Drowning does not happen the way most people think. On television and in movies, a frantic swimmer kicks, thrashes, and shouts, says Graham Snyder, an emergency room physician. But real-life drowning is nearly silent.
Drowning swimmers say nothing because they can barely breathe, Snyder explains. Rather than thrash, they bob up and down before quietly slipping below the surface. Amid the splashing and noise of pool play, a lifeguard’s eyes search for the child making no splashes and no sound. Drowning detection, Snyder says, is “trying to notice the unnoticeable.”
Snyder has treated many drowning victims in his 13 years working in the emergency room of WakeMed Health & Hospitals in Raleigh, NC. Realizing there was little he could do as a physician to prevent drowning, he decided to pursue a technology solution. SEAL Innovation, the Raleigh startup that Snyder co-founded, has developed a wearable drowning detection device to catch what the human eye can miss.
Drowning is the fifth leading cause of death from an unintentional injury in the United States, according to the Centers for Disease Control and Prevention. Children under 5 years old have the highest drowning rates. SEAL Innovation detects drowning with a neck band called SwimSafe that sounds an alarm when the wearer has been underwater too long. The SwimSafe system consists of the wearable bands, a portable hub that monitors the bands, and a charger. The system works by creating a mesh network connecting the bands. Each band continuously reports the swimmer’s status to the hub, and to the guard band worn by the lifeguard or parent. If a swimmer’s band has been submerged beyond a preset level—bands can be set to different levels according to swimming ability—the sensor triggers flashing lights and an audible alarm on the band and the hub. The guard band sounds and flashes, as well.
The concept sounds simple, but Snyder says developing the device was not straightforward. SEAL Innovation explored flotation alarms that release from a swimmer and sound a siren, as well as pendants that monitor swimmers. Meanwhile, other swimmer-monitoring technologies surfaced in the form of wearable wrist sensors. Inspiration for a neck-worn band came from a YMCA pool, where Snyder saw swimmers wearing neck bands indicating whether they were permitted in the deep end or not. He concluded that the neck was the best place for a drowning sensor because a submerged wrist device could mistakenly sound an alert when a child is merely standing in the pool.
Snyder says the biggest challenge was engineering a device that does not trigger a false alarm when a swimmer does something routine, such as swimming the butterfly stroke or diving in the pool for pennies. SwimSafe distinguishes between diving and drowning with patented technology that employs radio waves, Snyder explains. Radio waves move differently through water than they do through the air. A sensor in each band measures how the intensity of those radio waves changes in water, which allows the device to determine water depth. The sensor also measures the time at that depth.
The bands’ five settings are based on age and swimming ability. At level 0 for nonswimmers, the alarm sounds as soon as the band gets wet. At level 1 for toddlers, the alarm sounds at 10 seconds under water. A guardian sets the level on each band at the charger and once set, a child cannot change it, Snyder says. One charge lasts about six hours. The SwimSafe bands have a range of about 150 feet from the hub; if a child ventures too far, the band warns the swimmer with a flashing yellow light and beeping sounds. If those warnings are ignored, the beeps escalate.
The product most closely resembling SwimSafe is the iSwimband, a drowning-detection sensor developed by Redding, CT, company Aquatic Safety Concepts. Worn on the wrist or the head, iSwimband sends an alert to a smartphone or tablet if the band’s wearer has been underwater beyond preset time limits. It can also be configured to send an alert if a non-swimmer enters the water. Poseidon Technologies, a Norcross, GA-based company, takes a different approach with a system that uses a camera and image-processing software to detect drowning.
After five years in development, SwimSafe is now dipping into the market. A product launch is planned for later this month. SEAL Innovation is targeting commercial pool operators, swimming schools, and municipal pools. Snyder says a cruise line that he cannot yet disclose has already preordered the system. Consumers will be able to buy SwimSafe, as well. SEAL Innovation is placing SwimSafe in pool supply stores through resellers; consumers may also order from the company’s website. SwimSafe will sell for $449, which includes one band, the charger, and the hub. Additional bands cost $150. Snyder aims to sell SwimSafe globally and the company is lining up resellers in Europe and Australia.
SEAL Innovation is Snyder’s first company but it is not his first engineering effort. Before his medical career, Snyder trained as a chemical engineer. He used that engineering background at WakeMed to create the hospital’s Center for Innovative Learning, a “virtual hospital” that provides robotic medical simulations for physician training.
The six-employee SEAL Innovation has supported its efforts by raising just over $3 million in equity and debt financing from family, angel investors, and community development venture funds. Snyder says the startup is not currently seeking capital, but he’s keeping the door open for additional investment in the future.
Though SEAL Innovation is now Snyder’s full-time job, he still works in WakeMed’s emergency room two weekends a month where he still encounters drowning victims. Meanwhile, SEAL Innovation’s R&D continues. The company is researching a way to monitor an unguarded pool, where a person would not already be wearing a monitoring band. The company is also working on expanding the monitoring bands’ range in open water, which could make the technology useful in military training and triathlons. But it’s worth noting that Snyder and the other companies now selling drowning detection products say that these devices are intended to help lifeguards, not replace them.
“I see technology as a last defense,” Snyder says. “Technology without lifeguards would be useless.”