Californian technology company Saluswear Corp. has released a wearable designed to track and monitor individuals suffering from Alzheimer’s, dementia, or autism. The ‘SalusWear’ device employs Nordic Semiconductor-powered LTE-M connectivity and GNSS to report the location of the wearer to family, friends, or caregivers in the event they go missing, or if they have potentially been subject to a fall.
Locating loved ones
The miniaturised 25 by 38 by 13 mm waist-worn device is powered by Nordic Semiconductor’s nRF9160 SiP, and responds directly to specific SMS commands from pre-approved phone numbers, without the need for a smartphone app. For instance, a caregiver can text “LOCATE” to the device’s dedicated phone number to receive a map link to the wearer’s location, or “TRACK” to receive a map link with a location update every minute. The SalusWear device also includes an accelerometer to detect if the wearer falls, as well as to provide the wearer’s step count using the “STEPS” command.
“We know that a significant portion of our user base will be older, and can sometimes find new technology challenging, so we have designed this device with ease-of-use in mind,” says Chris Rotberg, president of Saluswear Corp. “In an emergency they can just send a quick text and not worry about finding the app on their phone or trying to remember a username and password. This is especially important because in the case of a missing person – time is of the essence.”
In addition to responding to concurrent incoming SMS commands from multiple pre-approved phone numbers, there is also a web interface from which caregivers can issue commands to the device via the Cloud, as well as add additional approved phone numbers for sending an SMS to the device directly.
Power efficient location tracking
Location tracking is enabled via a combination of Wi-Fi and GNSS, using Wi-Fi where possible to help conserve battery life. The nRF9160’s assisted and predictive GNSS also saves power by speeding up time-to-first-fix (TTFF). Combined with the nRF9160 SiP’s PSM and eDRX power-saving modes – which allows the device to sleep for longer periods of time – SalusWear’s 3.7 V 420 mAh battery can achieve three weeks of life between recharges. The status of the battery can be checked by sending the SMS command “BATTERY” to the device.
“We selected the nRF9160 because we needed a small and highly integrated SiP with low power consumption that was still powerful enough to provide all of key features we required,” says Rotberg. “In addition, Nordic has a great sales and support team that has helped us during development over the last two years. The engineers on the DevZone forum could answer any of the very technical questions we had.”