Bryan Woodward

Design of a telemedicine system using a mobile telephone

This paper describes the design of a prototype integrated mobile telemedicine system that is compatible with existing mobile telecommunications networks and upgradable for use with third-generation networks. The system, when fully developed, will enable a doctor to monitor remotely a patient who is free to move around for sports medicine and for emergency situations.

Underwater acoustic channel models for 4800 b/s QPSK signals

Two computer models are presented, one for short-range and one for long-range propagation of acoustic signals through an underwater channel from a transmitter to a receiver. In the short-range model, the received signal is due to a direct path (steady component) and a random path (diffused component) that could be the result of boundary scattering. For the long-range case, the received signal is the superposition of a number of time-delayed, randomly propagated components arriving by different paths. Both models assume perfect transmitter-receiver synchronization but use realistic channel time delays. They demonstrate the time-varying characteristics of underwater acoustic channels and are used in simulations to evaluate the performance of the detection technique. >

The comparative performance of mobile telemedical systems based on the IS-54 and GSM cellular telephone standards

The performance of mobile telemedical communications links based on the IS-54 and GSM cellular telephone standards the most widely used commercial systems in North America and Europe, respectively was studied by computer simulations. A photoplethysmography signal was used to investigate the transmission of medical data over simulated mobile phone channels. Various conditions were simulated in the communications path between a mobile transmitter and receiver, from perfect to distorted conditions. The results showed successful transmission, with bit error rates of better than 10-7 at the receiver for the IS-54 standard. The performance of the IS-54 standard was superior to that of GSM in terms of minimum path delay variations, especially in builtup urban areas.

Design of mobile telemedicine systems using GSM and IS-54 cellular telephone standards

This paper presents an overview of the design of mobile telemedical systems using cellular telephone channels. A mobile telemedicine communication system was studied using both the GSM and the IS-54 standards, which are the most widely used commercial cellular telephone systems in Europe and North America, respectively. A simulation using a photoplethesmography signal showed successful transmssion of data with bit error rates of less than 10-7 at the receiver for the IS-54 standard and less than 10-5 for the GSM standard, depending on the mobile channel conditions used.

Digital underwater acoustic voice communications

This paper describes the design of an underwater acoustic diver communication system controlled by a digital signal processor. The speech signal transmission rate is compressed by using linear predictive coding (LPC) and the extracted parameters are transmitted through the water to a synchronized receiver by employing digital pulse position modulation (DPPM). The pulse position in each time frame is estimated by an energy detection and decision algorithm which enables the received LPC parameters to be recovered and used to synthesize the speech signal.

Microcontroller-based underwater acoustic ECG telemetry system

The paper presents a microcontroller based underwater acoustic telemetry system for digital transmission of the electrocardiogram (ECG). The system is designed for the real time, throughwater transmission of data representing any parameter, and it was used initially for transmitting in multiplexed format the heart rate, breathing rate and depth of a diver using self contained underwater breathing apparatus (SCUBA). Here, it is used to monitor cardiovascular reflexes during diving and swimming. The programmable capability of the system provides an effective solution to the problem of transmitting data in the presence of multipath interference. An important feature of the paper is a comparative performance analysis of two encoding methods: pulse code modulation (PCM) and pulse position modulation (PPM).

Advances in telemedicine using mobile communications

Future telemedicine systems will exploit mobile communications technology so that patients who are free to move around at home or at work, or in emergency medical situations, can be monitored in a hospital. At present, the GSM mobile telephone cellular network is limited to 9.6 kbps, but with the introduction of the third generation (3G) network, data rates of 144 kbps will be available, giving scope for the transmission of much more biomedical data as well as voice and video data if required. The paper discusses some of the issues involved and outlines the types of systems that will be viable with the new technology. A modular structured GSM-based mobile telecardiology system is used to illustrate the concept. The system carried by the patient comprises a mobile telephone linked to a processing unit by an infrared channel. The telephone/processor unit accepts signals from one or more sets of sensors attached to the patient. The prototype version is designed to transmit digitised electrocardiogram signals to a hospital via the GSM mobile telephone cellular network.

Monitoring heart disease and diabetes with mobile internet communications

A telemedicine system is described for monitoring vital signs and general health indicators of patients with cardiac and diabetic conditions. Telemetry from wireless sensors and readings from other instruments are combined into a comprehensive set of measured patient parameters. Using a combination of mobile device applications and web browser, the data can be stored, accessed, and displayed using mobile internet communications to the central server. As an extra layer of security in the data transmission, information embedded in the data is used in its verification. The paper highlights features that could be enhanced from previous systems by using alternative components or methods.

Data acquisition in a wireless diabetic and cardiac monitoring system

A telemedicine system is described for monitoring the vital signs and general health indicators of patients with cardiac and diabetic conditions. Telemetry from wireless sensors and readings from other instruments are combined into a comprehensive patient health dataset. The data can be stored, accessed and displayed using mobile Internet communications with a server. The paper concentrates on the data acquisition process, using an alternative sensor network protocol to Bluetooth and manual data entry into a smartphone application and HTML5 web browser.

Design constraints and error analysis of the temporal correlation log

The basic principles of spatial and of temporal correlation sonar for velocity measurement of both surface vessels and autonomous underwater vehicles are considered, showing the advantages of using a pulsed temporal correlation log. To achieve correlation, the conditions for waveform invariance must be met, and there is a velocity-depth limitation to be observed; these are described in detail. Practical design constraints such as the effects of different transducer sizes/geometry and carrier frequencies are also considered. >