23 research outputs found
An enhanced lossless compression with cryptography hybrid mechanism for ECG biomedical signal monitoring
Due to their use in daily life situation, demand for remote health applications and e-health monitoring equipment is growing quickly. In this phase, for fast diagnosis and therapy, information can be transferred from the patient to the distant clinic. Nowadays, the most chronic disease is cardiovascular diseases (CVDs). However, the storage and transmission of the ECG signal, consumes more energy, bandwidth and data security which is faced many challenges. Hence, in this work, we present a combined approach for ECG data compression and cryptography. The compression is performed using adaptive Huffman encoding and encrypting is done using AES (CBC) scheme with a 256-bit key. To increase the security, we include Diffie-Hellman Key exchange to authenticate the receiver, RSA key generation for encrypting and decrypting the data. Experimental results show that the proposed approach achieves better performance in terms of compression and encryption on MIT-BIH ECG dataset
Enabling human physiological sensing by leveraging intelligent head-worn wearable systems
This thesis explores the challenges of enabling human physiological sensing by leveraging head-worn wearable computer systems. In particular, we want to answer a fundamental question, i.e., could we leverage head-worn wearables to enable accurate and socially-acceptable solutions to improve human healthcare and prevent life-threatening conditions in our daily lives? To that end, we will study the techniques that utilise the unique advantages of wearable computers to (1) facilitate new sensing capabilities to capture various biosignals from the brain, the eyes, facial muscles, sweat glands, and blood vessels, (2) address motion artefacts and environmental noise in real-time with signal processing algorithms and hardware design techniques, and (3) enable long-term, high-fidelity biosignal monitoring with efficient on-chip intelligence and pattern-driven compressive sensing algorithms.
We first demonstrate the ability to capture the activities of the user's brain, eyes, facial muscles, and sweat glands by proposing WAKE, a novel behind-the-ear biosignal sensing wearable. By studying the human anatomy in the ear area, we propose a wearable design to capture brain waves (EEG), eye movements (EOG), facial muscle contractions (EMG), and sweat gland activities (EDA) with a minimal number of sensors. Furthermore, we introduce a Three-fold Cascaded Amplifying (3CA) technique and signal processing algorithms to tame the motion artefacts and environmental noises for capturing high-fidelity signals in real time. We devise a machine-learning model based on the captured signals to detect microsleep with a high temporal resolution.
Second, we will discuss our work on developing an efficient Pattern-dRiven Compressive Sensing framework (PROS) to enable long-term biosignal monitoring on low-power wearables. The system introduces tiny on-chip pattern recognition primitives (TinyPR) and a novel pattern-driven compressive sensing technique (PDCS) that exploits the sparsity of biosignals. They provide the ability to capture high-fidelity biosignals with an ultra-low power footprint. This development will unlock long-term healthcare applications on wearable computers, such as epileptic seizure monitoring, microsleep detection, etc. These applications were previously impractical on energy and resource-constrained wearable computers due to the limited battery lifetime, slow response rate, and inadequate biosignal quality.
Finally, we will further explore the possibility of capturing the activities of a blood vessel (i.e., superficial temporal artery) lying deep inside the user's ear using an ear-worn wearable computer. The captured optical pulse signals (PPG) are used to develop a frequent and comfortable blood pressure monitoring system called eBP. In contrast to existing devices, eBP introduces a novel in-ear wearable system design and algorithms to eliminate the need to block the blood flow inside the ear, alleviating the user's discomfort
Algorithms for Compression of Electrocardiogram Signals
The study is dedicated to modern methods and algorithms for compression of electrocardiogram (ECG) signals. In its original part, two lossy compression algorithms based on a combination of linear transforms are proposed. These algorithms are with relatively low computational complexity, making them applicable for implementation in low power designs such as mobile devices or embedded systems. Since the algorithms do not provide perfect signal reconstruction, they would find application in ECG monitoring systems rather than those intended for precision medical diagnosis.
This monograph consists of abstract, preface, five chapters and conclusion. The chapters are as follows: Chapter 1 — Introduction to ECG; Chapter 2 — Overview of the existing methods and algorithms for ECG compression; Chapter 3 — ECG compression algorithm, based on a combination of linear transforms; Chapter 4 — Improvement of the developed algorithm for ECG compression; Chapter 5 — Experimental investigations.
Този труд е посветен на съвременните методи и алгоритми за компресия на електрокардиографски (ЕКГ) сигнали. В оригиналната му част са предложени два алгоритъма за компресия със загуби, които са базирани на комбинация от линейни преобразувания. Тези алгоритми се характеризират със сравнително невисока изчислителна сложност, което дава възможност да бъдат реализирани в устройства с ниска консумация на енергия, като например мобилни устройства или вградени системи. Тъй като алгоритмите не позволяват перфектно възстановяване на сигнала, те биха намерили приложение по-скоро в системите за ЕКГ мониторинг, отколкото в тези, предназначени за прецизна медицинска диагностика.
Монографията съдържа резюме, предговор, пет глави и заключение. Главите са както следва: Глава 1 — Въведение в електрокардиографията; Глава 2 — Обзор на съществуващите методи и алгоритми за компресия на ЕКГ сигнали; Глава 3 — Алгоритъм за компресия на ЕКГ сигнали, базиран на комбинация от линейни преобразувания; Глава 4 — Усъвършенстване на разработения алгоритъм за компресия на ЕКГ сигнали; Глава 5 — Експериментални изследвания
Documenting and predicting topic changes in Computers in Biology and Medicine: A bibliometric keyword analysis from 1990 to 2017
The Computers in Biology and Medicine (CBM) journal promotes the use of com-puting machinery in the fields of bioscience and medicine. Since the first volume in 1970, the importance of computers in these fields has grown dramatically, this is evident in the diversification of topics and an increase in the publication rate. In this study, we quantify both change and diversification of topics covered in CBM. This is done by analysing the author supplied keywords, since they were electronically captured in 1990. The analysis starts by selecting 40 keywords, related to Medical (M) (7), Data (D)(10), Feature (F) (17) and Artificial Intelligence (AI) (6) methods. Automated keyword clustering shows the statistical connection between the selected keywords. We found that the three most popular topics in CBM are: Support Vector Machine (SVM), Elec-troencephalography (EEG) and IMAGE PROCESSING. In a separate analysis step, we bagged the selected keywords into sequential one year time slices and calculated the normalized appearance. The results were visualised with graphs that indicate the CBM topic changes. These graphs show that there was a transition from Artificial Neural Network (ANN) to SVM. In 2006 SVM replaced ANN as the most important AI algo-rithm. Our investigation helps the editorial board to manage and embrace topic change. Furthermore, our analysis is interesting for the general reader, as the results can help them to adjust their research directions
Satellite Image Compression Using Wavelet
Image data is a combination of information and redundancies, the information is part of the data be protected because it contains the meaning and designation data. Meanwhile, the redundancies are part of data that can be reduced, compressed, or eliminated. Problems that arise are related to the nature of image data that spends a lot of memory. In this paper will compare 31 wavelet function by looking at its impact on PSNR, compression ratio, and bits per pixel (bpp) and the influence of decomposition level of PSNR and compression ratio.
Based on testing performed, Haar wavelet has the advantage that is obtained PSNR is relatively higher compared with other wavelets. Compression ratio is relatively better than other types of wavelets. Bits per pixel is relatively better than other types of wavelet
Wi-Fi based people tracking in challenging environments
People tracking is a key building block in many applications such as abnormal activity detection, gesture recognition, and elderly persons monitoring. Video-based systems have many limitations making them ineffective in many situations. Wi-Fi provides an easily accessible source of opportunity for people tracking that does not have the limitations of video-based systems. The system will detect, localise, and track people, based on the available Wi-Fi signals that are reflected from their bodies. Wi-Fi based systems still need to address some challenges in order to be able to operate in challenging environments. Some of these challenges include the detection of the weak signal, the detection of abrupt people motion, and the presence of multipath propagation. In this thesis, these three main challenges will be addressed.
Firstly, a weak signal detection method that uses the changes in the signals that are reflected from static objects, to improve the detection probability of weak signals that are reflected from the person’s body. Then, a deep learning based Wi-Fi localisation technique is proposed that significantly improves the runtime and the accuracy in comparison with existing techniques.
After that, a quantum mechanics inspired tracking method is proposed to address the abrupt motion problem. The proposed method uses some interesting phenomena in the quantum world, where the person is allowed to exist at multiple positions simultaneously. The results show a significant improvement in reducing the tracking error and in reducing the tracking delay
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ECG analysis and classification using CSVM, MSVM and SIMCA classifiers
Reliable ECG classification can potentially lead to better detection methods and increase
accurate diagnosis of arrhythmia, thus improving quality of care. This thesis investigated the
use of two novel classification algorithms: CSVM and SIMCA, and assessed their
performance in classifying ECG beats. The project aimed to introduce a new way to
interactively support patient care in and out of the hospital and develop new classification
algorithms for arrhythmia detection and diagnosis. Wave (P-QRS-T) detection was performed
using the WFDB Software Package and multiresolution wavelets. Fourier and PCs were
selected as time-frequency features in the ECG signal; these provided the input to the
classifiers in the form of DFT and PCA coefficients. ECG beat classification was performed
using binary SVM. MSVM, CSVM, and SIMCA; these were subsequently used for
simultaneously classifying either four or six types of cardiac conditions. Binary SVM
classification with 100% accuracy was achieved when applied on feature-reduced ECG
signals from well-established databases using PCA. The CSVM algorithm and MSVM were
used to classify four ECG beat types: NORMAL, PVC, APC, and FUSION or PFUS; these
were from the MIT-BIH arrhythmia database (precordial lead group and limb lead II).
Different numbers of Fourier coefficients were considered in order to identify the optimal
number of features to be presented to the classifier. SMO was used to compute hyper-plane
parameters and threshold values for both MSVM and CSVM during the classifier training
phase. The best classification accuracy was achieved using fifty Fourier coefficients. With the
new CSVM classifier framework, accuracies of 99%, 100%, 98%, and 99% were obtained
using datasets from one, two, three, and four precordial leads, respectively. In addition, using
CSVM it was possible to successfully classify four types of ECG beat signals extracted from
limb lead simultaneously with 97% accuracy, a significant improvement on the 83% accuracy
achieved using the MSVM classification model. In addition, further analysis of the following
four beat types was made: NORMAL, PVC, SVPB, and FUSION. These signals were
obtained from the European ST-T Database. Accuracies between 86% and 94% were obtained
for MSVM and CSVM classification, respectively, using 100 Fourier coefficients for
reconstructing individual ECG beats. Further analysis presented an effective ECG arrhythmia
classification scheme consisting of PCA as a feature reduction method and a SIMCA
classifier to differentiate between either four or six different types of arrhythmia. In separate
studies, six and four types of beats (including NORMAL, PVC, APC, RBBB, LBBB, and
FUSION beats) with time domain features were extracted from the MIT-BIH arrhythmia
database and the St Petersburg INCART 12-lead Arrhythmia Database (incartdb) respectively.
Between 10 and 30 PCs, coefficients were selected for reconstructing individual ECG beats in
the feature selection phase. The average classification accuracy of the proposed scheme was
98.61% and 97.78 % using the limb lead and precordial lead datasets, respectively. In addition,
using MSVM and SIMCA classifiers with four ECG beat types achieved an average
classification accuracy of 76.83% and 98.33% respectively. The effectiveness of the proposed
algorithms was finally confirmed by successfully classifying both the six beat and four beat
types of signal respectively with a high accuracy ratio