Abstract: Otoacoustic emission test instruments are now entering routine audiological practice. Two general classes of technique are in use in laboratory work--those employing spectrum analysers to observe the continuous generation of OAEs, both stimulated or unstimulated, and those using transient stimulation and waveform averaging to extract a delayed OAE or "cochlear echo" waveform from ear canal sound. Both methods have particular advantages in clinical applications. The transient OAE type of method has proved very effective in screening applications, particularly in neonates. It is possible to perform noninvasive screening acoustic cochleography in about a minute. The technique is also useful for characterizing cochlear mechanical status prior to long term monitoring. Achieving routinely reliable OAE test performance in clinical and screening applications under nonideal conditions makes special demands on the instrumental design and the response evaluation procedures. The essential requirements are reviewed and discussed in a general and specific context. We have tried to meet these requirements in a transient evoked otoacoustic emission system (the ILO88) which we designed to operate with a personal computer. We report on our design of probe, and our use of evaluation procedures for probe fit, and response quality. Signal processing methods have been developed to reject noncochlear acoustic responses, and to optimise the rejection of patient noise. Examples of its clinical use, and the practical problems typically encountered are given here.

Abstract: The purpose of this study was to determine the test-retest reliability of the Biodex (Biodex, Corp., Shirley, NY) isokinetic concentric mode for a healthy active population for knee extension/flexion utilizing the parameters peak torque and work. Nineteen healthy active male and female subjects ages 20-35 with no history of knee injury were tested bilaterally for concentric knee extension and flexion at 60, 180, 240, and 300 degrees /sec., utilizing standard Biodex protocol. Seven days following the pre-test, a post-test was administered using identical protocol. Data collection of pre- and posttesting was done via a Compaq Desk Pro personal computer and Biodex software programming. The parameters of peak torque and single repetition work were analyzed for knee extension/flexion. Statistical analysis of data showed the intraclass correlation coefficient (ICC) of knee extension peak torque at 60 degrees /sec to be r = 0.95; at 180 degrees /sec, r = 0.96; at 240 degrees /sec, r = 0.95; and at 300 degrees /sec, r = 0.97. Knee extension work ICC values were at 60 degrees /sec, r = 0.96; at 180 degrees /sec, r = 0.97; at 240 degrees /sec, r = 0.96 and r = 0.95 at 300 degrees /sec. All ICCs are significant at the 0.05 level. Therefore, the isokinetic concentric mode of the Biodex dynamometer was reliable for test-retest measures of peak torque, and single repetition work. J Orthop Sports Phys Ther 1990;11(7):298-300.

Abstract: An automated diabetes data interpretation method is provided which combines symbolic and numeric computing approaches in order to identify and highlight key clinical findings in the patient's self-recorded diabetes data. The patient data, including blood glucose levels and insulin dosage levels, recorded by a diabetic patient over a period of time by means of a glucose meter or the like, is initially downloaded into a central processing system such as a personal computer. The accepted diabetes data is subsequently processed to (a) identify insulin dosage regimens corresponding to predefined significant changes in insulin dosage which are found to be sustained for at least a predefined segment of the overall data collection period, (b) identify statistically significant changes in blood glucose levels resulting across adjacent ones of the identified insulin regimen periods, and (c) identify clinically significant changes in blood glucose levels from within the identified statistically significant glucose level changes. The results of the diabetes data processing are generated in the form of a comprehensive yet easily understandable data interpretation report highlighting the processing results, including details pertaining to the identified insulin regimens and the associated clinically significant changes in glucose levels.

Abstract: It is often necessary to measure soil water content at multiple points in space and time. Our goal was to develop an automated and multiplexed measurement system using time-domain reflectometry (TDR). Two systems are described; the first (A) uses an analog TDR unit, in which voltage signals sent from the TDR to a datalogger convey the shape of the waveform. The second (D) uses a digital TDR that communicates a digital representation of the oscilloscope wave to a personal computer. Both systems use the same multiplexing strategy, in which the TDR transmission line connects through a 12-position rotary switch to various waveguides positioned in the soil and to further rotary switches. The switches are turned by stepping solenoids that are activated by the datalogger in System A and the computer in System D. System D uses software to automatically analyze the incoming waveforms and calculate volumetric water content. Some of the possible uses of each system include observation of infiltration at multiple points within a field and measurement of unfrozen water content as a function of space and time during freezing and thawing. The system has also been used to estimate the reproducibility of water content measurement by TDR, which was found to be in the range of ±0.006 to ±0.008. The systems described should be useful for field research on many subjects, including studies of transport and biological processes in soil, and validation of root water-uptake models.

Abstract: Several cryptosystems based on exponentiation have been proposed in recent years. Some of these are of the public key variety and offer notable advantages in cryptographic key management, both for secret communication and for message authentication. The need for extensive arithmetic calculations with very large integers (hundreds of digits long) is a drawback of these systems. This paper describes a set of experimental programs that were developed to demonstrate that exponentiation cryptosystems can be efficiently implemented on the IBM Personal Computer (PC). The programs are organized into four layers, comprising procedures for: multiple precision integer arithmetic, modular exponentiation, prime number generation and testing, and cryptographic key generation. The major emphasis of the paper is on methods and techniques for improving execution speed. The items discussed include: the use of a specialized squaring procedure; a recursive splitting method to speed up squaring and multiplication; the computation of residues by using multiplication instead of division; the efficient encoding of residue information; and the use of thresholds to select the most effective primality testing algorithm for a given size number. Timing results are presented and discussed. Finally, the paper discusses the advantages of a mixed system that combines the superior key management capabilities inherent in public key cryptosystems with the much higher bulk-encryption speed obtainable with the Data Encryption Algorithm.

Abstract: Two efficient finite difference methods for solving Richards' equation in one dimension are presented, and their use in a range of soils and conditions is investigated. Large time steps are possible when the mass-conserving mixed form of Richards' equation is combined with an implicit iterative scheme, while a hyperbolic sine transform for the matric potential allows large spatial increments even in dry, inhomogeneous soil. Infiltration in a range of soils can be simulated in a few seconds on a personal computer with errors of only a few percent in the amount and distribution of soil water. One of the methods adds points to the space grid as an infiltration or redistribution front advances, thus gaining considerably in efficiency over the other fixed grid method for infiltration problems. In 17-s computing, this advancing front method simulated infiltration, redistribution, and drainage for 50 days in an inhomogeneous soil with nonuniform initial conditions. Only 16 space and 21 time steps were needed for the simulation, which included early ponding with the development and dissipation of a perched water table.

Abstract: A complete analysis of multilayer structures containing an arbitrary number of dielectric, metal, magnetic, and birefringent/dichroic layers is presented. An algorithm, based on simple 2×2 matrices, is derived which allows reflection, transmission, absorption, magneto‐optic conversion, birefringence, and dichroism of the structure to be computed on a personal computer. The incident beam is assumed to be plane monochromatic with arbitrary angle of incidence. There are no approximations involved, and the results are direct consequences of Maxwell’s equations.

Abstract: An algorithm for the calculation of the propagation constant of integrated-optics waveguides is developed. The waveguide may consist of any number of layers with complex refractive indexes due to gain and loss. It allows the additional determination of the field distribution. Thus, all parameters necessary for heterostructure laser development can be calculated. The resulting program was run on a personal computer; numerical results are presented. >

Abstract: A data processing system, such as a personal computer, contains bootable DOS programs that are stored in a ROM as an alternate file system in which the files are stored in packed format. When the system is powered on, the programs are rapidly booted up or loaded from ROM into RAM and executed to "instantly" (as it appears to the user) place the system in operation.

Abstract: Method and apparatus for educational games comprising a plurality of printed cards/boards, and a novel low-cost touch pad with interface cable to the personal computer game-port. When an eductional game is played, the player responds to computer questions/words/graphic object by pressing the corresponding answer in the printed card/board which is placed on top of the touch pad. This selection in terms of touched coordinates of the touch pad is sensed by the computer through the computer input/game port. Both computer generated sound and animation graphic pictures in terms of video games or others are used for either positive or negative feedback to the player. A variation of the same apparatus can be used for playing various computerized board games with a plurality of moving game pieces, and game boards by one or more players.

Abstract: A method for detecting the presence of a replacement disk in a fault tolerant, intelligent mass storage disk array subsystem having a microprocessor based controller in a personal computer system and rebuilding the replacement disk independent of the computer system processor. The method calls for the microprocessor controller to run a disk array check at system powerup or at specified intervals at which will detect the existence of a replacement drive. The microprocessor then builds a series of disk drive commands which attempt to read every sector on the replacement disk. The read commands will return a null data read, indicating that the sector must be restored. The microprocessor controller converts the replacement read commands for all sectors on the replacement disk to write-restore commands. The microprocessor executes the write commands and restores the data to the replacement drive.

Abstract: Summary: The neurocybernetic prosthesis (Cyberonics, Inc.) is an implantable, multiprogrammable pulse generator that delivers constant current electrical signals to the vagus nerve for the purpose of reducing the frequency and/or severity of epileptic seizures. The device is implanted in a subcutaneous chest pocket just below the clavicle, similar to cardiac pacemaker placement. The stimulation signal is transmitted from the prosthesis to the vagus nerve through a stimulation lead. The prosthesis can be programmed using any IBM-compatible personal computer with programming software and a programming wand. The electrodes used in the first group of patients were found to break at an unacceptable rate. Design modifications appear to have resolved this problem.

Abstract: Erica is a personal computer operated by eye-gaze. By looking at menu options displayed at different locations on the computer monitor, a disabled user can invoke commands without the need for standard input devices. The design of test entry software for Erica's gaze word processor is described. A basic encoding is accomplished through a static tree-structured menu system, which associates the 85 most common ASCII characters with unique sequences of menus and eye-gaze picks. The expected length of the pick sequences is minimized based on the approximate frequencies of individual characters determined from a 55882 character corpus of English language text. Text entry speeds are further enhanced by adding context-sensitive nodes to the static tree. The menu screens corresponding to these nodes contain the five characters most likely to follow the last two characters entered, based on character transition probabilities derived from the sample corpus. >

Abstract: A computer-controlled testing and licensing system is provided for administering a test to a plurality of users on individual, portable, microprocessor-controlled user testing devices. A license is issued to each user passing the test. Each testing device is microprocessor-controlled and includes an information storage medium such as a RAM card for storing information such as test questions and the user's answers thereto. A display on the device displays output information such as test questions from the information storage medium to the user. User entry pads are displayed at predetermined locations on the display for use in permitting the user to input predetermined information to the information storage medium. A touch screen cooperates with the display to enable the user to input selected predetermined input information such as the test answers by touching the screen at a selected user entry pad while such entry pad is displayed on the display. A personal computer is provided for issuing licenses and for storing information such as the test questions, an answer key to the test, and a comparison procedure to enable the computer to provide the test results. An interface device, such as a card reader, is connected with the computer to cooperate with the RAM card of the testing device to permit information to be transferred between the RAM card and the personal computer.

Abstract: Seventy-four undergraduate students voluntarily participated in a laboratory experiment involving the learning of WordStar, a personal computer word processing software package. The experiment constituted a 2X2X2 factorial design; two levels of computer anxiety (based on a pre-experimental questionnaire), two types of training (lecture/demonstration versus self-paced tutorial) and a matching/nonmatching of personal preference for a particular leaning mode. Results indicated that pre-experimental computer anxiety directly affected post-experimental computer anxiety, number of questions asked during training and future intentions to avoid using WordStar. Type of training affected the number of questions asked and marginally influenced the number of errors. Preferred choice of training demonstrated no main effects but did interact with the other independent variables.

Abstract: The creation and ordering of custom business forms is simplified for short-run orders, allowing the end user of the business form to design and transmit the order on a personal computer. Using appropriate design software, the business form is first designed, and then electronically transferred into a second software program which allows for the selection of a number of business form parameters, and also includes order parameters including quantity and delivery options. The business form parameters from the design software are automatically transferred to the ordering software, and any remaining parameters that must be selected are then selected in a sequence, the order quantity and delivery information is inputted, and the price is calculated, and then the custom business form and order are transmitted in machine form to a second computer remote from the first computer. At the second computer a confirmation of the order is produced, and the order is evaluated to determine where the best facility to print it is. The order is then electronically transferred to the printing location, and after printing it is shipped. The particular manner of highlighting and/or pictorially illustrating the options selectable, and a number of the particular parameters to be selected--such as the edge along which multipart forms are to be attached--are controlled for optimum utility.

Abstract: A video image bank system for preparing an edit tape and associated edit list from a library of stock video image sequences uses a set of video disks with an associated library index. A microprocessor or personal computer is loaded with the library index, and an operator selects an initial set of image sequences from a menu or by using key words, specifically or highlighted in a word processor text file, for a desired effect. Groups of still frames, one from each identified image sequence, are displayed and the operator selects any one of the represented image sequences for addition to the edit tape and the associated edit list. Once all the desired stock video image sequences have been selected from the library and transferred to the edit tape and associated edit list, these sequences may readily be added to a production video sequence using normal editing procedures.

Abstract: The present work is devoted to the numerical study of laminar natural convection flow from a heated horizontal cylinder under diverse surface boundary conditions using the spline fractional step method. A general formulation to treat mixed boundary conditions using the spline approximation has been presented. Numerical solutions have been obtained by solving the Navier-Stokes and energy equations. The results for the isothermal boundary condition as well as for the uniform heat flux are in good agreement with published experimental data and with other solutions presently available in the literature. Some new computations at very high Rayleigh numbers indicate the existence of attached separation vortices in the downstream plume region, the appearance of these vortices being dependent on the values of the Biot number. All results were computed on a personal computer using unequally spaced grids that provided good results with a minimum number of computational points. The numerical scheme presented here app...

Abstract: A security system to prevent un-authorized access to the hard drive of a personal computer system. The security system consists of a plug-in expansion card containing a program on an EPROM, a device driver program which requests the password for access, and other programs to establish the valid passwords for the security system, provide an audit trail of computer access, and other functions. The program on the EPROM disables the floppy drives until a valid password has been entered, forcing the booting process to be controlled and forcing the computer to boot off of the hard drive and request a password via the device driver. A skilled programmer, even with a complete knowledge of the security system's details of operation, can not write a program which can be booted off of a diskette in order to bypass the security system. The passwords and user IDs for the security system are stored on the hard drive of the computer inside the device driver program. The elimination of the need to provide any random access memory, EEROM or other non-volatile memory in which to store the passwords contributes to the low manufacturing cost for the security system.

Abstract: This invention relates to personal computer systems and in particular to an apparatus and method for loading BIOS into a personal computer system from a remote storage location. More particularly, this invention provides a personal computer adapted for use as an economical workstation in a local area network environment (a "LAN station") with provision for loading BIOS into the LAN station from a remote memory storage where the BIOS code is maintained apart from the LAN station.

Abstract: Changes in soil hydraulic properties with depth are common in field soils and need to be accounted for in simulations of field soil-water balances. We show that this is possible using the Kirchhoff transform (K transform) when solving Richards' equation numerically, even though the K transform is not continuous across boundaries between layers with different hydraulic properties. The solution is achieved by dividing the soil into depth elements, using the K transform to compute flow within each element, and then using matric potential (which is continuous across boundaries) to couple the elements. Combination of the K transform with iterative, implicit, mass-conserving methods of solving the flow equations results in efficient solutions that take no more than a few seconds on a personal computer to simulate infiltration. This is achieved with errors of only a few percent in the amount and distribution of soil water. Illustrative simulations using hydraulic properties that represent different soil profiles are given. These include simulation of infiltration into a layered profile consisting of tilled soil with a crust overlying an undisturbed soil, and gradational profiles with hydraulic properties of a sand varying linearly with depth to those of a clay, and conversely. Development and dissipation of surface ponding and perched water tables during simulation runs presented no difficulties. Nor did use of the Campbell formulations for the soil hydraulic properties, despite the discontinuity at the wet end.

Abstract: In the 1970s, the National Institute for Occupational Safety and Health developed a Life Table Analysis System to analyze occupational cohort studies. We have updated the original system by adding two new features: direct standardization with a test for linear trend, and analyses by lagged exposure (either duration of exposure or cumulative exposure). We have also updated US reference rates through 1989. The updated systems and documentation (version F) are available upon request. In collaboration with the National Cancer Institute, we have also developed multiple cause-of-death rate files, which consider contributory as well as underlying cause. These files (also available upon request) will enable investigators to derive the expected prevalence of diseases at death, which can then be compared with the observed prevalence in an exposed cohort. Work is currently underway to produce a personal computer version of the Life Table Analysis System.

Abstract: In a personal health monitor of the type which includes a personal computer capable of implementing a program to determine one or more clinical parameters of the patient and further in which the personal computer includes a display screen portion that folds up from a keyboard portion, an improvement including a housing having a compartment of a size to contain the keyboard portion of the personal computer and to allow the display screen portion of the personal computer to extend above the housing, a keyboard cover capable of covering the keyboard portion of the personal computer in order to prevent access to the keyboard portion of the personal computer and maintain the display screen portion up from the keyboard portion and an input panel capable of conveying input to the personal computer.

Abstract: A broadcast digital sound processing system includes an ISA (Industry Standard Architecture) bus compatible personal computer with a hard disk drove and a sound processor board installed in an expansion slot of the computer. The board includes a stereo input, analog to digital converter (ADC) and a stereo set of digital to analog converters (DAC's) interfaced to a digital signal processor (DSP) chip. A stereophonic audio signal is converted to digital data by the ADC and communicated to the computer by the DSP chip through a two port record first-in/first-out (FIFO) buffer for storage on the disk. A program is played back by communicating a program data file through a two port playback FIFO buffer to the DSP and from there to the DAC's for reconstruction to a stereo set of analog signals. The reconstructed audio signals may then be used as a modulating signal for radio broadcasting.

Abstract: A Bayesian method for monitoring vancomycin concentrations and adjusting regimens in patients with unstable renal function by using a two-compartment population model was evaluated with a personal computer. The population model was derived from data from 12 cardiac outpatients who received single doses of vancomycin. The performance of the method was then tested in 27 acutely ill patients who received multiple doses of vancomycin. Significant renal impairment was observed in 15 patients. Renal function changed in 15 patients. The vancomycin concentrations in the patients with changing renal function were not at steady state during the observation times. Two concentrations in serum (peak and then trough, or trough and then peak) were fitted along with the population model to individualize the parameter values for each patient. All the subsequent concentrations in serum for each patient were then predicted by using the parameter values for each patient. Future concentrations of 118 serum samples were predicted. The mean absolute prediction error was 3.6 +/- 4.5 micrograms/ml, and the mean prediction error was -0.7 +/- 5.3 micrograms/ml. These results confirm that a two-compartment pharmacokinetic model can be sufficiently individualized with the knowledge of just two concentrations of drug in patient serum; it is possible to predict closely subsequent concentrations in serum, and dosing regimens for individual patients can be well adjusted to achieve the chosen therapeutic goals.