Data in Medicine: Collection, Processing and Presentation

Nowadays clinical medicine is to a great extent dependent on techniques and instrumentation. Not infrequently, instrumentation is so complicated that technical specialists are required to perform the measurements and to process the data. Interpretation of the results, however, generally has to be done by physicians. For proper interpretation of data and good com­ munication with technical specialists, knowledge of, among other things, principle, advantages, limitations and applicability of the used techniques is necessary. Besides, this knowledge is required for critical comparison of systems to measure a certain variable. Critical evaluation as well as com­ parison of techniques and instruments ought to be an essential component of medical practice. In general, basic techniques and instrumentation are not taught in medi­ cal schools nor during residencies. Therefore, physicians themselves have to collect practical information about principle, advantages and limitations of techniques and instruments when using them in clinical medicine. This practical information, focussed on the specific techniques used in the various disciplines, is usually difficult to obtain from handbooks and manufacturers' manuals. Hence a new series of books is started on instru­ mentation and techniques in clinical medicine.

Contenu

1 Observation: how, what and why.- 1.1 Introduction.- 1.2 Problems in the observer.- 1.2.1 Linear thinking.- 1.2.2 Homogenization.- 1.2.3 Perspective.- 1.2.4 Circularity.- 1.3 Problems in the observed.- 1.3.1 Interfaces.- 1.3.2 Image intensification.- 1.4 Significance.- 2 Physical concepts.- 2.1 Introduction.- 2.1.1 General.- 2.1.2 Circulatory aspects.- 2.1.3 Acoustical aspects.- 2.2 Mechanical-electrical analogues.- 2.3 Hemodynamics.- 2.3.1 A simplified model of blood pressure ("Windkessel" model).- 2.3.2 The pulse wave.- 2.4 Pressure recording with catheters.- 2.5 Cardio-acoustics.- 2.5.1 General.- 2.5.2 Transducers on the chest wall.- 2.5.3 The mechanical impedance of the chest wall.- 2.5.4 Mechanical impedances of phonocardiographic microphones.- 3 The electronic approach to measurements.- 3.1 Introduction.- 3.2 Digital circuits.- 3.3 Analogue circuits.- 4 Radioactivity.- 4.1 Introduction.- 4.2 An overview of the physics of radioactive emissions.- 4.2.1 Atomic structure.- 4.2.2 Modes of decay.- 4.2.3 Stabilization after radioactive decay.- 4.2.4 Activity and half-life.- 4.3 Radiation detection system.- 4.3.1 Gamma detectors.- 4.3.2 Beta detectors.- 4.3.3 Signal processing.- 4.3.4 Processed gamma spectra.- 4.3.5 Processed beta spectra.- 4.4 Tracer sample counting.- 4.4.1 Gamma counting with a single tracer.- 4.4.2 Gamma counting with multiple tracers.- 4.4.3 Beta counting with a single tracer.- 4.4.4 Beta counting with multiple tracers.- 4.4.5 Decay corrections.- 4.4.6 Relative doses with reference to the experiment design.- 4.5 Applications.- 4.5.1 Applications of tracer dilution techniques to the measurement of volume and flows.- 4.5.2 Applications of tracer exchange techniques to the estimation of transmembrane fluxes.- 4.5.3 Neutron activation analysis.- 5 Image formation.- 5.1 Introduction.- 5.2 Image formation on the ray theory.- 5.2.1 Light gathering power of a lens.- 5.2.2 Depth of focus and depth of field.- 5.3 Optical resolution.- 5.4 Aberrations of spherical lenses and mirrors.- 5.4.1 Spherical aberration.- 5.4.2 Astigmatism.- 5.4.3 Coma.- 5.4.4 Curvature of field.- 5.4.5 Distortion.- 5.4.6 Chromatic aberration.- 5.4.7 Correction of aberrations.- 5.5 Resolution of lenses: the modulation transfer function.- 5.6 Choosing lenses.- 6 Photographic and television recording of images.- 6.1 Introduction.- 6.2 Detectability of an optical signal.- 6.3 The photographic process.- 6.3.1 Some fundamental concepts.- 6.3.2 Structure of photographic films.- 6.3.3 Properties of photographic emulsions.- 6.3.4 Resolution.- 6.3.5 Some comments on the use of photographic systems.- 6.4 Electronic aids to image sensing and recording.- 6.4.1 Some fundamental concepts.- 6.4.2 Image intensifiers.- 6.4.3 Television.- 6.5 Color recording.- 7 Storage systems.- 7.1 Introduction.- 7.2 Graphic recorders.- 7.2.1 Recorder mechanism.- 7.2.2 Recording format.- 7.2.3 Writing principles.- 7.2.4 General properties.- 7.3 Storage from the oscilloscope screen.- 7.4 The magnetic tape recorder.- 7.4.1 Introduction.- 7.4.2 Head properties.- 7.4.3 Tape characteristics.- 7.4.4 Direct recording.- 7.4.5 Frequency modulation.- 7.4.6 Pulse-code modulation.- 7.4.7 Recording codes.- 7.4.8 Tape transport mechanism.- 7.4.9 Time base error, flutter, and noise.- 7.4.10 Cassette recorders.- 7.4.11 Digital recorders.- 7.5 Transient recorders.- 7.6 Card and tape punchers.- 7.7 Digital memories.- 7.8 Videotape recording.- 8 Automation.- 8.1 Introduction.- 8.2 Analysis of automation of measurements in clinical medicine.- 8.2.1 Introduction.- 8.2.2 The data acquisition phase.- 8.2.3 The data processing phase.- 8.2.4 The interpretive phase.- 8.2.5 The decision phase.- 8.2.6 The action phase.- 8.3 Application of automation to measurements in clinical medicine.- 8.3.1 Introduction.- 8.3.2 Reasons for automating a particular task.- 8.3.3 Automating the acquisition/processing phase.- 8.3.4 Detection strategies.- 8.4 Automation and the computer.- 8.4.1 Introduction.- 8.4.2 If it's so complicated let's put it all in a computer and let it sort it out.- 8.4.3 How do we "put it in the computer"?.- 8.4.4 Programming.- 8.5 Automation and the microprocessor.- 8.5.1 Introduction.- 8.5.2 Tentative conclusions.- 8.6 Pocket calculators and computers as tools in the diagnosis.- 8.6.1 Introduction.- 8.6.2 Off-line processing and interpretation.- 8.7 Automating the decision/action phase.- 8.8 A last remark.- 9 Signal processing.- 9.1 Introduction.- 9.1.1 Definition of a signal.- 9.1.2 Purpose of analysis.- 9.2 Special techniques.- 9.2.1 Sampling.- 9.2.2 Digitizing.- 9.2.3 Discrete Fourier transform.- 9.2.4 Least-squares approach.- 9.3 Stochastic signals.- 9.3.1 Description in terms of statistical parameters.- 9.3.2 Autocorrelation function.- 9.3.3 Spectral density.- 9.3.4 Description in terms of an ARMA process.- 9.4 Deterministic signals.- 9.4.1 Model known (as function, as differential equation).- 9.4.2 Parameter estimation.- 9.4.3 Model unknown.- 9.5 Manipulation.- 9.5.1 Data reduction.- 9.5.2 Filtering.- 9.5.3 Differentiation.- 9.5.4 Integration.- 9.5.5 Interpolation.- 10 Statistical aspects.- 10.1 Introduction.- 10.2 The scope of applied statistics.- 10.2.1 Introduction.- 10.2.2 Description of results.- 10.2.3 Tests of significance.- 10.2.4 Populations and samples.- 10.2.5 Measurements and attributes.- 10.2.6 Non-parametric methods.- 10.3 Some experimental designs and statistical applications.- 10.3.1 Paired data.- 10.3.2 Non-paired data.- 10.3.3 Analysis of variance, single classification.- 10.3.4 Multiple classification.- 10.3.5 Multivariate samples.- 10.3.6 Correlation.- 10.3.7 Regression.- 10.3.8 Covariance.- 10.3.9 Multiple linear regression.- 11 Presentation of information for printed publications, slides and posters.- 11.1 Introduction.- 11.2 Investigating legibility.- 11.2.1 The reading process.- 11.2.2 Methods of research.- 11.3 Books, journals and reports.- 11.3.1 Introduction.- 11.3.2 Type forms.- 11.3.3 Typography and layout for text.- 11.3.4 Tables.- 11.3.5 Graphs, charts and diagrams.- 11.3.6 Indexes.- 11.3.7 Bibliographies.- 11.3.8 Page layout.- 11.3.9 Paper and ink.- 11.4 Slides.- 11.4.1 Introduction.- 11.4.2 Information content.- 11.4.3 Sources of material.- 11.4.4 Size of originals.- 11.4.5 Character size.- 11.4.6 Lettering.- 11.4.7 Layout of text.- 11.4.8 Tables, graphs and diagrams.- 11.4.9 Contrast.- 11.4.10 The use of color.- 11.4.11 Projection of slides.- 11.4.12 Overhead projection.- 11.5 Posters.- 11.5.1 Introduction.- 11.5.2 Content.- 11.5.3 Size.- 11.5.4 Character size.- 11.5.5 Character style.- 11.5.6 Layout for text.- 11.5.7 Tables, graphs and diagrams.- 11.5.8 Poste…