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It has been my objective to accomplish the following: (1) to devise a system of charting acuity of hearing by means of tuning forks; (2) to construct the mechanical means that will eliminate the examiner's ear in the test; (3) to make the device simple and free of all electrical and intricate elements, and to avoid bone or tissue conduction of sound to the examined ear, thus obviating erroneous records from this source; (4) to construct the device so that it may be produced inexpensively. MECHANISM The acoustimeter is an arrangement of tuning forks in series, mounted on a revolving base. A turn brings each fork into position to be struck by a hammer centrally mounted to serve all the forks. The hammer is actually a pendulum weighted on the free end. A stop-watch is connected with the pivotal end of the pendulum. When the hammer is released the watch

The hearing aid terminology uses definitions like “Peak Clip”, “AVC”, “Compression”, “LDC” etc.–and these words all cover one way out of several to limit the output of a hearing aid. Fitting a hearing aid is no easy task. There are many factors to take into consideration–and one is the output limitation characteristics of the instrument. This paper deals with the various principles of limiting the output. The principles are explained in a graphic system which is not related to any specific brands of hearing aids. In this way the author wants to clarify some of the discussion points in the debate of compression, and he also wants to widen the general knowledge of the principles of output limitation.Ndr man taler om horeapparater, bruges ordene “Peak Clip”, “AVC”, “Kompression”, “LDC” osv. for at betegne en eller anden form for begrœnsning of horeapparatets maksimale udgangslydtryk. Det har aldrig vœret let at tilpasse et horeapparat, da man skal sidde inde med en grundig viden om horeapparatets mange funkt...

SUMMARY A simple method employing single maximum expiratory efforts is presented as a means of defining the nature and extent of ventilatory insufficiency. The method involves the measurement of the 0.5 sec. expiratory capacity and the total vital capacity. Then by relating the 0.5 sec. expiratory capacity to the total vital capacity as a simple ratio, and expression of the maximum velocity of air flow during expiration, is obtained. The total vital capacity is a measure of maximum pulmonary stroke volume. Thus in a single test expressions of the velocity of pulmonary air flow as well as pulmonary stroke volume are found. If these functions are plotted against each other in a quadrant graphic system which is based on normal values for these two functions, a convenient and precise clinical method for defining the physiological nature of ventilatory insufficiency is obtained. This test is applicable even to the seriously debilitated patient who cannot perform the maximum breathing capacity test. Serial studies by this method provide a convenient and informative method of studying the nature of the change in ventilatory function during the course of the disease or resulting from therapy.

The purpose of this paper is to point out the advantages and disadvantages of using an on-line graphical computer for graduate student research. The system itself consists of an IBM 2250 model I graphic console operating through IBM 360/40,/75, and /91 computers. It was hoped that this would provide an interactive graphical system permitting the student to solve his dissertation problems in a novel fashion. The experience gained in this endeavor and the methodology which the student might develop could prove to be even more valuable than the solution of the problem itself and would constitute an integral part of his thesis. The paper reports on the work carried out for a Master's thesis and for a Ph. D. dissertation. The former consisted of an attempt to solve nonlinear programming problems in n dimensions by searching for the optima on a CRT screen exhibiting contour lines and constraints in two variables, the others being varied by on-line control. The other application consisted of developing a simulation language allowing for on-line graphical displays and interaction, and applying this language to the design and analysis of a complex digital computer system consisting, in particular, of a variable number of time shared consoles. The results of this work clearly showed the convenience of an interactive graphic system while underlining the difficulties experienced in operating either with an inherently slow system or a powerful system slowed down by batch background operation.

Computer controlled mass spectrometer system, processing spectral information data for on-line graphic system output

A method is described for providing an on-line bar graph display of physiological data. A conventional servo recorder is coupled with an 8-bit digital-to-analog converter, and provides a low-cost, hard-copy graphic display peripheral that can be added to any laboratory type minicomputer system with buffered output data lines. The graphic display technique requires minimal memory allocations and a simple software algorithm to provide a flexible graphic system that can accommodate various types of biological data.

A major feature of the Brunel Symposium was an exhibition of on-line equipment operating either from a local computer or over telephone lines to a remote backup processor. Manufacturers also presented lecture-demonstrations on applications of their systems, and participants were able to see and operate the graphic equipment.

Actuality of material is conditioned by the urgent necessities of society in preparation of future technologies teachers. Laboratory practical work on applied informatics helps students to capture necessary professional practical skills of work in the environment of the graphic system COMPASS-3D. The methodology of laboratory practical work is described in the article, maintenance and structure of laboratory works, examples of performance of works and corresponding recommendations are presented.

Most computer graphics systems in existence today are based upon the direct view, refreshed CRT. These systems, for the most part, are faiily expensive, generally costing well over $20,000. The recent availability of high resolution, moderate size, direct view storage C.R.T.s makes possible full computer graphics systems costing under $20,000. This chapter will compare several possible graphics systems based upon the direct view storage tube, and also some systems using the refreshed C.R.T. Emphasis will be on hardware and software tradeoffs permitting lowest system cost, and on the resulting performance and applications for such systems.

The TX-2 computer, an experimental machine at the M.I.T. Lincoln Laboratory, has been in operation for almost 10 years as an on-line, graphically oriented facility. In 1964, a time-sharing system for the TX-2 was started. This system, APEX, was to service a small number of consoles with graphic display capability. To achieve hardware economy, displays were to be refreshed from main core memory through a time-shared vector generator providing analog signals distributed to the individual console scopes. The displays were to be refreshed directly from a structured display file as experience with the Sketchpad developments of the early 1960's had indicated was highly desirable for interactive graphic applications. Although the APEX graphic system has evolved through several generations of display hardware and corresponding software changes, the initial design principles of displays refreshed from structured information in main core by a time-shared generator have remained. This paper is an attempt to collect and evaluate some lessons learned from our experience in developing and using this system.

The development of a performance evaluation technique, using simulation, for interactive graphics systems is described. The first step is the development of a simulation model for a single terminal graphic system. The model is a functional representation of the system. The functions modelled were identified by considering the activities occurring during a typical interaction. The model was used to simulate the operation of several different hardware configurations and the results of some of these simulations are presented. The simulation model developed for a multiterminal system is a more realistic representation of the logical organization and operation of an actual system. The four system components represented are hardware, users, system software, and application program loads. The events occurring in the system were identified by considering the sequence of processing activities characteristic of an interaction or batch job. The events and components are appropriately related to reflect the situation in an actual system wherein the system software is the interface between the hardware and the application program and the user interacts with the system through the hardware.

The importance of rapid accurate acquisition and interpretation of clinical laboratory data has increased as the services provided by the laboratory have become progressively more valuable. Expansion of scientific laboratory knowledge has enhanced the complexity of transmitting, retrieving, and interpreting laboratory information to the degree that computer assisted systems would appear to represent an essential component for the practice of medicine in the future. An interactive graphic system has been developed as an investigational tool to facilitate interpretation and utilization of laboratory data, and the system has been employed using liver disease as a model. The system appears to have potential for both research and practice, and the results are considered encouraging.

The big revolution in computer usage is, by now, an old story. No longer do users, programmers and computer operators always work independently and separately, communicating only through voluminous printouts. Engineers and designers can now participate continuously in the execution of their problems through displays. By accelerating design iterations, they can solve their problems more quickly and, at the same time, improve the quality of their solutions.