Bench Talk

Join journalist Tommy Cummings for a weekly look at all things interesting, new, and noteworthy for design engineers.

In the beginning, wearables such as Fitbit and Apple Watch only tracked fitness metrics. But they've evolved into real-time health-monitoring devices. The Apple Watch can now monitor cardiac arrhythmia, cardiac arrest, and general health.

More use cases for wearable health- monitoring devices are developing as the telehealth field grows. For instance, Shavini Fernando, a 33-year-old Sir Lanka native with a life-threatening condition¹ called Eisenmenger syndrome, redesigned an oximeter to better read blood oxygen for people with darker skin tones. The tiny oxygen-monitoring and emergency-alert system are worn on the ear. The device is seeking US Food and Drug Administration approval. But it’s currently finding a market in the sports world, where athletes are using it to monitor themselves in high-altitude environments.

Innovations, such as the one created by Shavini Fernando, show the resolve designers have in finding solutions with wearables. Today, insulin pumps, hearing aids, ECGs, and continuous glucose monitors are a few of the wearable medical devices on the market. A cellular connection transmits medical data and connects wearables to the cloud. More medical wearables will be developed as wireless connectivity evolves.

Developers do have room to innovate. Battery life with wearables can be limited, so designers will have to work within low-power capabilities, such as BLUETOOTH^® Low Energy, to make up for these limitations. In this week's New Tech Tuesday, we'll look at a diverse range of medical wearable solutions from Microchip Technology, Semtech, and Maxim Integrated.

Microchip Technology's line of Telehealth/Medical Solutions provides developers with a range of designs to address the increased need for Internet of Things (IoT) devices in the growing medical wearables segment. The manufacturer's Medical Products Group offers its line of devices without restrictions and long-term support. Developers can choose from a broad range of products, demonstration files, and design support.

Semtech's SX9210 Smart Proximity Sensor for Wearables is ideal for hearable applications where package size and power consumption are of increased importance. The SX9210 capacitive controller uses up to three capacitive sensor inputs. This sensor can use any of the three inputs, along with the Smart Sense Engine, for in-ear detection, on-table detection, and proximity detection. The SX9210 can control pause or change volume. It includes an on-chip, auto-calibration controller that performs sensitivity adjustments to maintain peak performance over a wide variation of temperature, humidity, and noise environments.

The MAX14745 from Maxim Integrated is a battery-charge-management solution ideal for low-power wearable applications. Several power-optimized peripherals are included with the device, including a linear battery charger with a smart power selector. The MAX14745 features two ultra-low quiescent current buck regulators and three ultra-low quiescent current low-dropout (LDO) linear regulators. With up to five regulated voltages, each with an ultra-low quiescent current, designers can minimize power consumption and extend battery life between charges in 24/7 operation devices, such as wearables.

The market for wearable medical devices is growing. Medical wearables allow clinicians to monitor patients remotely 24/7 in almost any setting. As telehealth capabilities improve, so do the solutions needed to address patient needs.

Source

1. Spiegel, Anna. “An Inventor’s Device Might Save Lives—Including Her Own.” Washingtonian. Washingtonian.com, September 12, 2022. https://www.washingtonian.com/2022/09/12/an-inventors-device-might-save-lives-including-her-own/.