Heidi Santiago has put a new twist on an old cliché. In her case it was frustration—not necessity—that became the mother of invention.

This energetic, former-middle-school teacher was used to motivating students, but when it came to motivating her young stepdaughter to use the potty, she was stumped.

Traditional methods like stickers and rewards didn’t work, and the conflicting advice she received didn’t help either.

“A lot of people were saying she was just being naughty,” Santiago recalls. She looked for something that would help shift the responsibility of using the toilet from the parent to the child and make the process enjoyable for the child. She couldn’t find a product like that—so she invented one.

“The idea just came to me,” she says of the WeeMinder Potty Training System. “My idea was to give the kids ownership and more control of the process.”

She designed the WeeMinder, a wearable alarm that sounds at preset intervals to remind children to use the restroom. And what’s a children’s product without a mascot? Santiago created Wally the Wallaby and wrote “Wally’s WeeMinder Adventure,” a brightly illustrated picture book that introduces children to the system in a fun and engaging way.

The creative mom also penned a catchy song that plays when it’s time for kids to use the potty. “Put a big smile on your face and hop, hop, hop to the potty place.”

That was the easy part. What came next was both time-consuming and expensive.

In 2003, Santiago and her husband, Cory, launched Divine Innovations to produce and market the potty-training system. First, they had several prototypes of their product made. The microchip technology has been around for a while, but the Santiagos wanted to use it in a new way.

“The WeeMinder utilizes a proprietary chip that’s designed to reset itself after the alarm is played,” she says.

The user can set the device to one of three different time settings: one hour, two hours and 2 1/2 hours. Santiago says a small speaker produces an alarm that’s loud enough to be heard but not so big that it drains the lithium battery. An additional on-off switch was added to the circuit to save batteries during downtime.

Because the product is worn by children, Santiago made sure the prototypes underwent rigorous testing.

“It had to be just right—no small pieces that would be a choking hazard,” she says. “We made sure the watch strap wouldn’t separate from the product.”

When they were satisfied with the design, Santiago took an extra step before unveiling the WeeMinder to the public.

She had picked up a copy of “Inventing for Dummies” by Pamela Riddle Bird, the founder and CEO of Innovative Product Technologies Inc. In the book, Santiago learned about the Innovation Institute. According to the company’s Web site, the WIN-I2 Innovation Evaluation Service is an inventor-assistance service that provides inventors, entrepreneurs and product-marketing and -manufacturing enterprises with an honest and objective third-party analysis of the risks and potential of their ideas, inventions and new products.

Santiago says, “We had a few prototypes, but we wanted to get feedback before we bought 10,000 chips from the factory.” She had her invention assessed by the Innovation Institute. The evaluation covered 45 categories, including safety, function, production feasibility, appearance and durability.