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P. Kaplanis

University of London, Medical PHysics and Biomedical Engineering, Alumnus

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Constantinos Pattichis

siti revalina ahmad

Kalaivani Chellappan

National University of Malaysia

Rubana chowdhury

Northern University Bangladesh

Christos C Kannas

University of Cyprus

Fernando di Sciascio

Universidad Nacional de San Juan

Lydia Abdul Latif

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Papers by P. Kaplanis

Multi-scale AM–FM analysis for the classification of surface electromyographic signals

Biomedical Signal Processing and Control, 2012

In this work, multi-scale amplitude modulation-frequency modulation (AM-FM) features are extracte... more In this work, multi-scale amplitude modulation-frequency modulation (AM-FM) features are extracted from surface electromyographic (SEMG) signals and they are used for the classification of neuromuscular disorders. The method is validated on SEMG signals recorded from a total of 40 subjects: 20 normal and 20 abnormal cases (11 myopathy, and 9 neuropathy cases), at 10%, 30%, 50%, 70% and 100% of maximum voluntary contraction (MVC), from the biceps brachii muscle. For the classification, three classifiers are used: (i) the statistical K-nearest neighbor (KNN), (ii) the self-organizing map (SOM) and (iii) the support vector machine (SVM). For all classifiers, the leave-one-out methodology is used to validate the classification of the SEMG signals into normal or abnormal (myopathy or neuropathy). A classification success rate of 78% for the AM-FM features and SVM models was achieved. These results also show that SEMG can be used as a non-invasive alternative to needle EMG for differentiating between normal and abnormal (myopathy, or neuropathy) cases.

A Surface Electromyography Classification System

The objective of this study was to investigate whether surface electromyography (SEMG) signals ma... more The objective of this study was to investigate whether surface electromyography (SEMG) signals may be used to discriminate between normal (NOR), myopathy (MYO) and neuropathy (NEUR) subjects. Ninety-one normal subjects participated and 20 patients (11 MYO and 9 NEUR). Recorded signals were obtained for 5 seconds at 10, 30, 50 70 and 100% of Maximum Voluntary Contraction (MVC). Five parameters were obtained, two from the time domain (turns and zero crossings per second), two from the frequency domain (median frequency and total power per second) and one from the bi-frequency domain (bispectrum peak amplitude). The KNN classifier with the leave-one-out method was used for classification whereas the Self Organising Feature Maps (SOFM) was used for cluster analysis and visualization of the group separation. Results have shown that separation of normal subjects from neuromuscular diseased patients is possible with a success rate of the order of 83%, whereas separation of subjects from th...

Analysis of Surface EMG Using Second and Third - Order StatistcsSpectra-Based Parameters

The objective of this ongoing study is to investigate if surface electromyography signals (SEMG),... more The objective of this ongoing study is to investigate if surface electromyography signals (SEMG), could be characterized using bispectrum and third–order statistics/spectra (HOS) – based parameters. In particular, the bicoherence index was used for measuring the degree of Gaussianity of the signal. The linearity of the signal, based on deciding whether or not the estimated bicoherence is constant, together with the amplitude of the bispectrum, its coordinates and its variance from the peak were estimated. Power spectrum and time domain parameters were also estimated. Experimental results from the analysis of real SEMG data recorded from thirty-three adult normal subjects (13 female and 20 male) aged between 20 and 50 years old, proved an influence of contraction on the aforementioned parameters (p<0.05). Further work is currently in progress in order to evaluate the usefulness of HOS in subjects suffering from neuromuscular disorders.

Analysis of neuromuscular disorders using statistical and entropy metrics on surface EMG

WSEAS Transactions on Signal Processing archive, 2008

This paper introduces the surface electromyogram (EMG) classification system based on statistical... more

Powers of generic ideals and the weak Lefschetz property for powers of some monomial complete intersections

Journal of Algebra, 2018

Given an ideal I = (f1, . . . , fr) in C[x1, . . . , xn] generated by forms of degree d, and an i... more Given an ideal I = (f1, . . . , fr) in C[x1, . . . , xn] generated by forms of degree d, and an integer k > 1, how large can the ideal I k be, i.e., how small can the Hilbert function of C[x1, . . . , xn]/I k be? If r ≤ n the smallest Hilbert function is achieved by any complete intersection, but for r > n, the question is in general very hard to answer. We study the problem for r = n + 1, where the result is known for k = 1. We also study a closely related problem, the Weak Lefschetz property, for S/I k , where I is the ideal generated by the d'th powers of the variables.

$Research paper thumbnail of Classification of surface electromyographic signals by means of multifractal singularity spectrum$

Classification of surface electromyographic signals by means of multifractal singularity spectrum

Medical & Biological Engineering & Computing, 2012

In order to effectively control a prosthetic system, considerable attempts have been made in rece... more In order to effectively control a prosthetic system, considerable attempts have been made in recent years to improve the classification accuracy of surface electromyographic (SEMG) signals. However, the extraction of effective features is still a primary challenge for the classification of SEMG signals. This study tried to solve the problem by applying the multifractal analysis. It was found that the SEMG signals were characterized by multifractality during forearm movements and different types of forearm movements were related to different multifractal singularity spectra. To quantitatively evaluate the multifractal singularity spectra of the SEMG signals, the areas of the singularity spectrum curves were calculated by integrating the spectrum curves with respect to the singularity strengths. Our results showed that there were several separate clusters resulting from singularity spectrum areas of different forearm movements when two channels of SEMG signals were used in this experimental research, which demonstrated that the multifractal analysis approach was suitable for identifying different types of forearm movements. By comparing with other feature extraction techniques, the multifractal singularity spectrum approach provided higher classification accuracy in terms of the classification of SEMG signals.

The international context of education, training and certification for medical physicists in Europe, North America and Australasia

IFMBE Proceedings, 2013

Problems faced after the transition from a film to a DDR Radiology Department

by P. Kaplanis, S P Spyrou, and A. Stefanoyiannis

IFMBE Proceedings

Page 1. T. Jarm, P. Kramar, A. upanič (Eds.): Medicon 2007, IFMBE Proceedings 16, pp. 879882, 2... more

Computer Aided Assessment of Certain Neuromuscular Disorders Based on Surface Electromyography

The objective of this study was to investigate the usefulness of Surface Electromyography (SEMG),... more The objective of this study was to investigate the usefulness of Surface Electromyography (SEMG), in the clinical laboratory. Towards this goal, recordings from 94 normal subjects (NOR) and 20 neuromuscular subjects (11 myopathy (MYO) and 9 neuropathy (NEURO)) were recorded at 10, 30, 50, 70 and 100% of maximum voluntary contraction. These signals were analysed in the time, frequency and bi-frequency domains. The time-domain parameters, turns and zero crossings per second, increased with force level (FL), for all three groups. Frequency-domain, median and mean frequencies, decreased with FL for the NOR group. Frequency at maximum power was unaffected with FL, but differences were found between all groups of subjects. Maximum and total power increased with FL for all groups, with MYO subjects having significantly higher values for the latter parameter. Bi-frequency parameter, bispectrum peak amplitude increased with FL only for the NOR group and significant differences were found bet...

Classification of Neuromuscular Disorders Using Wavelets and Entropy Metrics on Surface Electromyograms

Abstract: The aim of this study was an investigation whether the examined subjects can be classif... more Abstract: The aim of this study was an investigation whether the examined subjects can be classified as normal, myopathic or neuropathic, based on 4-channel surface electromyographic (SEMG) recordings of the biceps brachii muscle recorded at isometric voluntary contractions. Five different force levels were used: 10, 30, 50, 70 and 100 % of maximum voluntary contraction (MVC), with each recording lasting 5 seconds. The amplitude of SEMG recordings was processed using dyadic Haar wavelet and entropy metrics. In each scale, the entropy of transformed SEMG was calculated and a set of 80 features per subject was formed. From existing data, we created five dataset, where subject were labelled based on the type as: normal/abnormal, normal/myopathic, normal/neuropathic, myopathic/neuropathic and normal/myopathic/neuropathic. Five classification techniques from the WEKA machine learning package were used, i.e. decision trees j48, random trees, random decision forests, support vector machine...

Analysis of Neuromuscular Disorders Using Statistical and Entropy Metrics on Surface EMG

WSEAS Transactions on Signal Processing, Feb 1, 2008

Abstract:-This paper introduces the surface electromyogram (EMG) classification system based on s... more Abstract:-This paper introduces the surface electromyogram (EMG) classification system based on statistical and entropy metrics. The system is intended for diagnostic use and enables classification of examined subject as normal, myopathic or neuropathic, regarding to the acquired EMG signals. 39 subjects in total participated in the experiment, 19 normal, 11 myopathic and 9 neuropathic. Surface EMG was recorded using 4-channel surface electrodes on the biceps brachii muscle at isometric voluntary contractions.

Wavelet-based quantitative evaluation of a digital density equalization technique in mammography

IFMBE Proceedings, 2007

Wavelet-based quantitative evaluation of a digital density equalization technique in mammography

IFMBE Proceedings, 2007

Problems Faced After the Transition From a Film to a DDR Radiology Department

… Conference on Medical …, 2007

Page 1. T. Jarm, P. Kramar, A. upanič (Eds.): Medicon 2007, IFMBE Proceedings 16, pp. 879882, 2... more

The Education and training of clinical medical physicists in 25 European, 2 North American and 2 Australasian countries: Similarities and differences

Physica Medica, 2012

Biomedical Physics Education of Medical and Healthcare Personnel the Cyprus Experience

IFMBE Proceedings, 2009

ABSTRACT Physics has always been a component of the curriculum of non-physics healthcare professi... more ABSTRACT Physics has always been a component of the curriculum of non-physics healthcare professions. Current curricula content varies extensively across Europe. The physics education and training of non-physics healthcare professionals is becoming progressively more important mainly due to the rapid increase in the number and sophistication of medical equipment used by these professionals. In most institutions the Medical Physicist undertakes the task to fill the gap in the additional education and training requirements. This article presents the experience of the Medical Physics Department of Nicosia General Hospital in personnel education and training.

Comparison of Lead-free and Conventional x-ray aprons for Diagnostic Radiology

IFMBE Proceedings, 2009

Quality Assurance of Diagnostic Monitors

IFMBE Proceedings, 2009

... kcare.co.uk . Author: Stelios Christofides Institute: Nicosia General Hospital Street: 215 Ol... more

Education and training of medical physicists in South East Asia: accomplishments and challenges

Biomedical imaging and intervention journal

John Cameron has made significant contributions to the field of Medical Physics. His contribution... more John Cameron has made significant contributions to the field of Medical Physics. His contributions encompassed research and development, technical developments and education. He had a particular interest in the education of medical physicists in developing countries. Structured clinical training is also an essential component of the professional development of a medical physicist. This paper considers aspects of the clinical training and education of medical physicists in South-East Asia and the challenges facing the profession in the region if it is to keep pace with the rapid increase in the amount and technical complexity of medical physics infrastructure in the region.

Influence of isometric voluntary contraction on time and frequency domain parameters of surface EMG

The main objective of this paper was to investigate the effect of increase of isometric voluntary... more The main objective of this paper was to investigate the effect of increase of isometric voluntary contraction (IVC) on surface EMG recorded from the Biceps Brachii (BB) muscle. Five different force levels (FL) were used: 10, 30, 50, 70 and 100% of maximum voluntary contraction (MVC), with each recording lasting 5 seconds. The following sets of parameters were extracted:(i) in the time domain (turns (ts) and zero crossings per second (zc)), and (ii) in the frequency domain (median frequency (fp), frequency at maximum power (fx), ...

Multi-scale AM–FM analysis for the classification of surface electromyographic signals

Biomedical Signal Processing and Control, 2012

In this work, multi-scale amplitude modulation-frequency modulation (AM-FM) features are extracte... more In this work, multi-scale amplitude modulation-frequency modulation (AM-FM) features are extracted from surface electromyographic (SEMG) signals and they are used for the classification of neuromuscular disorders. The method is validated on SEMG signals recorded from a total of 40 subjects: 20 normal and 20 abnormal cases (11 myopathy, and 9 neuropathy cases), at 10%, 30%, 50%, 70% and 100% of maximum voluntary contraction (MVC), from the biceps brachii muscle. For the classification, three classifiers are used: (i) the statistical K-nearest neighbor (KNN), (ii) the self-organizing map (SOM) and (iii) the support vector machine (SVM). For all classifiers, the leave-one-out methodology is used to validate the classification of the SEMG signals into normal or abnormal (myopathy or neuropathy). A classification success rate of 78% for the AM-FM features and SVM models was achieved. These results also show that SEMG can be used as a non-invasive alternative to needle EMG for differentiating between normal and abnormal (myopathy, or neuropathy) cases.

A Surface Electromyography Classification System

The objective of this study was to investigate whether surface electromyography (SEMG) signals ma... more The objective of this study was to investigate whether surface electromyography (SEMG) signals may be used to discriminate between normal (NOR), myopathy (MYO) and neuropathy (NEUR) subjects. Ninety-one normal subjects participated and 20 patients (11 MYO and 9 NEUR). Recorded signals were obtained for 5 seconds at 10, 30, 50 70 and 100% of Maximum Voluntary Contraction (MVC). Five parameters were obtained, two from the time domain (turns and zero crossings per second), two from the frequency domain (median frequency and total power per second) and one from the bi-frequency domain (bispectrum peak amplitude). The KNN classifier with the leave-one-out method was used for classification whereas the Self Organising Feature Maps (SOFM) was used for cluster analysis and visualization of the group separation. Results have shown that separation of normal subjects from neuromuscular diseased patients is possible with a success rate of the order of 83%, whereas separation of subjects from th...

Analysis of Surface EMG Using Second and Third - Order StatistcsSpectra-Based Parameters

The objective of this ongoing study is to investigate if surface electromyography signals (SEMG),... more The objective of this ongoing study is to investigate if surface electromyography signals (SEMG), could be characterized using bispectrum and third–order statistics/spectra (HOS) – based parameters. In particular, the bicoherence index was used for measuring the degree of Gaussianity of the signal. The linearity of the signal, based on deciding whether or not the estimated bicoherence is constant, together with the amplitude of the bispectrum, its coordinates and its variance from the peak were estimated. Power spectrum and time domain parameters were also estimated. Experimental results from the analysis of real SEMG data recorded from thirty-three adult normal subjects (13 female and 20 male) aged between 20 and 50 years old, proved an influence of contraction on the aforementioned parameters (p<0.05). Further work is currently in progress in order to evaluate the usefulness of HOS in subjects suffering from neuromuscular disorders.

Analysis of neuromuscular disorders using statistical and entropy metrics on surface EMG

WSEAS Transactions on Signal Processing archive, 2008

This paper introduces the surface electromyogram (EMG) classification system based on statistical... more

Powers of generic ideals and the weak Lefschetz property for powers of some monomial complete intersections

Journal of Algebra, 2018

Given an ideal I = (f1, . . . , fr) in C[x1, . . . , xn] generated by forms of degree d, and an i... more Given an ideal I = (f1, . . . , fr) in C[x1, . . . , xn] generated by forms of degree d, and an integer k > 1, how large can the ideal I k be, i.e., how small can the Hilbert function of C[x1, . . . , xn]/I k be? If r ≤ n the smallest Hilbert function is achieved by any complete intersection, but for r > n, the question is in general very hard to answer. We study the problem for r = n + 1, where the result is known for k = 1. We also study a closely related problem, the Weak Lefschetz property, for S/I k , where I is the ideal generated by the d'th powers of the variables.

$Research paper thumbnail of Classification of surface electromyographic signals by means of multifractal singularity spectrum$

Classification of surface electromyographic signals by means of multifractal singularity spectrum

Medical & Biological Engineering & Computing, 2012

In order to effectively control a prosthetic system, considerable attempts have been made in rece... more In order to effectively control a prosthetic system, considerable attempts have been made in recent years to improve the classification accuracy of surface electromyographic (SEMG) signals. However, the extraction of effective features is still a primary challenge for the classification of SEMG signals. This study tried to solve the problem by applying the multifractal analysis. It was found that the SEMG signals were characterized by multifractality during forearm movements and different types of forearm movements were related to different multifractal singularity spectra. To quantitatively evaluate the multifractal singularity spectra of the SEMG signals, the areas of the singularity spectrum curves were calculated by integrating the spectrum curves with respect to the singularity strengths. Our results showed that there were several separate clusters resulting from singularity spectrum areas of different forearm movements when two channels of SEMG signals were used in this experimental research, which demonstrated that the multifractal analysis approach was suitable for identifying different types of forearm movements. By comparing with other feature extraction techniques, the multifractal singularity spectrum approach provided higher classification accuracy in terms of the classification of SEMG signals.

The international context of education, training and certification for medical physicists in Europe, North America and Australasia

IFMBE Proceedings, 2013

Problems faced after the transition from a film to a DDR Radiology Department

by P. Kaplanis, S P Spyrou, and A. Stefanoyiannis

IFMBE Proceedings

Page 1. T. Jarm, P. Kramar, A. upanič (Eds.): Medicon 2007, IFMBE Proceedings 16, pp. 879882, 2... more

Computer Aided Assessment of Certain Neuromuscular Disorders Based on Surface Electromyography

The objective of this study was to investigate the usefulness of Surface Electromyography (SEMG),... more The objective of this study was to investigate the usefulness of Surface Electromyography (SEMG), in the clinical laboratory. Towards this goal, recordings from 94 normal subjects (NOR) and 20 neuromuscular subjects (11 myopathy (MYO) and 9 neuropathy (NEURO)) were recorded at 10, 30, 50, 70 and 100% of maximum voluntary contraction. These signals were analysed in the time, frequency and bi-frequency domains. The time-domain parameters, turns and zero crossings per second, increased with force level (FL), for all three groups. Frequency-domain, median and mean frequencies, decreased with FL for the NOR group. Frequency at maximum power was unaffected with FL, but differences were found between all groups of subjects. Maximum and total power increased with FL for all groups, with MYO subjects having significantly higher values for the latter parameter. Bi-frequency parameter, bispectrum peak amplitude increased with FL only for the NOR group and significant differences were found bet...

Classification of Neuromuscular Disorders Using Wavelets and Entropy Metrics on Surface Electromyograms

Abstract: The aim of this study was an investigation whether the examined subjects can be classif... more Abstract: The aim of this study was an investigation whether the examined subjects can be classified as normal, myopathic or neuropathic, based on 4-channel surface electromyographic (SEMG) recordings of the biceps brachii muscle recorded at isometric voluntary contractions. Five different force levels were used: 10, 30, 50, 70 and 100 % of maximum voluntary contraction (MVC), with each recording lasting 5 seconds. The amplitude of SEMG recordings was processed using dyadic Haar wavelet and entropy metrics. In each scale, the entropy of transformed SEMG was calculated and a set of 80 features per subject was formed. From existing data, we created five dataset, where subject were labelled based on the type as: normal/abnormal, normal/myopathic, normal/neuropathic, myopathic/neuropathic and normal/myopathic/neuropathic. Five classification techniques from the WEKA machine learning package were used, i.e. decision trees j48, random trees, random decision forests, support vector machine...

Analysis of Neuromuscular Disorders Using Statistical and Entropy Metrics on Surface EMG

WSEAS Transactions on Signal Processing, Feb 1, 2008

Abstract:-This paper introduces the surface electromyogram (EMG) classification system based on s... more Abstract:-This paper introduces the surface electromyogram (EMG) classification system based on statistical and entropy metrics. The system is intended for diagnostic use and enables classification of examined subject as normal, myopathic or neuropathic, regarding to the acquired EMG signals. 39 subjects in total participated in the experiment, 19 normal, 11 myopathic and 9 neuropathic. Surface EMG was recorded using 4-channel surface electrodes on the biceps brachii muscle at isometric voluntary contractions.

Wavelet-based quantitative evaluation of a digital density equalization technique in mammography

IFMBE Proceedings, 2007

Wavelet-based quantitative evaluation of a digital density equalization technique in mammography

IFMBE Proceedings, 2007

Problems Faced After the Transition From a Film to a DDR Radiology Department

… Conference on Medical …, 2007

Page 1. T. Jarm, P. Kramar, A. upanič (Eds.): Medicon 2007, IFMBE Proceedings 16, pp. 879882, 2... more

The Education and training of clinical medical physicists in 25 European, 2 North American and 2 Australasian countries: Similarities and differences

Physica Medica, 2012

Biomedical Physics Education of Medical and Healthcare Personnel the Cyprus Experience

IFMBE Proceedings, 2009

ABSTRACT Physics has always been a component of the curriculum of non-physics healthcare professi... more ABSTRACT Physics has always been a component of the curriculum of non-physics healthcare professions. Current curricula content varies extensively across Europe. The physics education and training of non-physics healthcare professionals is becoming progressively more important mainly due to the rapid increase in the number and sophistication of medical equipment used by these professionals. In most institutions the Medical Physicist undertakes the task to fill the gap in the additional education and training requirements. This article presents the experience of the Medical Physics Department of Nicosia General Hospital in personnel education and training.

Comparison of Lead-free and Conventional x-ray aprons for Diagnostic Radiology

IFMBE Proceedings, 2009

Quality Assurance of Diagnostic Monitors

IFMBE Proceedings, 2009

... kcare.co.uk . Author: Stelios Christofides Institute: Nicosia General Hospital Street: 215 Ol... more

Education and training of medical physicists in South East Asia: accomplishments and challenges

Biomedical imaging and intervention journal

John Cameron has made significant contributions to the field of Medical Physics. His contribution... more John Cameron has made significant contributions to the field of Medical Physics. His contributions encompassed research and development, technical developments and education. He had a particular interest in the education of medical physicists in developing countries. Structured clinical training is also an essential component of the professional development of a medical physicist. This paper considers aspects of the clinical training and education of medical physicists in South-East Asia and the challenges facing the profession in the region if it is to keep pace with the rapid increase in the amount and technical complexity of medical physics infrastructure in the region.

Influence of isometric voluntary contraction on time and frequency domain parameters of surface EMG

The main objective of this paper was to investigate the effect of increase of isometric voluntary... more The main objective of this paper was to investigate the effect of increase of isometric voluntary contraction (IVC) on surface EMG recorded from the Biceps Brachii (BB) muscle. Five different force levels (FL) were used: 10, 30, 50, 70 and 100% of maximum voluntary contraction (MVC), with each recording lasting 5 seconds. The following sets of parameters were extracted:(i) in the time domain (turns (ts) and zero crossings per second (zc)), and (ii) in the frequency domain (median frequency (fp), frequency at maximum power (fx), ...