The Rise (Not Fall!) of the Smart Cane & Crutch

February 25, 2021

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We’re hopefully all still living longer. As a result, the active-ageing industry is on a huge upward path and assistive care technologies are evolving at a crazy pace.

It’s to the point that your grandma’s next cane may rival your smart phone in terms of the technology that is going into it.

Smart canes offer safety and new levels of independence by monitoring health vitals, integrating GPS, and sensors. If a user gets into trouble, has a fall, or is even showing an irregular heartbeat, it will know. Smart wireless connectivity features, whether cellular, Wi-Fi, or Bluetooth® can alert care services or paramedics during medical emergencies. Simple location-based services can offer further safety and reassurance, alerting a family member when someone wanders too far from home, or aiding lost individuals with directions back home. These are just a few of the services being offered through the latest generation of smart canes.

Demand for these devices is also being driven by hikers and walkers who are enjoying these features as well, especially when they’re off the beaten track.

To help designers get off the drawing board and spend time differentiating such products, our Renesas product experts have put together combinations of their Analog + Power + Embedded Processing products. These are known as Winning Combinations, and we provide them as ready to use reference designs across dozens of applications, including assistive care.

The smart crutch reference design uses a biometric date to monitor the health of the user, as well as keeping an eye on the environment for extreme heat, cold, and acceleration and inclination which is used detect a fall. GPS positioning and IoT connectivity track the user when necessary. There’s even an LED flashlight for making your way in the dark, and the whole thing is powered by a rechargeable Li-ion battery.

(Image courtesy of Renesas)

 

The heart of this design is an Arm® CortexⓇ-M4 Renesas RA4M1 microcontroller, which is designed to balance performance and connectivity with the need to run at low power. They provide up to 48MHz of CPU performance and up to 512kB of embedded flash memory, as well as USB, CAN, Bluetooth Low Energy 5.0, ADC, capacitive touch, LCD controller and security IP integration. All of this means everything you need to manage all the sensor data and the communications used in our smart crutch, including analysis of the 6-axis G-Sensor data.

The sensors in this design are also important. The OB1203 is a fully integrated optical sensing module for pulse oximetry (photoplethysmography, or PPG), multi-channel color sensing, ambient light sensing and proximity sensing. From here we can determine human heart rate, blood oxygen saturation (SpO2), respiration rate and heart rate variability. To monitor the environment, we have the HS3003 relative humidity and temperature sensor, which is very small but very accurate, with fast measurement response times that works fine even in harsh environments. To round off our sensor line-up, ISL29035 is an integrated ambient and infrared light-to-digital converter, using its advanced self-calibrated photodiode array to emulate human eye response with excellent IR rejection.

For our rechargeable battery, ISL9205D is a highly integrated single-cell Li-ion charger with input voltages down to 2.5V, so it will work with a variety of AC adapters. We then use ISL91127IR, a high current (4.5A) high efficiency buck-boost regulator with a proprietary buck-boost algorithm, and that maintains voltage regulation combined with excellent efficiency and very low output voltage ripple if the input voltage is close to the output voltage.

Using this reference design will provide a great head-start for a compact, robust smart cane or smart crutch design, but also make it easy to scale and add more features according to your market needs. Just visit our Winning Combinations page.