Publications by authors named "Maria G Martini"

12 Publications

  • Page 1 of 1

On the suitability of VMAF for quality assessment of medical videos: Medical ultrasound & wireless capsule endoscopy.

Comput Biol Med 2019 10 6;113:103383. Epub 2019 Aug 6.

Wireless Multimedia and Networking (WMN) Research Group, Faculty of Science, Engineering and Computing, Kingston University, KT1 2EE, London, United Kingdom. Electronic address:

With the rapid evolution in modern multimedia networks and systems, services such as telemedicine and tele-surgery are becoming more popular. Quality estimation and monitoring of medical videos is becoming important not only in the field of research, but also in real-time applications and services. The state-of-the-art video quality metric (VQM) called Video Multimethod Assessment Fusion (VMAF) is a promising solution for quality estimation of videos impaired by compression and scaling artifacts. The metric was developed by Netflix for entertainment video content and its good performance does not necessarily extend to medical videos. This paper focuses on evaluating the performance of VMAF in the context of quality assessment (QA) for medical videos. We consider in this paper medical videos compressed via High Efficiency Video Coding (HEVC) and refer in particular to medical ultrasound videos and wireless capsule endoscopy (WCE) videos for the performance estimation of VMAF. The correlation between the subjective scores of these two datasets and VMAF's quality estimates is studied and presented. The results show that VMAF outperforms other state-of-the-art VQMs in the context of WCE videos, but this is not the case for medical ultrasound videos.
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http://dx.doi.org/10.1016/j.compbiomed.2019.103383DOI Listing
October 2019

Bandwidth Modeling of Silicon Retinas for Next Generation Visual Sensor Networks.

Sensors (Basel) 2019 Apr 12;19(8). Epub 2019 Apr 12.

Wireless and Multimedia Networking Research Group, Faculty of Science, Engineering and Computing, Kingston University, Penrhyn Rd, Kingston upon Thames KT1 2EE 1, UK.

Silicon retinas, also known as Dynamic Vision Sensors (DVS) or event-based visual sensors, have shown great advantages in terms of low power consumption, low bandwidth, wide dynamic range and very high temporal resolution. Owing to such advantages as compared to conventional vision sensors, DVS devices are gaining more and more attention in various applications such as drone surveillance, robotics, high-speed motion photography, etc. The output of such sensors is a sequence of events rather than a series of frames as for classical cameras. Estimating the data rate of the stream of events associated with such sensors is needed for the appropriate design of transmission systems involving such sensors. In this work, we propose to consider information about the scene content and sensor speed to support such estimation, and we identify suitable metrics to quantify the complexity of the scene for this purpose. According to the results of this study, the event rate shows an exponential relationship with the metric associated with the complexity of the scene and linear relationships with the speed of the sensor. Based on these results, we propose a two-parameter model for the dependency of the event rate on scene complexity and sensor speed. The model achieves a prediction accuracy of approximately 88.4% for the outdoor environment along with the overall prediction performance of approximately 84%.
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http://dx.doi.org/10.3390/s19081751DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6515179PMC
April 2019

Lifetime and 12-month prevalence of eating disorders amongst women in mid-life: a population-based study of diagnoses and risk factors.

BMC Med 2017 Jan 17;15(1):12. Epub 2017 Jan 17.

Eating Disorders Research Unit, Psychological Medicine, Institute of Psychiatry, King's College London, London, UK.

Background: Eating disorders (EDs) are common amongst women; however, no research has specifically investigated the lifetime/12-month prevalence of eating disorders amongst women in mid-life (i.e., fourth and fifth decade of life) and the relevant longitudinal risk factors. We aimed to investigate the lifetime and 12-month prevalence of EDs and lifetime health service use and to identify childhood, parenting, and personality risk factors.

Methods: This is a two-phase prevalence study, nested within an existing longitudinal community-based sample of women in mid-life. A total of 5658 women from the UK Avon Longitudinal Study of Parents and Children (ALSPAC; enrolled 20 years earlier) participated. ED diagnoses were obtained using validated structured interviews. Weighted analyses were carried out accounting for the two-phase methodology to obtain prevalence figures and to carry out risk factor regression analyses.

Results: By mid-life, 15.3% (95% confidence intervals, 13.5-17.4%) of women had met criteria for a lifetime ED. The 12-month prevalence of EDs was 3.6%. Childhood sexual abuse was prospectively associated with all binge/purge type disorders and an external locus of control was associated with binge-eating disorder. Better maternal care was protective for bulimia nervosa. Childhood life events and interpersonal sensitivity were associated with all EDs.

Conclusions: By mid-life a significant proportion of women will experience an ED, and few women accessed healthcare. Active EDs are common in mid-life, both due to new onset and chronic disorders. Increased awareness of the full spectrum of EDs in this stage of life and adequate service provision is important. This is the first study to investigate childhood and personality risk factors for full threshold and sub-threshold EDs and to identify common predictors for full and sub-threshold EDs. Further research should clarify the role of preventable risk factors on both full and sub-threshold EDs.
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http://dx.doi.org/10.1186/s12916-016-0766-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5240354PMC
January 2017

CUQI: cardiac ultrasound video quality index.

J Med Imaging (Bellingham) 2016 Jan 14;3(1):011011. Epub 2016 Mar 14.

Kingston University , Wireless and Multimedia Networking Research Group, Penhryn Road, Kingston upon Thames, KT1 2EE, London, United Kingdom.

Medical images and videos are now increasingly part of modern telecommunication applications, including telemedicinal applications, favored by advancements in video compression and communication technologies. Medical video quality evaluation is essential for modern applications since compression and transmission processes often compromise the video quality. Several state-of-the-art video quality metrics used for quality evaluation assess the perceptual quality of the video. For a medical video, assessing quality in terms of "diagnostic" value rather than "perceptual" quality is more important. We present a diagnostic-quality-oriented video quality metric for quality evaluation of cardiac ultrasound videos. Cardiac ultrasound videos are characterized by rapid repetitive cardiac motions and distinct structural information characteristics that are explored by the proposed metric. Cardiac ultrasound video quality index, the proposed metric, is a full reference metric and uses the motion and edge information of the cardiac ultrasound video to evaluate the video quality. The metric was evaluated for its performance in approximating the quality of cardiac ultrasound videos by testing its correlation with the subjective scores of medical experts. The results of our tests showed that the metric has high correlation with medical expert opinions and in several cases outperforms the state-of-the-art video quality metrics considered in our tests.
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http://dx.doi.org/10.1117/1.JMI.3.1.011011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4790122PMC
January 2016

Real-time multimedia communications in medical emergency - the CONCERTO project solution.

Annu Int Conf IEEE Eng Med Biol Soc 2015 ;2015:7324-7

The management of medical emergency, in particular cardiac emergency, requests prompt intervention and the possibility to communicate in real time from the emergency area / ambulance to the hospital as much diagnostic information as possible about the patient. This would enable a prompt emergency diagnosis and operation and the possibility to prepare the appropriate actions in the suitable hospital department. To address this scenario, the CONCERTO European project proposed a wireless communication system based on a novel cross-layer architecture, including the integration of building blocks for medical media content fusion, delivery and access. This paper describes the proposed system architecture, outlining the developed components and mechanisms, and the evaluation of the proposed system, carried out in a hospital with the support of medical staff. The technical results and the feedback received highlight the impact of the CONCERTO approach in the healthcare domain, in particular in enabling a prompt and reliable diagnosis in challenging medical emergency scenarios.
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http://dx.doi.org/10.1109/EMBC.2015.7320083DOI Listing
September 2016

Guest editorial. Service science for e-Health.

IEEE J Biomed Health Inform 2014 Sep;18(5):1515-7

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http://dx.doi.org/10.1109/jbhi.2014.2337257DOI Listing
September 2014

A study on quality assessment for medical ultrasound video compressed via HEVC.

IEEE J Biomed Health Inform 2014 Sep 30;18(5):1552-9. Epub 2014 May 30.

The quality of experience and quality of service provided in the healthcare sector are critical in evaluating the reliable delivery of the healthcare services provided. Medical images and videos play a major role in modern e-health services and have become an integral part of medical data communication systems. The quality evaluation of medical images and videos is an essential process, and one of the ways of addressing it is via the use of quality metrics. In this paper, we evaluate the performance of seven state-of-the-art video quality metrics with respect to compressed medical ultrasound video sequences. We study the performance of each video quality metric in representing the diagnostic quality of the video, by evaluating the correlation of each metric with the subjective opinions of medical experts. The results indicate that the visual information fidelity, structural similarity index, and universal quality index metrics show good correlation with the subjective scores provided by medical experts. The tests also investigate the performance of the emerging video compression standard, high-efficiency video coding-HEVC, for medical ultrasound video compression. The results show that, using HEVC with the considered ultrasound video sequences, a diagnostically reliable compressed ultrasound video can be obtained for compression with values of the quantization parameter up to 35.
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http://dx.doi.org/10.1109/JBHI.2014.2326891DOI Listing
September 2014

3-D robotic tele-surgery and training over next generation wireless networks.

Annu Int Conf IEEE Eng Med Biol Soc 2013 ;2013:6244-7

The latest advances on robotic surgery enable the performance of many surgical procedures by utilizing minimally invasive techniques. In particular, recent 3-D endoscopes have improved the performance of minimally invasive surgical procedures. Based on these advances, performing or visualizing in real-time surgical procedures at a distance can be envisaged. In this paper, we present a performance evaluation of 3-D robotic tele-surgery and training over next generation wireless networks, namely wireless networks based on the long term evolution (LTE) 3GPP standard. Different scheduling strategies are compared and results are analyzed in term of the resulting quality of experience (QoE) for the surgeon.
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http://dx.doi.org/10.1109/EMBC.2013.6610980DOI Listing
August 2015

Flexible Macroblock Ordering for Context-Aware Ultrasound Video Transmission over Mobile WiMAX.

Int J Telemed Appl 2010 5;2010. Epub 2010 Aug 5.

Wireless Multimedia Networking Research Group, Kingston University, London, UK.

The most recent network technologies are enabling a variety of new applications, thanks to the provision of increased bandwidth and better management of Quality of Service. Nevertheless, telemedical services involving multimedia data are still lagging behind, due to the concern of the end users, that is, clinicians and also patients, about the low quality provided. Indeed, emerging network technologies should be appropriately exploited by designing the transmission strategy focusing on quality provision for end users. Stemming from this principle, we propose here a context-aware transmission strategy for medical video transmission over WiMAX systems. Context, in terms of regions of interest (ROI) in a specific session, is taken into account for the identification of multiple regions of interest, and compression/transmission strategies are tailored to such context information. We present a methodology based on H.264 medical video compression and Flexible Macroblock Ordering (FMO) for ROI identification. Two different unequal error protection methodologies, providing higher protection to the most diagnostically relevant data, are presented.
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http://dx.doi.org/10.1155/2010/127519DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2929589PMC
July 2011

Healthcare applications and services in converged networking environments.

Int J Telemed Appl 2010 20;2010:649597. Epub 2011 Apr 20.

Department of Telecommunication Systems and Networks, TEI of Messolonghi, 30300 Nafpaktos, Greece.

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http://dx.doi.org/10.1155/2010/649597DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3083002PMC
July 2011

A cross-layer approach for wireless medical video streaming in robotic teleultrasonography.

Annu Int Conf IEEE Eng Med Biol Soc 2007 ;2007:3082-5

CNIT, DEIS, University of Bologna, Italy.

M-health is an emerging area of research integrating emerging wireless technologies with healthcare systems. One of the key challenges in future research in this area, especially from the communications perspective, is medical video streaming over 3G and 4G systems. In this paper, video streaming in a robotic teleultrasonography system through a cross-layer approach based on tailor made controller structures is presented. Simulation results of the proposed system demonstrate the successful performance of the proposed controller structures in this advanced mobile telemedical environment.
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http://dx.doi.org/10.1109/IEMBS.2007.4352979DOI Listing
March 2008

Quality driven wireless video transmission for medical applications.

Conf Proc IEEE Eng Med Biol Soc 2006;2006:3254-7

DEIS, Bologna Univ., Bologna, Italy.

Wireless telemedicine is currently a reality, requiring also the transmission of medical video sequences over often unreliable links. The contrasting requirements of almost lossless compression and low available bandwidth have to be tackled in this case. On one side compression techniques need to be conservative, in order to avoid removing perceptively important information; on the other side error resilience and correction should be provided, with the constraint of a limited bandwidth. An approach based on quality driven, network aware, joint source and channel coding is described in this paper. The approach has been developed in the framework of the IST PHOENIX project (www.ist phoenix.org), focusing on wireless multimedia transmission over IP networks. After a description of the considered cross-layer approach and of the information to be exchanged among the system component blocks, the techniques considered for this information exchange and the concept of "JSCC/D controllers" are introduced. The implementation of the demonstrator realized is then described.
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http://dx.doi.org/10.1109/IEMBS.2006.260627DOI Listing
March 2008