Snooze Studies: Tools for Sleep Research

Comedic actress Mindy Kaling may have been speaking for everyone enamored with slumber when she wrote, “There is no sunrise so beautiful that it is worth waking me up to see it.”

Who hasn’t at one time preferred the restorative effects of a few extra hours of sleep to the harsh realities of the waking world? For both humans and other animals, sleep is indelibly linked to physical, mental, and emotional well-being.

In experimental biology, understanding sleep patterns and disruptions in both humans and animals provides essential insights into health, behavior, and neurological conditions. Techniques such as pulse oximetry, electroencephalography (EEG), and electromyography (EMG) provide critical data for unlocking the mysteries of sleep’s influence on human and animal biology.

Pulse oximetry is a noninvasive method that measures the oxygen saturation level of the blood, an indicator of respiratory efficiency during sleep. It is typically expressed as peripheral blood oxygen saturation or SpO2. This tool is especially useful in detecting sleep apnea and other breathing-related sleep disorders. EEG records electrical activity in the brain, offering a window into the different stages of sleep (from light sleep to deep sleep and rapid eye movement [REM] phases). It helps researchers understand how and why sleep patterns may be altered by various neurological diseases or conditions. EMG measures muscle activity and is crucial in examining the quality of sleep, particularly by identifying periods of muscle atonia during REM sleep, which can be disrupted in disorders like REM sleep behavior disorder.

BIOPAC and partner company Kissei offer SleepSign™ software, which provides essential tools and technologies that enhance the effectiveness of sleep studies. BIOPAC’s advanced multimodal setups can integrate data from EEG, EMG, pulse oximetry, and other sources for human participants and animals into a single coherent analysis platform. This integration allows for simultaneous recording and analysis of physiological and neurological signals during sleep.

boyA study published in the Sleep Research Society’s journal, Sleep, evaluated the effect of sleep on upper airway dynamics in obese children with obstructive sleep apnea syndrome (OSAS). Researchers used data gathered via a BIOPAC differential pressure transducer and flow transducer and fed into a data acquisition and analysis system to measure SpO2 and nasal-oral mask airflow of participants during MRI scans. The study results provided “further insight into the biomechanical basis of OSAS and assist in more effective management.”

SleepSign™ software plays a crucial role in automating the analysis of sleep data. It processes large volumes of EEG and EMG data, providing researchers with user-friendly interfaces and detailed reports that highlight anomalies and patterns in sleep stages. A study published in the 2023 issue of Neurobiology of Sleep and Circadian Rhythms investigated the long-lasting effects of sleep disruption on young prairie voles using a combination of BIOPAC’s AcqKnowledge software and SleepSign™ to acquire and analyze EEG and EMG data. The study concluded that early-life sleep disruption in postnatal voles has significant impacts on REM sleep patterns later in life.

These are just some of the technologies allowing researchers to dissect the nuances of sleep in both human health and animal models while also paving the way for novel therapeutic strategies to address sleep-related disorders. For additional information check our webinars on wireless animal EEG recordings and wireless logging.


Are you planning to explore the realm of sleep with your next study? Reach out to our experts for assistance selecting the best tools for gathering and analyzing sleep data.

Mind and Machine: Exploring Brain-Computer Interfaces

In neuroscience, the frontier of brain-computer interfaces (BCI) holds the promise of bridging the gap between the human brain and external devices, offering revolutionary applications in fields ranging from robotics and prosthetics to communication and beyond. In the lab, scientists studying and developing new BCI technology leverage the human brain’s electrical and physiological signals.

Electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and steady-state visually evoked potentials (SSVEP) are among the primary physiological and psychophysiological signals utilized in these investigations. Multimodal integration of two or more signal types allows researchers and engineers to take advantage of multiple data streams in their applications and studies.

EEG, which can measure electrical activity in the brain, is a cornerstone of BCI research. Researchers can decode various mental states and intentions by analyzing EEG patterns, enabling users to control external devices through mere thought. fNIRS complements EEG by measuring changes in blood oxygenation levels, offering insights into brain function with superior spatial resolution. SSVEP, on the other hand, capitalizes on the brain’s response to visual stimuli, providing a means for precise control in BCI applications.

The practical implications of BCI research extend far beyond the laboratory setting. In robotics, BCIs facilitate direct brain-to-machine communication, empowering users to manipulate robotic arms or navigate autonomous vehicles with their thoughts alone. A study published in the Journal of Information Science Engineering explored ways that an SSVEP-based BCI could be used to control assembly line robots via a headset measuring the operator’s EEG signals. The signals would communicate instructions to robots while operators identified defective parts, which the robots would pick out. During the experiment, EEG signals were obtained using a B-Alert X24 headset. The EEG-based BCI produced a 93.33% success rate in correctly identifying and removing defective parts from the assembly line process, allowing the operator to effectively “collaborate with the robot and communicate defective parts without manually operating the robot.”

Prosthetics benefit immensely from BCI advancements, enabling seamless integration with the user’s neural signals for intuitive control and enhanced functionality. A 2023 study by a team of researchers from the University of California Irvine explored the viability of creating low-cost cortical stimulators for bi-directional BCI (BD-BCI) research. BD-BCI takes brain-computer-interfaces to the next level with the brain not only providing motor commands to an artificial limb but also allowing it to receive sensory input from such a device. A BIOPAC data acquisition and analysis system was used to validate the charge balancing of subcortical electrocorticographic (ECoG) implants used in a stimulator. The charge balancing test was performed on phantom tissue designed to simulate real brain tissue. The resulting study successfully demonstrated “clinical validation of a fully-programmable electrical stimulator, integrated into an embedded BCI system.”

As researchers continue to refine BCI technologies, the possibilities for real-world applications are boundless. BIOPAC is among the companies on the cutting edge of BCI research, partnering with other innovators to provide the latest in multimodal BCI technologies such as Axon-R. For additional information on Axon-R, check out our recent webinar on the device.


Are you planning to explore the frontiers of BCI in the lab? Our regional customer reps have all the knowledge you need to integrate BIOPAC products into your BCI study.

Measuring Mindfulness: Ancient Awareness for Modern Research

The concept of mindfulness has garnered significant attention in recent years, transcending its roots in ancient meditation practices to become a focal point in modern scientific research, particularly in the fields of physiology and psychophysiology. Understanding mindfulness involves delving into its essence: a state of heightened awareness and acceptance of the present moment, free from judgment or attachment to external stimuli. But how exactly does this concept intersect with the realms of physiology and psychophysiology, and how do researchers measure its impact on the human body and mind?

At its core, mindfulness entails being fully present and engaged in the current experience, whether it be a sensation, thought, or emotion. This mental state has been associated with numerous health benefits, including stress reduction, improved cognitive function, and enhanced emotional well-being. In the realm of physiology and psychophysiology, researchers are keen to explore how mindfulness practices influence the body’s physiological processes and how these changes can be quantified and understood.

One of the primary methods used to measure mindfulness in laboratory settings is through the analysis of physiological signals, such as electrodermal activity (EDA) and heart rate variability (HRV). During mindfulness practices, individuals often experience a shift in these physiological parameters. For example, studies have shown that mindfulness meditation can lead to decreased EDA, indicating a reduction in sympathetic nervous system activity and arousal levels. Similarly, practitioners may exhibit increased HRV, reflecting greater parasympathetic nervous system dominance and improved adaptability to stressors.

A collaborative study by a team of researchers from Wake Forest University, the University of Utah, and San Diego State University examined the role of HRV in mindfulness-based pain relief practices. Specifically, the study looked at the role of high-frequency heart rate variability (HF HRV), a marker of parasympathetic nervous system (PNS) activity, during mindfulness-based pain relief versus a sham-breathing exercise that served as a control. Respiration and electrocardiogram (ECG) data was fed into a BIOPAC data acquisition and analysis system. While the study results were inconclusive, researchers determined that further study was needed to explore “parasympathetic activation in mindfulness-based pain relief as compared to other meditative techniques.”

lotusA study published in the 2023 edition of the Journal of Psychiatric Research compared how rest and breath-focused mindfulness could be used to regulate and control various symptoms of post-traumatic stress disorder (PTSD) and dissociative symptoms related to past trauma in female study participants. Researchers used skin conductance response (SCR), one of the components of EDA, to measure autonomic function as it relates to PTSD symptoms. SCR data were collected during alternating resting control and breath-focused mindfulness conditions via BIOPAC EDA electrodes connected to a BIOPAC data acquisition and analysis system. The study found that rest and breathing exercises had produced positive results for individuals with low to moderate levels of trauma but were less effective with higher levels.

One notable feature of BIOPAC’s technology is its ability to integrate multiple physiological signals simultaneously, allowing researchers to better understand how mindfulness practices impact various bodily systems. An example is a study by a group of researchers in Israel that examined the effectiveness of mindfulness-based interventions (MBI) in improving mental well-being and resilience. MBIs are non-religious adaptations of contemplative Buddhist practices that are used to reduce suffering and increase well-being. Researchers used a BIOPAC BioNomadix system to wirelessly record a range of physiological signals, including ECG, electromyography (EMG), and EDA. Their goal was to determine whether mindfulness could positively influence how interoceptive signals from the autonomic nervous system regulate one’s sense of well-being. The study concluded that “mindfulness seems to increase the sensitivity of regulatory selections to interoceptive signals, and this is associated with subjective well-being.”

Mindfulness represents a fascinating intersection between ancient contemplative traditions and modern scientific inquiry. To learn more about how BIOPAC is helping researchers uncover new insights into the physiological aspects of mindfulness and its potential implications for health and well-being, check out our webinar on The Science of Mindfulness.


Are you looking for techniques and tools to measure mindfulness in your study? Contact your regional BIOPAC sales representative to integrate everything you will need to gather and analyze data.

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 neuromusVR Shadowcular 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.

2023 in Review: The Best of Research Using BIOPAC

As another year winds to a close, it is a holiday tradition to look back on the last 12 months and take stock. ‘Tis the season of “top 10” lists, “best of” articles, and “year in review” segments in the media. So, not to be left out, we here at BIOPAC have been assessing 2023 from our own unique vantage point. We have put together a brief list of some of our favorite research studies from the year that relied on BIOPAC products to gather and analyze data. We have nervous passengers in driverless cars, killer clowns, and individuals giving us conspicuous side-eye, all for your reading pleasure.

Backseat Drivers

While the advent of self-driving vehicles offers considerable potential for increasing the convenience of transportation and travel, this developing technology is not without controversy. Both passengers and those who would potentially share the road with autonomous vehicles worry about safety issues. A recent study funded by the French National Research Agency examined how passengers in self-driving vehicles reacted when navigating shared-space areas with large concentrations of pedestrians. The study defined shared spaces as “areas where all forms of segregation between pedestrians and vehicles (e.g., road markings, traffic signals, signs, curbs, and barriers) are minimized or eliminated.” Study participants were seated in front of a computer-based driving simulator. EDA data was gathered via a BioNomadix wireless  EDA transmitter and amplifier connected to a BIOPAC data acquisition and analysis system. Data was gathered across a variety of variables including changes in vehicle speed, concentrations of pedestrians, and proximity. Among the study’s conclusions was the suggestion that cognitive processes involved in collision risk assessments may lead to physiological adaptations that allow passengers to cope with stress related to vehicle-pedestrian interactions in shared spaces.

Send in the (Demonic) Clowns

VR HMDAnother study that caught our attention in 2023 examined how stressors created in a virtual reality (VR) environment are manifested in measurable physiological stress reactions. VR has seen a growth of applications beyond entertainment in recent years. It is being used for a wide range of applications such as training in simulated environments where it is necessary to create stressful conditions that mimic real-world experiences. A team of German researchers examined a variety of physiological signals, including electroencephalography (EEG), electrodermal activity (EDA), and peripheral skin temperature (ST) to determine which are most reliable for accurately measuring the stress levels of participants while they experienced cinematic horror scenarios in a VR environment. Study participants wore a VR headset that displayed four-minute episodic horror movies featuring demonic clowns. EEG data was gathered with an SS2L electrode lead set and general-purpose electrodes connected to the left temporal lobe. ECG recording was conducted with a second lead using an SS2L electrode lead set. The research team used an SS3LA EDA transducer to collect EDA data. All data was fed to an MP36 system running Biopac Student Lab (BSL) software. The study successfully demonstrated that stress can be triggered in VR and leads to a physiological and measurable stress reaction.

Are You Looking at Me?

The third study that sparked our interest in 2023 looked at how individuals react to the gaze of another person. A team of researchers from Finland and China used facial electromyography (EMG), skin conductance response (SCR), and heart rate (HR) to measure affective and attentional responses to faces with a direct and averted gaze. The study sought to measure both vicarious responses to watching two individuals who were looking at each other as well as individuals looking directly at the participant. SCR was recorded using a BIOPAC EDA100C amplifier connected to an MP data acquisition system. The participant’s facial muscle activity was measured and amplified with an EMG100C amplifier. The electrocardiogram (ECG) signal was measured with electrodes placed on the left and right inner forearm and amplified with an ECG100C amplifier. While the study did not find significant vicarious eye contact response, it did measure considerable affective response from direct gaze from one or more individuals. The study’s results could provide a better understanding of the role physiology plays in non-verbal communication between individuals and groups.

This is just a small sampling of the many studies that relied on BIOPAC equipment to gather and analyze data in 2023. For more ideas on how BIOPAC is leading the way in physiology, psychophysiology, neurology, and other areas of research, check out our webinars or watch one of our many online training videos. See you in 2024!


Start 2024 right by leveraging BIOPAC products in your next research study. Reach out to your regional sales representative to learn more.

Imaging is Everything: Data Acquisition in the MRI Environment

The marriage of physiological data recording and magnetic resonance imaging (MRI) has allowed scientists to unravel intricate connections between the mind and body. However, this synergy comes with its unique set of challenges that researchers must be aware of to ensure the integrity of both data and the well-being of study participants.

One of the foremost challenges in recording physiological data within the MRI lab is the strong magnetic field. Traditional monitoring equipment can be rendered useless or, worse, pose extreme safety risks due to their ferromagnetic components. Another critical consideration is the impact of radiofrequency (RF) pulses used in the imaging process. RF pulses can introduce artifacts in physiological recordings, affecting the quality of data collected. In previous posts we have discussed the basics of integrating data collection in the functional MRI (fMRI) environment as well as techniques for avoiding artifacts and signal noise while recording data in the MRI.

Researchers must also contend with challenges related to the confined space and noise levels within an MRI environment. A 2021 study conducted by the Lab for Autonomic Neuroscience, Imaging and Cognition (LANIC) at Jena University Hospital in Jena, Germany, focused on how the functional MRI (fMRI) environment itself affected outcomes in autonomic research. Specifically, the study investigated the influence of a loud and cramped environment during MRI on resting heart rate variability (HRV) measures and whether a familiarization session with MRI equipment might lower anxiety levels among participants. The research team recorded an electrocardiogram (ECG) and a photoplethysmogram (PPG) over 15 minutes from participants using a BIOPAC data acquisition and analysis system connected to finger-attached PPG sensors during non-MRI recording. For recording in the fMRI, researchers used a separate BIOPAC data acquisition system equipped with an MR-Conditional PPG module. While the study did establish a link between participant anxiety and HRV levels in the lab and fMRI environment, it did not find that the familiarization sessions had a significant impact on HRV outcomes.

gas maskDespite the challenges, the recording of physiological signals in the MRI environment provides unique opportunities for gathering critical data. A study published in the journal Military Medicine in 2020 tested the effectiveness of F MRI (not to be confused with fMRI) scans in identifying cases of War Lung Injury (WLI) in Iraq and Afghanistan war veterans. WRI refers to reductions in lung function resulting from exposure to environmental factors such as sandstorms and burn pits. F MRI employs magnetic resonance imaging with perfluorinated gases as inhaled contrast agents to evaluate various pulmonary diseases. If successful, the approach would provide an alternative to surgical biopsy for diagnosing suspected WLI. The researchers measured respiratory waveforms throughout the imaging sessions, during both normal room air breathing and PFP-oxygen gas mixture breathing using a BIOPAC MR-Conditional pneumotachometer. The study found that “F MRI provides better insight regarding lung function abnormalities” than other standard methods and that “F MRI could provide a functional tool to assist in identifying subjects with the disorder and potentially could aid in the evaluation of novel therapeutic approaches.”

BIOPAC provides a wealth of tools and information resources for gathering data in the MRI environment. This includes multiple webinars on recording data in both MRI and fMRI settings. As the field continues to evolve, BIOPAC’s innovative solutions pave the way for groundbreaking discoveries at the intersection of physiological signal recording and medical imaging.


If you are interested in recording and analyzing physiological signals in your next MRI-based research study, BIOPAC sales representatives are standing by to help you choose the right tools and resources for the job.

Put a Ring on It: Wearables Offer New Research Options

Rings, watches, bracelets, and belts—we think of them as indispensable fashion accessories. A bit of bling can put the finishing touch on an outfit for a night on the town, but what about a day in the lab? Wearable technology is transforming the landscape of physiology research by enabling real-time, noninvasive data collection in a variety of settings.

For many, their first introduction to the potential of wearable physiology technology came through smartwatches and fitness bracelets. These consumer electronics offer a convenient and affordable way for anyone from professional athletes to fitness hobbyists to monitor their health data, which often includes pulse, blood oxygen levels, steps, and other basic physiological signals.

As the underlying technology has become more sophisticated, researchers have embraced the convenience offered by such devices. Portable, unobtrusive, and wireless wearables have entered the research device market and now allow a range of signals to be monitored under a variety of circumstances and environments.

smartphoneBIOPAC recently expanded its established line of wireless devices by introducing the Research Ring, a wearable device with a specific focus on physiological signals such as Photoplethysmography (PPG), Electrodermal Activity (EDA), Electrocardiography (ECG), and body temperature. Products like the Research Ring allow the capture of high-quality data via an unintrusive and accessible wearable device, making them ideal for a wide range of potential applications. These include psychophysiology research, sports and exercise studies, sleep and stress research, and aging and wellness studies, to name just a few.

BIOPAC is no newcomer to providing the research and education communities with wireless and portable solutions designed for gathering physiological data. The Bionomadix line of wearable remote monitoring devices set the standard for such products and have been used in thousands of cited studies. For example, researchers conducting a study of on-the-job stress among healthcare professionals collected EDA and PPG signals using a BIOPAC wireless PPG and EDA amplifier and a wireless respiration with ECG amplifier. Wireless technology proved to be a key component of the study’s success as it allowed the data to be gathered without interfering with the immersive quality of the simulated work environment.

A team of researchers from the University of Porto in Portugal utilized a BIOPAC wearable physiological signal logger to collect EDA and ECG data while studying the correlation between physiological signals and expressive writing. In the study, published in the journal Experimental Psychology, participants were able to engage in writing exercises without the distraction of more cumbersome and intrusive wired solutions.

BIOPAC’s latest entry into its line of wearable wireless data collection devices promises to add greater convenience and versatility to this burgeoning sector. For more information on the new Research Ring, check out the recent webinar BIOPAC hosted with ring developer and partner, Senstream.


If you are interested in adding wearable devices to your next physiology study, reach out to your regional sales representative today to learn which BIOPAC wireless solutions are right for you.

ENS: Signals for Studying the Body’s “Second Brain”

We have all heard the saying “thinking with one’s stomach,” a cliché that suggests basing one’s critical thought processes on the whims of their digestive system. However, there may be more than a little truth to this saying. Often referred to as the body’s “second brain,” the enteric nervous system (ENS) comprises a complex network of neurons and ganglia embedded within the walls of the gastrointestinal tract. In recent years, researchers have increasingly recognized the significance of the ENS and its application in physiological research.

The ENS is a division of the autonomic nervous system (ANS) responsible for regulating the digestive process. It consists of millions of neurons spread throughout the esophagus, stomach, small intestine, and large intestine. These neurons form an intricate network that can function independently of the central nervous system (CNS) but also communicates with it. The ENS controls essential gastrointestinal functions, such as peristalsis, secretion of digestive enzymes, and blood flow regulation within the gut.

Several effective techniques are available to researchers to evaluate and measure ENS activity for their studies. Electrogastrography (EGG) provides a noninvasive approach to measuring the electrical activity of the stomach muscles. EEG can help researchers understand the rhythm and coordination of stomach contractions, aiding in the diagnosis of motility disorders.

In addition to EGG, a range of other physiological signals may be applied to ENS research. A recent study published in the June 2023 edition of Nature Communication investigated the gut-brain relationship by measuring physiological response to stimulation of the digestive system via different noninvasive techniques: EGG, electroencephalogram (EEG), skin conductance response (SCR), heart rate (HR), and heart rate variability (HRV). Research participants ingested a small vibrating probe that provided varying levels of stimulation as it passed through the lower digestive tract. EGG, EEG, and SCR signals were recorded along with hemodynamic signals via a BIOPAC data acquisition and analysis system. Researchers concluded that these techniques provided a viable alternative to more invasive approaches to measuring the body’s response to sensory stimulation of the digestive tract with, according to the published report, “implications for understanding gut feelings and gut-brain interactions in healthy and clinical populations.”

ENS ResearchMore invasive techniques for studying the ENS can still provide researchers with valuable data. A 2023 study by a team of South Korean researchers investigated how radial stretching affects intestinal contractions. The study also examined how drugs targeting the ENS affect such contractions to develop treatments for gastrointestinal disorders. Samples of intestinal tissue were taken from participants undergoing aggressive treatment for colorectal cancer. Samples were preserved in a tissue chamber and connected to a BIOPAC isometric force transducer to measure contractions, with data recorded and analyzed with a BIOPAC MP160 system running AcqKnowledge software. The study was able to detect regional differences in the stretch reflex of colon tissue via electrophysiological recordings of intestinal smooth muscles.

These are some of the ways in which researchers are currently using BIOPAC technologies to better understand the relationship between the ENS and other neurophysiological processes. For additional information on this topic, see our page on AcqKnowledge’s Gastric Myoelectric Activity feature and our EGG citations.


If you would like to know more about how BIOPAC can help you plan and equip your ENS study, reach out to your regional sales representative today.

Noise Proof: Attack Artifacts Before They Ruin Data

After investing months of time, funds, and personal effort into your electrodermal activity (EDA) study, you begin combing through your data recordings when something catches your eye. Several of the recorded signals don’t look quite right. Rather than a narrow baseline in the signal graph, the baseline is thick and fuzzy, a sure sign of signal noise. To make matters worse, the recordings are broken by random peaks, artifacts unrelated to the EDA signal you sought to record. Noise and artifacts can corrupt research data, often rendering it useless. While it may be possible in some cases to clean up and salvage recorded data, such results often mean going back to square one and starting over.

The best option is to avoid bad data from the beginning. Several best practices can save researchers untold effort and expense by avoiding the pitfalls that can result in noise and artifacts. Noise and artifacts can be defined as unwanted changes to a signal caused by sources other than the target signal during recording. Noise and artifacts can originate from a range of sources—environmental (interference from other electromagnetic sources) or biological (signal changes from muscle activity in a participant), to name a few. The key is not to wait until all your data is recorded to tackle signal problems. Careful planning and testing procedures when designing and experimenting can avoid later headaches.

Most artifacts are caused by some form of electrical impedance interfering with a clean connection between the participant and the electrodes linking the data-gathering equipment. Sources could include dead skin or hair at the connection sight, dirty or improperly prepared electrodes, or electrodes that have come loose due to movement.

Using an impedance detector can help identify problematic signals before they corrupt data. An example of this can be found in a 2020 study at Ghent University in Belgium that examined how expert and novice map readers managed their cognitive loads using electroencephalogram (EEG) and eye tracking data. Researchers used a BIOPAC EL-CHECK impedance detector to ensure a good skin-electrode interface before recording data with AcqKnowledge software. This allowed the research team to keep the whole EEG circuit (ground, active EEG, and reference electrodes) at less than the recommended 10 K ohms (Herman, 2015; Teplan, 2002) to prevent unwanted signal noise.

noise checkStrategies for avoiding artifacts can vary depending on the type of signal being recorded. Some signals, such as EEG, may require light abrading of the skin at the point of electrode attachment for optimal conductance, while other signals, like EDA, do not require skin abrasion. Proper site preparation is recommended for most signals, skin should be clean and free of obstructions, such as excess hair. When gel is to be applied, make sure it is the correct type for the electrodes being used. Finally, the preparation of study participants can be critical to successfully recording clean data. In general, participants should be in an environment that is free of distractions and stimuli originating outside the study (sudden noises, distracting conversations, etc.).

For detailed information on how to proactively prevent signal noise and artifacts, check our AcqKnowledge Bootcamp webinar in which we discuss how to set up experiments to ensure quality data gathering. You can also consult our forthcoming guide with detailed instructions for the collection of optimal data.  Don’t wait until it’s too late; eliminating signal noise should be the first step in setting up a successful study.


Do you need help eliminating artifacts and signal noise in your recorded research data? BIOPAC’s regional sales representatives are ready to assist with tools and strategies to ensure you get only the best data possible. Contact us today!

4T|Phys 2023: BIOPAC Shares Tools, Trends, Techniques & Technology at UCSB

They hailed from across the globe, from Arkansas to Zanzibar and all points between. Students, teachers, researchers, and innovators gathered on the campus of UC Santa Barbara, overlooking the Pacific Ocean. They came to learn, share, and explore breakthroughs and best practices in physiology and related fields. 4T|Phys kicked off July 17 under clear California summer skies, an idyllic setting for discovering the Tools, Trends, Techniques, and Technology driving physiology education and exploration.

4T|Phys 2023 was the third installment in BIOPAC’s highly successful series of biennial industry conferences that began in 2017. After a two-year hiatus during the global Covid-19 pandemic, 4T came roaring back this summer with more workshops, more tracks, more sponsors, more presenters, and more countries represented than ever before. Over the course of three days, nearly 100 attendees participated in hands-on sessions with some of the top minds in physiology research, experiencing the latest tools for gathering and analyzing data.

BIOPAC’s in-house experts were joined by an array of authorities from the fields of physiology, psychology, imaging (fNIRS and fMRI), neuroscience, cardiovascular research, eye tracking, virtual reality (VR), biology, and engineering. Participants took part in workshop schedules drawn from five separate tracks that included fundamentals, which focused on the basics of data acquisition and analysis. The research track took attendees on a deeper dive into techniques and technologies, including recording evoked potentials, screen-based eye tracking, impedance cardiography using trans-radial bioimpedance velocimetry (TREV), stimulus presentation, exercise physiology, and many others. Participants were also able to tour UC Santa Barbara’s state-of-the-art Brain Imaging Lab to see up close how BIOPAC products are being used in both functional MRI (fMRI) and TREV studies.

“It was an incredible experience that left a lasting impact on me by helping me to understand more about physiological data collection and analysis,” said Dr. Parth Trivedi, a 4T|Phys attendee. “The choice of presenters and the topics covered were truly inspiring, offering valuable knowledge and fresh perspectives that enriched my understanding.”

4T|Phys 2023 Attendee MapThis year’s conference featured several new tracks such as a dedicated VR track led by partner company WorldViz. The WorldViz team showcased virtual reality solutions in a series of workshops that introduced how VR is being integrated in physiology and psychology research, explained how to create effective and immersive VR experiments, and demonstrated their latest PRISM technology for creating fully immersive projected 3D virtual environments.

Several other partner companies introduced their technologies and products both in the 4T exhibition hall and in workshop sessions. Argus Science presented their ETVision eye-tracking glasses that synch seamlessly with AcqKnowledge. Cognixion demonstrated the Cognixion One Axon-R—Research Edition wearable BCI-AR computing platform, which is being used to help individuals with neurodegenerative conditions and severe motor impairments communicate and interact with their environments assisted by augmented reality. Seenel Imaging showed off their MedelOpt Systems for whole-head EEG with fNIRS, including new VR integration. Participants also got a chance to try on the Research Ring by Senstream, a new user-friendly wearable research ring, which allows easy recording of EDA, PPG, Temperature, and ECG signals. CNSystems showed off the company’s NIBP continuous noninvasive blood pressure (NIBP) and hemodynamics devices.

If you missed the educational and networking opportunities at 4T|Phys 2023, don’t despair. We will be back again in a few years, bigger and better than ever. Watch this space for updates on our next installment. In the meantime, see our Video Tutorials and Webinars On Demand for trainings and seminars on our products and partners.


Make sure you never miss a BIOPAC event and keep up with the latest Tools, Trends, Techniques, and Technologies by contacting your local BIOPAC sales representative.

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