Biopac Student Lab | What I Learned This Summer

A Student’s Perspective

Guest post by Ashley F.

Like many of my university peers, I wrapped up my freshman year of college working a summer internship in hopes of gaining valuable professional experience. Rather than relaxing on the beach, I occupied my time between June and August with electronic breadboards and ice bucket plunges. All this took place at BIOPAC where I was tasked with reviewing the BSL PRO Lessons, helping the company continue to refine and improve these teaching aids.

Let me start by confessing that I am not a physiology or anatomy major, but rather a development and psychology major. Given this difference, I did not expect to find that so many of the BSL PRO Lessons connect to what I am studying. BSL PRO Lessons stand out compared to your average textbook for multiple reasons. For me, the primary difference is that with BSL PRO Lessons, you get to watch the data take shape in real-time. And it’s not just random data, but data from your own body—your heart beating, your finger twitching, your eyes tracking a pendulum. Because the data is from you and not a textbook, the lessons are more interesting to analyze.

Throughout the summer, I worked through each “human” BSL Lesson, gaining experience with the software, equipment, and workspace. Each lesson includes a ‘background’ section that provides context to the lesson and connects each one to different concepts. This context makes the data from each lesson relevant to more disciplinary studies than just physiology and anatomy, which in turn broadens the student’s knowledge. Because BIOPAC wanted to test the materials under realistic student lab conditions, I wasn’t given much guidance on how to approach individual lessons. Rather, I would simply read the manual and follow the instructions, which turned out to be surprisingly easy as I figured out how to do most of it on my own.

With a total of 39 BSL PRO lessons, you would expect at least a few to be quite similar. And yet, BIOPAC understood the importance of unique lessons and ensured that each one had a different background section, used different equipment, and covered a different topic.

Each lesson includes fun concepts to keep you engaged, like dunking your head in cold water to see how your heart rate changes in Lesson H08: Dive Reflex, using equipment to make your finger twitch in Lesson H06: Finger Twitch, or testing and timing your reflexes in H16: Reflexes & Reaction Time.

While each lesson is unique and covers a different topic in physiology and anatomy, the lessons do follow a clear progression as you move from BSL PRO Lesson 1 to 40. They start shorter, utilizing more basic concepts and equipment. Then, as you progress through the lessons, you begin to work through increasingly complex physiological concepts until you end on a lesson involving the use of a breadboard. This last lesson involves nine separate labs, each as involving as the earlier individual lessons. This amount of work may sound daunting at first, but the skills picked up while completing the previous lessons leave you well-prepared to complete the final lesson and analyze clear data.

Working through BSL PRO Lessons is a unique and interactive experience that allows students to learn, connect, and analyze personalized data from a broad range of physiological and anatomy concepts, leaving you with a well-rounded and contextualized education experience.

Learn more about BIOPAC’s education solutions, including complete teaching systems for a variety of life science disciplines. BIOPAC also provides a wide range of research systems for recording, displaying, classifying, and analyzing physiological signals & measurements.

BIOPAC Systems, Inc. helps life science researchers and educators
measure physiology anywhere, any time, from any subject.
Visit us at www.biopac.com.

Helping Students Learn Biomedical Engineering

Students entering the rigorous Biomedical Engineering (BME) discipline learn a gamut of separate physiological signals to best study healthcare applications of new technology. Simply put, as new, advanced medical devices make their way into the market, biomedical engineers are on the front lines of discovering how to best utilize these devices and corresponding software to better serve in healthcare. Well-equipped and prepared biomedical engineers study a number of signals, movements, and physiological concepts in their research, including some of the following:

Data Acquisition & Analysis Systems	Respiratory System & Pulmonary Function
Spectral Analysis & Histograms	Bioimpedance (Cardiac Output & Blood Flow)
Amplifiers, Transducers, and Calibration	Biomechanics—Angle, Acceleration, Distance, Velocity
ECG, EDA (GSR), EEG, EGG, EMG, and EOG	Physiological Control Systems
Force, Pressure, Strain, Flow, Temperature, Sound, Light	Chart, Overlap, Scope, and X/Y Displays
Brain Computer Interface	Blood Pressure & Heart Sounds
Signal Analysis & Processing	Compartmental Modeling
Filters (FIR & IIR)	Gait Analysis
Instrumentation Design

Related scientific citations are available for BME research in nearly all these areas of interest, but for students and educators, simplified practical labs can lay the groundwork for more advanced BME areas of interest, such as Gait Analysis or Brain Computer Interface (BCI). Inherent in the design of BME education is the fusion between virtual software-based analysis and physical laboratory applications—a dichotomy that favors software-based learning and research more and more. Educating students in biomechanics, biomeasurement, and biomaterials is crucial to set them up for success in the BME field, whether they go into research, education, health services, or industry. Trained biomedical engineers utilizing virtual tools in lieu of a larger laboratory instrumentation setup can save upwards of $80,000 in hardware costs for their institution. Skills taught with virtual tools are better suited to the real world “new world” of software-based analysis and signal processing.

Physiological Signal Processing Labs—colloquially known as “breadboards”—are an excellent tool to further biomedical engineering education, through both basic lessons and the physical construction of the signal processing lab device, a foray into the physical engineering side of the BME vocations. Recorded signals are analyzed and processed via Biopac Student Lab Software—a leader in BME education for university laboratories and undergraduate studies.

For example, the Biopac Student Lab Breadboard Lab Set covers lessons on constructing and running the following signal processes:

Square Wave Oscillator
Instrumentation Amplifier
Active Filter: High Pass
Active Gain Block & Low Pass
Notch Filter for 50/60 Hz Rejection
QRS Detection: Band Pass Filter
QRS Detection: Absolute Value Circuit
QRS Detection: Low Pass Filter and Overall System Test

BIOPAC also offers Biomedical Engineering curriculum for EMG-controlled robotic labs, modeling, filtering, FFT, as well as a “Best Practices for Good Data” on-demand training series on fundamentals of physiological signal processing and support for an array of BME research applications.

The benefits of this approach to BME Education help “…viscerally engage the student in an inquiry-based learning environment.”¹ Upon construction of their own Signal Processing lab, students verify signal processing models against mathematical simulations and test the models against measured signals sourced on their own bodies.

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, teaching, and analyzing Biomedical Engineering data, you can visit our product category for BME on the BIOPAC website.

¹ Alan Macy, R&D Director, BIOPAC Systems, Inc.

fNIRS and the Brain: How cognition is defined and recorded

As the most crucial organ of the human body that quintessentially defines humanity, the brain is still our greatest puzzle to solve. Medical doctors, neuroscientists, physiological scientists, and others have been trying to understand how its functions affect our actions, dating all the way back to the dark days of phrenology. In our study of the brain, the popular research is directed towards conscious thought, thinking, or the scientific term, cognition. In physical terms, the brain is separated into different areas of grey matter for different tasks, and like an electricity operator supplies a power grid with different levels of electricity on demand, regions of the brain gearing up for critical thought are saturated with fresh, oxygenated blood to boost performance: again a sign of an active cognitive state.

In modern scientific research, one of the popular means to measure this oxygenation is through Spectroscopy—more specifically, a unique field called functional near infrared spectroscopy. How does fNIRS work in measuring human cognition? These measurements are performed with optical diodes and sensors measuring a near infrared wave pattern.

Dedicated fNIRS software displaying tissue oxygenation — A graphical display of oxygenation in the prefrontal cortex

Near infrared light is sent through the skull in a spectrum that can pass through bone and tissue, and the sensors record the plots of photons absorbed by tissue or reflected back. Naturally with such a delicate subject such as the human brain, this process is both safe for the participant and painless.

The practical benefits of this spectroscopic measurement are numerous—continuous and real time values on changes in hemoglobin levels in the prefrontal cortex (measured as oxyhemoglobin [Hb] and deoxygenated hemoglobin [HbO₂]) as subjects perform different tasks, either in a stationary recording position or in a mobile experiment environment. fNIRS technology offers standalone and field-deployable technology able to determine localized brain activity. Modern recording tools such as the fNIR103M offer a wireless recording platform, so research subjects can react naturally in real-world situations outside of the lab environment while continuously recording spectroscopic data.

fNIRS is a popular signal to record simultaneously with other physiological signals such as heart rate, ECG, HRV, EMG, respiration, and more to get a clear picture of a subject’s physiological reactions. Application areas for this signal typically include pain assessment, geriatrics, attention, sports science, Human-Computer Interface, virtual reality, stress, workload assessment, and learning. Thousands of scholarly citations have been written featuring functional near-infrared spectroscopy, as studies visualize how the brain works through cognitive problems and processes. To further your physiological research, BIOPAC’s AcqKnowledge software can record multiple physiological signals at once and provide automated analysis tools for event related potentials and ensemble averaging. fNIRS easily integrates with other physiological and neurobehavioral methods of assessing brain activity, including eye tracking, pupil reflex, respiration, and electrodermal activity.

BIOPAC Systems, Inc. provides life science researchers and educators with data acquisition and analysis systems that inspire people and enable greater discovery about life. Visit us at www.biopac.com. We invite you to look at our fNIRS webinars from BIOPAC. BIOPAC also offers a line of wired and wireless fNIRS imagers for research and education.

THE BIG 3: Crucial Signals for Interdisciplinary Psychophysiology Research

This guest post was written by Michael Hogan, BIOPAC’s Southeast Regional Representative. Contact him at michaelh@biopac.com

Even trained psychologists can be daunted by the interdisciplinary applications involved with recording objective physiological data. However, it is not necessary to learn the intricacies of bio-medical engineering, physics, statistics and underlying physiological mechanisms of the body just to incorporate these objective measures into your research. With just a few key signals of interest, and a simple hardware and software setup, a trained researcher can record and interpret the objective physiological responses of participants in a physiology study.

How to get started? Begin with a protocol you are already studying and incorporate “THE BIG 3”

ECG: Electrocardiography is a biopotential, meaning direct measurement of the electrical voltage potential changes of the heart as it completes its “cardiac cycle.” Since we can record these voltage changes and graphically represent them as a waveform through analog to digital conversion, we are able to identify changes in the behavior of the heart in response to the presented stimulus. We can then establish a recurring reference point in the “R-Peak” of the QRS complex, we are able to measure the distance between these R-Peaks and establish an R-to-R interval, this measure tells us the time in-between cycles or “beats” of the heart. From one beat to the next, we can establish the participant’s heart rate. Once we have established a heart rate, we are able to extract valuable measures, such as Heart Rate Variability: how the heart rate changes over an observed set of time intervals or in response to the correlated stimulus.

Respiration: The respiration cycle is what is known as a transduced physiological signal. This means we utilize a mechanical apparatus to create a voltage potential in response to the inhalation and exhalation phases of the respiratory cycle. These voltage changes can then be measured and graphically represented as a waveform for further analysis. The respiratory cycle waveform can tell us the following:
- Respiratory rate: the number of cycles that occur within a given time interval or changes in response to a stimulus.
- Amplitude: What is the change in magnitude of the cycle, shallow vs. deep breathing.
- Respiratory Sinus Arrythmia (RSA): When collected along with an ECG signal, this analysis accounts for the changes in the participant’s heart rate as a response to the inhalation and exhalation phases of the respiratory cycle. For example, the heart rate elevates when the participant inhales and decreases when the participant exhales.

EDA: Electrodermal Activity has been adopted as the newest nomenclature for Galvanic Skin Response “GSR.” To this day EDA is touted as the best measure of sympathetic nervous system “activation.” As a derivative physiological measure, we pass a small, imperceptible current (0.5 V) into the participant’s body and measure the change from this known value as the participant responds.

As the autonomic nervous system responds to stimuli, it stimulates the eccrine glands to produce sweat. The sweat produced lowers the impedance to the current passing into the participant. We can then measure the change and extract meaningful data regarding how the participant responded to the chosen stimulus.

Skin Conductance Response (SCR): The magnitude of the response that occurred as a result of the stimulus from its onset to its peak.
Skin Conductance Level (SCL): How long it took for the response to occur following the chosen stimulus from its onset to its peak.
Recovery time: How long it takes the response to diminish and return to “baseline/normal” values.

With these “BIG 3” physiological measures we can perform hundreds of research protocols and objectively correlate patterns of behavior. Once these measures have been employed, we can integrate other measures for more comprehensive studies, such as:

EEG and fNIR for cognitive processing and learning metrics
Non Invasive Blood Pressure (NIBP) for stress and cardiovascular metrics
Facial EMG, fEMG, or Facial Coding Software for affective emotional states metrics

Visit us at www.biopac.com or click the following links for information on:

Signal-Specific Webinars
Detailed Application Notes
Signal Specific Analysis Video Tutorials
Physiological Recording Knowledge Base
Signal guides for ECG and EDA

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

EEG on the Go

Not to spike our own signal about it, but we really love recording EEG. In fact, over 6,500 research & scientific citations have been published recording EEG with BIOPAC equipment. So, let’s think about EEG. Why do we love this signal and when should you be recording it? One strong reason: EEG is perfect for on the go research such as in the field studies or wireless recording of mobile subjects. Let’s dive into advanced applications of electroencephalography that researchers are using right now.

EEG is a powerful tool in the medical and research communities for measuring brain function and regional brain activity. The correlation of specific brain waves with sleep phases, emotional states, psychological profiles, and types of mental activities is the subject of thousands of scientific articles and citations. Several scientific journals are dedicated expressly to the study of EEG-related research, and what secrets this physiological signal holds. Since the discovery of EEG as a physiological signal in the 1920s, the scalp has been the traditional recording place of this signal. Flash forward several decades, and noninvasive surface EEG recording can be performed wirelessly on human participants, increasing subject mobility and freedom of motion.

Cognitive State Analysis

Multi-rhythm analysis is a very popular means to monitor subject fatigue, stress, confusion, engagement, and workload. These measurements are often taken as background cognitive state monitoring during experiments testing subject actions or responses.

Stimulus Presentation

Introducing an outside stimulus to measure deviance from baseline can produce significant findings when recording EEG, making stimulus delivery events a popular application for EEG recording.

Spectral Analysis

The power spectrum of the EEG indicates the power of each frequency component present in the source time domain waveform. For individual time epochs derived from EEG Signals, BIOPAC’s AcqKnowledge software estimates the power spectrum of that epoch to extract mean power, median frequency, spectral edge, and peak frequency.

ERP Analysis

Event-Related Potential Analysis consists of a workflow to present visual and auditory stimuli through one computer, while your data collection software records stimuli event markers (EEG) and psychological responses on another. This workflow is popular in EEG research as it aids in identifying similarities in different stimuli responses.

Evoked Responses

Evoked Responses include haptic, auditory, visual, and somatosensory evoked responses. Evoked Response studies typically measure response to stimuli and test multiple physiological responses, including but typically not limited to an EEG-based response.

EEG Filtering

EEG Filtering allows recording of single- or multi-channel montages with on-line calculation channels for Delta, Theta, Alpha, and Beta wave activity. Users can employ various transformations to filter the data off-line for further analysis.

The best way to run these specific advanced EEG analyses is with AcqKnowledge software, which can fully automate several of these functions. For more information on BIOPAC’s wide range of tools for recording, displaying, and analyzing EEG signals from human and animal subjects, including automated EEG analysis, seizure detection, evoked responses and many others, visit BIOPAC’s EEG Analysis page or view BIOPAC’s full line of electrodes, amplifiers, and wearable, wireless transmitters and loggers.

Remote Learning and Ventilator Testing: Our COVID-19 Response in 2020

A common thread uniting the world community is near-universal agreement that 2020 has been the most challenging year in decades. From young to old, life as we know it has been upended. Virtually everything we have come to take for granted, from employment, to education, socializing with friends, or buying toilet paper has been put on pause as we grapple with an implacable enemy that recognizes no political or demographic boundaries. We have had to quickly adapt and adopt common sense mitigation strategies until we prevail in the nearly year-long battle against COVID-19. And with a vaccine imminent, we are collectively answering that challenge.

When the first stay-at-home orders hit California in March of this year, BIOPAC Systems, along with hundreds of other offices in the Santa Barbara area, shut down to protect our employees. As small businesses made masks, and automakers retooled assembly lines to produce ventilators, we assessed how to best use our own resources in this pandemic.

We brought together our senior team of engineers and applied existing BIOPAC technologies for one early tool that has been instrumental in saving lives.The Ventilator Ventilation System can be used in ventilator prototyping, large-scale production testing for new ventilator manufacturing, and field testing for existing ventilators. Critical pressure and airflow measurements are tracked through the system. Test automation and workflow management is available through scripting. Technician instructions, procedures and prompts ensure the correct procedure is performed and a pass/fail audit trail is documented.

The BIOPAC Ventilator Validation Kit was used at Ford Motor Company, Virgin Orbital, NASA/STARK Industries and with others to increase their ventilator production capacity and, in Ford’s case, meet their goal of producing 50,000 ventilators for U.S. Hospitals.

As educators also struggled with changes to their classrooms with nearly all U.S. universities going to virtual learning or hybrid classroom environments, we sought to safely preserve some of the in-person learning experience.

In June, the Biopac Student Lab Practical Lab Learning Kit was released, or BSL Home. This single-channel data acquisition system preserved the lab experience even for students learning physiology from their homes; Lessons on EMG, ECG, EEG, EOG, respiration, biofeedback, and aerobic exercise are pre-configured and included with a handheld device that includes integrated hardware and software.

Watch: Live Demo: BSL Home in Action

BIOPAC offers a wide array of wired and wireless equipment that can be used in your research. To find more information on the Ventilator Validation Kit or the BSL Home Practical Lab Kit, please visit the BIOPAC website.

Photo by Long Truong on Unsplash

Libraries in 2020: From Curbside Pickup to Practical Lab Kits

Libraries can support remote students with distance learning tools like BSL Home practical lab kits, accessible wifi or hotspot loaners, and more.

By: Jasmine Anderson, Biopac Student Lab Product Manager

People call the library the heart of the university campus, which speaks for the memories students and alumni associate with it. It’s the essential college stomping ground and uniquely serves as both a quiet refuge for studying and a meeting place for free-flowing ideas. At the library, peers mingle, study groups collaborate, and you can find solace from the stress of student life between the book stacks. Well, at least that was true before COVID-19…

Now facing the pandemic, libraries are performing their own open-heart surgery to maintain the flow of shared knowledge and support a thriving academic experience. They are redesigning ways to safely provide information and tools to students, facilitating inter-disciplinary course reserves and collaboration, and helping to maximize resource funding and logistics across campus.

“Quiet, please” doesn’t apply these days…talk to your librarian to discover new funding options!

To maintain their role in the college experience while also evolving with the recent changes to academia, libraries are adopting electronic print collections, virtual technology, and self-service stations. Adding these services—along with the infrastructure for self-checkout, curbside pickup, and the ability to loan technology such as laptops, anatomical models, and lab kits—helps support the transition to distance learning at universities.

Libraries can also help students in the sciences by providing funding for portable lab kits to fill the gap left by practical lab closures. In the fall, students can reserve BSL Home kits on loan from the library to participate in hands-on physiology experiments from anywhere. With BSL Home, students record and analyze data from their own bodies and receive the same authentic, open-ended, and complex learning framework that’s true of the traditional lab.

To champion this, the Association of College & Research Libraries (ACRL) put forth guidelines for instruction programs stating that libraries should demonstrate a “commitment to purchasing and providing support for classroom technologies.” Alongside the University of Wisconsin, several other institutions are following suit by providing resources and funding to support classroom technologies. A handful of these universities are listed below with their library action plan (Table 1).

Institution/University Library	Action Plan
Auburn University	Auburn’s subject librarians offer services to help faculty by purchasing books, journals, and electronic resources as well as supporting teaching and research in specific disciplines.
Case Western University	Case Western’s Library equipment borrowing program takes suggestions for what they should be carrying online.
Georgia Southern University	Georgia Southern provides a materials request form that faculty can complete online to request the purchase of teaching and research materials.
Michigan State University	Michigan State allows instructors to request item purchases to place them on course reserve, similar to the University of Wisconsin MERIT Library.
University of California, Santa Barbara	UCSB allows similar reserve requests by directing faculty to make requests to their subject librarians.
University of California, Los Angeles	UCLA utilizes CCLE (Common Collaboration and Learning Environment), a campus-wide service that makes collaboration possible across schools, divisions, and departments and helps to advance remote teaching, learning and research.
University of Nevada, Las Vegas	UNLV takes faculty purchase recommendations through a form on their website which can specifically be recommended to their healthcare library.

Table 1 – A list of Institution/University Libraries paired with their action plan to support classroom technologies.

Even though libraries will not operate in their normal manner this fall, they still remain at the heart of campus life, working to support the student body in stimulating and innovative ways. The students of 2020 won’t have the same memories in the library as classes before them, but with new technology available online and kits to take home, it’s encouraging to see the library continue to be a place of shared knowledge and scholarship. For more information on how your school can accommodate practical labs with BSL Home, talk to your librarian and reach us at info@biopac.com.

Top 10 Objections to Distance Learning

By: Jasmine Anderson, Biopac Student Lab Product Manager

Simulations are not enough. Students need a practical hands-on lab experience with room to make mistakes.
Internet is not reliable for students or the instructors and reading material alone does not lend to effective learning.
Instructors’ hands are tied with limited budgets for investing in distance learning tools.
Instructors struggle to adapt curriculum to new distance learning programs.
Most lab kits and software are too complicated for students to use without guidance.
Students lose the opportunity to collaborate and troubleshoot together while working in groups.
Many learning tools discourage academic integrity with answers visibly posted online.
Privacy concerns over personal data used in digital lab and simulation tools.
Online e-Learning does not accommodate many learning styles – especially for social and/or kinematic students.
Nothing compares to in-person labs and you won’t find a substitute.

Whether you’ve taught online in the past or are planning for your first time teaching online this fall, most educators agree that it’s not their preferred instruction method. However, the value of online education technology and its innate flexibility became clear this spring when campuses were forced to close early.

Now educators are planning for the fall and are once again having to evaluate how they will meet their learning objectives and goals in an online environment. There’s no question that the landscape of the traditional practical lab is changing, and we are now forced to ask ourselves: what is the “heart” of the practical lab and how can we translate that to the online classroom?

Simulations, virtual labs, and kitchen experiments meet a few of the marks, but none of them touch on the important interpersonal and professional skills gained in the laboratory. How can instructors incorporate communication skills and cooperative learning into the online classroom? And is it even possible to provide that HyFlex (high flexibility) course model given the current online tools?

These are valid and central questions to the new landscape of higher education. After seeing the consequences of the temporary plans put in place by educational institutions in the spring, BIOPAC worked to re-design our student lab systems for the new world of socially distanced learning.

In the old world, students would work around our lab stations in groups, completing guided lessons where they record physiological data from their own bodies. This encouraged cooperative learning, peer-to-peer instruction, and—most importantly—students learned effectively by doing.

With BSL Home, all the above is possible in an online environment. BSL Home includes the same trusted Biopac Student Lab physiology curriculum that is already used in 99% of the top 100 US universities and brings the physiology lab to your students, wherever they are.

BIOPAC can ship BSL Home kits to instructors on campus or directly to a student’s home address. It also comes with affordable purchase options to rent or buy. Unfortunately, the traditional lab is no longer a safe option and simulations or experiments using pipe cleaners and Play-Doh aren’t making the cut.

Practical lab experiments are critical for students that need a Bachelor of Science degree for a career in the medical front line, working in industry, or continuing their education. With BSL Home we can help you preserve your practical lab. For more information on how BSL Home can save your lab this fall, please join us for a live demo and contact us for BSL Home info.

VR—New Worlds to Explore

Use VR to Expand the Capabilities of Your Lab

The immersive technology of virtual reality (VR) literally offers whole new worlds to explore. Combining VR/Immersive Solutions with Physiology Data allows researchers to create virtual worlds that are impossible or prohibitively expensive in the real world. Additionally, researchers can synchronize VR events with physiological response data to record and analyze physiological, behavioral, and subjective response data. Multimodal stimulation can deliver visual (3D), auditory, olfactory, haptic, and/or electric stimulus to add an incredible degree of realism to the immersive world!

Interfacing a VR workstation with a data acquisition system can add a new dimension to your research by combining objective measures with a tightly controlled experimental protocol. Immersive environments can take the subject anywhere and allow you to unlock the boundaries of your physical lab space and budget.

Create rich 3D environments that are 100% personalized to match your protocol.
Send physiological data back to the VR world to make decisions based on the participant’s physiological responses

Participants can move around naturally within the virtual world while their physiological data is captured. Record any combination of signals: ECG, EDA, EEG, EOG, EMG, EGG, temperature, respiration, and pulse. Include eye tracking to track subjects’ gaze as they view the immersive environment during the experiment. Close synchronization between the stimuli and the physiological signals is achieved through digital markers.

Monitor data in real time and use detailed signal analysis for post-acquisition scoring of the data. Automated analysis routines can streamline the analysis process, eliminate subjectivity, and save time—see AcqKnowledge for some powerful options.

VR software provides you with an unlimited degree of flexibility to create a specific world and control people and items within the world. VR software is easy to use and adaptable, so researchers can make subtle changes to an experiment without having to redesign the entire protocol.

Immerse your subjects in a BIOPAC VR world and record physiological data as the virtual environment influences the subject. Applications are varied and include Psychology, Biomechanics & Kinesiology, Ergonomics, Marketing/Consumer Research, Healthcare, Computer Modeling/Simulation, Education, Training: hazard, medical, etc.,

Use a feedback loop for greater control and automation of the VR world. This allows the world to change in real time, based on the participant’s responses. Timing events are recorded for tight synchronization with physiological data for meaningful analysis.

See VR Resources here for more examples of how VR can expand the capabilities of your lab!

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.

Photo by stem.T4L on Unsplash

Eye Tracking Basics

To understand how eye tracking works, it is important to have a basic knowledge of the structure of the eye.

pupil—an aperture, or opening, in the iris that allows light to enter into the eye unless viewed exactly on-axis with a light source, the pupil appears black
iris—the colored part of the eye, opens and closes to control the pupil size
cornea—a thin, film-like tissue that covers the eye
- on its way to the pupil, light passes through the cornea
- the cornea is mostly transparent; however, some light is also reflected from the cornea
sclera—the white part of the eye

Some eye tracking systems, such as ETVision, use a tracking technique known as “Pupil to CR” Tracking that uses the relationship between two eye features, the black pupil and mirror reflections from the front surface of the cornea (Corneal Reflections, or CRs), to compute gaze within a scene.

pupil-to CR- eye tracking technique — “Pupil to CR” eye tracking

Light from a pair of harmless near infra-red LEDs on the head gear illuminate the eye area. The near IR light is almost invisible to the user, so it does not cause a distraction, however it is visible to the eye camera. The mirror reflections of these light sources from the front surface of the cornea (CRs) appear in the camera image as a pair of bright dots. When the eye rotates in its socket, the center of the pupil moves relative to the spots. By comparing the relative position of the pupil and the CRs, the eye tracking system can compute the pointing direction of the eye visual axis relative to a coordinate frame centered at the scene camera.

During periods when the headgear remains stationary on the head, eye gaze direction can also be computed from pupil or CR position alone, and this can allow the system to continue to compute gaze when only a subset of the eye image features can be successfully identified. By computing the point at which the lines of gaze from the two eyes converge, the gaze point can be represented as spot on the scene camera image.

Since the geometry of the eye structures and the position of the optics with respect to the face vary somewhat from person to person, gaze computation accuracy can be improved by incorporating data from calibration points (points at which the person wearing the optics is known to be fixating a particular point on the scene camera image). Excellent accuracy is often achieved with a single calibration point, but can sometimes be improved with additional points.

Eye tracking has many specific applications for academic research, HCI, market research (ergonomics & design), sports performance, virtual reality, etc., and can easily be added to any study to increase feedback from participants in any environment.

Adapted from the ETVision Manual

Ready to learn more?

Watch Eye Tracking Fundamentals now or visit our Webinars and Video Tutorial pages.

BIOPAC offers a wide array of wired and wireless equipment that can be used in your research. For more information on solutions for recording and analyzing life science signals and measurements, visit the Research > Applications section on the BIOPAC website.