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Kaur, R., Gholamhosseini, H. & Lindén, M. (2025). Advanced Deep Learning Models for Melanoma Diagnosis in Computer-Aided Skin Cancer Detection. Sensors, 25(3), Article ID 594.
Open this publication in new window or tab >>Advanced Deep Learning Models for Melanoma Diagnosis in Computer-Aided Skin Cancer Detection
2025 (English)In: Sensors, E-ISSN 1424-8220, Vol. 25, no 3, article id 594Article in journal (Refereed) Published
Abstract [en]

The most deadly type of skin cancer is melanoma. A visual examination does not provide an accurate diagnosis of melanoma during its early to middle stages. Therefore, an automated model could be developed that assists with early skin cancer detection. It is possible to limit the severity of melanoma by detecting it early and treating it promptly. This study aims to develop efficient approaches for various phases of melanoma computer-aided diagnosis (CAD), such as preprocessing, segmentation, and classification. The first step of the CAD pipeline includes the proposed hybrid method, which uses morphological operations and context aggregation-based deep neural networks to remove hairlines and improve poor contrast in dermoscopic skin cancer images. An image segmentation network based on deep learning is then used to extract lesion regions for detailed analysis and calculate the optimized classification features. Lastly, a deep neural network is used to distinguish melanoma from benign lesions. The proposed approaches use a benchmark dataset named International Skin Imaging Collaboration (ISIC) 2020. In this work, two forms of evaluations are performed with the classification model. The first experiment involves the incorporation of the results from the preprocessing and segmentation stages into the classification model. The second experiment involves the evaluation of the classifier without employing these stages i.e., using raw images. From the study results, it can be concluded that a classification model using segmented and cleaned images contributes more to achieving an accurate classification rate of 93.40% with a 1.3 s test time on a single image.

Place, publisher, year, edition, pages
MDPI AG, 2025
Keywords
skin cancer, melanoma, classification, segmentation, deep learning
National Category
Medical Engineering
Identifiers
urn:nbn:se:mdh:diva-70285 (URN)10.3390/s25030594 (DOI)001419653200001 ()39943236 (PubMedID)2-s2.0-85218234612 (Scopus ID)
Available from: 2025-02-26 Created: 2025-02-26 Last updated: 2026-03-17Bibliographically approved
Hultman, L., Eklund, C., von Heideken Wågert, P., Söderlund, A., Lindén, M. & Elfström, M. (2025). Development of an eHealth Intervention Including Self-Management for Reducing Sedentary Time in the Transition to Retirement: Participatory Design Study. JMIR Formative Research, 9, Article ID e63567.
Open this publication in new window or tab >>Development of an eHealth Intervention Including Self-Management for Reducing Sedentary Time in the Transition to Retirement: Participatory Design Study
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2025 (English)In: JMIR Formative Research, E-ISSN 2561-326X, Vol. 9, article id e63567Article in journal (Refereed) Published
Abstract [en]

Background: Having a great amount of sedentary time is common among older adults and increases with age. There is a strong need for tools to reduce sedentary time and promote adherence to reduced sedentary time, for which eHealth interventions have the potential to be useful. Interventions for reducing sedentary time in older adults have been found to be more effective when elements of self-management are included. When creating new eHealth interventions, accessibility and effectiveness can be increased by including end users as co-designers in the development process.

Objective: The aim was to explore the desired features of an eHealth intervention including self-management for reducing sedentary time and promoting adherence to reduced sedentary time in older adults transitioning from working life to retirement. Further, the aim was to develop a digital prototype of such an eHealth intervention.

Methods: The study used the participatory design approach to include end users, researchers, and a web designer as equal partners. Three workshops were conducted with 6 older adults transitioning to retirement, 2 researchers, and 1 web designer. Thematic analysis was used to analyze the data from the workshops.

Results: Participants expressed a desire for an easy-to-use eHealth intervention, which could be accessed from mobile phones, tablets, and computers, and could be individualized to the user. The most important features for reducing sedentary time were those involving finding joyful activities, setting goals, and getting information regarding reduced sedentary time. Participants expressed that the eHealth intervention would need to first provide the user with knowledge regarding sedentary time, then offer features for measuring sedentary time and for setting goals, and lastly provide support in finding joyful activities to perform in order to avoid being sedentary. According to the participants, an eHealth intervention including self-management for reducing sedentary time in older adults in the transition to retirement should be concise, accessible, and enjoyable. A digital prototype of such an eHealth intervention was developed.

Conclusions: The developed eHealth intervention including self-management for reducing sedentary time in older adults transitioning to retirement is intended to facilitate behavior change by encouraging the user to participate in autonomously motivated activities. It uses several behavior change techniques, such as goal setting and action planning through mental contrasting and implementation intention, as well as shaping knowledge. Its active components for reducing sedentary time can be explained using the integrated behavior change model. Further research is needed to evaluate the feasibility and effectiveness of the eHealth intervention.

Place, publisher, year, edition, pages
JMIR Publications, 2025
Keywords
adherence, affective determinants, autonomous motivation, behavior change intervention, integrated behavior change model
National Category
Public Health, Global Health and Social Medicine
Identifiers
urn:nbn:se:mdh:diva-69950 (URN)10.2196/63567 (DOI)001447515800020 ()39832361 (PubMedID)2-s2.0-85215675819 (Scopus ID)
Available from: 2025-01-29 Created: 2025-01-29 Last updated: 2026-04-15Bibliographically approved
Abdullah, S., Kristoffersson, A. & Lindén, M. (2024). Skin Cancer Diagnosis through Machine Learning: An Educational Tool for Improved Detection. In: : . Paper presented at Medicinteknikdagarna, Göteborg 8–10 oktober 2024.
Open this publication in new window or tab >>Skin Cancer Diagnosis through Machine Learning: An Educational Tool for Improved Detection
2024 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Skin cancer is a rapidly growing and potentially deadly form of cancer, making early detection crucial for improved patient outcomes. This study introduces a machine learning-based educational system designed to aid early detection of skin cancer. The system leverages machine learning techniques to analyse skin lesion images from the ISIC-ISBI 2016 and 2017 datasets providing a non-invasive and cost-effective alternative to traditional biopsies. The primary objective of this dataset collection was to generate an automated prediction of lesion segmentation boundaries using dermoscopy images, where each image has a manual tracing of lesion boundaries done by an expert. To accommodate the diverse images acquired using many different devices, pre-processing and segmentation using OTSU thresholding isolate the region of interest, followed by extraction of detailed features such as texture, shape, and color. Principal component analysis (PCA) refines these features. An SVM ensemble classifier, trained on labeled images and evaluated on the ISIC-ISBI datasets, distinguishes cancerous from non-cancerous lesions. The system achieves an impressive95.73% accuracy, a 95.51% average similarity rate in segmentation, and a low mean squared error(MSE), demonstrating its effectiveness. This system operates in real-time as a user-friendly application executable on any desktop computer, tablet, or laptop. The application takes an image asinput, pre-processes it, and extracts relevant features. Using this feature matrix, the classifier determines whether the input image indicates a malignant or benign melanoma. The output provide sa clear label of 'cancerous melanoma' or 'benign melanoma' for each analyzed image. This system offers significant educational value for dermatology students and doctors. It can be used for hands-on learning and classroom training, enabling accurate diagnosis without the need for invasive biopsies. The system's potential portability makes it a valuable tool for resource-limited settings and large-scale educational initiatives focused on skin cancer detection.

National Category
Signal Processing
Identifiers
urn:nbn:se:mdh:diva-68808 (URN)
Conference
Medicinteknikdagarna, Göteborg 8–10 oktober 2024
Available from: 2024-11-05 Created: 2024-11-05 Last updated: 2025-10-10Bibliographically approved
Zolfaghari, S., Kristoffersson, A., Folke, M., Lindén, M. & Riboni, D. (2024). Unobtrusive Cognitive Assessment in Smart-Homes: Leveraging Visual Encoding and Synthetic Movement Traces Data Mining. Sensors, 24(5), 1381-1381
Open this publication in new window or tab >>Unobtrusive Cognitive Assessment in Smart-Homes: Leveraging Visual Encoding and Synthetic Movement Traces Data Mining
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2024 (English)In: Sensors, E-ISSN 1424-8220, Vol. 24, no 5, p. 1381-1381Article in journal (Refereed) Published
Abstract [en]

The ubiquity of sensors in smart-homes facilitates the support of independent living for older adults and enables cognitive assessment. Notably, there has been a growing interest in utilizing movement traces for identifying signs of cognitive impairment in recent years. In this study, we introduce an innovative approach to identify abnormal indoor movement patterns that may signal cognitive decline. This is achieved through the non-intrusive integration of smart-home sensors, including passive infrared sensors and sensors embedded in everyday objects. The methodology involves visualizing user locomotion traces and discerning interactions with objects on a floor plan representation of the smart-home, and employing different image descriptor features designed for image analysis tasks and synthetic minority oversampling techniques to enhance the methodology. This approach distinguishes itself by its flexibility in effortlessly incorporating additional features through sensor data. A comprehensive analysis, conducted with a substantial dataset obtained from a real smart-home, involving 99 seniors, including those with cognitive diseases, reveals the effectiveness of the proposed functional prototype of the system architecture. The results validate the system’s efficacy in accurately discerning the cognitive status of seniors, achieving a macro-averaged F1-score of 72.22% for the two targeted categories: cognitively healthy and people with dementia. Furthermore, through experimental comparison, our system demonstrates superior performance compared with state-of-the-art methods.

Keywords
trajectory mining, visual feature extraction, smart environments, machine learning, environmental sensors, ambient sensing, ambient assisted living
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:mdh:diva-66143 (URN)10.3390/s24051381 (DOI)001182917700001 ()38474917 (PubMedID)2-s2.0-85187467922 (Scopus ID)
Available from: 2024-02-28 Created: 2024-02-28 Last updated: 2025-10-10Bibliographically approved
Abdullah, S., Hafid, A., Folke, M., Lindén, M. & Kristoffersson, A. (2023). A Novel Fiducial Point Extraction Algorithm to Detect C and D Points from the Acceleration Photoplethysmogram (CnD). Electronics, 12(5), Article ID 1174.
Open this publication in new window or tab >>A Novel Fiducial Point Extraction Algorithm to Detect C and D Points from the Acceleration Photoplethysmogram (CnD)
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2023 (English)In: Electronics, E-ISSN 2079-9292, Vol. 12, no 5, article id 1174Article in journal (Refereed) Published
Abstract [en]

The extraction of relevant features from the photoplethysmography signal for estimating certain physiological parameters is a challenging task. Various feature extraction methods have been proposed in the literature. In this study, we present a novel fiducial point extraction algorithm to detect c and d points from the acceleration photoplethysmogram (APG), namely “CnD”. The algorithm allows for the application of various pre-processing techniques, such as filtering, smoothing, and removing baseline drift; the possibility of calculating first, second, and third photoplethysmography derivatives; and the implementation of algorithms for detecting and highlighting APG fiducial points. An evaluation of the CnD indicated a high level of accuracy in the algorithm’s ability to identify fiducial points. Out of 438 APG fiducial c and d points, the algorithm accurately identified 434 points, resulting in an accuracy rate of 99%. This level of accuracy was consistent across all the test cases, with low error rates. These findings indicate that the algorithm has a high potential for use in practical applications as a reliable method for detecting fiducial points. Thereby, it provides a valuable new resource for researchers and healthcare professionals working in the analysis of photoplethysmography signals.

Place, publisher, year, edition, pages
MDPI AG, 2023
National Category
Medical Engineering
Identifiers
urn:nbn:se:mdh:diva-62004 (URN)10.3390/electronics12051174 (DOI)000947098400001 ()2-s2.0-85149747017 (Scopus ID)
Available from: 2023-03-03 Created: 2023-03-03 Last updated: 2026-06-12Bibliographically approved
Abdelakram, H., Abdullah, S., Lindén, M., Kristoffersson, A. & Folke, M. (2023). Impact of Activities in Daily Living on Electrical Bioimpedance Measurements for Bladder Monitoring. In: : . Paper presented at 2023 IEEE 36th International Symposium on Computer-Based Medical Systems (CBMS), 22-24 June 2023, L'Aquila, Italy. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Impact of Activities in Daily Living on Electrical Bioimpedance Measurements for Bladder Monitoring
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2023 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Accurate bladder monitoring is critical in the management of conditions such as urinary incontinence, voiding dysfunction, and spinal cord injuries. Electrical bioimpedance (EBI) has emerged as a cost-effective and non-invasive approach to monitoring bladder activity in daily life, with particular relevance to patient groups who require measurement of bladder urine volume (BUV) to prevent urinary leakage. However, the impact of activities in daily living (ADLs) on EBI measurements remains incompletely characterized. In this study, we investigated the impact of normal ADLs such as sitting, standing, and walking on EBI measurements using the MAX30009evkit system with four electrodes placed on the lower abdominal area. We developed an algorithm to identify artifacts caused by the different activities from the EBI signals. Our findings demonstrate that various physical activities clearly affected the EBI measurements, indicating the necessity of considering them during bladder monitoring with EBI technology performed during physical activity (or normal ADLs). We also observed that several specific activities could be distinguished based on their impedance values and waveform shapes. Thus, our results provide a better understanding of the impact of physical activity on EBI measurements and highlight the importance of considering such physical activities during EBI measurements in order to enhance the reliability and effectiveness of EBI technology for bladder monitoring.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Series
IEEE International Symposium on Computer-Based Medical Systems, ISSN 2372-9198
National Category
Medical Engineering
Identifiers
urn:nbn:se:mdh:diva-64033 (URN)10.1109/CBMS58004.2023.00316 (DOI)001037777900135 ()2-s2.0-85166470920 (Scopus ID)979-8-3503-1224-9 (ISBN)
Conference
2023 IEEE 36th International Symposium on Computer-Based Medical Systems (CBMS), 22-24 June 2023, L'Aquila, Italy
Available from: 2023-08-16 Created: 2023-08-16 Last updated: 2026-02-26Bibliographically approved
Abdullah, S., Abdelakram, H., Lindén, M., Folke, M. & Kristoffersson, A. (2023). Machine Learning-Based Classification of Hypertension using CnD Features from Acceleration Photoplethysmography and Clinical Parameters. In: Proceedings - IEEE Symposium on Computer-Based Medical Systems: . Paper presented at 36th IEEE International Symposium on Computer-Based Medical Systems, CBMS 2023, Aquila, 22 June 2023 through 24 June 2023 (pp. 923-924). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Machine Learning-Based Classification of Hypertension using CnD Features from Acceleration Photoplethysmography and Clinical Parameters
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2023 (English)In: Proceedings - IEEE Symposium on Computer-Based Medical Systems, Institute of Electrical and Electronics Engineers (IEEE) , 2023, p. 923-924Conference paper, Published paper (Refereed)
Abstract [en]

Cardiovascular diseases (CVDs) are a leading cause of death worldwide, and hypertension is a major risk factor for acquiring CVDs. Early detection and treatment of hypertension can significantly reduce the risk of developing CVDs and related complications. In this study, a linear SVM machine learning model was used to classify subjects as normal or at different stages of hypertension. The features combined statistical parameters derived from the acceleration plethysmography waveforms and clinical parameters extracted from a publicly available dataset. The model achieved an overall accuracy of 87.50% on the validation dataset and 95.35% on the test dataset. The model's true positive rate and positive predictivity was high in all classes, indicating a high accuracy, and precision. This study represents the first attempt to classify cardiovascular conditions using a combination of acceleration photoplethysmogram (APG) features and clinical parameters The study demonstrates the potential of APG analysis as a valuable tool for early detection of hypertension.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Series
IEEE International Symposium on Computer-Based Medical Systems, ISSN 2372-9198
Keywords
acceleration photoplethysmography, cardiovascular, fiducial points, hypertension, PPG, Acceleration, Classification (of information), Learning systems, Statistical tests, Support vector machines, Cardiovascular disease, Causes of death, Clinical parameters, Machine-learning, Photoplethysmogram, Photoplethysmography
National Category
Cardiology and Cardiovascular Disease Medical Engineering
Identifiers
urn:nbn:se:mdh:diva-63964 (URN)10.1109/CBMS58004.2023.00344 (DOI)001037777900162 ()2-s2.0-85166469701 (Scopus ID)9798350312249 (ISBN)
Conference
36th IEEE International Symposium on Computer-Based Medical Systems, CBMS 2023, Aquila, 22 June 2023 through 24 June 2023
Available from: 2023-08-16 Created: 2023-08-16 Last updated: 2026-02-26Bibliographically approved
Abdullah, S., Hafid, A., Folke, M., Lindén, M. & Kristoffersson, A. (2023). PPGFeat: a novel MATLAB toolbox for extracting PPG fiducial points. Frontiers in Bioengineering and Biotechnology, 11, Article ID 1199604.
Open this publication in new window or tab >>PPGFeat: a novel MATLAB toolbox for extracting PPG fiducial points
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2023 (English)In: Frontiers in Bioengineering and Biotechnology, E-ISSN 2296-4185, Vol. 11, article id 1199604Article in journal (Refereed) Published
Abstract [en]

Photoplethysmography is a non-invasive technique used for measuring several vital signs and for the identification of individuals with an increased disease risk. Its principle of work is based on detecting changes in blood volume in the microvasculature of the skin through the absorption of light. The extraction of relevant features from the photoplethysmography signal for estimating certain physiological parameters is a challenging task, where various feature extraction methods have been proposed in the literature. In this work, we present PPGFeat, a novel MATLAB toolbox supporting the analysis of raw photoplethysmography waveform data. PPGFeat allows for the application of various preprocessing techniques, such as filtering, smoothing, and removal of baseline drift; the calculation of photoplethysmography derivatives; and the implementation of algorithms for detecting and highlighting photoplethysmography fiducial points. PPGFeat includes a graphical user interface allowing users to perform various operations on photoplethysmography signals and to identify, and if required also adjust, the fiducial points. Evaluating the PPGFeat’s performance in identifying the fiducial points present in the publicly available PPG-BP dataset, resulted in an overall accuracy of 99% and 3038/3066 fiducial points were correctly identified. PPGFeat significantly reduces the risk of errors in identifying inaccurate fiducial points. Thereby, it is providing a valuable new resource for researchers for the analysis of photoplethysmography signals.

Place, publisher, year, edition, pages
Frontiers Media SA, 2023
Keywords
photoplethysmography, PPG features, fiducial points, MATLAB, toolbox, signal processing, acceleration photoplethysmography, velocity photoplethysmography
National Category
Medical Engineering
Identifiers
urn:nbn:se:mdh:diva-63035 (URN)10.3389/fbioe.2023.1199604 (DOI)001020124900001 ()37378045 (PubMedID)2-s2.0-85163601193 (Scopus ID)
Available from: 2023-06-09 Created: 2023-06-09 Last updated: 2026-06-12Bibliographically approved
Abdelakram, H., Difallah, S., Alves, C., Abdullah, S., Folke, M., Lindén, M. & Kristoffersson, A. (2023). State of the Art of Non-Invasive Technologies for Bladder Monitoring: A Scoping Review. Sensors, 23(5), Article ID 2758.
Open this publication in new window or tab >>State of the Art of Non-Invasive Technologies for Bladder Monitoring: A Scoping Review
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2023 (English)In: Sensors, E-ISSN 1424-8220, Vol. 23, no 5, article id 2758Article, review/survey (Refereed) Published
Abstract [en]

Bladder monitoring, including urinary incontinence management and bladder urinary volume monitoring, is a vital part of urological care. Urinary incontinence is a common medical condition affecting the quality of life of more than 420 million people worldwide, and bladder urinary volume is an important indicator to evaluate the function and health of the bladder. Previous studies on non-invasive techniques for urinary incontinence management technology, bladder activity and bladder urine volume monitoring have been conducted. This scoping review outlines the prevalence of bladder monitoring with a focus on recent developments in smart incontinence care wearable devices and the latest technologies for non-invasive bladder urine volume monitoring using ultrasound, optical and electrical bioimpedance techniques. The results found are promising and their application will improve the well-being of the population suffering from neurogenic dysfunction of the bladder and the management of urinary incontinence. The latest research advances in bladder urinary volume monitoring and urinary incontinence management have significantly improved existing market products and solutions and will enable the development of more effective future solutions.

Place, publisher, year, edition, pages
MDPI AG, 2023
National Category
Medical Engineering
Identifiers
urn:nbn:se:mdh:diva-62006 (URN)10.3390/s23052758 (DOI)000947664800001 ()36904965 (PubMedID)2-s2.0-85149769899 (Scopus ID)
Available from: 2023-03-03 Created: 2023-03-03 Last updated: 2026-06-12Bibliographically approved
Kristoffersson, A. & Lindén, M. (2022). A Systematic Review of Wearable Sensors for Monitoring Physical Activity. Sensors, 22(2), Article ID 573.
Open this publication in new window or tab >>A Systematic Review of Wearable Sensors for Monitoring Physical Activity
2022 (English)In: Sensors, E-ISSN 1424-8220, Vol. 22, no 2, article id 573Article, review/survey (Refereed) Published
Abstract [en]

This article reviews the use of wearable sensors for the monitoring of physical activity (PA)for different purposes, including assessment of gait and balance, prevention and/or detection of falls,recognition of various PAs, conduction and assessment of rehabilitation exercises and monitoringof neurological disease progression. The article provides in-depth information on the retrievedarticles and discusses study shortcomings related to demographic factors, i.e., age, gender, healthyparticipants vs patients, and study conditions. It is well known that motion patterns change with ageand the onset of illnesses, and that the risk of falling increases with age. Yet, studies including olderpersons are rare. Gender distribution was not even provided in several studies, and others includedonly, or a majority of, men. Another shortcoming is that none of the studies were conducted inreal-life conditions. Hence, there is still important work to be done in order to increase the usefulnessof wearable sensors in these areas. The article highlights flaws in how studies based on previouslycollected datasets report on study samples and the data collected, which makes the validity andgeneralizability of those studies low. Exceptions exist, such as the promising recently reported opendataset FallAllD, wherein a longitudinal study with older adults is ongoing. 

Place, publisher, year, edition, pages
MDPI AG, 2022
National Category
Medical Engineering
Identifiers
urn:nbn:se:mdh:diva-57024 (URN)10.3390/s22020573 (DOI)000758446500001 ()35062531 (PubMedID)2-s2.0-85122671604 (Scopus ID)
Funder
Knowledge Foundation, 20180158
Note

This research was conducted within the scope of the scope of the ESS-H+ (Embedded Sensor Systems for Health Plus). The project is funded by the Swedish Knowledge Foundation (project number: 20180158).

Available from: 2022-01-21 Created: 2022-01-21 Last updated: 2026-06-15Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1940-1747

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