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1.
目的 本文对超声骨密度测量系统中的高速数据采集和传输关键技术进行了研究,设计了数据采集系统.方法 该系统基于 Nios II软核,以现场可编程门阵列(field programmable gate array,FPGA)芯片EP2C8Q208C8为核心,选择ADC12C105芯片进行模数转换,然后经USB接口芯片CY7C68013A上传至PC机进行分析、存储.最后对CY7C68013A的传输速度进行了测试.结果 实验结果证实本文所设计的系统采样率高,数据传输速度快.结论 该高速数据采集和传输系统是超声骨密度测量系统的研发基础.  相似文献   

2.
目的设计基于背向散射信号来评判骨密度情况的便携式超声骨密度仪,为实现超声骨密度仪的低成本和便携性提供一种解决方案。方法使用现场可编程门阵列(field programmable gate array,FPGA)作为主控以控制整个系统正常工作,配合信号调理、高速模数转换器(analog-to-digital converter,ADC)和USB传输电路,来实现高压脉冲控制模块、增益控制模块、信号采集、数据传输。最后对系统噪声和采集到的背向散射信号进行测试,并用松质骨样本进行骨密度测量的测试。结果系统整体尺寸为15 cm×10 cm×3 cm,数据传输速率可达60 MB/s,噪声水平低。结论设计了一种USB接口的便携式背向散射超声骨密度仪,在USB接口供电时,可以有效地获取背向散射信号。  相似文献   

3.
为了更好地满足现代超声骨密度测量的要求,从软件方面提出并实现改进测量骨密度精度和速度的方案。采用高速USB接口芯片FT232H,配合高速AD转换芯片,通过PC软件处理计算超声声速(SOS)与宽带超声衰减(BUA)等骨密度参数。该方案提高了测量数据的精度,减少了测量时间,提高了图像显示质量。本设计通过高速USB接口技术和软件处理技术可以有效提高骨密度测量数据的精度和传输速度。  相似文献   

4.
目的对市售的韩国超声骨密度仪(型号为OsteoProUBD2002A)进行改进,设计以现场可编程门阵列(fieldprogrammablegatearray,FPGA)作为控制芯片的高精度超声骨密度仪,克服其准确度不高及检测速率低等问题。方法该系统以FPGA芯片XC3S250E-4为核心,采用MAX1449芯片进行模数转换,使用K6T4016V3C—TF70进行数据存储,通过USB芯片FT232H进行数据传输。最后对系统的传输速度和整体性能进行了测试。结果实验结果证实该系统采样率高,数据传输速度快。结论该高精度测量系统是超声骨密度仪性能提升的核心。  相似文献   

5.
在数字化超声成像系统中,由于原始数据量大,传输速率快,数据的有效传输一直是影响系统性能的主要瓶颈。我们介绍了一种基于光纤传输和PCI总线的高速医学超声数据传输系统的设计方案和功能特性。该系统应用于全数字化高帧率医学超声成像系统的数据传输,实现了将采集到的超声回波信号实时传送到计算机中进行成像处理。经测试,本系统实现的数据传输率可达80 MB/s。由于此数据传输系统具有较强的通用性,因此也可以应用于其他高速数据采集系统的数据传输。  相似文献   

6.
目的设计并实现一种便携式A/P型眼科超声生物测量系统。方法硬件结构包括10 MHz和20 MHz超声发射电路,分别用于A型和P型超声波测量。回波信号经放大后进行200 MHz、12 bits的模数转换,所获得的数字信号通过现场可编程门阵列(FPGA)实现相应的数字信号处理。使用计算机的一个通用串行总线(USB)接口所提供的5 V、500 m A作为整个硬件系统的供电。计算机软件系统包括人机界面设计、数据捕获、显示及打印等功能。结果在长105 mm、宽40 mm的PCB线路板上实现了高频超声信号的发射、采集与数字信号处理,并通过USB接口连接计算机,完成数据信息的传输与控制。结论设计的便携式眼科超声生物测量系统携带方便,系统兼容,数据可靠,完全可以满足临床应用要求。  相似文献   

7.
CCD(电耦合器件)数据采集系统要求其接口能够实现快速稳定的数据传输。CY7C68013是一款集成USB2.0方案的芯片,其设计能充分体现USB2.0的数据带宽特征。本文结合CCD数据采集系统的特点,利用CY7C68013芯片设计USB2.0数据接口,重点分析了GPIF(通用可编程接口)模式下的固件程序设计,包括GPIF波形设计、端点配置和读事务处理等,实现基于USB2.0的单向数据传输功能。在测试实验中,将外部信号源发出的数据由外设FIFO(先入先出存储器)传输至上位机,实现了高速的数据传输,测得最大的传输速度为113.6Mb/s。  相似文献   

8.
在神经工程研究领域,神经信号模拟器用于验证神经解码算法和脑机接口系统的性能,设计实现一种基于FPGA和上位机的128通道神经信号模拟器。上位机负责生成神经信号和常用典型信号(如正弦波、三角波、方波)数据集,通过USB接口发送给下位机转换成模拟信号输出。其中,USB实际通信速率需大于7.68MB/s,使用USB控制器芯片CY7C68013A结合FPGA实现这一功能。下位机最终实现的基本参数如下:128通道、30kSPS采样率、±10mV幅值输出范围、12位DAC分辨率。使用业内应用最广泛的神经信号采集系统,对模拟器产生的信号进行分析,得到采集设备与模拟器的整体信噪比为75dB。该模拟器具有可编辑性强、通道数易拓展、噪声小等优点,可应用于神经信号采集系统的性能测试、神经科学研究、脑机接口等领域。  相似文献   

9.
经颅多普勒(TCD)是研究颅内大血管中血流动力学的常用技术,但传统TCD中依然存在着对大脑血管定位困难和对微栓子检测不确定等缺点。为了克服这些弊端,本研究设计了一种功率M模式TCD测量系统。该系统通过FPGA设计、USB固件驱动以及PC数据后处理等模块共同实现。数字电路模块以FPGA为核心进行状态机设计,并采用高速AD采样和双FIFO乒乓工作模式来确保良好的实时性;硬件电路部分和PC之间的数据传输依靠高速USB实现;软件模块结合功率M模式多普勒成像技术、短时傅里叶变换和伪彩色图像处理,对超声波束发射方向上整体深度的血流状态进行监测,方便定位血管深度,并为临床医生提供选通深度的声谱图信息。  相似文献   

10.
目的目前常见的超声骨密度仪软件处理部分大多在PC端,不能满足使用者对便携性的要求,而已有的嵌入式架构多基于Linux+QT等。本文设计一款嵌入式基于Android平台的超声骨密度仪,解决了用户对便携性的需求。方法软件在eclipse环境中开发,配合测量模块对人跟骨进行测量,通过USB接收回波数据,应用程序对回波数据进行显示,并计算出回波参数声速(speed of sound,SOS)和超声宽带衰减(broadband ultrasound attenuation,BUA),并选取型号为OsteoPro的超声骨密度仪进行比较。结果该仪器实现了骨密度仪的功能,包括数据的高速采集、参数的计算等。此外,作为一个嵌入式应用设备,应用软件还支持对患者的信息和测量的结果进行存储,打印出测量报告。结论 Android平台和USB的使用,使仪器在便携性和可移植性都得到极大的提升。  相似文献   

11.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
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.  相似文献   

12.
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.  相似文献   

13.
About 1900, modern food selection and processing caused widespread 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 panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse 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 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.  相似文献   

14.
There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.  相似文献   

15.
16.
Newton H 《Medical history》2011,55(2):153-182
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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