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At least 577 records · Page 32Linked to original sources
PubMed1995

MicroPharm-K, a microcomputer interactive program for the analysis and simulation of pharmacokinetic processes.

PURPOSE: The microcomputer program, MicroPharm-K (MP-K) was developed for pharmacokinetic modeling, including analysis of experimental data and estimation of relevant parameters, and simulation. The intention was to provide a user-friendly, interactive, event-driven program for PC computers. METHODS: The data are ascribed to a predefined model from a library including various routes of administration, oral or intra-venous, bolus or infusion, and various compartmental interpretations, 1 to 3. Single and multiple administrations are supported. The program provides initial estimates of the parameters in most cases, and the parameters are then fitted to the model by non linear model fitting using either the Simplex, Evol, Gauss-Newton, Levenberg-Marquardt or Fletcher-Powell algorithms. The non linear model fitting is based on the maximum likelihood method, and the criterion to minimize is either the weighted least squares (Chi 2 criterion) or the extended least squares. Graphical representations of non-fitted or curve-fitted data are immediately available (including log-scale representation), as well as pharmacokinetic typical parameters such as area under the curve, clearance, volumes, time-rate constants, transfer rate constants, etc. RESULTS: Simulated and experimental data were analysed and the results were similar to those obtained by other programs. CONCLUSIONS: This non linear fitting program has been proved in our laboratory to be a very effective package for pharmacokinetic studies, including estimation and simulation. Because it is easy-to-use and runs on basic computers, the program could also be used for educational purposes.

Administration, Oral↗
PubMed1985

Low-cost microcomputer-based densitometer.

We have constructed low-cost equipment for the measurement of the optical density of x-ray films. This equipment is based on a video system connected via an analog to digital converter to an Apple microcomputer. The optical density of an x-ray film can thus be accessed by commands in BASIC or machine-code programs. By using a calibrated step-wedge film, we have found a stable linear response for optical densities of up to 0.8.

Computers↗
PubMed1989

A microcomputer system for the analysis of dental radiographs.

A system for the digital storage and computer analysis of dental radiographs is described. The system is based on popular microcomputer, of a type commonly used for other purposes in general dental practice. The analysis system includes methods to compensate for variations due to exposure and development in serial radiographs. Interactive software allows a detailed analysis of the radiograph, producing qualitative and quantitative data for diagnosis and monitoring. An example of its application is given.

Alveolar Process↗
PubMed1987

Kinetic properties of hexokinase as assembled with a microcomputer data base.

We have constructed a relational data base containing the kinetic properties of the isoenzymes of hexokinase using the Knowledgeman data-base program on an IBM PC microcomputer. The natural subunit of this data base is the refereed publication, 165 of which were included. Reported values for the Mr (approx. 97,000) are in good agreement, but this agreement becomes progressively worse as one examines the Km values for glucose and ATP and the Ki for glucose 6-phosphate, where the reported values are spread over three orders of magnitude. Some quantities are very thinly or unreliably determined. Experimental conditions, especially free Mg2+ concentration, are rarely close to physiological. Reasons for the spread or uncertainty of numbers, and the distinctions that can be made between isoenzymes despite this spread, are discussed.

Adenosine Triphosphate↗
PubMed1984

Microcomputers to control the pH of growing micro-organisms.

Negative feedback control can usefully be used in biochemistry for a variety of purposes. Two examples are presented which utilize microcomputers to generate the transfer function of the feedback loop. The first demonstrates the control of NADH concentration during an enzymic reaction, and the second shows that if the pH is held constant whilst growing E. coli the yield can be increased. In both these cases it is convenient, even essential, to use a computer because computers are both very stable over the long term and the feedback transfer function can be accurately and quickly specified.

Cell Division↗
PubMed1989

An analysis of velopharyngeal timing in normal adult speakers using a microcomputer based photodetector system.

Using a microcomputer interface and dedicated software, a photodetector was employed to collect data on the timing of velopharnygeal movements during the production of speech by 10 normally speaking adult subjects. The duration of velopharnygeal closing gestures varied consistently across productions of /m/, /n/ and /n/ in both normal and fast speech. Velopharyngeal opening movements also appeared to be affected by the nasal consonant that was produced. These phenomena are explained in terms of biomechanical constraints known to act upon the velopharyngeal mechanism.

Adult↗
PubMed1989

The automatic extraction of pitch perturbation using microcomputers: some methodological considerations.

A program for the automatic extraction of jitter (PAEJ) was developed for the clinical measurement of pitch perturbations using a microcomputer. The program currently includes 12 implementations of an algorithm for marking the boundary criteria for a fundamental period of vocal fold vibration. The relative sensitivity of these extraction procedures for identifying the pitch period was compared using sine waves. Data obtained to date provide information for each procedure concerning the effects of waveform peakedness and slope, sample duration in cycles, noise level of the analysis system with both direct and tape recorded input, and the influence of interpolation. Zero crossing extraction procedures provided lower jitter values regardless of sine wave frequency or sample duration. The procedures making use of positive- or negative-going zero crossings with interpolation provided the lowest measures of jitter with the sine wave stimuli. Pilot data obtained with normal-speaking adults indicated that jitter measures varied as a function of the speaker, vowel, and sample duration.

Adult↗
PubMed1983

Financial modelling on microcomputers.

The financial modelling packages for microcomputers can be considered as falling into one of three categories:- visual spread sheets, micro base structured models and structured models which are compatible across, and allow communications between, micros and mainframes. This paper describes the three types of package, discusses the pros and cons of each, and offers a guide to system selection.

Computers↗
PubMed1985

The measurement of differential thresholds for lifted weights by microcomputer-controlled apparatus.

The measurement of differential thresholds (DLs) for lifted weights normally involves lengthy test sessions. This is due partly to the statistical techniques for measuring the threshold and partly to the methods adopted to present the stimuli. Attempts to speed up test procedures tend to produce unreliable DL estimates, or to measure the sense of force or effort rather than weight perception. To facilitate the measurement of DLs for lifted weights, an Apple microcomputer was programmed to generate Wetherill tracking procedures and was interfaced with two stimulus bearing turntables. Various lifting methods are easily implemented, and DLs are reliably and quickly measured. The adaptation of the apparatus for general use in investigating the haptic sense modality is discussed.

Computers↗
PubMedDate not supplied

ProsthesisWare: concepts and caveats for microcomputer-based aids to everyday living.

Two main approaches have been taken in using the microcomputer as an aid to the elderly for everyday living. The first strategy is often termed cognitive rehabilitation and uses the computer as a tutor for the training or retraining of such general cognitive skills as memory or attention. The strength of this strategy is that it is inexpensive and deliverable; its weakness is that it is ineffective for many people because it requires plasticity and the ability to generalize to real-life situations. The second strategy, termed ProsthesisWare, uses the computer as a prosthetic or augmentative device for any deficiencies in cognitive or motor abilities. The strength of the ProsthesisWare approach is that it can be effective in providing compensation and in maintaining the independent home environment that most people desire; its weakness is that it requires acceptance, maintenance, and idiosyncratic customization. As an illustration of the ProsthesisWare program. SpeechWare is presented. This software serves as a prosthetic aid for those who, as a result of stroke, amyotrophic lateral sclerosis, or other neurological impairment, have lost the ability to communicate and who may also have severe motor impairments. SpeechWare also includes telephone, distance electronic, and written communication functions as well as basic control of household appliances and environment.

Aged↗
PubMed1984

Enhancing the usability of safety software for microcomputers.

With the proliferation of microcomputers, increasing effort is being made to write programs dealing with occupational safety and health. So as to assure the widespread use of this material, it is important that it be prepared in a manner easy to use. Ignoring this consideration may cause the potential users to be repelled by it from the start, or that its use will be difficult and error-prone. This article dwells on some of the points that need to be borne in mind when writing such software to make it easy and pleasant to use. Additionally, a project, carried out by the author, is described, which makes use of a free-form program access approach, as opposed to a purely menu-driven one. Two potential extensions of this approach are then described.

Computers↗
PubMed1986

A prototype microcomputer-based decision support system for industrial hygienists.

A prototype Industrial Hygiene Decision Support System (IH-DSS) was designed and implemented in a microcomputer environment using an integrated knowledge management system as the implementation vehicle. The heart of the system is a relational data base designed to minimize redundant data entry and to support flexible retrieval. An industrial hygienist's routine and ad hoc requirements for information retrieval and analysis support are met by screen displays, printed reports, and graphical summaries which may be presented on the screen, in a printed form, or as multicolored plots. A petroleum refinery was selected as the application environment for the prototype system because of the variety of processes, agents, and sampling methodologies involved in industrial hygiene support in that environment.

Computers↗
PubMed1983

Data processing for radioimmunoassay standard curve using microcomputer: a new BASIC program for weighted logit-log transformation.

A new BASIC program of the weighted linear, quadratic and cubic logit-log regression methods for data processing of radioimmunoassay standard curve was developed using a microcomputer. Using this program, three regression analyses are calculated and the table for root mean square of residuals in each regression are shown for the selection of the regression method. The data of three radioimmunoassays of human pancreatic enzymes and pancreatic secretory trypsin inhibitor were examined by this program and compared with those processed by the four parameter logistic method. The weighted cubic logit-log regression showed better fit in radioimmunoassays of human pancreatic enzymes with larger molecular weights. The present program is useful and practicable for its simplicity and accuracy.

Computers↗
PubMed1984

A microcomputer based system for quantifying the spatial distribution of inhaled particles in histological lung sections.

A system is described for quantifying the spatial distribution of inhaled particles in complete lobar histological sections of rodent lung. It is based on a semi-automatic image analyser, linked to a readily available microcomputer. Application of the system to quantify the aggregation of particles, and their distances from airways and lung periphery is described. The observed distributions are compared with the expected distributions from a random set of particles, and the significance of the difference is calculated. Each statistical test is illustrated by an example.

Aerosols↗
PubMed1986

The use of a microcomputer for non-linear optimisation of doses in external radiotherapy.

The study presents software for a microcomputer designed to determine the optimum dose distribution in external radiotherapy, either by calculating the doses delivered and the field width (in linear programming) or, in addition, by calculating the beam geometry (non-linear optimisation). Various optimisation criteria can be selected, namely the homogeneity, the concentration on the target and the total dose in a sensitive area. The article outlines an example.

Humans↗
PubMed1983

A cotside microcomputer monitoring system for use in the neonatal intensive care unit.

A dedicated cotside microcomputer unit is described. It is designed to collect and to display graphically all continuously recorded variables from an infant in a neonatal intensive care unit. The data are collected from existing monitoring equipment and the graphical displays demonstrate both short and long term trends in data. In addition, the system allows data collected intermittently to be entered on a simple keyboard and to be displayed on plots that are time-correlated with the on-line data displays. A permanent record of the monitoring interval may be generated and the facility for closed-loop control of the partial pressure of arterial oxygen is being developed for integration into the system.

Computers↗
PubMed1993

The use of a microcomputer to automate measurement of action potential duration for both transmembrane and monophasic action potentials.

Measurement of action potential duration is made more valuable if it can be made simultaneously with other variables, to which it may be related. We have developed a microcomputer-based system which allows measurement of action potential duration, both for transmembrane action potentials and for monophasic action potentials. The system allows simultaneous recording and analysis of action potentials and intraventricular pressures. Both end-diastolic and maximum systolic pressures have been analysed. Action potential duration was assessed at four different levels of the repolarization curve. We have analysed the consistency of measurements made by the computer, and compared them to measurements made manually, using results from six dog experiments. For action potential duration, there was no systematic difference between the manual and the computer methods, but the computer was significantly more consistent. In the case of the pressure measurements, the two methods were approximately the same in their consistency, and again there was no systematic difference. We have demonstrated that potential errors in determination of the average diastolic potential did not significantly affect the results obtained by our method. The variances of action potential duration measurements made at different levels of repolarization were equal. We demonstrated that there was no effect of amplitude on the action potential duration of potentials recorded under steady-state conditions.

Action Potentials↗
PubMed1984

A microcomputer based audit of fracture of the proximal femur in the elderly.

A microcomputer was used for patient record management and statistical analysis to study prospectively an elderly female population with femoral neck fracture. Of 150 patients studied, 58% presented with a cervical fracture and 42% with a trochanteric fracture. The patients with trochanteric fracture were significantly older than the patients with cervical fracture (P less than 0.001), required a longer stay in hospital (P less than 0.01) and returned to their previous environment less frequently. The proportion of trochanteric fractures increased with age. In view of the ageing population and the rising incidence of femoral neck fracture, these findings have important implications for the future allocation of hospital resources.

Aged↗