Hidden Mental Health Patterns: What Wearable Health Monitoring Devices Actually Reveal

Smart ring for mental wellness
Smart ring for mental wellness

The global wearable medical devices market, valued at USD 27.29 billion in 2022, reshapes our understanding of mental health. These devices detect heart irregularities with 97% accuracy and enable quick medical interventions. Smart health monitoring devices have grown from basic fitness trackers into advanced tools that predict health changes, stress levels, and mood swings.

Research shows that people who use wearables feel less anxious and have better moods because they can track their body's signals. The devices monitor vital signs like heart rate and breathing patterns that give clear insights into a person's mental state. The devices also merge with mindfulness features like guided breathing exercises and show promising results by reducing depression and anxiety symptoms. These advanced monitoring systems reveal hidden patterns in our mental health and change how we handle psychological wellness.

The Science Behind Wearable Health Devices for Mental Health

Psychiatric disorders show up as major disruptions in thinking, emotional control, and behavior patterns. Wearable health monitoring devices have become essential tools that collect objective data about these conditions by measuring physiological parameters continuously.

How physiological markers reflect mental states

Mental health conditions rarely have measurable biological indicators, which makes them hard to assess. Physiological markers from wearable devices offer insights into our mental states. Our bodies change during stress - heart rate variability drops and skin conductance goes up, showing our psychological state directly.

Studies show that stressful situations cause certain heart rate measurements (AVNN, RMSSD, and pNN20) to drop, while the LF/HF ratio rises. This shows how stress affects the sympathovagal system. These physical responses happen because mental health conditions trigger our autonomic nervous system, specifically balancing activities between the sympathetic nervous system (SNS) and parasympathetic nervous system (PNS).

Wearable sensors also track behavioral patterns like sleep quality, physical activity, and social interactions - all telling signs of someone's mental wellbeing. Changes in these patterns often point to conditions like depression or anxiety before obvious symptoms appear.

Key biomarkers tracked by current wearable technology

Today's wearable devices track several key biomarkers that relate to mental health:

  • Heart Rate & HRV: Heart rate variability acts as a sign across different mental illnesses, showing autonomic dysregulation. HRV typically drops by measurable amounts during stress.

  • Electrodermal Activity (EDA): This measures skin conductance, which rises during stress and anxiety. Research shows higher skin conductance relates to aggressive incidents in psychiatric settings (P=0.04).

  • Body Temperature: People with depression have substantially higher body temperature than healthy individuals (98.38 vs. 98.13 °F, P=0.03).

  • Sleep Architecture: Wearables monitor REM sleep, total sleep time, and how long it takes to fall asleep. These factors relate to mental wellbeing.

  • Biochemical Markers: Advanced wearable sensors detect cortisol, dopamine, and serotonin - key psychiatric biomarkers.

Research confirms that wearable sensor features (skin conductance, skin temperature) classify poor mental health (87%) and stress (78.3%) better than mobile phone tracking alone. Continuous EDA tracking gives the most accurate and reliable picture of a user's mental health.

The mind-body connection in digital monitoring

The basic idea behind wearable mental health monitoring comes from the mind-body connection - mental and physical health affect each other. This two-way relationship means physical symptoms often appear with mental health conditions and the other way around.

To name just one example, see how unusual biomarker levels might show biological, neurological, and developmental problems in psychiatric patients. Wearable devices help calculate what used to be impossible to measure.

A newer study, published by Massachusetts General Hospital, looked at how depression relates to various biomarkers. They checked health metrics of 150 participants with different depression levels using Galaxy Watch. The results help develop a mental health index so users can better understand their mental state.

Brigham & Women's Hospital studies how biomarkers relate to resilience - the speed at which someone bounces back from major stressors. This research captures body and mind responses to big events like disease and surgery.

The wrist seems to work best for mental health monitoring devices since people see them as accessories, making them more likely to wear them. This practical benefit, plus the science behind the mind-body connection, makes wearable health monitoring devices work well for ongoing mental health assessment.

Heart Rate Variability: The Window to Anxiety Detection

Image Source: Nature

Heart rate variability (HRV) has become one of the most promising ways to detect anxiety through wearable health monitoring devices. HRV goes beyond simple heart rate measurement. It tracks the time differences between consecutive heartbeats and gives us a window into how the autonomic nervous system works.

Understanding HRV patterns during anxiety episodes

HRV shows us how the sympathetic and parasympathetic branches of the autonomic nervous system interact constantly. People's HRV measurements change in specific ways during anxiety episodes. Research shows that stressed individuals have lower average normal-to-normal intervals (AVNN), decreased root mean square of differences between successive rhythm-to-rhythm intervals (RMSSD), and reduced percentage of successive R-R intervals that differ by more than 20 ms (pNN20). The low frequency/high frequency (LF/HF) ratio goes up by a lot during anxious states, which shows how stress affects the sympathovagal balance.

These changes happen because anxiety triggers the "fight-or-flight" response. This activates the sympathetic nervous system and suppresses parasympathetic activity at the same time. A newer study shows that people with anxiety disorders have consistently lower HRV even when resting, which suggests ongoing physiological stress whatever the environment. This pattern tells us that anxious people maintain physiological responses that don't match their current situations.

Wearable devices can spot these subtle changes through continuous monitoring. A study with 652 participants used wrist-worn devices and achieved classification accuracies of up to 83% to detect stress and anxiety levels from five-minute HRV data. Another study showed that portable devices that collect both electrocardiogram and breathing signals could spot important biomarkers that tell anxiety-induced states from non-anxiety states.

Research validation of HRV as anxiety predictor

Clinical research strongly backs HRV's role in predicting anxiety. A detailed meta-analysis found that anxiety disorders consistently link to significant reductions in HRV, showing small-to-moderate effect size. Note that medication use and other medical and psychiatric conditions didn't change these results.

These anxiety disorders show confirmed HRV changes:

  • Panic disorder

  • Post-traumatic stress disorder

  • Generalized anxiety disorder

  • Social anxiety disorder

Each condition shows much lower time-domain and high-frequency HRV measurements. This relationship isn't just by chance. Anxiety happens when someone can't inhibit their cognitive, emotional, behavioral, and physiological responses properly. This leads to reduced vagal outflow and lower HRV.

State-of-the-art wearable technology has made this knowledge practical. A study used machine learning algorithms with HRV features from affordable wearable devices and achieved accuracy up to 85% in telling stress from relaxed states. Another study looked at HRV during exercise and recovery in college students. It predicted no anxiety with 89.3% accuracy, mild anxiety with 83.6% accuracy, and moderate to severe anxiety with 74.9% accuracy.

The neurovisceral integration model explains this connection. It shows how the prefrontal cortex controls inhibitory function through a vagally mediated pathway that HRV measures. This biological mechanism lets wearable healthcare devices work as early warning systems for anxiety episodes, which could help prevent them from getting worse. These findings tell us a lot about the link between reduced HRV, anxiety, and physical health.

Sleep Patterns as Mental Health Indicators

Sleep disturbances act as both risk factors and symptoms of mental health conditions. They are vital indicators for early detection and intervention. Research shows 80% of depression patients deal with insomnia, while 15-35% experience hypersomnia. This makes sleep a powerful biomarker for mental health.

REM sleep disruptions and depression correlation

Depression changes sleep architecture, especially REM (rapid eye movement) sleep patterns. People with depression show what researchers call "disinhibition of REM sleep." This condition includes shorter REM latency between falling asleep and the first REM period, longer first REM periods, and increased REM density in rapid eye movements. These changes aren't just symptoms - they could be biological markers of depression.

Sleep disorders and mental health conditions share a two-way relationship. Sleep problems can signal upcoming anxiety or depression. The reverse is also true - anxiety and depression can lead to sleep disorders. Each mood disorder leaves its own sleep signature. Manic episodes in bipolar disorder link to less sleep, while depressive episodes associate with either insomnia or hypersomnia.

The data shows higher percentages of REM sleep associate with lower risk of heart failure (HR 0.51) and generalized anxiety disorder (0.80). Higher deep sleep percentages also link to reduced risk of atrial fibrillation (0.59) and anxiety disorders (0.84).

How wearables track sleep architecture

Wearable health monitors have come a long way from basic motion detection. They now use multiple biosensors to track sleep architecture. The original devices only used accelerometer data to tell sleep from wake states. This often meant they mistook still wake periods for sleep.

Today's wearable healthcare devices combine motion sensors with photoplethysmography (PPG), skin temperature sensors, and other tech to track sleep stages. These multi-sensor systems can reasonably tell "light sleep" from REM sleep. However, they still struggle to consistently identify slow wave sleep and wake states.

Studies comparing wearables to polysomnography (PSG, the gold standard) show these devices excel at detecting sleep with over 90% sensitivity. They're less accurate at spotting wake periods. This leads them to overestimate total sleep time and underestimate wake periods after sleep onset.

One validation study found these devices measure sleep quantity accurately compared to PSG. The differences showed low bias and precision errors.

Using sleep data to predict mood fluctuations

Scientists have developed AI-based algorithms that predict mood episodes using sleep-wake patterns. These models work remarkably well, with 80% accuracy for depressive episodes, 98% for manic episodes, and 95% for hypomanic episodes.

Circadian phase turned out to be the most important factor affecting mood episodes. Later sleep and wake times increased depression risk. Earlier sleep and wake times made manic episodes more likely.

This connection between irregular sleep and mental health goes beyond mood disorders. A study revealed that irregular sleep patterns increased the odds of various conditions. These included essential hypertension (1.56), major depressive disorder (1.75), anxiety disorder (1.55), and bipolar disorder (2.27).

Social jetlag - the gap between workday and weekend sleep schedules - is another sleep metric that affects mental health. Japanese workers with two or more hours of social jetlag were 2.14 times more likely to show signs of depression.

These findings show how wearable health devices that track sleep are a great way to get early warning signs of mental health conditions.

Electrodermal Activity and Stress Response Monitoring

Electrodermal activity (EDA) opens a fascinating window into our psychological state through sweat. EDA measures subtle electrical changes across the skin. These measurements provide unique insights into our emotional experiences that other physiological signals can't capture.

How skin conductance reveals emotional states

The science behind EDA works in a simple yet powerful way. Our sympathetic nervous system activates when we experience psychological arousal or stress. This activation increases sweat production. Sweat changes our skin's electrical conductance, which health monitoring devices can detect and measure. Our bodies show this physiological response even before we realize our emotional state. This makes EDA an objective indicator of our subconscious reactions.

EDA consists of two distinct components:

  • Tonic component (SCL): The slow-changing, background characteristics that reflect long-term stress levels

  • Phasic component (SCR): Fast-changing elements that indicate immediate responses to stimuli, also known as skin conductance response

These components create a complete picture of our emotional state. The tonic level shows our baseline stress, while phasic responses reveal our reactions to specific triggers. Research shows that EDA stands out as one of the most informative signals to measure physiological arousal. It performs better than many other biomarkers.

Research shows that EDA by itself can classify stress levels with over 94% accuracy. This matches the performance of systems that combine multiple physiological signals.

Real-time stress detection capabilities

Modern wearable healthcare devices use EDA to detect stress right away and enable quick interventions. The SKINTRONICS device combines electrodermal sensing with temperature recording. Its skin-conformant, flexible design monitors stress levels accurately. MIT researchers created the MOXO sensor that looks like a bulky smartwatch. It measures skin conductance changes wirelessly to detect stress and frustration.

EDA data processing has made great strides. Current systems use sophisticated algorithms including:

  1. Continuous deconvolution analysis (CDA)

  2. Convex optimization approach (cvxEDA)

These methods separate the SCR from raw skin conductivity data with high precision. Machine learning has taken stress detection to new levels. Support Vector Machine (SVM) algorithms using EDA data achieve 92.9% accuracy in telling stressed states from non-stressed ones.

EDA allows healthcare providers to monitor emotional and physiological states outside traditional settings. This gives them a better understanding of patients' conditions in their natural environment. EDA also helps in biofeedback therapy. Patients can watch their own stress responses and practice relaxation techniques to reduce anxiety as it happens.

Some challenges still exist. Most studies use wearable EDA sensors in labs rather than real-life situations. Field studies have grown in recent years. Researchers aim to apply this technology in everyday situations to help people manage stress better.

Combining EDA monitoring with other physiological signals improves detection accuracy. Multiplexed sensor systems that track EDA along with heart rate, temperature, and other biomarkers point to the future of wearable stress monitoring technology.

Materials and Methods: How Wearable Healthcare Devices Collect Mental Health Data

Image Source: ResearchGate

Wearable health monitoring devices now use advanced sensor arrays and data processing techniques that turn physiological signals into valuable mental health insights. These devices have made continuous mental health monitoring readily available beyond clinical settings.

Sensor technologies in modern wearables

Modern healthcare wearables use multiple types of sensors to capture physiological data linked to mental health states. Here are the most common sensors:

  • Photoplethysmography (PPG): Measures blood volume changes through light-based technology, enabling heart rate and HRV tracking

  • Electrocardiogram (ECG): Records electrical activity of the heart with higher precision than PPG, often found in medical-grade wearables

  • Electrodermal Activity (EDA): Detects changes in skin conductance related to sweat gland activity, directly reflecting emotional arousal

  • Accelerometers: Track physical movement patterns that relate to mood states and activity levels

  • Skin Temperature Sensors: Monitor temperature fluctuations that may indicate stress responses

Many devices have proven their clinical validity for these measurements. The EQ02 LifeMonitor belt shows strong correlation with standard laboratory devices across all physiological measures. The Hexoskin Smart Garment also provides reliable heart rate and respiratory rate measurements compared to reference standards.

Data collection protocols and frequency

Sampling frequency of data collection strikes a crucial balance between battery life and measurement precision. Research shows high sampling rates offer more detailed pattern information but substantially affect device longevity. Mental health applications commonly track HRV, EEG, galvanic skin response, skin temperature, blood pressure, sleep patterns, and blood oxygen saturation.

Patient compliance plays a vital role in data collection protocols. Research shows patients prefer wrist-worn devices because they look like regular accessories. This explains why Fitbit has become the most popular brand among wearable devices in research studies.

Research studies typically collect data over extended periods from days to months. One study with university students gathered data every third day for two months. This approach balanced regular sampling needs with practical considerations.

Signal processing techniques for mental health metrics

Raw sensor data goes through several processing steps to extract meaningful mental health indicators. Pre-processing filters eliminate noise and artifacts that could affect measurement accuracy. Mental health detection systems often use wavelet transforms and Kalman filters.

After noise reduction, feature extraction algorithms spot relevant patterns in the data. Standard features include mean, standard deviation, skew, root mean square, kurtosis, quartile ranges, and frequency domain metrics. Machine learning algorithms then use these features to classify mental states based on processed signals.

Mental health detection typically relies on support vector machines (SVM), k-nearest neighbor algorithms, random forests, artificial neural networks, and logistic regression. These algorithms convert raw physiological data into clinically relevant mental health assessments. Classification accuracies reach 80% for depression and up to 98% for manic episodes detection.

AI Algorithms That Decode Mental Health Patterns

Image Source: Sage Advance

AI has become the driving force that turns raw physiological data from wearable health monitoring devices into applicable information about mental health. This blend of technology creates new opportunities to detect and intervene in mental health conditions early.

Machine learning approaches to pattern recognition

Mental health pattern recognition builds on two main machine learning approaches. Supervised Machine Learning (SML) uses pre-labeled data to distinguish between conditions like major depressive disorder and its absence. This method connects input features from sociodemographic, biological, and clinical measures to create highly accurate predictions. On the flip side, Unsupervised Machine Learning (UML) works without predefined labels and finds similarities among input features to reveal inherent data patterns. Though more challenging, UML helps discover hidden structures within datasets with minimal pre-existing bias.

Several algorithms now show exceptional results in mental health pattern recognition:

  • Support Vector Machines (SVM) show 92.9% accuracy when they distinguish stressed from non-stressed states

  • XGBoost classifiers reach accuracy values of 0.925, 0.984, and 0.985 to predict depressive, manic, and hypomanic episodes respectively

  • Random Forests and Artificial Neural Networks help analyze multi-modal sensor data

How predictive analytics anticipate mental health episodes

Predictive analytics has revolutionized mental health monitoring by forecasting mood changes before symptoms show up. Research shows that models using sleep-wake patterns alone can predict depressive episodes with 80% accuracy, manic episodes with 98% accuracy, and hypomanic episodes with 95% accuracy. The circadian phase emerged as the key predictor, where delays and advances in estimated circadian phase contribute to depressive and manic episodes.

A meta-analysis of wearable AI applications for depression detection revealed compelling numbers: pooled mean accuracy of 0.89, sensitivity of 0.87, and specificity of 0.93 across 35 studies with 249,203 participants. These algorithms analyze sleep architecture, heart rate variability, and activity patterns to spot subtle changes that suggest potential mental health decline.

Case studies: Successful early intervention systems

Algorithms have shown real success in clinical settings. One case study found that biometric indicators from smartwatches predicted hospital admission for patients with psychosis and borderline personality disorder. Changes in circadian rhythm and electrodermal activity served as early warning signs.

The XGBoost algorithm combined with three months of Fitbit data achieved an AUC of 0.712 to predict mental illness onset. Sleep-related indices played a crucial role in this model, which highlights how sleep abnormalities—particularly unstable sleep rhythms—predict mental illness onset.

An AI-based decision support system now helps detect and diagnose various mental disorders by analyzing electronic health records, diagnostic tests, and behavioral patterns efficiently.

Clinical Applications in Mental Healthcare Settings

Healthcare providers are changing faster as they add wearable health monitoring devices to treatment protocols. This addition creates new possibilities for mental healthcare delivery and boosts traditional therapeutic approaches.

Integration with traditional therapy approaches

Wearable healthcare devices work as powerful complementary tools within therapy frameworks that are decades old. These tools help mental health professionals make more informed clinical decisions. Traditional therapy heavily depends on self-reporting, but wearables now add objective physiological data that can verify or challenge patient perceptions. Mental health providers who use wearable data among other self-report assessments learn more about the connection between mind and body, which creates a complete picture of patient wellbeing.

These devices monitor continuously and extend therapeutic reach beyond scheduled sessions. Therapists identify specific situations when patients experience heightened stress, which aids more targeted interventions. To cite an instance, biometric indicators from smartwatches have preceded hospital admission for patients with psychosis and borderline personality disorder. Detectable changes in circadian rhythm serve as early warning signs.

Mindfulness exercises through wearable health devices boost conventional treatment methods. These devices provide timely reminders for breathing techniques and relaxation strategies that work especially when you have stress and anxiety.

Wearable technologies have showed remarkable results in medication management. One study reported a 96.6% detection rate of medication ingestion by wearable sensors. Another study found that patients who participated with wearable monitoring systems showed substantially improved medication adherence rates—from 0.62 in moderately engaged groups to 0.87 in highly engaged groups.

Healthcare institutions should think over several critical factors to implement these successfully in clinical settings:

  • Integration with electronic health records for uninterrupted data flow

  • Development of personalization strategies to reduce "wearables fatigue"

  • Investment in staff training to support patients between visits

  • Establishment of environmentally responsible reimbursement models

Medical professionals must work with engineers to address implementation challenges and discover the full potential of these technologies as this field advances.

Remote monitoring for high-risk patients

Wearable health monitoring devices give patients with severe mental health conditions a lifeline that goes beyond traditional clinical care. People at high risk, especially those who experience suicidal thoughts, schizophrenia, or bipolar disorder, see huge benefits from continuous physiological tracking that alerts care teams to potential crises.

These remote monitoring systems work through a three-part structure. Wearable sensors collect data, algorithms process patterns, and alert systems notify both patients and providers when concerning trends emerge. This approach helps teams intervene before full-blown episodes occur, which has led to fewer hospitalizations among monitored patients.

Digital phenotyping, which quantifies behavior moment-by-moment through personal digital devices, has shown remarkable results. These systems use passive data collection to capture subtle behavioral changes that suggest deteriorating mental health. Digital biomarkers effectively provide an objective window into subjective experiences and help detect concerning patterns in high-risk populations early.

Medication effectiveness tracking

Smart medical devices are changing how we handle the persistent challenge of medication adherence in mental healthcare. Smart pill bottles with sensors record exact medication timing, while wearable devices track the body's response to these medications.

This combined monitoring approach serves multiple purposes:

  • Verifies medication consumption patterns

  • Documents physiological responses to treatment

  • Identifies optimal dosing schedules based on individual biorhythms

  • Detects adverse effects through abnormal physiological patterns

Healthcare providers now learn about medication effectiveness in ways that go way beyond patient self-reporting. To name just one example, subtle changes in sleep architecture, heart rate variability, or electrodermal activity often show whether a medication works as intended.

The most effective way to implement these systems today involves shared monitoring between patients, caregivers, and healthcare providers. This creates a supportive network that balances autonomy with safety for those who face the highest risk of mental health crises.

Limitations of Current Wearable Medical Devices

Wearable technology has made remarkable progress, yet these devices still face major limitations that affect their reliability in mental health monitoring. Healthcare providers and users need to understand these constraints to get reliable insights.

Accuracy challenges in real-life settings

These health monitoring devices struggle with accuracy outside the lab environment. A survey shows that only 9% of respondents were hesitant to share their wearable data with doctors. Yet 37% of this group worried that wrong data might harm their health. The limited resources in these devices make them prone to measurement errors. Many of them send login details and process data through clear text HTTP, which reduces how reliable their measurements are. These technical shortcomings make it hard for devices to give consistent results in daily use.

False positives and their psychological impact

Wrong alerts from medical wearables often cause needless worry and stress. A big problem occurs when these devices flag normal conditions as problematic. To cite an instance, wearables have mistaken regular flu for COVID-19 because both conditions show similar body signals. The fitness app Strava showed us the collateral damage of data sharing in 2018 when it accidentally revealed U.S. military base locations by tracking user activity.

Demographic and physiological variations in data interpretation

The algorithms in healthcare wearables come from non-probability samples that might have hidden bias. The data usually comes from internet users who match U.S. population demographics. Nobody knows if these samples represent other countries' populations well. This creates problems in understanding data from a variety of populations.

Privacy and security concerns

Privacy remains the biggest problem in wearable tech adoption. An intrinsic review points out that poor encryption and weak authentication methods leave user data open to hackers. Companies collect huge amounts of sensitive data like heart rate and blood pressure. They send this data to cloud servers to analyze it. The MyFitness Pal hack in 2018 exposed about 150 million users' data, which hackers later sold on the dark web.

Conclusion

Wearable health monitoring devices are great tools that help assess and manage mental health. These devices track vital physiological markers such as heart rate variability, electrodermal activity, and sleep patterns. They provide objective data about mental states. The clinical potential shows in their impressive accuracy - 83% for anxiety detection and up to 98% for mood episode prediction.

Technology faces some challenges with accuracy, privacy, and demographic representation. We have a long way to go, but we can build on this progress. Machine learning algorithms now make pattern recognition better, and improved sensor technologies give more reliable measurements. Healthcare providers merge these devices with traditional therapy approaches to create complete treatment strategies for mental health conditions.

What a world of mental health monitoring through wearables looks like is exciting. Advanced AI algorithms paired with sophisticated sensor arrays will make early detection and intervention better. These developments could change mental healthcare delivery, particularly for high-risk patients who need continuous monitoring.

Mental health assessment and treatment are at a technological turning point. Wearable devices give us an unprecedented look into our psychological well-being. They bridge the gap between physical and mental health monitoring. Their development from simple fitness trackers to sophisticated mental health tools shows how far we've come in understanding and managing mental health conditions.

FAQs

Q1. What types of wearable devices are effective for monitoring mental health? Several wearable devices are designed specifically for mental health monitoring, including Fitbit, Lief, Abilify MyCite, Muse, TouchPoints, Oura Ring, and Thync. These devices track physiological parameters like heart rate, sleep patterns, and electrodermal activity to provide insights into mental well-being.

Q2. How do wearable sensors contribute to mental health monitoring? Wearable sensors continuously track physiological parameters such as heart rate, breathing patterns, and skin conductance. These measurements can provide valuable insights into an individual's mental state, helping to detect stress, anxiety, and other mental health conditions.

Q3. What are the key features of health monitoring wearables? Health monitoring wearables typically include sensors for tracking heart rate, sleep patterns, physical activity, and sometimes more advanced metrics like electrodermal activity or blood oxygen levels. They often integrate with smartphone apps for data analysis and may provide alerts or recommendations based on the collected data.

Q4. How accurate are wearable devices in detecting mental health issues? While accuracy varies, some studies have shown that wearable devices can detect anxiety with up to 83% accuracy and predict mood episodes with up to 98% precision. However, real-world accuracy may be lower due to various factors, and these devices are best used in conjunction with professional medical advice.

Q5. What are the main limitations of current wearable health monitoring devices? Current limitations include accuracy challenges in real-world settings, potential for false positives, privacy and security concerns, and demographic variations in data interpretation. Additionally, some users may experience "wearables fatigue" or find the devices intrusive. Ongoing research and development aim to address these limitations.