To be released.

Findings
Existing guidelines lack pragmatic application and systematic approach for device selection.
Device choice is dependent on measurement objectives, user population, and available resources.
Current frameworks do not systematically consider verification, validation, feasibility, and protocol design.
Rapid obsolescence of digital devices due to technological advancements.
Need to incorporate social/psychological factors into device selection.

Recommendations
Develop a practical guide with a systematic approach for selecting wearable devices.
Use five core criteria: continuous monitoring capability, device suitability and availability, technical performance, feasibility of use, and cost evaluation.
Prioritize feasibility of use to ensure user needs are incorporated into the selection process.
Adapt guide criteria to accommodate novel innovations.
Foster clarity and transparency in decision-making among researchers, HCPs, and device users.

Regulatory Considerations
Follow FDA guidance for digital health technology usage in clinical investigations.
Consider CTTI recommendations for improving clinical trial quality and efficiency.
Use ePRO Consortium's factors for device suitability in regulatory trials.
Apply international guidelines for specific measurements when available.

Findings
The Library of Human Factors Resources compiles external documents related to human factors, human-centered design, and usability in the context of Digital Health Technologies (DHTs), especially sensor-based DHTs (sDHTs). The resources in the library are categorized by usability validation activity:
Use-related risk assessment (topics include user tasks, use-errors, use-related hazards, and risk mitigation).
Design considerations (topics relate to product design).
Formative evaluation (topics related to usability evaluation of a prototype product).
Summative evaluation (topics related to usability evaluation of a final-version or marketed product).

Recommendations
The page recommends that users, developers, and evaluators utilize the library's interactive index to find relevant documents to their DHT:
Use the Search by Activity tab to filter by one of the usability validation activities listed above.
Use the human factors topic column to further narrow the search.
Review the document name, issuing body, and product of focus columns to identify the most relevant document.
Click the hyperlink to access the selected document, then use the information in the relevant sections column to locate the specific topics of interest.

Regulatory Considerations
The library is a collection of resources for accelerating sDHT adoption, and it specifically includes documents like regulatory guidance and industry standards. This emphasizes the importance of understanding and applying human factors principles for validation and achieving regulatory acceptance for sDHTs.

Findings
The QS regulation under 21 CFR Part 820 has been effective but requires updates to align with global standards like ISO 13485.
Adopting ISO 13485 will harmonize FDA requirements with international practices, benefiting manufacturers that sell devices globally.
FDA’s proposed amendments retain some unique provisions to ensure alignment with the Federal Food, Drug, and Cosmetic Act (FD&C Act).
The incorporation of risk management principles throughout the product lifecycle is more explicit in ISO 13485 than in the current QS regulation.
The proposed changes are expected to reduce regulatory burdens and enhance device quality and accessibility.

Recommendations
Align quality management systems with ISO 13485 to ensure compliance with both U.S. and international regulatory requirements.
Establish documentation processes that meet FDA’s additional requirements, such as those for traceability and complaint handling.
Incorporate risk management throughout the device lifecycle, as emphasized in ISO 13485.
Manufacturers should train personnel and update their systems to comply with the new requirements within the proposed one-year transition period.
Provide comments on the proposed rule to FDA before the deadline to address any potential concerns or suggestions for improvement.

Regulatory Considerations
The proposed rule incorporates ISO 13485:2016 by reference and aligns FDA’s QS regulation with international QMS standards.
FDA-specific requirements include:
Traceability for certain life-supporting devices.
Documentation of unique device identifiers (UDI) in compliance with FDA’s regulations.
Complaint handling and servicing records that meet FDA standards.
FDA inspections will not issue ISO 13485 certifications but will assess compliance with the proposed Quality Management System Regulation (QMSR).
Manufacturers must continue to comply with existing FDA regulations where conflicts with ISO 13485 arise.

Findings
Quantitative imaging extracts numerical values from medical data that are subject to systematic error and random variation. The utility of these values depends on well-characterized performance and sufficient user information for interpretation. Performance specifications often change throughout the operating range of a device, such as volumetric reproducibility varying by structure size. Fully automated functions require more robust analytical validation than manual or semi-automated functions because they lack the opportunity for expert user correction. While phantoms serve as high-quality reference standards for ground truth, they are simplifications that may not fully reflect clinical performance.

Recommendations
Manufacturers should provide a detailed technical description of the quantitative imaging function, including the measurand, algorithm training paradigms, and level of automation. Performance specifications should incorporate objective reference values when available to allow for comparisons between subject and predicate devices. A sensitivity analysis should be conducted to determine the impact of sources of error like patient characteristics, image acquisition protocols, and image processing. Labeling must include clear instructions for user-performed quality assurance and specify any limitations where the function has been found ineffective. For automated devices, manufacturers should help users understand scenarios where the function might generate an incorrect output that is not easily identifiable.

Regulatory Considerations
The FDA recommends following a ten-step technical performance assessment process, ranging from defining the measurand to comparing statistical results against pre-defined acceptance criteria. Premarket submissions should include performance data demonstrating that the device meets claims regarding bias, precision, linearity, and limits of quantitation. Uncertainty should be reported in units of the measurand and cover the entire operating range of the function. Manufacturers are encouraged to use the Q-Submission process to address questions regarding regulatory status or specific requirements. Software implementation details should align with existing FDA guidance for the content of premarket software documentation.

Findings
The review includes 275 studies, with neurology, musculoskeletal disorders, and cardiology as the most common therapeutic areas.
The studies focused on sensor performance (48%), algorithm development (86%), operational feasibility (46%), and software development (9%).
Gaps in reporting included insufficient details on software used (27%), comparator measures (17%), and participant demographics (e.g., age and gender were missing in 9% and 15% of studies, respectively).
Sixty-seven percent of the studies used wearable sensors, while others incorporated smartphones, tablets, cameras, and implantable devices.
The lack of methodological and reporting standards across studies hinders reproducibility and broader applicability.

Recommendations
Develop methodological and reporting standards to improve consistency across feasibility studies.
Include comprehensive participant demographic data, including sociodemographics and health indicators, to ensure inclusivity and generalizability.
Conduct small feasibility studies to validate sensors, optimize algorithms, and identify operational challenges before launching full-scale trials. Use the database created from this review to inform trial design and technology selection, ensuring alignment with specific research goals.
Encourage collaboration among investigators, sponsors, and regulators to standardize methods and share insights to avoid redundant studies.

Regulatory Considerations
Align sensor verification and algorithm validation processes with regulatory requirements for reliable clinical endpoints.
Ensure secure and ethical data transfer, storage, and sharing practices for compliance with privacy regulations.
Address barriers to participation for underrepresented populations by assessing and reporting equity-related data during feasibility studies.

Findings
Verification involves testing the accelerometer's technical specifications (e.g., accuracy and precision) through peer-reviewed studies.
Validation of the algorithm relies on "ground truth" data, gathered through infrared video recordings and manual scoring of movements.
Cross-validation was used to assess the algorithm's performance, with additional validation in independent samples planned.
The separation of verification and validation allows greater flexibility, enabling the algorithm's use with multiple accelerometer devices that meet minimum standards.

Recommendations
Conduct separate verification and validation processes to ensure the reliability of both the device and the algorithm.
Use peer-reviewed publications to document the performance of DHTs and their limitations.
Ensure validation includes testing with representative populations to confirm the algorithm’s utility across diverse contexts.
Promote industry-wide standards to facilitate scalability and regulatory acceptance of DHTs in clinical trials.

Regulatory Considerations
Ensure DHTs undergo rigorous verification to meet accuracy and precision standards documented in peer-reviewed studies.
Validate algorithms using empirical "ground truth" data to demonstrate their ability to measure clinically meaningful outcomes.
Align the design and validation of DHTs with regulatory expectations for reliable and transferable performance across devices.

Findings
DHT selection should be guided by the trial's scientific goals, unmet needs, and potential to reduce participant burden.
Verification ensures the DHT accurately measures physical parameters, while validation confirms it reliably captures the desired clinical outcomes.
Conducting feasibility studies is essential to identify potential usability or compliance issues before full trial implementation.
Clear communication, training, and support plans for participants and sites are critical to the success of DHT-enabled trials.
Operational challenges, including DHT malfunctions, must be anticipated with robust management and mitigation plans.

Recommendations
Define Measurement Goals: Identify the scientific and patient-centered needs driving the decision to use DHTs.
Specification-Driven Selection: Tailor DHT selection based on technical performance, trial needs, and participant preferences, collaborating with manufacturers for transparency.
Verify and Validate Technologies: Conduct both verification and validation processes in controlled and real-world settings, focusing on the target population.
Pilot Feasibility Studies: Test the DHT in small-scale studies to assess usability, compliance, and real-world functionality.
Operational Planning: Develop detailed standard operating procedures (SOPs) for managing DHTs, addressing potential malfunctions, and supporting participants.

Regulatory Considerations
Regulatory status should not solely determine DHT selection; instead, focus on its fit-for-purpose performance in the trial context.
Maintain transparency with manufacturers to document DHT performance characteristics and limitations for regulatory submissions.
Validate endpoints and DHT data to meet evidentiary standards required by regulatory agencies.
Ensure clear roles and responsibilities for managing DHTs to align with regulatory compliance requirements.
Address interoperability, data privacy, and security concerns to adhere to ethical and legal standards in clinical trials.

Findings
The glossary establishes consistent terminology for digital health technologies, improving clarity in clinical research.
Definitions cover key aspects of digital measurement, including accuracy, precision, and validation.
Data integrity, security, and authentication are emphasized, particularly regarding structured and real-time data.
The glossary distinguishes between raw and processed data, providing clarity on data attribution and authenticity.
It includes terms relevant to both consumer-grade and regulated medical devices, supporting their appropriate use in clinical trials.

Findings
Lack of widely accepted tools for digital mobility assessment.
Challenges in technical and clinical validation due to multiple expertise requirements.
Inconsistent testing procedures and variations in norms.
Limitations of current mobility measurement methods.
Need for real-world mobility assessment.

Recommendations
Adopt best practices and innovate with standards and open access tools.
Ensure transparency through regular interaction with stakeholders.
Develop algorithms in an agnostic and fully documented manner.
Make data accessible through a digital data biobank.
Aim for regulatory approval with accurate real-world mobility measurement.

Regulatory Considerations:
Engage in early dialogue with regulatory authorities.
Understand different regulatory requirements based on context of use.
Focus on qualification of new methodologies for safety and efficacy.
Use DMOs to monitor disease progression and as surrogates for secondary endpoints.
Adopt a staged approach to regulatory qualification.

Findings
Lack of security and confidence in digital health technologies hampers adoption.
Absence of suitable guidance for selecting BioMeTs based on clinical requirements.
BioMeTs (DHTs) and algorithms are often created without expert guidance and transparency.
No standardized evaluation resources for testing, verifying, and validating BioMeTs.
Inconsistencies in algorithm application across different cohorts.

Recommendations
Develop a standardized BioMeT and algorithm evaluation framework.
Create professionally tailored standardized guidelines for BioMeT use.
Implement a framework with unique identifiers for BioMeTs and algorithms.
Establish mechanisms for dynamic updates of hardware or software.
Use systematic reviews and Delphi processes to inform framework development.

Regulatory Considerations
Assign unique identifier numbers to BioMeTs and algorithms.
Provide mechanisms for dynamic hardware or software updates.
Ensure robust deployment through standardized evaluation protocols.

Findings
The MDR/IVDR enhance the focus on cybersecurity for devices incorporating electronic programmable systems and software. Cybersecurity risk is inherently linked to patient safety and effectiveness; manufacturers must reduce all risks, including security risks with safety impacts, to an acceptable level. The management of security risks should be integrated into the product's overall Risk Management System. Due to the rapid change in the threat landscape, security maintenance is a critical, ongoing requirement across the entire product lifecycle. Other EU legislation, such as GDPR (data protection) and the NIS Directive (network security), also apply in parallel.

Recommendations
Manufacturers must follow a "Secure by design" strategy throughout the Design and Development phase, adopting a "Defense-in-Depth strategy". This includes:
Risk Management: Conduct a Security Risk Assessment (using techniques like Threat Modelling) to identify vulnerabilities and their potential impact on safety and effectiveness.
Risk Control: Prioritize mitigating risks in this order: eliminate/reduce risks through safe design; take adequate protection measures (e.g., encryption, authentication, alarms); provide information for safety and training .
Minimum IT Requirements: Clearly set out the minimum hardware, IT network, and IT security requirements for the device's operating environment and communicate these in the Instructions for Use. Devices should be as autonomous as possible in terms of security and avoid sole reliance on the operating environment.
Vigilance: Establish a robust Post-Market Surveillance (PMS) System to actively collect information, review data, and timely implement corrective actions (e.g., security updates/patches) for security vulnerabilities and incidents throughout the device's lifespan. Manufacturers must report all serious incidents and Field Safety Corrective Actions (FSCA).

Regulatory Considerations
Manufacturers must ensure that technical documentation includes information demonstrating conformity with all general safety and performance requirements, including justification and verification/validation of security solutions. Instructions for Use must include information on residual risks related to IT security and detailed instructions for secure installation, configuration, operation, and deployment of security updates. The entire process is a continuous, iterative cycle, requiring regular updates to technical documentation, risk management, and clinical evaluation