信息科学与电子工程专业英语王朔中清华.ppt

Technical English,For Information Science and Electronic Engineering,Unit 14,Telemedicine and Biomedical Signal Processing,Part I,Telemedicine,3,New Words,4,New Words,5,New Words,6,1,Telemedicine may be as simple as two health professionals discussing a case over the telephone,or as complex as using satellite technology and video-conferencing equipment to conduct a real-time consultation between medical specialists in two different countries.1,远程医疗可以简单到两名医务工作者通过电话讨论病情，或者复杂到通过卫星技术和视频会议系统在两个不同国家的医学专家之间进行实时的医疗咨询。,7,1,It can also involve the use of an unmanned robot.Telemedicine generally refers to the use of communications and information technologies for the delivery of clinical care.,通常，远程医疗指的是通过通信和信息技术来进行临床保健。,8,2,Care at a distance(also called in absentia care),is an old practice which was often conducted via post;there has been a long and successful history of in absentia health care,which has metamorphosed into what we know as modern telemedicine thanks to the modern communication technology.2,缺席医疗服务具有漫长而成功的历史，由于有了现代通信技术，它已发展成为现在我们所了解的现代远程医疗。,9,3,In its early manifestations,African villagers used smoke signals to warn people to stay away from the village in case of serious disease.In the early 1900s,people living in remote areas in Australia used two-way radios,powered by a dynamo driven by a set of bicycle pedals,to communicate with the Royal Flying Doctor Service of Australia.,在20世纪初，生活在澳大利亚偏僻地区的人们用由自行车踏板驱动的发电机提供能源的双向无线电来与澳洲皇家飞行医生服务进行通信,10,4,The terms e-health and telehealth are at times wrongly interchanged with telemedicine.Like the terms“medicine”and“health care”,telemedicine often refers only to the provision of clinical services while the term telehealth can refer to clinical and non-clinical services such as medical education,administration,and research.3,就像医疗和保健两个词有所不同一样，远程医疗通常仅指提供临床服务，而远程保健可以指临床和非临床的服务，后者如医学教育、行政管理和研究。,11,4,The term e-health is often,particularly in the UK and Europe,used as an umbrella term that includes telehealth,electronic medical records,and other components of health IT.,12,5 Types of telemedicine,Telemedicine is practiced on the basis of two concepts:real time(synchronous)and store-and-forward(asynchronous).,远程医疗基于两个概念来实行：实时（同步）和保存并转发（异步）,13,6,Real time telemedicine could be as simple as a telephone call or as complex as robotic surgery.It requires the presence of both parties at the same time and a communications link between them that allows a real-time interaction to take place.Video-conferencing equipment is one of the most common forms of technologies used in synchronous telemedicine.,14,6,There are also peripheral devices which can be attached to computers or the video-conferencing equipment which can aid in an interactive examination.4,另外还有外部设备可以接到计算机或视频会议设备上，在交互检查中提供帮助。,15,6,For instance,a tele-otoscope allows a remote physician to see inside a patients ear;a tele-stethoscope allows the consulting remote physician to hear the patients heartbeat.Medical specialties conducive to this kind of consultation include psychiatry,internal medicine,rehabilitation,cardiology,pediatrics,obstetrics and gynecology and neurology.,有助于这种咨询的医学专科包含精神病学、内科医学、康复学、心脏病学、小儿科学、妇产科学以及神经学,16,7,Store-and-forward telemedicine involves acquiring medical data(like medical images,biosignals etc.)and then transmitting this data to a doctor or medical specialist at a convenient time for assessment offline.It does not require the presence of both parties at the same time.Dermatology,radiology,and pathology are common specialties that are conducive to asynchronous telemedicine.A properly structured Medical Record preferably in electronic form should be a component of this transfer.,17,8,Telemedicine is most beneficial for populations living in isolated communities and remote regions and is currently being applied in virtually all medical domains.Specialties that use telemedicine often use a“tele”prefix;for example,telemedicine as applied by radiologists is called teleradiology.Similarly telemedicine as applied by cardiologists is termed as telecardiology,etc.,18,9,Telemedicine is also useful as a communication tool between a general practitioner and a specialist available at a remote location.,19,10,The focus of telemedicine has mainly been consultative,meaning a general practitioner consulting a specialist or a specialist consulting another specialist.Monitoring a patient at home using known devices like blood pressure monitors and transferring the information to a caregiver is a fast growing emerging service.These remote monitoring solutions have a focus on current high morbidity chronic diseases and are mainly deployed for the First World.,20,10,In developing countries a new way of practicing telemedicine is emerging better known as Primary Remote Diagnostic Visits whereby devices examine a patient and a connected doctor residing in another location virtually examines the patient and treat him.5,在发展中国家正在出现一种新的远程医疗实施方法，常称为“基本远程诊断访问”，通过该系统用设备对病人进行检查，而实际上由另一个国家的联线医生来进行检查和治疗。,21,10,This new technology and principle of practicing medicine holds big promises to solving major health care delivery problems in for instance Southern Africa because Primary Remote Diagnostic Consultations not only monitors an already diagnosed chronic disease,but has the promise to diagnosing and managing the diseases a patient will typically visit a general practitioner for.6,这一新的医疗实践技术和原则对于解决为诸如南部非洲这样的地区提供基本保健服务的问题是一大希望，因为基本远程诊断咨询不仅可监测已诊断出的慢性病，还可对病人通常会求助于全科医生的疾病进行诊断和管理。,22,11 Teleradiology,Telemedicine is the delivery of healthcare and exchange of health care information across distance.Teleradiology is the ability to send radiographic images(x-rays)from one location to another.For this process to be implemented,three essential components are required,an image sending station,a transmission network,and a receiving/image review station.,23,12,The teleradiology process begins at the image sending station.The radiographic image and a modem are required for this first step.The image is scanned and then sent to the modem.,24,13,The transmission network can be wire,fiber optics,or microwave.After the digital information has been sent to the modem,electrical impulses are sent along to the transmission network to the receiving/image review station.The receiving/image review station consists of a modem,a computer with sufficient storage capabilities,a display,and sometimes a printer to provide hard copies to the end user.,25,13,The electrical impulses created through the transmission network are received by the modem on the review station.These impulses are converted back to the original digital image once it reaches the review station.This image is then stored and can be viewed on the display for diagnostic purposes.A hard copy can be printed for more convenience.,26,14,Clearly with the number of companies focusing on telemedical devices and the specialization of these companies one can expect telemedicine to become a significant way that physicians,hospitals,and veterinarian offices operate in the near future.,Part II,Computerized Tomographic Imaging,28,New Words,29,New Words,30,1,Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.The impact of this technique in diagnostic medicine has been revolutionary,since it has enabled doctors to view internal organs with unprecedented precision and safety to the patient.,通过从许多不同方向照射物体，根据透射或反射的数据对物体断面成像,31,1,The first medical application utilized x-rays for forming images of tissues based on their x-ray attenuation coefficient.More recently,however,medical imaging has also been successfully accomplished with radioisotopes,ultrasound,and magnetic resonance;the imaged parameter being different in each case.,层析成像最初的医学应用是用X射线对组织进行成像,用放射性同位素、超声、磁共振也成功地实现了医学成像，在每一种情况下用不同的参数成像,32,2,There are numerous non-medical imaging applications which lend themselves to the methods of computerized tomography.,33,2,Researchers have already applied this methodology to the mapping of underground resources via cross-borehole imaging,some specialized cases of cross-sectional imaging for nondestructive testing,the determination of the brightness distribution over a celestial sphere,and three-dimensional imaging with electron microscopy.1,研究者已经将此方法用在许多方面，例如通过钻孔成像测绘地下资源，无损检测中断面成像的某些特殊案例，确定天球面上的亮度分布，以及电子显微镜三维成像。,34,3,Fundamentally,tomographic imaging deals with reconstructing an image from its projections.In the strict sense of the word,a projection at a given angle is the integral of the image in the direction specified by that angle,as illustrated in Figure 14.1.,某一角度的投影是图像在该角度所指定的方向上的积分,35,3,However,in a loose sense,projection means the information derived from the transmitted energies,when an object is illuminated from a particular angle;the phrase“diffracted projection”may be used when energy sources are diffracting,as is the case with ultrasound and microwaves.2,然而在宽泛的意义上，投影是指物体从某一角度受到照射时由发出的能量所形成的信息。若辐射源是衍射性的如超声波或微波，可使用“衍射投影”一词。,36,4,Although,from a purely mathematical standpoint,the solution to the problem of how to reconstruct a function from its projections dates back to the paper by Radon in 1917,the current excitement in tomographic imaging originated with Hounsfields invention of the x-ray computed tomographic scanner for which he received a Nobel prize in 1979.3,虽然从纯数学的角度，对于如何根据投影数据重建图像这一问题的解要追溯到1917年Radon的论文，但当前在断层成像方面令人激动的成就源自Hounsfield发明的X光CT扫描，他因此项发明而于1979年获得了诺贝尔奖。,37,4,He shared the prize with Allan Cormack who independently discovered some of the algorithms.His invention showed that it is possible to compute high-quality cross-sectional images with an accuracy now reaching one part in a thousand in spite of the fact that the projection data do not strictly satisfy the theoretical models underlying the efficiently implementable reconstruction algorithms.4,他的发明显示，尽管投影数据并未严格满足有效实现重建算法赖以成立的理论模型，仍有可能计算精度达千分之一的高质量断面图像。,38,4,His invention also showed that it is possible to process a very large number of measurements(now approaching a million for the case of x-ray tomography)with fairly complex mathematical operations,and still get an image that is incredibly accurate.,39,5,It is fair to say that the breakneck pace at which x-ray computed tomography images improved after Hounsfields invention was in large measure owing to the developments that were made in reconstruction algorithms.5,可以说自从Hounsfield的发明以来X光CT图像改进的快速度在很大程度上要归功于重建算法方面的发展。,40,5,Hounsfield used algebraic techniques,and was able to reconstruct noisy looking 8080 images with an accuracy of one part in a hundred.This was followed by the application of convolution backprojection algorithms,first developed by Ramachandran and Lakshminarayanan and later popularized by Shepp and Logan,to this type of imaging.,重建大小为8080的噪声颇大的图像，精度为百分之一,41,5,These later algorithms considerably reduced the processing time for reconstruction,and the image produced was numerically more accurate.As a result,commercial manufacturers of x-ray tomographic scanners started building systems capable of reconstructing 256256 and 512512 images that were almost photographically perfect(in the sense that the morphological detail produced was unambiguous and in perfect agreement with the anatomical features).,所形成的形态细节清晰可辩，并与解剖结果完全一致，在这一意义上这些图像几乎达到了照相术上完美的程度,42,6,Given the enormous success of x-ray computed tomography,it is not surprising that in recent years much attention has been focused on extending this image formation technique to nuclear medicine and magnetic resonance on one hand;and ultrasound and microwaves on the other.,43,6,In nuclear medicine,our interest is in reconstructing a cross-sectional image of radioactive isotope distributions within the human body;and in imaging with magnetic resonance we wish to reconstruct the magnetic properties of the object.In both these areas,the problem can be set up as reconstructing an image from its projections of the type shown in Figure 14.1.,在这两个领域都可以建立起如图14.1中这类投影来重建图像的问题。,44,6,This is not the case when ultrasound and microwaves are used as energy sources,although the aim is the same as with X-rays,viz.,to reconstruct the cross-sectional image of,say,the attenuation coefficient.6 X-rays are non-diffracting,i.e.,they travel in straight lines,whereas microwaves and ultrasound are diffracting.,尽管其目的和X光（CT）相同，即重建某一参数（例如衰减系数）的断层图象，用超声波和微波作能源时情况有所不同。,45,6,When an object is illuminated with a diffracting source,the wave field is scattered in practically all directions,although under certain conditions one might be able to get away with the assumption of straight line propagation;these conditions being satisfied when the inhomogeneities are much larger than the wavelength and when the imaging parameter is the refractive index.7,当使用衍射源照射物体时，波实际上向四面八方散射，虽然在场的不均匀范围远大于波长，并且用折射率作为成像参数时我们可以满足于直线传播的假设。,46,6,For situations when one must take diffraction effects(inhomogeneity caused scattering of the wave field)into account,tomographic imaging can in principle be accomplished with the algorithms based on the Fourier diffraction theorem.,