Alexander Johannes Wiederhold

Mr. Alexander Johannes Wiederhold

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2024 in Interactive Journal of Medical Research
Verified
Journal Article
Open access
CGChristopher Gundler
Christopher Gundler
KGKarl Gottfried
Karl Gottfried
AWAlexander Johannes Wiederhold
Alexander Johannes Wiederhold
MAMaximilian Ataian
Maximilian Ataian
MWMarcus Wurlitzer
Marcus Wurlitzer
FÜFrank Ückert
Frank Ückert
Background: Clinical routine data derived from university hospitals hold immense value for health-related research on large cohorts. However, using secondary data for hypothesis testing necessitates adherence to scientific, legal (such as the General Data Protection Regulation, federal and state protection legislations), technical, and administrative requirements. This process is intricate, time-consuming, and susceptible to errors. Objective: This study aims to develop a platform that enables clinicians to use current real-world data for testing research and evaluate advantages and limitations at a large university medical center (542,944 patients in 2022). Methods: We identified requirements from clinical practitioners, conceptualized and implemented a platform based on the existing components, and assessed its applicability in clinical reality quantitatively and qualitatively. Results: The proposed platform was established at the University Medical Center Hamburg-Eppendorf and made 639 forms encompassing 10,629 data elements accessible to all resident scientists and clinicians. Every day, the number of patients rises, and parts of their electronic health records are made accessible through the platform. Qualitatively, we were able to conduct a retrospective analysis of Parkinson disease over 777 patients, where we provide additional evidence for a significantly higher proportion of action tremors in patients with rest tremors (340/777, 43.8%) compared with those without rest tremors (255/777, 32.8%), as determined by a chi-square test (P<.001). Quantitatively, our findings demonstrate increased user engagement within the last 90 days, underscoring clinicians’ increasing adoption of the platform in their regular research activities. Notably, the platform facilitated the retrieval of clinical data from 600,000 patients, emphasizing its substantial added value. Conclusions: This study demonstrates the feasibility of simplifying the use of clinical data to enhance exploration and sustainability in scientific research. The proposed platform emerges as a potential technological and legal framework for other medical centers, providing them with the means to unlock untapped potential within their routine data.

24 July 2024 in JMIR Medical Informatics
Verified
Journal Article
Open access
LBLouis Bellmann
Louis Bellmann
AWAlexander Johannes Wiederhold
Alexander Johannes Wiederhold
LTLeona Trübe
Leona Trübe
RTRaphael Twerenbold
Raphael Twerenbold
FÜFrank Ückert
Frank Ückert
KGKarl Gottfried
Karl Gottfried
Background: Interpretability and intuitive visualization facilitate medical knowledge generation through big data. In addition, robustness to high-dimensional and missing data is a requirement for statistical approaches in the medical domain. A method tailored to the needs of physicians must meet all the abovementioned criteria. Objective: This study aims to develop an accessible tool for visual data exploration without the need for programming knowledge, adjusting complex parameterizations, or handling missing data. We sought to use statistical analysis using the setting of disease and control cohorts familiar to clinical researchers. We aimed to guide the user by identifying and highlighting data patterns associated with disease and reveal relations between attributes within the data set. Methods: We introduce the attribute association graph, a novel graph structure designed for visual data exploration using robust statistical metrics. The nodes capture frequencies of participant attributes in disease and control cohorts as well as deviations between groups. The edges represent conditional relations between attributes. The graph is visualized using the Neo4j (Neo4j, Inc) data platform and can be interactively explored without the need for technical knowledge. Nodes with high deviations between cohorts and edges of noticeable conditional relationship are highlighted to guide the user during the exploration. The graph is accompanied by a dashboard visualizing variable distributions. For evaluation, we applied the graph and dashboard to the Hamburg City Health Study data set, a large cohort study conducted in the city of Hamburg, Germany. All data structures can be accessed freely by researchers, physicians, and patients. In addition, we developed a user test conducted with physicians incorporating the System Usability Scale, individual questions, and user tasks. Results: We evaluated the attribute association graph and dashboard through an exemplary data analysis of participants with a general cardiovascular disease in the Hamburg City Health Study data set. All results extracted from the graph structure and dashboard are in accordance with findings from the literature, except for unusually low cholesterol levels in participants with cardiovascular disease, which could be induced by medication. In addition, 95% CIs of Pearson correlation coefficients were calculated for all associations identified during the data analysis, confirming the results. In addition, a user test with 10 physicians assessing the usability of the proposed methods was conducted. A System Usability Scale score of 70.5% and average successful task completion of 81.4% were reported. Conclusions: The proposed attribute association graph and dashboard enable intuitive visual data exploration. They are robust to high-dimensional as well as missing data and require no parameterization. The usability for clinicians was confirmed via a user test, and the validity of the statistical results was confirmed by associations known from literature and standard statistical inference.

1 January 2021 in Neoplasma
Verified
Journal Article
Open access
PMPeter Mikolajcik
Peter Mikolajcik
ZLZora Lasabova
Zora Lasabova
DLDusan Loderer
Dusan Loderer
MGMarian Grendar
Marian Grendar
MKMichal Kalman
Michal Kalman
LLLudovit Laca
Ludovit Laca
Detection of therapeutically relevant and concomitant rare somatic variants in colorectal cancer

21 July 2025 in Sensors
Verified
Journal Article
Open access
PDF file
AWAlexander Johannes Wiederhold
Alexander Johannes Wiederhold
QZQi Rui Zhu
Qi Rui Zhu
SSSören Spiegel
Sören Spiegel
ADAdrin Dadkhah
Adrin Dadkhah
MPMonika Pötter-Nerger
Monika Pötter-Nerger
CGChristopher Gundler
Christopher Gundler
During the in-hospital optimization of dopaminergic dosage for Parkinson’s disease, drug-induced dyskinesias emerge as a common side effect. Wrist-worn devices present a substantial opportunity for continuous movement recording and the supportive identification of these dyskinesias. To bridge the gap between dyskinesia assessment and machine learning-enabled detection, the recorded information requires meaningful data representations. This study evaluates and compares two distinct representations of sensor data: a task-dependent, semantically grounded approach and automatically extracted large-scale time-series features. Each representation was assessed on public datasets to identify the best-performing machine learning model and subsequently applied to our own collected dataset to assess generalizability. Data representations incorporating semantic knowledge demonstrated comparable or superior performance to reported works, with peak F1 scores of 0.68. Generalization to our own dataset from clinical practice resulted in an observed F1 score of 0.53 using both setups. These results highlight the potential of semantic movement data analysis for dyskinesia detection. Dimensionality reduction in accelerometer-based movement data positively impacts performance, and models trained with semantically obtained features avoid overfitting. Expanding cohorts with standardized neurological assessments labeled by medical experts is essential for further improvements.

14 July 2026 in Sensors
Verified
Journal Article
Open access
PDF file
AWAlexander Johannes Wiederhold
Alexander Johannes Wiederhold
LHLea Haidar
Lea Haidar
MPMonika Pötter-Nerger
Monika Pötter-Nerger
CGChristopher Gundler
Christopher Gundler
Hypomimia, the reduced facial expressiveness commonly seen in Parkinson’s disease (PD), is clinically relevant, yet routine assessment usually relies on a single ordinal rating item in major rating scales such as the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). This study aimed to develop and iteratively refine a wearable, cap-mounted device for hypomimia recording during routine inpatient ON/OFF assessments and to examine its usability and technical feasibility. A staged co-development process with four prototypes was conducted. After clinician workflow requirements had been incorporated, Prototype 3 was evaluated during clinical routine using the System Usability Scale (SUS) and short free-text feedback. These findings informed a patient-centered redesign that resulted in Prototype 4. Bench testing confirmed stable operation, robust housing, and reliable closed Wi-Fi streaming. Usability improved from moderate in Prototype 3 (mean SUS 44.7, SD 18.2; n = 15) to good in Prototype 4 (mean SUS 80.0, SD 12.6; n = 50). Mixed-effects regression showed an increase of approximately 33 SUS points for the redesigned device (95% CI 27.7–39.4; p < 0.001). Mean effective sampling rate was 4.79 frames/s (SD 0.33), with face detection in 95.4% of frames. These feasibility and usability results indicate that technical robustness and patient-centered design are critical prerequisites for later clinical validation and support the integration of a wearable hypomimia capture device into routine assessments.

3 August 2023 in JMIR Preprints
Verified
Preprint
Open access
CGChristopher Gundler
Christopher Gundler
KGKarl Gottfried
Karl Gottfried
AWAlexander Johannes Wiederhold
Alexander Johannes Wiederhold
MAMaximilian Ataian
Maximilian Ataian
MWMarcus Wurlitzer
Marcus Wurlitzer
FÜFrank Ückert
Frank Ückert
BACKGROUND Clinical routine data derived from university hospitals hold immense value for health-related research on large cohorts. However, using secondary data for hypothesis testing necessitates adherence to scientific, legal (such as the General Data Protection Regulation, federal and state protection legislations), technical, and administrative requirements. This process is intricate, time-consuming, and susceptible to errors. OBJECTIVE This study aims to develop a platform that enables clinicians to use current real-world data for testing research and evaluate advantages and limitations at a large university medical center (542,944 patients in 2022). METHODS We identified requirements from clinical practitioners, conceptualized and implemented a platform based on the existing components, and assessed its applicability in clinical reality quantitatively and qualitatively. RESULTS The proposed platform was established at the University Medical Center Hamburg-Eppendorf and made 639 forms encompassing 10,629 data elements accessible to all resident scientists and clinicians. Every day, the number of patients rises, and parts of their electronic health records are made accessible through the platform. Qualitatively, we were able to conduct a retrospective analysis of Parkinson disease over 777 patients, where we provide additional evidence for a significantly higher proportion of action tremors in patients with rest tremors (340/777, 43.8%) compared with those without rest tremors (255/777, 32.8%), as determined by a chi-square test (P<.001). Quantitatively, our findings demonstrate increased user engagement within the last 90 days, underscoring clinicians’ increasing adoption of the platform in their regular research activities. Notably, the platform facilitated the retrieval of clinical data from 600,000 patients, emphasizing its substantial added value. CONCLUSIONS This study demonstrates the feasibility of simplifying the use of clinical data to enhance exploration and sustainability in scientific research. The proposed platform emerges as a potential technological and legal framework for other medical centers, providing them with the means to unlock untapped potential within their routine data.