From problem to production: lessons in measuring children’s growth

An idea born out of frustration more than 15 years ago is finally poised to improve communities’ lives.

Diane Baik is the Nutrition Technical Director at World Vision International. Years ago, she found herself in a community walking house-to-house, lugging the wooden contraption needed to measure children’s height.

The measuring boards were heavy, she noticed, and often inaccurate. On top of that, they were expensive to produce and wore out quickly. Diane suspected there was a lighter, better way.

Routine height and length measurements are an important part of monitoring children’s growth. Children’s height, paired with measures like their weight and upper arm circumference, help health workers to identify malnutrition concerns like stunting or wasting.

• Stunting is when a child is too short for their age, usually because of poor nutrition or illness over a long period of time.
• Wasting is when a child is too thin for their height, usually because they aren’t getting enough food or when illness, like diarrhea, keeps their body from absorbing nutrients.

Timely, accurate growth measurement ensures that children who are malnourished can be spotted early and referred for treatment.

Why measuring a child is not as simple as it appears

The standard tool used to measure children’s height is a solid wood board certified by UNICEF. It has long been considered the “gold standard,” but as Diane observed, it has limitations.

• The board is heavy, bulky and hard to carry.
• It’s expensive— between US$500 and US$750, including shipping.
• It requires a flat wall to lean against—yet the reality is that measuring often happens on uneven ground with no wall.
• The ruler can be hard to read, and measurers can make mistakes while recording the numbers.
• When boards are made locally using cheaper wood, quality issues arise—they tend to warp and their rulers may not start at zero.

Young children are also naturally squirmy! Especially those under age two. They often resist being measured, so getting an accurate read is not straightforward.

Partnering on a new design

Diane spent years looking for a partner to help design and produce a different kind of tool. Tech companies and donors turned her down, uninterested in the concept or its potential for profit. Then an ad on Kickstarter led her to Magpie Tech, a company with a patented triple-laser technology, and IGES, its manufacturer.

World Vision International partnered with Magpie and IGES to co-design a new laser measuring device that could transform the process for health workers and children alike.

World Vision Canada helped fund the first round of prototype testing and field assessment, gave technical guidance on the design of the first prototype, and contributed to the research and piloting of later versions.

The resulting device was lightweight, compact and durable, and lower in cost than traditional boards.

Testing the new design in Vietnam

In May and June of 2025, the design went through its first decisive test: a validation study during a growth monitoring campaign in Quang Tri province, Vietnam. There, health workers measured the height of 571 children under age five, comparing the new device against the gold-standard wooden board. The study had local ethics approval from the Hanoi University of Public Health.

What did the researchers find?

• The laser board had an accuracy of 99.9 per cent and a precision of 99.8 per cent, which was comparable to the wooden board.
• It was 30 per cent faster to measure height for children aged 24 months and older (measured standing), and 32 per cent faster measuring length for children under 24 months (measured lying down).
• Volunteers could use it accurately enough to meet World Health Organization standards (within a difference of 4mm). This means community health workers—not just professional health staff—could successfully take the measurements.
• The design made it possible for two people to measure a child, while the wooden board required three.

Children and health workers speak up

In addition to the measurement analysis, researchers also ran focus group discussions. Two sessions were held with 10 caregivers and their children (aged 4–5) who had been measured. Two were held with community health workers and Ministry of Health staff who had used the device.

The children had positive things to say. Among the comments: the device was not scary because the headpiece looked more stable than the wooden boards.

Compared with the wooden board, parents, volunteers and local staff said the laser board looked more approachable and child-friendly, and that it was easier to use and more accurate. They liked the large display, and the remote control was especially useful when measuring length. Overall, they felt it was faster, more accurate and easier to read.

Also, safer. As they said, “We don’t have to worry about the headpiece falling on a child’s head.”

What’s next for the laser board

The project is moving from research to implementation. The Vietnam study is being submitted for peer review, and the device is on track for mass production and commercial availability by the end of 2026. Discussions have been underway with UNICEF about using the laser board in large-scale nutrition surveys, and Ministries of Health in Honduras and Ethiopia have expressed interest in piloting it.

Through the laser board collaboration with Magpie, World Vision earned two 2025 Anthem Awards for responsible technology. The Anthem Awards celebrate purpose-driven work that makes a measurable impact on society.

Did you know your donations can support award-winning work like this?

World Vision Canada is committed to constant innovation, learning and improvement. See what else we’ve learned over the past few years:

• These programs help in the most difficult places—do they work? A major evaluation across 11 fragile countries finds emergency relief, long-term development and peacebuilding work best together.
• When mothers have safe childcare, what changes? Lessons from Ethiopia on how childcare opportunities are helping mothers earn and children grow.
• Measuring what matters: Our latest lessons in data monitoring show why community insights must remain at the heart of our global systems.
• Learning and re-learning the power of youth voices: What happened when we invited adolescents into the annual outcome monitoring process of our AHADI project in Tanzania.

Written by Katie Hackett with contributions from Diane Baik, Kioko Munyao and Miriam Booy.

* Based on results from across the global World Vision Partnership