M.S. Young

Temperature measurement system based on ultrasonic phase-shift method

The purpose of this study describes an ultrasonic system which can measure air temperature based on the variations of sound speed in the air. Changes of the sound speed are in turn determined by detecting the phase-shift variations of a 40 kHz continuous ultrasonic wave. Phase angle differences between transmitted and received signals are determined by a FPGA digital phase detector and then analyzed in an 89C51 single-chip microcontroller. Theoretical accuracy of measurement is within 0.05 L at an inter-transducer distance of 10 cm. Temperature variations are measured within 10 ins. The main advantages of the temperature measurement system are high resolution, rapid temperature measurement, noncontact measurement and easy implementation.

An Accurate Ultrasonic Distance Measurement System with Self Temperature Compensation

Abstract This study proposes an accurate distance measurement system which has self-temperature-compensation (STC) with the environmental average temperature in space, rather than a single point temperature. This system combines both the amplitude modulation (AM) and the phase modulation (PM) of the pulse-echo technique. The proposed system can reduce error caused by inertial delay and the amplitude attenuation effect when using the AM and PM envelope square waveform (APESW). The proposed system adopts two identical measurement hardware sets using the APESW ultrasonic driving waveform. The first set measures the sound velocity (the environmental average temperature information is also involved) as the result of the temperature compensation data for the second distance measuring set. Without using a temperature sensor, experimental results indicate that the proposed STC distance measurement system can accurately measure the distance. The experimental standard deviation of the linearity with respect to the distance is found to be 0.21 mm at a range of 50 to 500 mm. Moreover, the proposed systems temperature uncertainty effect produced a standard deviation of 0.093 mm, while the temperature sensor systems uncertainty effect produced a standard deviation of 0.68 mm. The STC manner is simple and can be easily adapted for robotic applications for which the temperature sensors can not easily be set up and placed. The main advantages of this STC distance measurement system are: high resolution, low cost, and ease of implementation.

Implementation of an Internet‐Based Data Acquisition System Prototype for Drugs Storage

Abstract This study presents an Internet‐based data acquisition system (IDAS) prototype for monitoring the storage temperature and humidity of drugs. It allows direct real‐time TCP/IP protocol interface of any serial‐interfaced and parallel‐interfaced device to an Ethernet, even the Internet, providing a non‐proprietary communication link between virtually any type of host, with both passive and active connection capabilities. The main advantages of IDAS are easy implementation, low cost, rapid measurement, anti‐virus capabilities, and the avoidance of new dedicated wiring tangles by use of existing telephone, Ethernet or Internet linkage. IDAS theory and practical implementation are presented, as well as experimental verification for a variety of conditions. It is found that actual performance is limited by server PC performance, specifically, PC interruptions resulting from computer viruses, operational errors by unauthorized users, automatic updating of the PC operating system, etc. Both system set‐up and operational costs are far lower than in traditional systems using individual PCs to connect remote sensors to the Internet.

Respiratory Rate Monitoring Gauze Mask System Based on a Pyroelectric Transducer

This paper presents a gauze mask type respiratory rate monitoring system. The proposed system attaches a flexible piezo film sensor to a gauze mask to sense the respiratory airflow. During breathing, the temperature of respiratory airflow varies in inspiration and expiration phases. This temperature variation could be detected by the pyroelectricity of the piezoelectric film sensor. Monitoring the sensor output variation therefore could monitor the subjects respiratory rate. This pyroelectric response is faster than traditional temperature-sensitive devices (thermistors and thermocouples). In addition, the flexible property of the evaluated piezo film sensor makes it easily been attached with a gauze mask. The advantages of this respiratory rate monitoring system are rapid response time, low cost, and ease of implementation.

Design of an ultrasonic system for temperature measurement in an infant incubator

In this paper, we develop a binary frequency shift-keyed (BFSK) ultrasonic measurement method based on the speed of sound to measure the temperature. The proposed algorithm combines both time-of-flight (TOF) method and the phase-shift method. A single-chip microcomputer-based BFSK signal generator and phase detector was designed to record and compute the TOF, two phase shifts and the resulting temperature, which were then sent to PC. The PC is used for calibrating the system and recording or controlling the temperature in an infant incubator. Theoretically, the resolution of temperature was found to be within /spl plusmn/0.2/spl deg/C when the distance between the transmitter and receiver is 1 m. But the temperature can be verified by with an accuracy of /spl plusmn/1/spl deg/C by our laboratory prototype. The main advantage of this ultrasonic velocity measurement system is a quick and precise monitoring of the temperature in an infant incubator.

A new ultrasonic measurement system for tremor

A new binary amplitude-shift-keyed (BASK) ultrasonic tremor measurement system for use in isothermal air is developed. Our microcomputer-based system includes two important parts. One of which is BASK modulation signal generator. The other is a phase meter designed to record and compute the phase shifts of the three different frequencies and the result motion is then sent to either an LCD for display or a PC for calibration. By the proposed method, we can conduct larger range measurement than the phase-shift method and also get higher accuracy compared with the time-of-flight (TOF) method. Experiments are done in the laboratory using BASK modulation for the frequencies of 200 Hz and 1 kHz with a 40 kHz carrier.

Design of a Three-Lead Synthetic ECG Generator Using the Simplified McSharry's Model

Abstract Recently, due to the dramatic improvement in computing capabilities and processing speed of microcontrollers and digital signal processors, many analytic algorithms for electrocardiograms (ECGs) have been developed and applied to a variety of portable electronic devices. In order to test whether the algorithms can analyze the various morphologies of electrocardiogram well, it is necessary to expend much effort collecting various ECG samples to establish an ECG database. Therefore, this paper simplifies and adopts a synthetic electrocardiogram model composed of three coupled differential equations proposed by Dr. McSharry et al. (2003), as well as utilizes an improved fourth-order Taylor series to quickly approximate the exponential function within the differential equation of a simplified synthetic ECG model so that, when studying ECG analytic algorithms, the graphical user interface (GUI) application “Synthetic Waveforms Control Panel,” developed by the author using LabVIEW, can be used to attain the desirable morphology of electrocardiogram as well as the time intervals between peaks (P, Q, R, S, T) and heart rate. The parameters of the adjusted synthetic ECG model are then sent to the memory of a synthetic ECG generator through a USB interface, and the ECG generator will generate three synthetic electrocardiograms of Einthovens triangle for testing the electrocardiogram analytic algorithms.

Design and Implementation of a Three-Dimensional Temperature Measurement System for Indoor Object Monitoring

Abstract In this paper, we report the design of a system equipped with a multielement thermopile for monitoring the temperature of indoor objects. We evaluate the performance of our measurement system, which comprises two microcontrollers, an analog-to-digital converter, two stepping motors, and four microswitches. We use an RS-232 or a wireless RS-232 interface that transmits temperature values and uses colors to indicate the temperature range on a PC screen. The system is inexpensive and can be used for three-dimensional temperature measurements. The effective detection range of this system is from −20°C to 120°C or 180°C; the measurement error is within ±1°C. Experimental results demonstrate the effectiveness of the system for monitoring temperatures of remote indoor objects. Hence, it is possible to identify a hot spot in electrical heating equipment, a smoldering source hidden in upholstery, or the activities of a person in a room.

User Interface for Multitasking on Internet‐Based Embedded Systems

Abstract User interfaces are designed for particular operating systems (OSs). Designing a user interface for no specific OS is a difficult task. This task becomes increasingly complex when a user interface is needed for multi‐tasking, particularly for Internet‐based embedded systems. Furthermore, storage size is a critical component of resource‐limited systems. This work presents a novel method for writing a very small program that can function as a universal interface for multi‐tasking embedded systems, regardless of which OS is used or whether an OS exists. This study presents a model‐driven approach. Both menu models and item models are designed as programming models. These models are written in C language. The proposed method can be implemented regardless of the hardware and computer language used. The proposed method is implemented in an Internet‐capable data acquisition system with a two‐row LCD display. Implementation results are discussed.

A Web-based data acquisition system

This study presents a Web-based data acquisition system which measures instrument data through Internet. We named this Web-based data acquisition system, IIG (Internet-based Instrument Gateway). IIG supports passive connection and active connection. In one experiment, IIG is set on private network and server is set on public network. This situation need IIG creates connection from private network actively. After the connection between IIG and server established, instrument data can be delivered to the server. The binary data are analyzed and then displayed on window. Those data can be saved to the database for future analysis. The main advantages of IIG are easy implementation, rapid measurement, anti-virus, and selectable active or passive connection. It is very suitable for instrument measuring system and easily integrated into instrument.