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Addressing the Challenges of Designing for Medical Markets

peripherals for signal acquisition and conditioning.
Texas Instruments offers a wide portfolio of low-absorption solutions
with analog front ends that are particularly suitable for electromedical
applications. An example is its combined high-performance Wi-Fi/
Bluetooth module, based on proprietary WiLink technology. This solu-
tion allows you to add Wi-Fi (2.4 and 5 GHz) and dual-mode Bluetooth
4.2 to an electromedical device.
WiLink series modules can be directly connected to a host micro-
processor (MPU) via the serial interface (Figure 2). The WL1837MOD
device from the WiLink series offers the highest level of safety available
thanks to its FIPS 140-2 Level 1 certification, which allows it to be used
Figure 2: Block diagram of a WiLink combo device on hospital electromedical devices.
(Image: Texas Instruments) Another fundamental component of electromedical devices is
represented by the DC/DC converter, which must have high-insulation
and CE but also mobile network operator, if the solution uses the characteristics. An example is given by the converters of the REMOM
cellular network. series of RECOM Power, equipped with 250-VAC insulation with contin-
uous operation and a creepage/clearance distance greater than 8 mm.
COMPONENTS FOR MEDICAL APPS REMxE converters are equipped with single or dual output, as well as
Even if each electromedical application has different requirements, protection from short-circuits, overcurrent, overvoltage, and undervolt-
there is a common need to use microcontrollers capable of provid- age lockout (UVLO). Leakage current of only 1 µA makes these devices
ing high performance in terms of processing times, reliability, safety, ideal for electromedical applications.
absorption, and connectivity. The primary constraint of thin, small, and lightweight wearable
The explosion of connected devices favors the introduction of devices will always be battery life. Conventional batteries such as
cybersecurity mechanisms implemented at the chip level. The demand lithium-ion (Li-ion) batteries may be suitable for such devices.
for ultra-low-power microcontrollers equipped with analog peripherals However, there are also other challenges, notably safety and security.
has been growing. Benefits include high reliability, low latency, reduced Your internet connection will expose data collected by your medical
noise, and lower costs, particularly significant in devices such as glucom- device for a potential breach. This problem becomes serious in the
eters, heart-rate monitors, and implantable devices. medical device industry, as the data may represent a privacy violation
An example of a low-power microcontroller with integrated analog or an impediment to correct measurement and misanalysis. ■
peripherals is Renesas Electronics’ Synergy S1 series of MCUs. The
Renesas devices (Figure 1) include a 48-MHz Arm Cortex-M23 core Maurizio Di Paolo Emilio is a staff correspondent at AspenCore,
with safety functionality, equipped with programmable analog editor of Power Electronics News, and editor-in-chief of EEWeb.

MEDICAL
Smartphone Sensor Gauges Blood Pressure

with Clinical Accuracy

By Maurizio Di Paolo Emilio

eman Micro Devices (LMD) has a product is part of a coming wave of medical ment could bring about qualitative progress
patented sensor-based solution that devices integrated with phones — not just toward more effective prevention and treat-
can reside on a smartphone and take wearable devices, but standardized medical ment of hypertension.
Lblood pressure measurements that are solutions that read vital signs with clinical Temperature is another frequently mea-
clinically accurate. precision. Instead of measuring what is easy, sured parameter. A sensor on the smartphone
For nearly 120 years, there has been they will measure what is useful. Instead of will be able to perform this required function
only one accurate, non-invasive means of seeking a medical use for what can be mea- for medical purposes as well as in various
measuring blood pressure that does not sured, they will make measurements that are industrial circumstances.
require constant recalibration: the Riva-Rocci medically meaningful. Pulse rate, respiration rate, and blood oxy-
technique, which was devised by Scipione The smartphone will be even more integral gen level are other parameters. Together, they
Riva-Rocci in 1896 and employs the use of in the IoT ecosystem when it becomes a criti- represent a powerful diagnostic tool that can
physical pressure, typically in the form of an cal tool for the medical sector. be combined with other sensors to monitor a
inflatable arm cuff. LMD said it has developed One goal is to measure blood pressure wide range of cardiovascular conditions.
a variation of the Riva-Rocci technique that quickly and easily, without any personal cali-
makes use of sensors that LMD proposes can bration, in accordance with the ISO standard. THE PHYSICS BEHIND THE
be easily built directly into smartphones. LMD’s V-Sensor literally puts critical MEASUREMENTS
LMD’s technology can be used to gauge a information in the hands of people who Technologies are transforming the health
person’s diastolic and systolic blood pres- have never measured, and have no idea of, industry, particularly through the continuous
sure as well as measure other vital medical their blood pressure. Better blood pressure monitoring of people, at home, during leisure
parameters through its V-Sensor. The monitoring outside of a clinical environ- time, and even at work, recording events that

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