R. Patz

Implementation of Elliptic-Curve Cryptography on Mobile Healthcare Devices

Over the past few years, much research attention has been afforded to the application of remote patient monitoring using embedded mobile devices. However, relatively little research has been done to investigate the security aspects of such scenarios. The present work describes the implementation of a cryptographic algorithm based on elliptic curves on an embedded mobile device useful for healthcare purposes. A personal digital assistant (PDA) has been chosen to be the hardware platform for the implementation as it is particularly suitable for remote patient monitoring applications. The motivation for this paper was to formulate a secure protocol which comprises of signature, encryption and authentication (SEA) as a combined ingredient of secure remote patient monitoring application using mobile devices. This needed to be easy to use and computationally efficient in order to be acceptable to both clinicians and patients and the results indicate a positive outcome.

Performance of a FPGA-based Direct Digitising Signal Measurement module for MIT

A novel MIT Direct Digitising Signal Measurement (DDSM) module has been developed aiming to replace the centralised NI PXI system and PC processing of the Cardiff Mk2 MIT system, thus offering potentially faster measurement cycles. The proposed module replaces the signal acquisition and offers local processing. The core of the system is a Xilinx Spartan-3 FPGA, paired with a dual 14-bit ADC capable of 120 MS/s. The FPGA provides a flexible and fast platform for data acquisition and processing. The phase is measured using a two channel phase sensitive detection via I/Q demodulation. Built-in averaging reduces the data to a single signal period of 12 samples before multiplying and accumulating the data with the I/Q signals. The system provides the I/Q values for both channels directly, eliminating the long download and processing times required by the centralised NI PXI system currently used in the Cardiff Mk2 MIT system. The module acquires both the measurement and the reference signal and has a phase noise as low as 7.5m° using a measurement time constant of 6ms. The phase drift over 6 hours is considerable at 119m°. Details of the module, circuits and algorithms employed are provided as are the results of the performance measurements.

A Magnetic Induction Tomography system with sub-millidegree phase noise and high long-term phase stability

This paper describes the design and performance of a 5-channel multi-frequency Magnetic Induction Tomography (MIT) data acquisition system operating in the frequency range 0.5 – 14MHz. A novel phase stabilization scheme is employed to reduce phase drift of the system. The signals detected by the sensors are amplified and digitized using a 60MS/s high speed data acquisition system. The amplitude and phase are measured using an FFT-based algorithm.

Parallelization methods for implementation of a magnetic induction tomography forward model in symmetric multiprocessor systems

This paper describes four parallelization approaches used in a finite-difference-based electromagnetic modeller for application in magnetic induction tomography (MIT) and suitable for implementation on computer systems with symmetric multiprocessor (SMP) architecture. The approaches include: (i) splitting by coils using a distributed memory approach, (ii) splitting by physical domain using a distributed memory approach, (iii) splitting by physical domain using hybrid distributed/shared memory approach and (iv) splitting by both coils and physical domain using multi-level distributed and shared memory approaches respectively. All four approaches were implemented and tested on an IBM SP supercomputer. Coil parallelization was the most efficient method due to low inter-processor communication requirements but was limited by the number of coils in the MIT system. Approaches (ii) and (iii) allowed a larger number of processors to be employed but the efficiency versus number of processors was found to drop at a faster rate in comparison to (i). The fourth approach both allowed a larger number of processors to be employed and was found to provide higher efficiency than the parallelization by physical domain only. This multi-level hybrid approach therefore appears to offer an effective parallelization method for implementation of the MIT forward model on SMP clusters.

Conformance Testing of Complex Services Exemplified with the IMS' Presence Service

Testing of network elements on conformance to their respective protocol specification has become a common phase during the development process. For this purpose, special programming languages, such as TTCN-3, as well as tools are available. In the context of testing complex communication architectures on conformity, further difficulties were revealed. When testing hybrid network elements with multiple interfaces and different protocols, new testing methods are needed. Systems under test have to be stimulated on all interfaces with emulated network elements, which have to be controlled and synchronised. This paper considers the requirements, design, implementation and application of testing methods for complex communication architectures. We developed an executable set of test cases for IP Multimedia Subsystems Presence Service, as prominent example for a complex communication architecture. It is our plan to use these developed test cases as an input for ETSIs work on the conformance and interoperability standardisation process for IMS. This paper is based on a current research project funded by the government of Lower Saxony within the AGIP Programme and a co-operation with the University of Glamorgan, Wales and Testing Technologies IST, Berlin as commercial partner.

Evaluation of Parallel FFT Implementations on GPU and Multi-core PCs for Magnetic Induction Tomography

Magnetic Induction Tomography is a relatively new non-invasive modality for the imaging of the electrical properties of materials which is currently under investigation for a variety of industrial and biomedical applications, in particular the detection and monitoring of cerebral haemorrhage. The speed of FFT-based phase measurement algorithms employed in some current MIT systems is however a major limit to higher data acquisition rate and precision.

A method for increasing the phase-measurement stability of Magnetic Induction Tomography systems

A novel method for increasing the phase measurement stability of Magnetic Induction Tomography (MIT) systems is described. The principle of the method is discussed and practical implementations of the method for (i) an MIT system in which the sensors are sensitive to the primary magnetic field, and (ii) an MIT system employing gradiometer sensors, are described. The results of measurements of the phase noise and long term phase stability of MIT systems employing the new method are given. The method was found to provide very significant improvements in the measurement stability of MIT systems, in particular for the long term amplitude and phase drift performance of systems of type (i). The new method potentially enables high precision / low frequency MIT system to be implemented without the use of gradiometers and may be particularly suitable for use in long-term monitoring applications.

Micro-Sized Enterprises, Innovation and Universities: A Welsh Perspective

This study considers the linkage between micro-sized enterprises and other organizations, especially universities, in relation to the innovation process. The focus of the research is on non-start-up enterprises in Wales and how they develop their products. The research methodology adopted is a thematic literature review and the case study approach. The findings demonstrate that there are additional barriers to innovation in terms of legislation and regulation when micro-sized enterprises endeavour to overcome their knowledge gap through collaborating with universities. It is noted that there has been minimal research examining the knowledge gap encountered by micro-sized enterprises and how they attempt to overcome the barriers to collaborating with universities.

Magnetic Induction Tomography Measurement System Based on a Fixed Point DSP Module

Magnetic Induction Tomography (MIT) is a noncontact method for imaging the passive electrical properties of objects. An array of excitation coils are employed to induce eddy currents within objects placed within the MIT system and an array of detector coils are then used to detect the resulting perturbation of the primary magnetic fields produced by the eddy currents. Measurement of both the detected signal magnitude and phase must be made.

A Parallel Implementation of a Forward Model for Magnetic Induction Tomography

This paper describes a parallel implementation of a Magnetic Induction Tomography (MIT) forward model on a PC workstation cluster. The forward modeler is a finite-difference based algorithm and is used to compute the sensitivity matrix with the reciprocity theorem. The parallelization works by either splitting the problem by different excitation and detection coils or by splitting the physical space into multiple layers. This paper provides results of parallelization by coils. A distributed memory approach was implemented using a Message Passing Interface library (MPICH) with FORTRAN.