基于脉搏波传导时间和脉搏波特征参数的连续血压无创检测

本研究为克服在基于脉搏波传导时间(pulse transit time,PTT)方法无创血压检测中个体差异对测量准确性的影响,分析了个体脉搏波特征参数与血压值的相关性,并将个体脉搏波特征参数中与血压值相关度高的参数作为优化脉搏波特征参数加入PTT与血压的校正模型中,以提高模型普适性。基于偏最小二乘法(partial least squares,PLS)对50名志愿者200组PTT和脉搏波特征参数数据进行训练建模,得到舒张压、收缩压的预测模型。再选取5名新志愿者的PPT和脉搏波特征参数进行预测,最大预测误差小于5 mm Hg,满足AAMI国际电子血压计标准。将优化的脉搏波特征参数和PTT引入到连续血压预测模型当中,有助于提高血压预测模型的准确度和普适性,有助于无创连续血压检测的临床应用。     

AVR单片机下脉搏传导时间与收缩压的关系

目的利用MIMIC Datebase(mimicdb)数据分析有创收缩压和脉搏传导时间(pulse transit time,PTT)的关系。制作AVR信号采集系统,并在PC下采集心电和脉搏的实时信号,分析无创收缩压和PTT的关系。方法利用Matlab软件分析MIMIC数据库内5个个体的数据,得出PTT和有创收缩压的相关系数。利用AVR单片机采集用6名正常血压的男性(年龄27~31周岁)的心电和脉搏信号,用蓝牙发送至计算机。通过两个月对比试验,比较PTT和收缩压之间的关系是否发生很大的变化。结果PTT同有创和无创收缩压都有较好的线性相关性,波谷作为PTT特征点和收缩压有更好的线性关系。结论 AVR数据采集系统小巧、便携,可应用于家用监护。     

基于脉搏-心电的便携式血压仪的研制

设计一种体积小巧,测量过程无任何束缚的基于脉搏波传导时间(pulse wave transit time,PWTT)的血压仪。从反射式容积脉搏波(photoplethysmography,PPG)和心电波形(electrocardiogram,ECG)中提取脉搏波传导时间,再综合心率、每搏输出量和外周阻力对血压的影响,通过回归分析建立血压模型,最终实现血压测量。应用样机对20名志愿者进行血压测量,同时以传统水银血压计的测量结果作为标准,结果显示收缩压和舒张压的95%一致性界限分别为(-8.3,11.6),(-9.9,12.7),说明两种方法所测的血压值有较好的一致性。血压仪样机实体小巧,使用方便,使用过程没有任何束缚,同时在理论上对基于脉搏波传导时间的血压测量方法进行优化,实现了收缩压和舒张压的测量。     

基于脉搏波传导时间的连续血压监测系统

为了实现无创连续血压测量,提出了一种基于脉搏波传导时间(pulse transit time,PTT)的连续血压测量方案。通过同步采集心电(electrocardiogram,ECG)信号与光电脉搏波(photoplethysmograph,PPG)信号,以ECG的R波峰值点作为PTT的开始点,PPG信号的最大值点作为PTT的结束点,得到PTT,与水银血压计测得舒张压(diastolic blood pressure,DBP)与收缩压(systolic blood pressure,SBP)进行回归分析,得到了DBP和SBP的数学模型。利用该方法对41名身体健康的青年人进行实验,利用本方案得到的SBP与水银血压计的相关系数为0.82,其差值的平均数与标准偏差为0.15±2.05 mm Hg;得到的DBP与水银血压计的相关系数为0.73,其差值的平均数与标准偏差为0.12±2.16 mm Hg。利用Bland-Altman差值法对本系统血压测量方法与水银血压计测血压方法进行一致性检验,结果显示两种血压测量方法具有很好的一致性。     

颈动脉超声对冠状动脉粥样硬化性心脏病评估价值研究

目的:探讨颈动脉超声对冠状动脉粥样硬化性心脏病评估价值。方法:选择2018年2月至2019年9月的疑似冠心病患者107例进行研究。患者入组后均行冠状动脉造影剂颈动脉超声检查,根据冠状动脉造影结果将患者分为阴性组(n=33)、单支病变组(n=31)、双支病变组(n=27)及三支病变组(n=16)。对比各组血管内中膜厚度(Intimate-media thickness,IMT))、脉搏波传导速度(Pulse wave velocity,PWV)及硬度指数β(Lβ),并将颈动脉超声参数与冠状动脉病变程度进行相关性分析进行相关性分析。以ROC法评估各指标诊断价值。结果:不同组患者IMT、PWV及Lβ对比差异均具有统计学意义,且均随病变严重程度增加而增加(P0.05)。各颈动脉超声参数与冠状动脉病变支数呈显著正相关关系(P0.05)。ROC分析结果显示:联合诊断灵敏度和特异度均显著高于单独诊断(P0.05)。结论:颈动脉超声检查IMT、PWV及Lβ对冠状动脉心脏病均有较高的诊断灵敏度、特异度,联合诊断后灵敏度、特异度更高。     

基于波形时域特征和动态差分阈值的脉搏波传导时间检测算法EI北大核心CSCD

针对传统脉搏波传导时间(PTT)检测方法对脉搏波(PPG)信号幅值变化敏感、计算量大等问题,提出了一种综合波形时域特征和动态差分阈值的PTT检测算法。采用动态差分阈值检测心电(ECG)信号R波,根据波形时域特征缩短脉搏波信号主波检测区间,利用R波检测脉搏波信号主波,从而计算PTT。利用美国麻省理工学院MIMIC数据库和实验室实测数据对上述算法进行验证。结果表明,该方法能够准确地提取特征点并检测出PTT,对实测和数据库样本的PTT检测准确率分别为99.1%和97.5%,效果优于传统检测方法。     

基于波形时域特征和动态差分阈值的脉搏波传导时间检测算法

针对传统脉搏波传导时间(PTT)检测方法对脉搏波(PPG)信号幅值变化敏感、计算量大等问题,提出了一种综合波形时域特征和动态差分阈值的PTT检测算法。采用动态差分阈值检测心电(ECG)信号R波,根据波形时域特征缩短脉搏波信号主波检测区间,利用R波检测脉搏波信号主波,从而计算PTT。利用美国麻省理工学院MIMIC数据库和实验室实测数据对上述算法进行验证。结果表明,该方法能够准确地提取特征点并检测出PTT,对实测和数据库样本的PTT检测准确率分别为99.1%和97.5%,效果优于传统检测方法。     

基于舒张期时间的个体化血压建模方法研究

本研究提出了一种基于脉搏波舒张期时间(diastolic time,DT)的无袖带式血压估计方法,能够有效提升可穿戴式设备的血压测量精度。该方案首先从脉搏波(photoplethysmography,PPG)中提取DT,再利用线性回归方法建立个体化血压估计模型。本研究对采集的30个样本的实验数据,进行血压建模并加以验证,实验结果显示收缩压的平均误差为1.859 mmHg,标准差为5.640 mmHg;舒张压的平均误差为1.049mmHg,标准差为6.107 mmHg,证明了该方案的可行性。通过将该方案的估计结果与基于脉搏波传导时间(pulse transit time,PTT)的血压模型的估算结果进行对比研究,结果表明交感神经活动较强时,基于DT的血压模型能够有效提升血压估计精度。     

基于光电容积脉搏波的呼吸波提

本研究通过人体指端的光电容积脉搏波,提取呼吸波信号。同时采用小波分析和经验模态分解方法对脉搏波信号进行分解并重构呼吸信号,然后与采集的呼吸波信号做相关性分析。通过对5名志愿者的实验,结果显示采用经验模式分解方法所提取的呼吸波具有更好的相关性。通过分析数据显示,其波形相关系数在0.5左右,AR频谱相关系数在0.8以上。由此可以证明,经验模式分解法可有效提取人体指端光电容积脉搏波中所包含的呼吸波成分。     

基于波形分析的多种PWV获取系统的设计

主动脉脉搏波速度(aoPWV)是心血管疾病的独立预测因子,但难以采用波形分析方法直接获取,医学界采用颈股PWV(cfPWv)、臂踝PWV(baPWV)、心股PWV(hfPWV)近似代替aoPWV.目前三种指标在国内外均有应用,但三者的差异性尚未得到深入研究.我们设计了一种无创脉搏波检测仪器,同步采集心电、心音和多路脉搏...     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.