of healthy adults, but wide LoA are making it difficult to trust individual measurements.     

增加胎心监护检查频率对降低新生儿窒息率的影响

目的评价增加胎心监护检查频率方法的临床意义,探讨降低胎监假阳性率的方法,提高胎儿宫内窘迫的诊断,降低新生儿窒息率.方法取2001年在我院分娩的1087例产妇为观察组,孕37w后住院期间实行每天一次胎监检查,产时进行连续监护,1997年分娩的1091例产妇为对照组,孕37w后住院期间每周一、两次胎监检查,产时间断监护.用x2统计两组胎监假阳性率、剖宫产率、新生儿窒息率,回顾分析胎监异常与临床结局的关系.结果2001年组的因胎监异常剖宫产率为20.6%,假阳性率27.45%,新生儿窒息率6.53%,1997年组因胎监异常剖宫产率为26.4%,假阳性率为46.51%,新生儿窒息率11.73%,两组相比有显著性差异P＜0.01.结论增加胎监检查频率的方法能降低胎监的假阳性率,降低新生儿窒息率.     

Specific features in the secretory activity of enterochromaffin cells of the duodenal mucosa of red-cheeked souslik under different physiological conditions

The ratio of the synthetic and secretory phases of the activity of duodenal enterochromaffin cells of the hibernating red-cheeked souslik under hypo- and normothermia is compatible with the functional significance of serotonin, one of their secretory products. The synthesis and accumulation of the secretion predominate during normothermia in summer and winter, whereas during deep torpor serotonin is mainly released from the cells. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 3 pp. 337–340, March, 1996 Presented by V. P. Kaznacheev, Member of the Russian Academy of Medical Sciences     

基于聚偏氟乙烯薄膜的穿戴式呼吸检测系统

【摘 要】 针对人体呼吸信号的特点设计一种基于聚偏氟乙烯（PVDF）压电薄膜材料的可穿戴式呼吸检测系统。人体呼吸时PVDF薄膜受力产生的感应电荷较少,经信号调理电路将电荷量转换成电压量。单片机通过模数转换器获得呼吸信号数据,通过蓝牙发送给上位机。上位机从获得的数据中提取呼吸波形,并进行平滑滤波、自适应双阈值来计算呼吸率。试验结果表明,本系统可以实时准确地检测出人体的呼吸波形,呼吸次数识别的准确率在90%以上,可以满足人体呼吸监护的需求。     

Detection of fetal breathing and cardiac movements and rhythms in ultrasonic Doppler signal recorded on the surface of the maternal abdomen

It is proposed to use information on the direction of reflector movement and extensive filtering in the detection of fetal breathing and cardiac movements in the ultrasonic Doppler signal recorded on the surface of the material abdomen. The method appears fairly insensitive to spurious signals and allows those of interest to be distinguished without any reference technique. A decision rule for breathing and cardiac rhythm detection, incorporating movement direction, amplitude, shape and periodicity criteria, is also proposed.