Feasibility of a remote monitoring system for patients with an implantable left ventricular assist device using Personal Handy-Phone System telecommunication technology

We have been developing a remote monitoring system for patients with implanted artificial hearts. The remote monitoring system consists of two digital data links: an electromagnetic transcutaneous digital-data transmission (TDT) system between an artificial heart controller inside the body and a mobile computer outside the body, and a public high-speed data transmission service using PHS (Personal Handy-Phone System) between the mobile computer and a host computer in a hospital. The TDT system mainly consists of an ASK (Amplitude Shift Keying) circuit with carrier electromagnetic wave frequencies of 4MHz and 10 MHz and corresponding demodulation circuit, thin loop coil antennas for transmission and receiving, and a one-chip microcomputer for the alarm system for indicating misalignment of antennas outside the transmittable range to ensure error-free data transmission. In our remote monitoring system, motor current and motor rotational angle data from the implanted controller are framed together by a control code for data error checking and correcting at the receiving site, and the data are sent through the PHS connected to the mobile computer. GPS (Global Positioning System) positioning data are also sent to the host computer with control codes. The host computer calculates pump outflow and arterial pressure and displays the data in real-time waveforms. The host computer also displays the patient's position on the map and the condition of the batteries. The results of this study showed that the driving condition of the artificial heart and the subject's position could be remotely monitored on the host computer. It could be concluded that this monitoring system is useful for remote monitoring of patients with an implanted artificial heart.     

A computer program for planimetric analysis of digitized images.

Planimetrical measurements are made to calculate the area of an entity. By digitizing the entity the planimetrical measurements may be done by computer. This computer program was developed in conjunction with a research project involving measurement of the pneumatized cell system of the temporal bones as seen on X-rays. By placing the X-rays on a digitizer tablet and tracing the outline of the cell system, the area was calculated by the program. The calculated data and traced images could be stored and printed. The program is written in BASIC; necessary hardware is an IBM-compatible personal computer, a digitizer tablet and a printer.     

Patient-directed intelligent and interactive computer medical history-gathering systems: a utility and feasibility study in the emergency department

INTRODUCTION: Patients can be used as a resource to enter their own pertinent medical information. This study will evaluate the feasibility of an intelligent computer medical history-taking device directed at patients in the emergency department (ED). METHODS: Two of the authors (MB, RE) developed an expert system that can take patient-directed medical histories. Patients interacted with the computer in the ED waiting room while it gathered a medical history based on chief complaint (CC). A survey was completed post history. A sub-study assessed the computer's ability to take an adequate history for an index CC. We compared the computer and emergency physician histories for the presence or absence of important historical elements. RESULTS: Sixty-seven patients used the interactive computer system. The mean time to complete the history was 5 min and 32s +/- 1 min and 21s. The patient response rate was 97%. Over 83% felt that the computer was very easy to use and over 92% would very much use the computer again. A total of 15 patients with abdominal pain (index CC) were evaluated for the sub-study. The computer history asked 90+/-7%, and the emergency physician asked 55+/-18%, of the important historical elements. These groups were statistically different with a p-value of <0.00001. CONCLUSION: This feasibility study has shown that the computer history-taking device is well accepted by patients and that such a system can be integrated into the normal process of patient triage without delaying patient care. Such a system can serve as an initial mode for documentation and data acquisition directly from the patient.     

A simple computerized system for plotting the locations of cells of specified sizes in a histological section

A computerized plotting system is described which generates an outline of a histological section on an oscilloscope screen, and displays within its boundaries the positions of labeled neurons whose coordinates are sent to the computer electronically. Measured cell diameters can also be entered, allowing the computer to generate displays of the distributions of cells within specified size ranges. All data are saved by the computer, and any portion of a distribution may be examined oscilloscopically at several levels of magnification; moreover, three-dimensional displays may be generated with appropriate programs.     

Generation of dynamic random-element stereograms in real time with a system based on a personal computer

A new system capable of generating static and dynamic random-element stereograms is designed and implemented. The stereogram is composed of a rectangle that can be varied in size, element density, orientation, and horizontal and vertical disparties, and can be swept at several velocities. The system is based on an inexpensive personal computer (Amiga 500), designed to work as a slave system under the control of a host computer (e.g. any personal computer). A colour monitor or two black and white monitors are suitable display devices to view the stereograms. This system is used to perform psycophysical experiments in humans and neurophysiological experiments in behaving monkeys, with the purpose of studying depth perception and binocular vision.     

An on-line computer system for histopathology reporting.

An on-line computer system was developed for issuing histopathology reports as part of an integrated hospital information system. Input is through a Cossor visual display unit with a typewriter keyboard to a Univac 418 III computer. Stored information is available to authorised hospital staff via similar visual display units located in the wards and laboratories. Existing programs and computer staff were used to provide the new service. It has resulted in better method, speedier communication, and saving of laboratory staff time. The system has yet to be fully tested but initial reactions are favourable and indicate that the investment in computer staff time and extra laboratory equipment will be cost effective.     

Computer modeling of interactions of an electric motor, circulatory system, and rotary blood pump

The innovative ventricular assist systems (IVAS) is the next generation ventricular assist device for use as a permanent implantable device. Its practical application depends upon control of the electric motor and interactions of the electric motor, blood pump, and circulatory system. Computer modeling and simulation are necessary to investigate and evaluate the interactions and feasibility of sophisticated control algorithms. In this paper, a computer model of the complete system, including the cardiovascular system, blood pump, and electric motor, is proposed. The model is obtained based on an electric circuit model of the cardiovascular system, a parametric model of the blood pump, and a dynamic model of the electric motor. The cardiovascular system uses nonlinear parameters to simulate the time-varying property of the ventricles, and the cannula collapse effect caused by over-pumping. The blood pump model can be obtained either from pump design data, or test data. The motor control can be operated with closed-loop regulation, depending upon physiologic requirements. Different operation modes (current or speed) of the electric motor can be simulated. The computer model is implemented using MATLAB. Various motor operation modes are simulated and their effects are evaluated. By adjusting the motor input, the pump can achieve proper output so that normal physiology can be obtained. In addition to evaluating existing operation modes and their effect on the physiologic system, the computer simulation results show that this computer model can contribute significantly to the development of new physiologic control algorithms. It is demonstrated that, using this motor-pump-physiology interaction model, development of an innovative ventricular assist system can be greatly facilitated.     

心血管循环系统建模和仿真研究中的功率键合图方法

建立一种心血管循环系统的计算机仿真模型,即描述心血管循环系统内血流动力学变量变化规律的状态方程。该仿真模型可用于生理医学研究及医学辅助教学．文中提出的功率键合图建模方法能够较好地完成对人体循环系统建立仿真模型的工作,并对一个简化的循环系统生理模型进行了计算机仿真研究,仿真结果表明,功率键合图建模方法在生理医学的系统仿真中具有良好的可行性和有效性,作为一种易于理解和统一的建模方法在生理系统仿真领域有     

A surgical pathology reporting and encoding system using industry-standard hardware and software

I describe an efficient, inexpensive, industry-standard computer system that is designed for word processing of surgical pathology reports as well as encoding in Systematized Nomenclature of Medicine (SNOMED) and data storage. This system is capable of maintaining a large database of patient information with coded diagnoses. It is designed to be utilized with readily available stock computer hardware and software without significant customization or any additional programming. The hardware is easily purchased from and can be maintained by a retail, business-oriented computer store. The system described incorporates WordPerfect for word processing and the CAP/SNOMED system for diagnosis encoding and data storage and retrieval.     

基于掌上电脑的袖珍式血压Holter研制

介绍了一种基于掌上电脑的新型袖珍式血压Holter系统。采用低功耗单片机控制血压测量过程，配置与掌上电脑的接口，根据用户需要可通过掌电脑存储，显示，分析血压数据，可对测量参数进行控制修改，并实现数据的远程传输。该系统硬件部分由模拟电路的部分，智能单元部分，外设接口部分三大部分组成，分别给出了各部分结构和工作原理。软件部分主要介绍了血压数据的获取及Holter系统前端与掌上电脑的通信接口部分，该系统具有轻便，智能，操作方便，精度高，功耗低，性能稳定性的特点，有望成为家庭血压监护的理想仪器。     

Evaluation in health informatics: computer simulation

The evaluation of complex medical informatics applications involves not only the information system, but also its impact on the organizational environment in which it is implemented. In instances where these applications cannot be evaluated with traditional experimental methods, computer simulation provides a flexible approach to evaluation. The construction of a computer simulation model involves the development of a model that represents important aspects of the system under evaluation. Once validated, the model can be used to study the effects of variation in system inputs, differences in initial conditions and changes in the structure of the system. Three examples are discussed, namely, a wide-area health care network, physician order entry into a hospital information system, and the use of an information system designed to prevent medical errors that lead to adverse drug events in hospitals.     

Computer analysis system of blood oxygen saturation in an animal hypoxia model

An experimental animal hypoxia model has been developed. It consists of two sensors (an in vitro and in vivo model), an experimental device and a computer signal processing system. This method can easily be applied to determine and analyse blood oxygen saturation at various hypoxia levels. It can also be used to evaluate the accuracy of pulse oximetry over a wide range of oxyhemoglobin desaturation levels. The DC and AC components of recorded red and infra-red signals, the dual-wavelength ratio R₁₂ and the reading of a pulse oximeter (SpO₂) can be automatically calculated and displayed on a computer screen. Preliminary results of the animal hypoxia test indicate that the measurements made by the instrument correlate well with the oxygen saturation readings of the automatic blood gas analyser AVL945. The computer analysis system is suitable for repeated estimations in the animal model.     

A computer data base for information on cancer treatment

The Physician Data Query (PDQ) system is a clinically oriented computer data base developed to make recent information on cancer treatment widely available to the medical community. It represents an effort by the National Cancer Institute to promote diffusion of information about the treatment of cancer throughout the country, facilitate access to clinical trials, and accelerate the practical application of advances in research. The computer system provides information about state-of-the-art cancer treatment, which is updated monthly by an editorial board. It also includes a file of active cancer-research protocols and a directory of physicians and organizations providing cancer care to which physicians can gain access by geographic location as well as other features. PDQ was designed for physicians who may not be familiar with computers, to permit them to search for and display information without learning a specialized search language. PDQ uses a computer mainframe, which allows a large amount of data to be stored and made available to physicians rapidly and accurately. Transmission of information about cancer over commercial telecommunication networks gives health professionals access to PDQ by means of a computer terminal and local telephone lines.     

Development of a wearable computer system with a hands-free operation interface for the use of home health caregiver.

We previously developed a network-based medical care support system called the Hyper Hospital, a computer network with an interface that is dedicated to patient care. In this study, we developed a wearable information system that is designed so that a caregiver can obtain information and control various support devices within the home-care environment. In our system, the wearable computer itself consists of a computer network built into a jacket. Each required function is implemented by a dedicated small computer connected to the in-jacket network. A new function may easily be added to the system by connecting additional computers. A network comprising such a set of single-function computers becomes a highly efficient information system when applied to health care support.     

Consultation use of a computer by general practitioners

Reporting on an experimental field study of computer use by general practitioners during consultations, this paper focuses particularly on the experiences of the doctors in their efforts to communicate concurrently with a patient and a computer. Through the analysis of logs of computer use, video recordings of consultations and interviews with doctors, the authors report on the uptake of the computer facilities, the impact of such use on information handling during the consultation, the doctors' views about using the system, and finally the relationship between doctors' `natural' consulting styles and their uptake and views of the system.     

Control of scintigram presentations by means of a digital computer

A digital computer operates on-line in connection with a colour scanner. All information obtained by the latter in scanning the radionuclide distribution in a patient's organ is passed via an interface into a core memory which serves as a data memory. The main memory of the computer contains an operating system which controls the reproduction programs in addition to accepting data from the scanner and teletype. By this means the scintigrams contained in the data memory can be manipulated in various ways and presented on a storage oscilloscope. There are also additional programs to produce high-speed-printer outputs of a scan, as well as an optimal reproduction, calculated and controlled by the computer, of one or more colour scintigrams.     

A microcomputer keyboard substitute for the disabled

A microcomputer keyboard substitute for use by the disabled is described. The system displays the characters of a standard keyboard as a matrix where each character is enunciated by an LED. The matrix of characters is scanned by two simple switches until the desired character is reached. This is then entered into the computer using one of the two switches. The system is designed for use on the BBC Model B microcomputer but is relatively easily adapted for use on other machines. It operates in parallel with the conventional keyboard and does not depend on additional system software. It does not use any of the standard computer interfaces, and the character grid can be changed to suit the needs of a particular user.     

辅以体外反搏的胸部充气背心辅助循环装置的控制系统

本文描述一套新型无创辅助循环实验装置的控制系统，该实验装置主要用于无创辅助循环方法治疗心衰等心脏疾病的研究。本控制系统采用上下位机结构，上位机是IBM PC兼容机，下位机是单片机系统，上下位机之闻采用USB接口通讯。下位机的主要功能是根据上位机系统传递下来的控制参数，按照特定的算法，产生8路控制脉冲信号，控制电磁阀组动作。上位机的主要功能是实现整个系统的协调控制，模拟信号采集、显示和存盘，ECG的R波识别，控制脉冲的显示，监测参数设置与存盘，工作模式选择，控制方案设置、存盘与调用，以及为用户提供友好的人机交互界面等。为了使系统具有功能可扩展性，满足科研的需要，该系统利用了PSD芯片技术和设计了功能扩展插槽。     

An IBM-PC and Commodore 64 microcomputer-based system for elicitation and recording of eyeblink reflexes

The eyeblink reflex is well suited for the study of habituation, sensitization, reflex modification and classical conditioning in humans. A microcomputer-based system for elicitation and recording of the eyeblink reflex is described. The system consists of three functional units: (1) an air-pressure bottle and pressure-reducing valves for delivery of air puffs to the eye in order to elicit the eyeblink reflex, and a CBM 64 computer for presentations of auditory stimuli in conjunction with air puffs; (2) a pair of light-emitting diodes and photocells placed in a pair of goggles placed on the subject for detection of eyeblinks; (3) an IBM-compatible personal computer, equipped with the ASYSTANT + software for eyeblink data acquisition and overall control of experiment and parameters. The system is presently in use in our laboratory, and technical details about the system can be obtained by writing to the first author.     

Real-time digital-filter-based data-acquisition system for the detection of neural signals

A data-acquisttion system has been built which performs real-time digital finite-impulse-response filtering to aid in the detection of neural signals. The system acts as an intelligent peripheral to a host laboratory computer, Digital filtering is done by a special-purpose LSI signal-processing chip, while the system's controller is a standard microprocessor, The system is programmable, permitting many acquisition modes to be exectuted, and can be replicated to create a multiple-channel system. A typical sampling rate is 20 kHz; maximum rates depend on the acquisition mode. Significant data compression can be achieved using the system resulting in longer permissible experimental recordings.