Sandia LabNews

From Rim to Rim

Arizona landmark is laboratory for Sandia’s R2R WATCH program

Labs’ project collects data to study the health, performance of Grand Canyon rim-to-rim hikers

The R2R WATCH (Rim-to-Rim Wearables at the Canyon for Health) study drew together a diverse Sandia team from across four divisions in partnership with the University of New Mexico’s Health Sciences Center and the National Park Service. To capture the unique nature of this ongoing project, Lab News reporters Patti Koning and Michael Padilla (both 8524) traveled to the Grand Canyon to witness the R2R WATCH team interacting with rim-to-rim hikers at the start and end of their journeys. This article gives Patti’s perspective from the hike start at the Grand Canyon’s South Rim and Michael’s from the trail end at the North Rim.

Pre-dawn at the South Rim

It’s the North Rim, baby!

Pre-dawn at the South Rim

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CHECKING IN — Dr. Risa Garcia, (far left) and Dr. Kristin Anchors (far right), from the University of New Mexico Department of Emergency Medicine, collect basic medical data on two rim-to-rim hikers who have volunteered to participate in the R2R WATCH study.  (Photo by Patti Koning)

When the hikers’ express shuttle rolls up to the South Kaibab trailhead at 5 a.m. on Friday, Oct. 14, some two dozen hikers pile out into the pitch black to face the South Rim of Grand Canyon National Park. They have no time to waste; their destination, the Grand Canyon’s North Rim, is 24 miles away.

But researchers from Sandia and the University of New Mexico (UNM) are waiting near the shuttle stop to ask the hikers for a few precious minutes to participate in a study. The researchers are collecting data on rim-to-rim hikers before, during, and after their journeys.

Studying rim-to-rim hikers

Called R2R WATCH, for Rim-to-Rim Wearables at the Canyon for Health, the research project involves surveys, basic medical information such as weight and blood pressure, blood samples, wearable fitness devices such as Fitbits, and cognitive tests.

“The overall goal of the study is to determine if a pattern of biological and cognitive markers can be identified that precedes serious health events such as hyponatremia, a decrease of sodium levels in the blood,” says Glory Aviña (8962), Sandia’s principal investigator (PI) for R2R WATCH.

The three-year research project, funded by the Defense Threat Reduction Agency (DTRA), joined an existing study of rim-to-rim hikers conducted by UNM and the National Park Service (NPS). The UNM/NPS investigation began in May 2015 with surveys of hikers at the start and end of their hikes. In May 2016, an expanded version of the study asked hikers for volunteer blood samples and detailed information about what they ate and drank on their journeys.

The R2R WATCH project has three levels: survey only, which includes basic medical data like blood pressure, oxygen saturation, and weight; survey and blood samples or wearable devices; and survey, blood samples, and wearable devices. UNM manages the collection of nutritional data and blood samples, while Sandia oversees the wearable device study. As this research project grows, UNM and Sandia are synergizing their efforts by sharing data to answer questions from various research domains, from medical assessments to performance in extreme environments.

An extreme challenge

The rim-to-rim hike is the equivalent of a marathon in distance, with a 1-mile change in elevation and temperatures that range from below 30 degrees Fahrenheit to more than 110 degrees. In addition, the Grand Canyon rim-to-rim hike is an inverse challenge; the first half is easier than the second.

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DESTINATION, PLEASE – UNM undergraduate students survey hikers starting at the South Kaibab Trail to determine the total number of rim-to-rim hikers during the R2R WATCH study. (Photo by Patti Koning)

“In most challenging hikes, like Mount Whitney in California, if you become exhausted, you can turn around and head downhill,” says Cathy Branda (8620), Sandia’s project manager for the study. “In the Grand Canyon, it’s very easy to underestimate just how difficult it is to hike out of the canyon.”

Rim-to-rim hikers present a unique opportunity for Jon Femling, an emergency room physician and UNM assistant professor of emergency medicine. “Trauma is difficult to study because you generally can’t plan for it,” he says. “But if people are going to willingly put their bodies through a hike this extreme, we can learn a lot.”

Emily Pearce, a former Grand Canyon park ranger who now works for UNM’s department of emergency medicine, first thought of studying rim-to-rim hikers in 2014.

“The National Park Service began experiencing a series of challenges with rim-to-rim hikers, including an increase in requests for assistance, which greatly taxed the rescue resources in the park,” she says. “With a small staff, rangers were becoming dangerously fatigued with the number of rescues occurring on peak R2R weekends.”

With a small staff, rangers were becoming dangerously fatigued with the number of rescues occurring on peak R2R weekends.

Emily Pearce

Additionally, Pearce adds, the prevalence of hyponatremia was increasing, especially in rim-to-rim hikers. Analysis of blood samples from the May 2016 UNM/NPS rim-to-rim study showed that one hiker was moderately hyponatremic at the trail end. Acute hyponatremia can cause cerebral edema, or brain swelling, which in turn can lead to coma or death within hours if left untreated.

This type of hyponatremia, known as exercise-associated hyponatremia, requires a specialized set of skills for treatment. Insights from the R2R WATCH study will provide a deeper understanding of the illness to better target preventive education and treatment.

Danger in the Grand Canyon

According to Over the Edge: Death in the Grand Canyon, nearly 700 recorded deaths have occurred at the Grand Canyon. In a 2012 interview with the Arizona Daily Sun, the book’s authors, Tom Myers and Michael Ghiglieri, said that over the last decade, proportionally more people have been dying from environmental problems — mainly heat — while hiking.

During peak season in the spring and fall, as many as 1,100 people per weekend set out on a rim-to-rim hike. About 350 people are rescued from the Grand Canyon each year, 150 to180 by helicopter.

“The Grand Canyon is an incredible place, but it can also be extremely dangerous. Access to water is limited on the Bright Angel and North Kaibab trails and nonexistent on the South Kaibab Trail,” says Pearce. “Our goal is to help visitors stay safe while they enjoy this natural wonder.”

The results of the UNM/NPS rim-to-rim study have already helped NPS manage the unique and formidable challenges of the Grand Canyon. “We gathered a lot of useful data the first time we did this study, and rangers have now integrated much of this data into their education of visitors,” says Pearce. “When rangers tell hikers that the average time for rim-to-rim is 12 hours, people think twice.

The physical challenges of a rim-to-rim hike — extreme heat, rough terrain, lack of water — apply to other scenarios of interest to Sandia, particularly those relevant to the nation’s armed services.

Physiological, cognitive effects of extreme hiking

At first, most of the hikers decline to participate in the R2R WATCH study. They don’t want to delay the start of their extreme trek. But later a sort of herd mentality sets in. Once the researchers explain what they are trying to do, a few hikers agree to participate because they think the study is important. Then more join in.

This leads to a frenzy of activity as the UNM team members collect medical data and Sandia staff explain the wearable devices, which range from simple temperature sensors to electromyography shorts that measure voltages across the glutes, quads, and hamstrings.

We’re looking for signs of fatigue, like muscles activating more slowly.

Rob Abbott

“We’re looking for signs of fatigue, like muscles activating more slowly,” says Rob Abbott (1463), a computer scientist in the Cognitive Sciences and Systems department.

Each hiker who opts for the wearable devices is also given an iPod Touch loaded with cognitive tests to take every three hours.

“We’re looking for combinations of cognitive and physiological markers that predict decline in this extreme situation,” says Kristin Divis (1463), a cognitive psychologist specializing in human performance and visual cognition.

The R2R WATCH study takes place over two days. At the North Rim of the Grand Canyon, 24 miles by trail away, another team waits to collect the wearable devices and post-hike medical data.

It’s the North Rim, Baby!

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WEARABLE INSIGHT — Glory (8962) and Isaac Aviña (8625) record data from two hikers who completed the rim-to-rim trek. Part of the R2R WATCH study is to determine which commercial off-the-shelf devices work best in extreme environments.   (Photo by Michael Padilla)

It’s just a few minutes before noon when the first hiker emerges from the North Kaibab Trail at the Grand Canyon’s North Rim. Covered in sweat and grinning ear-to-ear, she knows she has beaten the 12-hour average for the 24-mile hike. In fact, she has crossed the canyon in just under seven hours.

Glory and Isaac Aviña (8625), a project volunteer, quickly remove the wearable devices from the elite athlete, an ultramarathoner who recently finished a 100-mile run. The hiker then completes her final cognitive test. Study participants take these tests — fast-paced electronic questionnaires involving colors, arrows, and happy and sad faces — before their hikes, at three-hour intervals, and at the end.

“The tests measure their working memory, executive function, and other cognitive factors that could be used as early health indicators of performance,” Glory says. “For example, we expect that as people are more physically tasked, their reaction time will slow.”

Worried about her partner who is still in the canyon, the hiker wipes off her sweat and heads back down to ensure his safety. Soon everyone gathered at the North Rim cheers as the two hikers climb up the pathway. When the second hiker nearly collapses at the finish, the volunteers rush and tend to his medical needs. He’s tired but will be OK, and Glory is at his side to collect the wearable devices.

Real-time data collection

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TESTING THE LIMITS — A hiker completes a fast-paced electronic cognitive test following the completion of the rim-to-rim hike.  (Photo by Michael Padilla)

Two of the study’s goals are to determine which commercial off-the-shelf devices work best in extreme environments and to identify the physiological and cognitive markers that provide the earliest yet reliable indication of health decline.

“The project enables us to use real-time data collection and quantitatively show how markers relate to a non-laboratory, mission-relatable performance task,” Glory says. “Findings on individual markers will also inform which wearable devices are most useful both in the attributes they measure and the logistics of use.”

She also is using Sandia’s expertise in device development and cybersecurity to identify how data can best be collected and protected, especially since network connectivity in the Grand Canyon is inconsistent and unreliable.

Tracking wearable devices

The R2R WATCH team put together 75 wearable packages that included iPod Touch units loaded with cognitive tests and more than 300 wearable devices — typical fitness gear like watches, chest straps, foot pods, and hats with sensors.

“The wearables we’re using are non-invasive fitness devices that can capture the hikers’ physical state while engaged in physical activity,” says Glory. “DTRA was interested in funding this study because not only does it test which wearable devices are best related to measuring aspects of human performance, but, at the basic research level, it also examines the underlying relationships between cognitive, physiological, and biological markers.”

We can’t disturb hikers’ experience at the canyon by having them each wear seven to 10 devices.

The team focused on devices that measure multiple markers, while considering price and performance reviews. “A device that is really good at measuring heart rate but costly wasn’t going to be feasible budget-wise,” says Glory. “And we can’t disturb hikers’ experience at the canyon by having them each wear seven to 10 devices.”

Victoria Newton, a student intern in the Cognitive Sciences & Systems department (1463), purchased and calibrated all of the wearable devices. Sandia/California’s medical staff, Dr. Stephanie Ball, Emily Rada, and Gina Madison (all 8527), served as subject-matter experts for physical fitness and nutrition. The R2R WATCH study also was heavily reviewed by the human subjects boards at Sandia — led by Craig Nimmo (3300) — and UNM to ensure safety and ethics.

“Both our procurement and medical staff were extremely helpful to us in preparing for this study, and we are grateful for their assistance,” says Sandia project manager Cathy Branda.

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Data analysis underway

The team is in the process of evaluating the devices, extracting the data from each wearable, and analyzing the data. They are looking for relationships between physiological and cognitive markers, as well as performance and health outcomes. They will also determine which devices were the most effective in terms of battery life, functionality, and the ability to accurately capture physiological markers.

These results will feed into the next round of data collection for the R2R WATCH study, scheduled for mid-May 2017.

“This initial study of both physiological and cognitive markers was a great success. We collected wearable device data from 50 people, and over 100 people participated in the overall study in one weekend,” says Cathy. “But this is just the beginning. This unique setting and our partnership with UNM and the NPS create the opportunity to learn a great deal about predicting medical events. We expect to have more participants and to be more targeted in the data we collect in May.”


R2R WATCH Study Team

The study is supported by nearly 75 volunteers from UNM and Sandia:

DTRA PM Edward Argenta; Sandia PM Cathy Branda (8620); Sandia PI Glory Emmanuel Aviña (8962); and core team members Rob Abbott and Kristin Divis (both 1463), Clifford Anderson-Bergman (8962), and Victoria Newton (1463).

University of New Mexico Department of Emergency Medicine: UNM PI Jon Femling, emergency room physician; Emily Pearce; and Lucie Jelinkova.

Additional Sandia support: Patricia Benguerel (8532); K. Kelly Riley (10247); Karim Mahrous (8970); Robert Spulak (5331); Isaac Aviña (8625); Kerstan Cole, Eric Moyer, Scottie-Beth Fleming, and Walter Gilmore (all 0431); Kris Hearrean (8971); Joe Schoeniger (8623); and Stephanie Ball, Emily Rada, and Gina Madison (all 8527).