July, 2018: Light Intensity

Light is a fascinating thing.  From the dual nature of light as a particle and wave, to the combination of colored light to make new colors, it is an illuminating element that we often take for granted.  How often does that average person consider the color-temperature of their office lamp for instance?  In Shedding Light, we aim to bring understanding to issues surrounding illumination.  In March’s issue we discussed coaxial lighting and Pure Light Technology (Color Temperature), and in this issue we will be discussing light intensity.

The first thing to know about light intensity is the language that surrounds the topic.  Many have probably heard the term lumens (and some may have heard foot-candle), but in the modern world of surgical lighting “lux” is king.  Lux is the International System of Units (SI) measure of illuminance and refers to the number of lumens per square meter.  The area part of the equation is crucial in defining intensity.  If you produce the same number of lumens (think amount of light) over a larger area, it will appear dimmer and less intense.

Fig. 1

Intensity and area of illumination lead to one of the most crucial factors in rating a surgical light source: working distance.  To start this discussion, we will use the analogy of a car headlight.

A car’s headlight emits the same amount of light all the time, but the farther away from the source you go, the more area the light inhabits, and the lower the intensity. Think about the driver of a car:  the road directly in front of the car is very well illuminated, but farther down the road everything is still dark.

Fig. 2 (2)


When it comes to surgical lighting, the same is true. An LED Headlight will appear much more intense at a close working distance than at a far one.  If you were to put on a Surgical LED Headlight and shine it at a white wall your eyes would not feel very good two inches from the wall; It would get easier on the eyes as you moved away.

To exemplify this fact, we looked at Enova’s brightest LED Surgical Headlight: the XLT-225A.  The 225 in this headlight’s name stands for 225,000 and refers to the lux output at a working distance of 14” (35.6 cm).  This headlight produces 225,000 lux 14” from the source, an average working distance of many surgeons.

To show how intensity decreases over distance from the source, we used a lux-meter to measure output at distances other than 14”.  Below you will find the data showing the same effect as the car’s headlights. LED headlights appear much brighter the closer you are to the source.

Fig. 3

What does this mean for surgeons and other headlight users?  It means the intensity of light that you experience is directly related to the distance at which you work, not just the output of the headlight you use.

When trialing or purchasing new headlights, it is important that you consider the reported working distance of the headlight, as well as your standard working distance as a user.

We consider 14″ (36 cm) to be a standard working distance for measurement, but the industry has no defined standard, and some headlights are reported at 12″ or less. An LED headlight may say (in the case of our XLT-125A) that it puts out 125,000 lux at 14”, but if you work at 12” it will appear much brighter than that.

The aim of our articles is to increase your knowledge and understanding of LED Surgical Lighting and the communities that use it.  After reading July’s issue we hope you better understand the numbers associated with these devices.  At the very least we hope that you have been intrigued by the phenomenon of illumination.  It still intrigues us here at Enova.

emma enova


June, 2018: Dr. Edelstein

IMG_2066“In Haiti, you really are a general surgeon” says Dr. Peter Edelstein. General surgery can be characterized, in the case of Dr. Edelstein, by the performing of circumcisions followed by cosmetic facial surgery followed by a hysterectomy. This range of surgeries doesn’t exist for general surgeons in modern day America, as doctors and surgeons have become ever more specialized. But in places like Haiti, all maladies must be treated (often in an advanced state), and surgical help is extremely limited.

Dr. Edelstein recently traveled to Bolivia with Medical Ministry International (MMI) and to Haiti (sponsored by Lumiere Ministries) to perform procedures for those that need it most. Trained in General and Trauma Surgery and specializing in Colon & Rectal Surgery, Dr. Edelstein has spent his recent years as an international physician executive. His trip south was not just a return to the O.R., but a chance to give back.

Haiti is the poorest country in the western hemisphere, a country whose situation has been made worse by earthquakes, corruption, and disease. “Benign diseases cripple and kill all the time in Haiti,” says Dr. Edelstein. “Diseases often become very advanced because there is very limited surgical care.” The annual yearly salary in Haiti is $450 USD, garbage is everywhere, and the power goes on and off all day. And it’s very, very hot and humid.  But that doesn’t stop the people from having hope. “Their optimism in the face of poverty is astounding,” Dr. Edelstein reflects.

When it comes to operating in countries like Haiti and Bolivia, the situation and equipment are less than ideal. The operating rooms are often lit by a single dim, incandescent bulb, and power outages are routine.  Thus, to perform the numerous deep cavity surgeries (and even the more superficial procedures), illumination is often a serious rate-limiting resource. Without the ability to see clearly, many operations become difficult and dangerous. It’s at this point that Enova lends a big hand with our headlights.

Edlestein 3

“We could never have done abdominal, pelvic, or neck surgeries without the Enova lights. It just wouldn’t have been safe,” Dr. Edelstein explains. Enova’s Mission Program gives surgeons like Dr. Edelstein the light they require, providing illumination where there previously was not enough.  And Enova gives patients something that they would otherwise not have: the opportunity to undergo needed surgical care. “It was on the mission to Bolivia with two other Surgeons that

I was first introduced to your amazing  headlights,” he says.  “Knowing I was off to Haiti – alone- in May, I reached out to Enova for headlight support. I knew that without this powerful tool, my ability to do the needed broad range of procedures would be severely curtailed.”

What is clear through stories like Dr. Edelstein’s is that there are many people dedicated to doing good across the globe by providing medical services for others. In the places of the world that need it most, you will find courageous and generous physicians making a difference. By helping individuals, the world becomes a better place. And often, the attitudes of those being helped is one of the greatest gifts of all: “I feel I was more blessed by these amazing experiences and by those dedicated providers and grateful patients who I met than they were.”

Dr. Edelstein’s time in Bolivia and Haiti can teach us a lot about the way in which humans inhabit the world, and it can also teach us all to be a little more generous. As a company, Enova is committed to being a positive force in the global community, and we will continue to do our small part to help people like Dr. Edelstein as they work to improve the lives of others. If you or someone you know is ever in need of illumination on an upcoming mission, please reach out to us, and we can give you a hand. If Enova can help those who help others, the world becomes a bit brighter.

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May, 2018: Untethered Mobility

Mobility is key.  Whether it’s in your car, on foot, or in some other manor, moving around is one of the important components to human life.  Road-trips and traveling are cultural phenomena, and globalization and air travel have brought the people of the world closer than ever before.

Medical technologies usually define innovation, giving the world products and services that make life easier and healthier. So why is it that the O.R. often remains a zone of confined movement in an untethered world?  With fiber optic lights, surgeons are tied to the wall, and must have cumbersome light-boxes in tow.  In a world in motion, it is time the O.R. became freer.

LED technology, by virtue of its unending list of uses, has come a very long way in providing possibilities for the future of lighting. What was once a blip on the technological radar is now giving surgeons long-overdue freedom.  Welcome to the world of self-contained surgical lighting. Consider yourself untethered.

Enova Illumination and other LED Surgical Headlight companies manufacture light-sources for the modern surgeon. The light produced is the same – up to 250,000+ lux of pure white homogenous light – but with LED the power is at your hip (and sometimes on your head – more on that later).Powerpack free

LED Surgical headlights utilize lithium ion batteries to provide power in a self-contained “power-pack”. Not much bigger than a deck of cards, these power packs provide up to 10 hours of maximum light (depending on headlight and battery model) in a nifty little box.  In 2018 all a surgeon needs to be tethered to is his/her own belt.

Why remain attached to the wall when total mobility is so attainable? Dr. John Chovanes at Coopere University Hospital’s Trauma Center says “And, [LED Headlights are] portable, which allows me to move quickly. I’m not tethered by a power cord and can move around the operating table without unplugging or moving a cord.”

If moving freely is your wish, you needn’t look any further than LED.  And just to prove that LED innovation is ceaseless, I bring you Enova’s Freestyle battery pack (below).  Attached to the headband of the headlight itself, the Freestyle battery makes the self-contained headlight that much more compact.  No cables, no cords, no tethers.

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If you like to move freely, consider LED, and give Enova a call.  Enova offers free 30-day trial periods on all of our models, giving you the chance to experience untethered mobility for yourself.  Visit www.goenova.com/programs/evaluation-program/ to sign up for a trial, or email info@goenova.com to speak to one of our representatives. There’s never been a better time to untether!

The Henderson Family, Santa Cruz del Quiché, Guatemala

2.jpgBorn overseas, Dr. Winnie Henderson experienced poor healthcare firsthand.  “They don’t put a lot of money into healthcare”, she says, explaining that corruption and poor facilities are huge problems. Yet ever since her first Mission trip in 2015 with Cascade Medical Team, she’s been hooked. She says it is really rewarding, allowing her and others to “go to places where there is nothing.”  It gives surgeons like her a chance to give back to communities in need.

Many people are familiar with the idea of doctors doing Mission work.  In our heads we may imagine some brave doctors in the jungle providing treatment to those that may need it most.  These images would be correct, but in some cases there is a bit more to it than that.  In some cases, mission work is a family affair.  In early 2018 Dr. Henderson embarked on another mission – her third in four years – but this time her son and husband came along.


Cascade Medical Team performing surgery

The location of the mission was Santa Cruz del Quiché, Guatemala.  Stationed in an old military base, HELPS INTERNATIONAL in Guatemala retrieved mission equipment from previous years in order to set up temporary operating rooms for the surgeons.  With a population of 90,000, the area surrounding the makeshift hospital lived with very little. “They have nothing”, Dr. Henderson says, adding that 65% of the inhabitants of the area live in poverty.

With so little in the way of money and resources, medical attention is a much-needed asset for the locals.  Yet, surgeries and clinical visits aren’t the only thing needed: cue Dr. Henderson’s family.

For this specific mission, the goals were twofold: provide medical care, and build stoves for the local people.  This is where Bill Henderson, Dr. Henderson’s husband, comes in. The need for medical care is easy to understand, but the building of stoves is, as Dr. Henderson explained, a very important component to the success of the community.  Many of the surgeries that Dr. Henderson performed while in Santa Cruz del Quiché were hernia surgeries, a problem that arises from Guatemalans transporting large amounts of wood for the inefficient and archaic stoves that they use to warm their houses and for cooking.  Old stoves like those in use by the local people also contribute to COPD, a lung disease commonly associated with long-term tobacco users and prolonged smoke inhalation; The standard stoves are basically an open fire without a vent. The ONIL efficient stoves installed by Cascade Medical Team also save thousands of trees and contribute to improving the environment as well as improving the health of the Guatemalans.

Bill Henderson was part of the team that built stoves for the community, hoping to decrease the instances of hernias, COPD, and accidental burns that the surgeons in the makeshift hospital were treating. Instead of solely addressing the effects, Cascade Medical Team Guatemala’s mission attempted to address and combat the causes as well.  By eliminating some of the causes, the need for comprehensive surgery can also be eliminated for many in the future.


Dr. Henderson (right) performs surgery in Santa Cruz del Quiché.

Anyone involved in mission work will tell you they need every bit of help they can get.

This is where Michael, the third and final Henderson, comes in.  Michael Henderson joined his mother and father as team photographer, snapping photos of the surgical and stove-building teams.  But his additions to the trip were not just in the form of documentation.  Dr. Henderson and Michael – who is currently in college and had the primary mission assignment of sterile processing – went to the field early with the triage team.  The triage team sees patients early and signs them up for upcoming surgery blocks.  Despite being a photographer by nature, Michael helped the anesthesiologists set up their equipment, prepared the hospital for the busy week ahead, and worked diligently sterilizing surgical instruments for the surgical team.

What becomes clear through the story of the Hendersons in Guatemala is that Mission work is a much more all-encompassing endeavor than many of us realize.  Mission work is not just about performing surgeries; It’s is also about building stoves and setting up communities of volunteers.

Through helping communities in need, in whatever form necessary, the people doing mission work inspire us to give back.  Some are able to give back in the form of time, some give back in the form of expertise, and others give back in the form of love.  Many, like the Hendersons, give back in all these ways.


Dr. Henderson (left) and Dr. Robert Schauer (right) with some happy patients.

As a medical product manufacturer, one of Enova’s main goals is to give back in the form of light.  As is typically the protocol, Enova sent two headlights with Dr. Henderson for use in the makeshift hospital.  What Enova did not anticipate, however, was how exactly the lights would be used.

Dr. Henderson described the campus as operating rooms and sleeping quarters separated by an old runway (this was a military base after all), adding “When the sun goes down, it’s dark.”  As it turns out, the XLT-125A doubles as a useful beacon for the crossing of the airstrip.  But the headlights were (as we hoped) also quite useful for surgery. Dr. Henderson said 2 out of 4 O.R.s on the base were without power, needing generators to power their tools.  In some instances, the generators would shut down and the anesthesiologists had to scramble to cover these shut-downs, pumping fluids by hand.  But because the LED Headlight batteries were charged each night, the surgeons could still see, despite the outages.


Dr. Henderson in local attire with her patients.

Speaking with Dr. Henderson about this trip taught me a lot about community, altruism, and multi-functionality.  I wish I could recount all the funny and touching things that Dr. Henderson had to say, but as a tease here are some tiny summaries of some of her stories: fundraising event for Cascade Medical Team called “Docs and Ducks” (Oregon Ducks), a surgical colleague accidentally winning a headlight competition with Dr. Henderson’s light, and embracing the Mayan culture (check out the photo at right). Thanks for chatting with us Dr. Henderson, we loved learning about your trip.  Don’t forget to reach out to us the next time you need light!


Photos by Michael Henderson, team photographer.  Find him on Facebook as the page Lifewithhenderson.  To learn more about Enova’s Mission program visit goenova.com.

March, 2018: Coaxial Lighting

The Benefits of Coaxial Alignment

When it comes to surgical illumination there are a few things that can’t be compromised.  Surgical headlights must be bright enough to illuminate the operating cavity; They must be light enough to wear all day for long procedures; They must be durable so as not to need constant care.  While we strive to excel in all these departments, we also believe in the power of proper alignment.  At Enova, we have put in a lot of time and effort developing a bracket for our headlights that suits the needs of those that use our products (but don’t worry, the time was enjoyed).  For maximum benefit, light needs to come from the same axis as the user’s vision – this is coaxial alignment

Think of it this way: shadows are bad.  While performing complicated procedures – and simple ones at that – it is imperative that all the nooks and crannies of the surgical cavity are illuminated when they need to be.  With overhead lighting or misaligned headlights, shadows can arise in places they shouldn’t.  However, when light is properly aligned, the beam follows the gaze of the surgeon.  Using coaxial alignment, the necessary body parts are always illuminated without interference from shadows.  With Enova’s four-point pivot bracket, coaxial alignment has never been easier.

Overhead vs coaxial

Step One:  Put headlight onto head and adjust ratchet(s) and top strap (if applicable).  Headlight should fit snugly onto head, without feeling tight or constricting.

Step Two: Using two hands, adjust pivot bracket such that headlamp is in line with vision, situated near the bridge of your nose.  Make sure lamp is not obstructing view but is coaxial with eyesight.

Step Three:  Plug headlight into PowerPack and turn on using red power button.  Adjust brightness using “+” and “-“ buttons to your needs.

Step Four:  Move head side-to-side and up and down to make sure your field-of-view is properly illuminated, and there are not shadows in the surgical field.

Step Five:  If illumination is incorrect, readjust to obtain coaxial alignment and desired brightness.

coaxial jordyn


Pure Light Technology (PLT)

All light sources that humans encounter in their lives illuminate surroundings in different ways.  Our eyes receive electromagnetic waves from objects based on how the objects are interacting with the light sources around them.  Put more simply, light isn’t just bright or dim but instead encompasses many other qualities.  Two very important qualities of light sources is their color temperature and their color rendering index. 165 blue circle

Color temperature has any number of applications but can be seen visibly as the apparent color of the light source.  For instance, blueish-white (like halogen bulbs) or yellowish-red (traditional incandescent light).  Warmer color temperatures are associated with less eye fatigue.

Color rendering index (CRI) is a measure of a light source’s ability to faithfully reveal colors.  In applications such as surgery, higher CRI allows for greater tissue distinction through color differentiation.

Enova’s PLT series utilizes the benefits of warm color temperature and high CRI to maximize tissue color differentiation and comfort of use.  The PLT-165A, for instance, has a color temperature of 4500 Kelvin (warm) and a CRI of 95 (out of 100) all while pumping out 165,000 lux.  This means your surgical subject will stay well-illuminated with market-leading tissue color differentiation, and your eyes will stay focused and awake throughout the surgery.

With five PLT models Enova has the illumination you need, no matter what your specialty.  Check out our full line of headlights at



February, 2018: Dr. Humphreys


Kijabe, Kenya

Craig Humphreys grew up in Alaska, looking up to a mother that worked with the state’s native communities through teaching. Dr. Humphreys’ expertise as a spinal surgeon drew him to other continents in his pursuit of giving back to the world.  From trips to India, St. Lucia, and China, Dr. Humphreys has dedicated his free time to helping those in need. “There are so many people that want to do good”, says Dr. Humphreys, who is one of those people himself, currently giving back toKenya 1.jpg the communities in Kijabe, Kenya.

Dr. Humphreys started going to Kenya in 2012 with the World Medical Mission. After realizing the potential for positively affecting the community, he went back to Kenya in 2014 in the hopes of finding a local hospital to partner with to provide spine care.  On this trip, he encountered CURE Kenya, and has been going back ever since.

Dr. Humphreys has performed 43 spinal surgeries on these trips and is working towards developing a medical education program for spinal surgery.  His hope is to find funds for the construction of medical and training facilities over the next 12-18 months.  Upon completion, the facilities will have lectures 4 days a week, while providing patient care and surgical training to residents.

While providing help in the ways of surgical knowledge and resources, he says the transmission of knowledge is not one-directional. “We give the people we work with technology, they give us life lessons,” he says, adding “People there teach you so much, it really changes who you are.”

In the drive to create positive change, doctors face many challenges.  Dr. Humphreys describes, for instance, teaching the local aircraft mechanic in Nairobi how to fix microscopes used in spinal surgery. Yet, in the form of equipment, many companies and organizations try their best to support those that dedicate their time to helping the world.

At Enova, we strive to give aid in the form of light.  Dr. Humphreys has taken some of our headlights with him on previous trips and says they are invaluable.  On a recent trip, he left the headlights in Kenya because it was clear they were needed to save lives.  “They had tears in their eyes, they were so happy.  And these are guys that don’t cry a lot.”

Dr. Humphreys and his team will be going back to Kenya in February, and he asked Enova to lend some more lights for this trip. Giving back to the world is one of our core missions at Enova, and we will be following Dr. Humphreys’ next adventure with open eyes and open hearts.  In an upcoming issue of Shedding Light, we will catch back up with Dr. Humphreys and learn about this February trip.  Good luck on your mission Dr. Humphreys, we will talk to you soon!


Enova has Moved

In July of 2017, Enova’s headquarters made the 14-mile trek to a new permanent location in Minneapolis. As Enova grew, and its products got a new look, it only made sende to start fresh in a new city.

Long situated in north St. Paul, you can now find Enova just off I-35W in northeast Minneapolis.  The move took its toll on the patience of Enova’s employees (and continues to do so for some certain Wisconsonites), but the new facilities offer better office space, a more state-of-the-art warehouse, and plenty of room for growth.

Enova associates had a few things to say about the new location.  Anders Berglund (production and Quality) says, “The coffee from the Holiday [Gas Station] comes in large, delicious quantities, and it could not be closer.” Jordyn Kaufer (Sales and Marketing) says he loves the Catrinas Mexican Restaurant situated close enough for a quick lunch break.  Although, he adds, “It took me two hours to get Locale.jpghome in the snow.” To be fair, snow in Minnesota is a given, so Jordyn’s complaints garner little sympathy.

Enova President Roger Heegaard loves the new location, and welcomes visits from customers and friends alike.  So, if you are curious about how Enova is coping in the big city, stop by and say hello.

1717 Broadway St. NE  |  Minneapolis, MN 55413



Enova’s newest AssociateMatt

At the start of 2018, Matt Johnson joined the sales team here in snowy Minneapolis.  After playing professional hockey in Sweden, he is settling in nicely to the Enova routine.  Matt lives in Saint Paul Park just south of St. Paul, and likes sunflower seeds and Ford F-250s.  Stop by the office to say hello, or welcome him over the phone when you call Enova’s service line.