Stimulators Archives - BIOPAC Blog

No Pain, All Gain: How EMG and Other Physiological Signals Aid Injury Avoidance

It can happen anywhere, anytime: on the pickleball court, during a pristine nature hike, or even while stepping off the front porch on the way to work. An ankle turns, a knee buckles, and suddenly you’re on the ground wondering what just happened. While such injuries often seem random, researchers who study human movement know they are rarely without warning.

Kinesiologists, scientists who study the mechanics and physiology of movement, have found that subtle changes in muscle activation, fatigue, coordination, balance, and neuromuscular control often emerge long before a strain, sprain, or overuse injury becomes apparent. To better understand these hidden danger signs, researchers increasingly rely on physiological measurements that reveal how the body’s muscular, nervous, cardiovascular, and biomechanical systems respond to activity. Such insights help identify injury risk factors and guide strategies designed to keep people moving safely and effectively.

Among the many tools used in kinesiology research, electromyography (EMG) is one of the most common because it reveals when and how muscles activate during movement. However, EMG is only one part of the story. Researchers also study force production, joint motion, movement acceleration, cardiovascular activity, respiration, muscle oxygenation, and neural activity to better understand how the body adapts to physical demands. Together, these measures provide a more complete picture of movement and help uncover patterns that observation alone may miss.

The applications of this work extend far beyond sports. Physiological monitoring helps clinicians evaluate rehabilitation progress, guide return-to-activity decisions, support fall-prevention efforts among older adults, and help design safer workplaces and training programs. Increasingly, researchers are shifting from simply treating injuries to identifying and addressing the factors that contribute to them before they occur.

Researchers in India conducted a cross-sectional study comparing elite and recreational university badminton athletes to explore whether physiological and neuromuscular characteristics could serve as injury-risk markers. The investigators collected a range of performance and neuromuscular measurements, including surface EMG recordings, to examine differences between competitive levels and establish preliminary benchmarks for injury-risk stratification. Surface muscle activity was recorded using a BIOPAC two-channel data acquisition system as part of the neuromuscular assessment protocol. The study found that elite athletes exhibited distinct physiological and neuromuscular profiles compared to recreational players, suggesting that objective physiological markers may help identify movement patterns and performance characteristics associated with increased injury vulnerability. These conclusions support the growing use of physiological profiling to identify athletes who may benefit from targeted injury-prevention strategies before injuries occur.

A team of researchers in Tunisia investigated how fatigue of the ankle evertor muscles affects force perception and neuromuscular function in healthy adults. Ankle injuries are among the most common musculoskeletal injuries in both athletic and recreational populations, making ankle stability an important area of study. Using surface EMG to measure muscle activity before and after a fatigue protocol, the researchers examined how localized fatigue affected participants’ ability to accurately reproduce force levels. Researchers used a BIOPAC EMG amplifier and data acquisition system to record electrical activity from muscles involved in ankle stabilization. The researchers found that fatigue impaired force perception and altered neuromuscular responses, suggesting that fatigue may reduce the body’s ability to control ankle movements accurately. The study results add to growing evidence that fatigue-related physiological changes can increase injury risk, particularly during prolonged exercise or competition when neuromuscular control begins to decline.

A multi-institutional team of researchers from the United States examined neuromuscular function in individuals who had undergone anterior cruciate ligament (ACL) reconstruction, comparing them with healthy controls. The researchers wanted to better understand whether the relationships between muscle performance, muscle activation, and nervous system function change after ACL surgery. Participants completed a series of strength and neuromuscular assessments, with quadriceps muscle activity recorded using a BIOPAC data acquisition system with AcqKnowledge software and an EMG amplifier. BIOPAC isolated stimulators were also used during testing to help determine how fully participants could activate their quadriceps muscles. The study found that several relationships observed in healthy knees were no longer present after ACL reconstruction, suggesting that changes in neuromuscular control can persist long after surgery and rehabilitation are complete. These findings highlight how physiological monitoring can uncover hidden deficits that may not be apparent during routine recovery assessments, helping clinicians make more informed return-to-sport decisions and potentially reducing the risk of future injury.

As these examples demonstrate, physiological measurements give researchers powerful tools to identify injury risk before injuries occur, understand how fatigue alters movement control, and evaluate recovery following musculoskeletal injury. By revealing the physiological mechanisms that influence human movement, signals such as EMG and related neuromuscular measures help bridge the gap between laboratory research and practical injury-prevention strategies. As kinesiology research continues to evolve, physiological monitoring will likely play an increasingly important role in supporting safer movement, more effective rehabilitation, and improved long-term physical performance.

Are you planning a kinesiology-focused study? BIOPAC local sales representatives have the information you need to design and equip your research project.

Aesthetically Pleasing: Exploring How the Brain Perceives the Arts

Beauty is in the eye of the beholder—a mostly subjective experience, so the saying implies. While we may share many common ideals about beauty and aesthetics, our reactions to art, music, and literature can diverge, converge, and overlap to a myriad of degrees. Neuroaesthetics explores how the brain perceives and responds to art, music, and other aesthetically evocative experiences. Combining neuroscience with psychology and the arts, researchers seek to understand why humans find certain images, sounds, or designs appealing and how these perceptions influence our emotions, cognition, and behavior. This interdisciplinary science has practical applications across a wide range of fields, including design, marketing, education, and mental health therapy, where understanding aesthetic experience can inform and enhance user engagement, learning, and emotional well-being.

Biometric signals provide insight into emotional and cognitive processing, allowing researchers to gain valuable data on how the brain creates and responds to aesthetically engaging stimuli. Commonly used techniques include electrodermal activity (EDA), which measures changes in skin conductance linked to emotional arousal; electroencephalography (EEG), which tracks brainwave patterns associated with attention and engagement; functional near-infrared spectroscopy (fNIRS), which monitors blood flow changes in the brain; and functional magnetic resonance imaging (fMRI), which provides high-resolution images of neural activity.

Additionally, the use of virtual reality (VR) and augmented reality (AR) is expanding in neuroaesthetics research, allowing scientists to create controlled, immersive environments that mimic real-world experiences. These technologies offer new ways to investigate how individuals engage with art and design in dynamic, interactive settings, pushing the boundaries of how we understand and harness aesthetic experiences.

Researchers in Shanghai, China, for example, investigated how different visual modes—2D and 3D VR—affect emotional arousal, demonstrating how immersive environments influence emotional experiences. The research team utilized EEG to monitor brain activity and EDA to measure skin conductance responses, both indicators of emotional arousal. EDA and EEG data were recorded while study participants wore VR headsets to view 2D and 3D environments. Data was collected and analyzed using a BIOPAC MP system with AcqKnowledge software. The findings revealed that 3D VR environments elicited more intense emotional stimulation than 2D settings, as evidenced by higher beta (21–30 Hz) EEG power and increased EDA responses. According to the published findings, results suggest that enhanced perception in 3D environments leads to greater emotional engagement, highlighting the potential of 3D VR in applications such as immersive therapy, virtual training, and interactive entertainment.

A team of German researchers recently examined the intersection of neurology, psychology, music, and literature. Their findings, published in the journal NeuroImage, explored how melodic features influence the neural processing of spoken poems and songs, examining the interplay between language and music. Researchers employed fMRI to investigate the neural mechanisms underlying the processing of musical and nonmusical verse. The fMRI data revealed that both spoken poems and songs activated bilateral temporal auditory areas of the brain. One aspect of the study was the measurement of participants’ emotional responses to the stimulus, i.e., whether they liked the song or poem to which they were listening while the fMRI scan was conducted. To gather this data, participants interacted with a BIOPAC differential pressure transducer connected to the participants’ right and left index fingers to record the degree to which they enjoyed the music. The researchers stated the findings suggest that melodic properties are central to the aesthetic experience of both speech and music.

A study published by Britain’s Royal Society looked at the connection between aesthetic appreciation and emotional states, specifically how exposure to art or music can shift feelings of anxiety to curiosity. To understand how the brain perceives beauty, the researchers used EDA to assess participants’ physiological arousal during exposure to aesthetically pleasing stimuli, such as music. EDA data was gathered using a BIOPAC EDA amplifier connected to a data acquisition and analysis system while participants were administered anxiety-inducing electrical tactile stimulation during music listening sessions. The study demonstrated that aesthetic appreciation can reduce anxiety and promote curiosity by analyzing the EDA data alongside self-reported measures. The research team concluded that their results “might have potential applications across different human activities such as learning and therapy. The idea that aesthetic appreciation might affect anxious states and that expecting aesthetic rewards can transform anxiety into arousal and curiosity plays a central role in some psychotherapeutic models of human change.”

These examples provide a rough outline of a bigger picture, illustrating the many ways researchers use physiological signals to better understand the human mind’s response to art, music, and literature. For more information on the tools BIOPAC provides to assist in neurological and physiological research, see our online training and webinars.

Are you planning a research project to investigate the intersection of aesthetics and neuroscience? Contact a BIOPAC representative in your area to identify the right resources and equipment for a successful study.

Only the Lonely: The Human Impact of Social Isolation

Humans by their nature are social creatures. A sense of community, daily interactions, and shared experiences are tied to our overall mental and physical well-being. Few events in modern history have shut down such interactions more thoroughly than the outbreak of COVID-19, which forced millions into prolonged isolation. As lockdowns and social distancing became the norm, an increasing number of people reported heightened feelings of loneliness, anxiety, and depression. Beyond the pandemic, other modern social factors contribute to isolation, including the growing reliance on social media and virtual interactions in place of face-to-face connections. While technology offers new ways to stay in touch, excessive screen time and digital communication can sometimes deepen feelings of loneliness by reducing meaningful, in-person social engagement. In the wake of these societal shifts, researchers are working to understand the long-term consequences of social isolation on both mental and physical health.

Studies suggest that loneliness isn’t just an emotional experience—it has measurable physiological effects on the body. Using advanced biometric signals, researchers are trying to uncover how isolation influences our nervous system, stress responses, and overall wellness. Heart rate variability (HRV) provides insights into autonomic nervous system balance, while electrodermal activity (EDA) reflects changes in stress and emotional arousal. Respiration patterns, electromyography (EMG) readings, and other physiological markers help paint a complete picture of how isolation affects both mind and body. By combining psychological assessments with physiological data, scientists aim to better understand how chronic loneliness can contribute to conditions such as cardiovascular disease, weakened immune function, and mental health disorders.

In one such study published in Britain’s Royal Society Open Science journal in 2024, researchers looked at the effect of social isolation on human adolescents, specifically their ability to learn to perceive threats. Study participants between the ages of 16 and 19 underwent sessions of complete isolation and isolation combined with virtual social interaction, as well as baseline sessions. Following each session, study participants reported their psychological state and completed a threat learning task (participants learned to associate neutral shapes with an aversive sound) to measure physiological response to learned threats and safety cues. During these sessions, researchers recorded participants’ EDA signals using BIOPAC EDA finger transducers connected to an MP36R data acquisition and analysis system running AcqKnowledge software. Results showed heightened EDA levels during threat extinction following isolation compared to the baseline. Researchers reported that their findings suggest that isolation and loneliness among adolescents might increase vulnerability and increase the instances of emotional disorders such as phobias, anxiety, and obsessive-compulsive disorder (OCD).

A team of researchers in Brazil compared how giving and receiving of social touch as well as heart rate variability serve as accurate predictors of loneliness in college-age adults. Participant loneliness levels were measured using the UCLA Loneliness Scale. Participants completed a psychiatric screening questionnaire that reported loneliness, social support, and social touch levels. Participant HRV measurements were taken via electrocardiographic (ECG) signal processing using a BIOPAC ECG amplifier connected to a 16-channel MP data acquisition and analysis system running AcqKnowledge. According to the researchers’ published findings, “social support and social touch, specifically receiving touch, accounted for a significant proportion of the variance in loneliness. However, neither giving touch nor resting HRV was a significant predictor of loneliness.”

A study by researchers from the University of Bonn examined the link between loneliness and how males and females process trauma and react to fear-inducing stimuli. Over three days, participants were exposed to experimental trauma and evoked intrusive thoughts. Researchers employed functional magnetic resonance imaging (fMRI) scans to assess neural habituation to fearful faces and fear learning (conditioning and extinction) before trauma exposure. Fear conditioning and extinction tasks used a BIOPAC MP system to deliver stimulus in the form of electric impulses. EDA and respiration data were recorded using the BIOPAC data acquisition and analysis system. Study results revealed “a significant interaction between loneliness and sex such that loneliness is associated with more intrusions in men, but not in women.” The implication is, according to the study’s authors, “that loneliness may confer vulnerability to intrusive memories after trauma exposure in healthy men and that this phenotype relates to altered limbic processing of fear signals.”

As the physiological and psychological effects of the COVID-19 pandemic continue to resonate and we grapple with the isolating influence of technology, increasing numbers of research studies are being launched to measure these impacts. Studies into human isolation and loneliness represent just one small corner of a broad spectrum of research on the topic. For information on how BIOPAC equipment is being used in such research areas, check out our on-demand webinars for additional ideas on how to deploy BIOPAC resources in your next study.

Are you planning a research project investigating the effects of isolation, loneliness, or other related subjects? Reach out to our team of experts to help you get started with the right resources and equipment.

Everybody Hurts: Studying the Physiological and Neurological Components of Pain

A Buddhist saying states, “Pain is inevitable, but suffering is optional.” Pain’s dual nature has presented a conundrum for philosophy and the sciences. As a warning system, it protects us from harm, but it can also be the source of profound psychological and emotional damage. Pain is a complex and deeply subjective experience, yet it is one of the most critical areas of study in neuroscience.

Understanding pain involves not only exploring its physical origins but also decoding the neural circuits and physiological signals that contribute to its perception and regulation. Neuroscientific research into pain aims to answer fundamental questions about how pain is processed in the brain, how it varies from person to person, and how we can develop better treatments for chronic conditions.

This research uses various physiological signals to provide insights into pain mechanisms. Electroencephalography (EEG) captures brainwave activity, revealing how different regions of the brain respond to painful stimuli. Photoplethysmography (PPG) tracks blood flow changes, while electrocardiography (ECG) and skin conductance response (SCR) measure autonomic nervous system activity, offering clues about how the body reacts to stress and discomfort. Respiration patterns, too, are key indicators, as breathing can change in response to pain. Together, these signals help scientists map the body’s response to pain, shedding light on the underlying neural pathways and guiding the development of more effective pain management strategies. Understanding these physiological markers is a critical step toward personalized pain care and improving the quality of life for millions worldwide.

Pain research commonly focuses on the neurological mechanisms of pain to better understand its causes and how it can be treated. Researchers publishing their findings in the Journal of Biomedical and Health Informatics developed a device for studying pain perception biomarkers using thermal stimulation. Their device generates minutely controlled thermal stimuli using a computer-driven Peltier cell while simultaneously capturing EEG and PPG signals. Researchers identified the heat pain threshold (HPT) for each subject, defined as the maximum the subject can withstand when the Peltier cell gradually increases the temperature. The team used two-dimensional spectral entropy (SE) obtained from both the EEG and PPG signals to differentiate the condition of pain. EEG and PPG signals were fed to a BIOPAC MP36 data acquisition and analysis system running Biopac Student Lab (BSL) software. The study concluded that hemodynamics, brain dynamics, and their interactions can be used to discriminate thermal pain perception, which could have practical applications in monitoring pain perception. Possible applications include the study and treatment of “pathologies that affect the peripheral nervous system, such as small fiber neuropathies, fibromyalgia, or painful diabetic neuropathy.”

The pain mechanism associated specifically with fibromyalgia, one of the most common chronic pain disorders, was the focus of a study at the University of Jae´n in Spain. Despite its prevalence, much is still unknown about the underlying cause of this condition. Clinical and experimental studies of individuals diagnosed with fibromyalgia syndrome (FMS) have revealed autonomic nervous system (ANS) deficiencies. While both the parasympathetic and sympathetic components of the ANS have been studied, less is known about the sympathetic component as it relates to FMS. In this study, researchers used SCR as an indirect measure of the sweat response, which is controlled by the sympathetic mechanisms of the ANS. Researchers used a BIOPAC MP36 running AcqKnowledge to collect SCR data via an EDA lead set connected to participants’ fingers. The study found reduced skin conductance levels (SCL) and SCR in FMS patients compared to the non-FMS control group, indicating lower levels of sweating and reduced sympathetic activity in the skin. These factors provided the research team with a better understanding of the sympathetic nervous system’s role in FMS, with the potential for revealing new routes to better pain management and treatment.

For several decades, researchers and clinicians have studied the use of hypnosis to treat chronic pain. More recently, new technologies such as virtual reality have been incorporated into these techniques. A team of researchers from the University of Strasbourg in France studied the application of virtual reality hypnosis (VRH) to regulate HPT in healthy adult participants. Researchers used several physiological signals to measure autonomic function during the experiment, including ECG, respiration, SCR, and EEG. ECG signals were recorded using the BIOPAC ECG amplifier, while respiration rate was measured by a thermistor transducer that determined the difference in temperature between inhaled and exhaled air. SCRs were measured from the index and middle fingers of the dominant hand with a BIOPAC skin conductance transducer. Physiological signals were fed into a BIOPAC data acquisition system for analysis. A computer-generated immersive environment was created in VR and combined with a hypnotic auditory script. As with classical hypnosis treatments, the VRH scheme in this study began with an “induction period” followed by a “dissociation” period (separation between the mental state and the environment), followed by suggestions of pain reduction as analgesia. The study results supported a positive correlation between VRH and an increase in the participants’ pain threshold with promising implications for new non-pharmacological approaches to pain management and treatment.

These are just some of the ways that BIOPAC equipment is being used to explore the frontier of pain research and help ease the suffering of millions who deal with chronic pain and its physical and psychological effects. See our webinars page for additional information on how physiological signals can be applied to your next study.

Are you planning a study on pain or any related neurological or physiological area of research? Our team of experts is ready to help you find the tools to ensure success.

Facing Fear: Measuring What Scares Us

In many countries, October ushers in the season of ghosts, goblins, and all manner of frightening things that inhabit our deepest fears. While the popularity of Halloween reflects the thrills many derive from a good scare, facing one’s fears is not always fun and games. Our fears can protect us from danger, but they can also hamper individuals from performing the simplest tasks and negatively impact one’s quality of life and mental health.

The study of fear conditioning and fear learning sheds light on how humans and animals develop responses to threatening stimuli. Research often relies on psychophysiological measurements—techniques that capture the body’s physical responses to fear. Key among these measurements are skin conductance response (SCR), electrodermal activity (EDA), heart rate variability (HRV), respiration, and electromyography (EMG).

SCR and EDA track changes in sweat gland activity, providing a direct measure of emotional arousal when a person experiences fear. HRV and respiration rate reveal the autonomic nervous system’s reaction to stress, indicating shifts between sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) states. EMG measures muscle activity, especially facial muscles, to detect subtle expressions or physical tension associated with fear. Understanding these mechanisms has practical applications in understanding and treating anxiety disorders, phobias, and post-traumatic stress disorder (PTSD). By analyzing the body’s automatic fear responses, scientists can develop targeted therapies to help individuals recondition or dampen these reactions.

A study published in the Journal of Behavior Therapy and Experimental Psychiatry used a range of indices to assess learned fear (unconditioned stimulus expectancy or US-expectancy) in individuals. These included both self-reporting and measurements of autonomic response such as skin conductance. Researchers using E-Prime Stimulus Presentation Systems, paired various neutral visual stimuli with unconditioned stimuli in the form of electrical shocks delivered via a constant voltage stimulator coupled with a BIOPAC STM100C amplifier. After a brief break, both neutral stimuli were administered without shock. Skin conductance response data was gathered and analyzed during each phase with a BIOPAC data acquisition and analysis system and software. Results showed a positive correlation between US-expectancy ratings and skin conductance response.

Researchers at the University of Bologna in Italy took a different approach to measuring the psychophysiological mechanisms of fear learning by focusing on HRV. In their study, published in the journal Psychophysiology, they explained that “understanding transient dynamics of the autonomic nervous system during fear learning remains a critical step to translate basic research into treatment of fear-related disorders.” Researchers gathered SCR and electrocardiogram (ECG) data. As with the previous study, mild electrical shocks were applied as unconditioned stimuli and paired with neutral or conditioned stimuli (CS). SCR signals were acquired using a skin conductance transducer attached to the participants’ fingertips connected to a BIOPAC EDA amplifier. ECG data was collected using disposable surface electrodes connected to an ECG100C amplifier. EDA and ECG signals were processed with a BIOPAC data acquisition and analysis system running AcqKnowledge software, which calculated HRV from the ECG data. Researchers concluded that “learned fear elicited a transient heart rate deceleration in anticipation of noxious stimuli.” They added that the study’s findings “provide a proximal measure of the involvement of cardiac vagal dynamics into the psychophysiology of fear learning and extinction, thus offering new insights for the characterization of fear in mental health and illness.”

Another study published in the journal Psychophysiology examines fear learning by applying a broad range of physiological signals and responses to determine which provides the “optimal measurement of human trace fear conditioning.” For this study, researchers compared SCR, pupil size response, heart period response (via ECG), respiration amplitude response, and electromyography (EMG) to measure participants’ responses to electrical current, audio, and visual stimulation. EDA data was gathered via a BIOPAC EDA amplifier, while ECG, EMG, and respiration data were fed to BIOPAC ECG100C, EMG100C, and RSP100C amplifiers, respectively. All data was processed using BIOPAC data acquisition and analysis systems and software. Results of the experiment suggested that startle eye-blink response through EMG provided the most sensitive metric for measuring fear conditioning.

Fear is just one of the emotions that can be studied through the body’s affective response to stimuli. Read more about the relationship between affect and emotion or watch our webinar on Emotion and Objective Physiological Measures.

Are you facing the reality of putting together your own fear-based study? Don’t be afraid to contact your local BIOPAC customer service representative for help finding the right tools for the job.

VR Integration: Enhancing Research with Virtual Environments

Measuring the human body and brain’s response to real-world conditions and stimuli has long challenged researchers. This problem has usually been dealt with in one of two ways. The first approach is to take research participants into the field—not impossible with today’s mobile data recording technology but not always safe or convenient. The second option is to imitate real-world conditions in the lab using screens, audio equipment, and even scent delivery, but in the end, it is difficult to completely remove the lab setting from the participant’s experience—that is, until the introduction of Virtual Reality (VR) technology in research.

Just as it has revolutionized everything from entertainment to training, VR has provided researchers with the opportunity to create immersive experiences in the lab that mimic the real world. Advances in technology have not only made these simulated environments more realistic, but they have also made it easier to integrate a wide range of signals and stimulus delivery to enhance the recording of physiological and psychophysiological data.

BIOPAC, through cooperation with several partner companies, offers a range of data recording options that integrate seamlessly with third-party VR devices. fNIR Devices, for example, designs solutions for recording functional near-infrared spectroscopy (fNIRS) signals that can easily be incorporated with standard VR head-mounted displays (HMD) to measure neural activity and hemodynamic response in the prefrontal cortex while participants experience VR environments. BIOPAC partner Seenel has created MedelOpt, a line of whole-head wearable devices that combine electroencephalography (EEG) and fNIRS, including a VR option that integrates an HMD. Finally, partner company WorldViz offers a full spectrum of VR solutions from complete VR kits to full-room Projection VR technology to software that can be combined with both wired and wireless data recording technologies to provide a complete array of bio-signal data, from eye tracking to electrodermal activity.

A Canadian study published in 2023 used a combination of BIOPAC and WorldViz products to investigate how sensory feedback and arousal influence neuromus cular control and posture. Researchers measured arousal via electrodermal activity (EDA) and psychosocial questionnaires, rating perceived fear and anxiety in both real-world situations in VR environments that simulated standing both at ground level and on a raised platform. Participants wore a commercial HMD running WorldViz’s Vizard VR toolkit software. Electrical nerve stimulation was provided via a BIOPAC linear isolated stimulator. The study found the “physiological and perceptual indicators of fear and anxiety increased” in the VR platform simulation, providing “novel evidence that VR can be used to modulate upright postural control.”

A similar study published in the 2022 issue of the Journal of Sport Rehabilitation examined the effect non-physical mental training has on balance skills. The study used fNIRS technology to measure hemodynamic response in the prefrontal cortex of participants experiencing virtual environments through VR HMDs. Participants were instructed to imagine themselves imitating balance exercises viewed through an Oculus VR HMD while also fitted with an fNIR Devices Imager headband. Data was gathered using Cobi Studio software and analyzed via fNIRSoft software. The study identified several advantages of virtual reality mental training (VRMT) over conventional mental training (CMT).

These are just a few examples of how VR technology can be integrated with a variety of methodologies for gathering research data. For additional information on the subject, check out our Virtual Reality Resources, which include an array of online training on integrating VR into research.

Are you planning a research product and need help integrating VR with other data acquisition and analysis equipment? Contact your local BIOPAC sales rep to find the right solutions for you.

Projection VR: Virtual Rooms Turn Science Fiction into Reality

Fans of Star Trek have long marveled at the technological innovations spawned from the imaginations of its creators—from warp drives that bend space to transporters beaming individuals from point A to B. Few of these speculative innovations inspired more wonder than the “holodeck,” a room that creates a simulated sensory experience nearly indistinguishable from reality, where crew members can train, study, or engage in recreation within the space’s artificial environments.

The border between science fiction and fact can be fluid, as proven by the proliferation of virtual reality (VR) technology in recent years, providing an immersive experience like that promised by the fictional holodeck. When thinking about VR in the modern sense, one usually envisions a person fitted with a head-mounted display (HMD) that delivers visual stimuli directly to the eyes, with movement and views controlled by directional sensors in the HMD and hand controllers.

While this can certainly deliver an immersive experience, HMD systems have their limitations. HMDs and controllers are often tethered via cables to the high-end computers needed to generate realistic imagery. This can limit the user’s ability to move and interact naturally in a virtual environment. A variation is something much closer to the holodeck of science fiction—a room in which a virtual environment is projected onto walls rather than displayed on a headset screen. This is the world of projection VR.

Virtual reality innovators like WorldViz are taking projection VR to the next level by creating highly-customizable virtual environments that can be scaled and adapted to a variety of tasks. One application in which VR projection rooms are being used is to train emergency medical technicians (EMT) and other first responders in realistic environments, such as on a virtual roadside. Trainees can move about performing first aid as cars seem to rush by, safe from real traffic hazards.

Outside of training and educational applications, projection VR and VR rooms have proven to be affective in a variety of research studies. These technologies have been used in machine learning and behavioral studies focusing on children with autism spectrum disorders (ASD). In such applications, HMD systems may cause motion sickness or discomfort for the participants with ASD. Projection rooms, however result in no significant negative impacts on the participants’ comfort while still providing an immersive experience.

As mentioned, projection VR experiences allow for additional technologies to be introduced seamlessly into the virtual experience. A 2020 study of driver gaze habits integrated driving environments created in Vizard 5.0 and projected on a screen with eye tracking to determine how drivers process visual information behind the wheel. Participants were able to interact with real driving controls while their “vehicle” moved through the virtual environment as they focused on visual cues.

VR projection rooms are no longer restricted to fictional flights of fancy. Their real world use is limited only by the imaginations of those applying these potent tools in the classroom and research lab.

For more information on how projection VR can benefit research, education, and training, join a webinar hosted by BIOPAC as we explore this virtual frontier where science fiction becomes science reality.

‘Tis the Season for Stress: Research Tools for Anxious Times

Holiday-related stress is as much of a seasonal tradition as family gatherings, frantic shopping forays, and over-indulgence in food and drink. Add to this potent mixture nearly two years of pandemic-induced tension and we have a volatile cocktail of emotions and anxiety awaiting us in November and December. What better time to study the causes and effects of stress?

Research has established strong links between stress and our moods and sense of well-being, not to mention overall mental and physical health. While certain types of stress during development can teach individuals to adapt to life’s many challenges, excessive and prolonged stress is shown to contribute to chronic disease and a range of psychological disorders. According to the American Psychological Association, which conducts an annual survey monitoring stress, the COVID pandemic has had an unprecedented impact on stress levels across all demographics, particularly among young people.

The pandemic is just one of many factors driving demand for new approaches to stress research. Thankfully, researchers now have access to a myriad of technologies to support any experiment design. In a recent webinar on techniques for measuring physiological changes related to stress, BIOPAC head of European Sales, Alex Dimov, outlined a range of stress-connected physiological responses that can be measured in the lab with available technologies. These include heart rate, heart rate variability (HRV), trans-radial-ulnar electrical bioimpedance velocimetry (TREV), cardiac output, blood pressure, EDA, pulse, respiration, EMG, EEG, and functional near infrared spectroscopy (fNIRS).

One of the challenges of measuring stress in a natural environment is finding the right data gathering tools to support the mobility of test participants. A 2019 study tackled this by examining a variety of techniques for measuring stress in day-to-day life using mobile phones and wearable sensors. Settings included the lab, automobile, office, school, and other daily life locations. Along with consumer products like smartphones, smartwatches, and fitness bands, researchers also employed wearable sensors, including the BioNomadix wireless PPG transmitter to measure blood volume pulse (BVP) using a photo plethysmogram (PPG) signal. Researchers found that the BIOPAC device provided a high level of accuracy (80%) when employed outside of the traditional lab environment.

Stress research technologies are not limited to data gathering. Stimulus presentation tools offer researchers options for both inducing and alleviating stress in the lab. A 2019 University of Wisconsin study investigating the role scents can play in reducing stress utilized EDA, heart rate, and respiratory rate to measure how rose scent reduced anxiety among students taking a difficult test. Respiratory rate was measured using a BIOPAC respiratory transducer while EDA data was collected with an EDA finger transducer. Data was collected and analyzed via the Biopac Student Lab System. While rose scent was delivered using scented lotion, it should be noted that BIOPAC offers a new modular scent delivery system that is capable of delivering up to eight scents per experiment, with more than 120 scent options.

With so many data gathering tools available, planning your next experiment should not leave you feeling on edge. Let your BIOPAC sales rep help you take the stress out of stress research.

BIOPAC offers a wide array of wired and wireless equipment that can be used in your research. To find more information on solutions for recording and analyzing signals such as ECG, heart rate, respiration, and more using any platforms mentioned in this blog post, you can visit the individual application pages on the BIOPAC website.

The Right Tools: Streamlining Stimulus Presentation

Our nervous system processes information from a dizzying array of stimuli—visual, auditory, thermal, olfactory, and tactile, among others. How organisms respond to stimuli provides researchers with a wealth of information on how they adapt, learn, and live. The complex interaction between stimulus and response presents a myriad of challenges when it comes to creating effective stimuli in the research environment and accurately gathering data from subjects.

Today’s researchers have been gifted with a variety of stimulus presentation options to suit their individual needs. Complex experiments may call for robust solutions that integrate a wide range of stimulus presentation and data acquisition hardware and software, often from various industry leading manufacturers such as BIOPAC, E-Prime, and Cedrus. Such experiments can combine multiple stimuli with advanced stimulus controls and data gathering techniques.

Stimulus presentation, however, is not a one-size-fits-all proposition and some researchers may prefer a simpler solution that integrates visual stimulation presentation tools with powerful eye-tracking, as is available with BIOPAC’s screen-based Eye Tracking system. Additionally, AcqKnowledge now offers native integration and synchronization of stimulus presentation, eye tracking, and physiology data acquisition and analysis, all easily managed from a single application.

The seamless integration of stimulus presentation in data gathering and analysis allowed a team of researchers from the University of Connecticut and Emory University to monitor electrodermal activity (EDA) in subjects as they responded to pain stimuli induced by electrothermal grills. The goal of the study was to determine the viability of using such grills to induce pain without causing physical harm to research subjects. Researchers recorded and stored EDA signals from electrodes attached to the subjects’ fingers with a BioNomadix® wireless amplifier and MP160 data acquisition device connected to a computer running AcqKnowledge. A STMISOC programmable stimulus isolation adapter provided EP stimulation, allowing software-controlled adjustment of stimulus pulse width, repetition, and setup of an arbitrary pulse stimulus sequence via AcqKnowledge.

Using a single integrated system doesn’t necessarily equate sacrificing utility, nor does cross-platform integration need to be complicated. A group of researchers in Beijing recently explored the connection between fear response, conditioning, and memory that required the application of electrical shocks of varying intensity. A constant current STM200 stimulator delivered the shocks, in this case controlled by E-Prime software while data was collected by an MP150 running AcqKnowledge. In its current build, AcqKnowledge also integrates stimulus presentation and data acquisition, potentially streamlining the design of such an experiment.

Studies requiring the simultaneous introduction of multiple stimuli can raise the level of complexity for researchers, as it did in a recent study that examined a link between pleasant touch and scent with facial muscle activity and heart rate. Facial EMG and ECG data were collected using a BIOPAC MP Research System with a BioNomadix® wireless system connected to a computer running AcqKnowledge; current builds of the software provide full integration of scent delivery hardware.

BIOPAC’s new integrated stimulus presentation meshes seamlessly with Eye Tracking and data acquisition, providing researchers with an integrated solution to save valuable time and effort.

BIOPAC Systems, Inc. provides life science researchers and educators with data acquisition and analysis systems that inspire people and enable greater discovery about life.

Synchronize Participant Video with Physiological Data

AcqKnowledge software includes a Media feature that allows you to record and link participant video with physiological data. A common issue that crops up when analyzing physiological data with linked participant video is a lack of synchronization between the resulting video playback and onscreen data. This most often occurs when a USB webcam-type video camera is used. These types of cameras typically support a 30 frame-per-second rate whereas AcqKnowledge and the MP System can sample at rates up to 200,000 Hz. These factors can introduce an unwanted delay or misalignment between the video playback and data in the resulting AcqKnowledge graph.

So how do we synchronize these disparate signals to dovetail perfectly before recording our data and video? Fortunately, AcqKnowledge provides adjustment tools for addressing this common issue. This simple procedure requires the use of the AcqKnowledge software’s powerful Stimulator feature and a BIOPAC OUT103 LED Video Sync Cable.

Here is the sync method in a nutshell: With the OUT103 LED connected to the Analog Output of the MP160 unit’s HLT100C module, the AcqKnowledge software’s Stimulator is used to output a 5-volt square wave pulse into an AcqKnowledge graph, Using this setup, the LED illuminates when the 5-volt pulse is applied. The trick now is to use the AcqKnowledge Media feature and webcam to record a short video of the LED illuminating while the 5-volt pulse is being applied.

In the resulting graph, it’s easy to see in the Media playback screen when the light comes on by slowly advancing the AcqKnowledge software’s I-beam cursor through the graph data. Does the LED in the recorded video illuminate before the cursor reaches the 5-volt pulse? After? Or at the same time? Chances are, the recorded light will pop on slightly before or after the cursor reaches the pulse.

To compensate for this, the AcqKnowledge Delta-T measurement is used to determine the time interval between the pulse and when the recorded LED illuminates. For example, if the recorded LED lights up an indicated 185 ms before the onset of the pulse, then this discrepancy can be removed by setting a delay of 185 ms in the Media setup tools. If the LED lights up after the pulse onset, a negative delay must be set (ex. -185 ms). Once the playback delay is eradicated, the experiment can continue with confidence that all video and physiological data will be properly aligned.

It’s features such as this that enhance the usability AcqKnowledge Media feature, making it a powerful tool for recording and synchronizing participant video and audio during experiments. After a bit of practice, dialing in the playback video for linked Media acquisitions becomes second nature.

To see AcqKnowledge Media Synchronization in action, we invite you to view a free on-demand webinar covering this procedure in detail.

BIOPAC offers a wide array of wired and wireless equipment that can be used in your research. To find more information on solutions for recording and analyzing signals such as ECG, heart rate, respiration and more using any platforms mentioned in this blog post, you can visit the individual application pages on the BIOPAC website.