Tried and Tested: How the Duo Surgical Headlamp Earned Ergonomic Certification

After a long day in the operating room, how quickly do you remove your surgical headlamp? Studies show that nearly 70% of surgeons report suffering from musculoskeletal pain during their career and longer operations are associated with more significant pain.

Wearing a headlamp may be necessary, but after hours of operating and trying to get the best light while balancing a lamp on your head, it can be exhausting if not painful.

Standing on your feet for hours, reaching, twisting, bending, even the operating room setup, can lead to pain. One study showed surgeons reporting pain as a 5 out of 10 following a routine day’s work in the operating room. And there’s evidence that poor ergonomics may be scaring some residents away from pursuing a surgical specialty.

The Case for Ergonomics

After a series of tests, the Integra® DUO LED Surgical Headlight System is now the first surgical headlamp ^[1] to receive ergonomic product certification from United States Ergonomics. ^[2]

“From an ergonomic perspective, you want to minimize fatigue, because the risk of injury increases once the muscle becomes tired,” says Kevin Costello, president of U.S. Ergonomics, which has tested thousands of products since the company was founded in 2001.

US Ergonomics employs certified professional ergonomists, biomedical engineers, human factors specialists, industrial engineers, and health and safety professionals with decades of experience. The team has provided services to both large and small companies across of variety of industries, from aerospace and automotive to consumer products and healthcare.

Ergonomic Product Certification: Behind the Scenes

For the DUO’s ergonomic certification, the company’s testing was both qualitative and quantitative. They employed subjective assessments of comfort and balance as well as electromyographic measures of muscle exertion that were developed by assuming different postures that mimicked those often used in the operating room. The assessments were made, in part, by people who had operating room experience and some with medical experience wearing headlamps during surgery.

“There are always two parts of our certification process,” Costello says of US Ergonomics’ testing. “There are controlled tests of the product in our lab where we simulate how the product would be used in the working environment. For the DUO, we did physically what the surgeon might be going through, the balance and muscle effort required to support the device on the head. Part two is validation of the product with users in the field. We can do all the tests we want in our lab, but we still need the real experience of users in the field to validate our findings in the lab.”

The lab tests measured subjects’ muscle exertion levels, arthrometric fit, dynamic head and neck movement and user perceptions of weight, balance, device security and comfort while wearing the DUO for approximately 30 minutes.

Baseline measurements were taken while participants had nothing on their heads, then with the DUO. Participants had sensors placed on different head and neck muscle groups for the testing, including those used in turning and nodding the head (bi-lateral sternocleidomastoid and cervical paraspinal) and head stabilization (upper trapezius).

“Muscles generate micro-volts of electricity proportional to their level of activity,” Costello says. We calibrate these signals to determine how much muscle effort is required to use a product or complete a task. The calibrated signal is referred to as the percentage of the individual’s maximum voluntary contraction (MVC).”

The lab tests for DUO set the acceptable criteria at 20% MVC. Ergonomic studies have demonstrated that 15% MVC can be held indefinitely. W. Rohmert conducted the original research in 1964 (read those studies here and here), and in 1990 AD Price came to a similar conclusion, that anything below a MVC of 15% does not produce muscle fatigue. DUO lab test results showed that during simulated surgical postures the maximum voluntary contraction never exceeded 10% during any of the tests. ^[3]

To verify the laboratory findings, US Ergonomics conducted an investigation of surgeons’ experiences while using the DUO headlamp in surgical applications. Nine surgeons across different specialties in the U.S. who had been using DUO for anywhere from less than six months to up to two years were interviewed and completed detailed surveys regarding their experiences.

As a result of these findings, US Ergonomics granted the Integra Duo an ergonomic product certification.

[1] Date on file, (Email from Kevin Costello), (Nov. 24, 2021)

[2] Data on file, (Ergonomic Testing & Certification of the Integra Duo LED Surgical Headlight), (Oct. 6, 2021)

[3] Data on file, (Ergonomic Testing & Certification of the Integra Duo LED Surgical Headlight), (Oct. 6, 2021)

Integra DUO LED Surgical Headlight System

Rx ONLY

Caution: Federal (USA) law restricts this device to sale by or on the order of a physician.

INDICATIONS

The Integra DUO LED Surgical Headlight System is designed to provide supplemental illumination aiding visualization during surgical, diagnostic, or therapeutic procedures.

CONTRAINDICATIONS

The Integra DUO LED Surgical Headlight System is contraindicated for use in neonatal transillumination, ophthalmic procedures, photosensitive patients or patients who have received photosensitizing agents (hematoporphyrin derivatives) within three months.