Clinical grade, convenient and efficient, portable medical equipment enters the homes of ordinary people

In fact, not only the domestic market, but also portable medical equipment has huge business opportunities around the world. According to an analysis report by Data Bridge Market Research, the global portable medical and health care equipment market size will be US$64.58 billion in 2022 and is expected to reach US$137.43 billion by 2030, with a compound annual growth rate of 9.9% during 2023-2030.

Figure 1: Global portable medical and healthcare device market size

(Source: Data Bridge Market Research)

Figure 2: TI CGM block diagram

(Source: TI)

Then, if we reclassify the devices in different units, we can conclude that: the information collection unit is mainly composed of sensors and digital-to-analog conversion devices; the information processing and transmission unit is mainly composed of MCU, DSP, I/O, and wireless connection devices ;The battery power supply unit includes various batteries and power management devices. Therefore, we get a block diagram of a portable medical device as shown below.

Figure 3: Portable medical device block diagram

(Source: Mouser Electronics)

当前，便携式医疗设备具备方便快捷、高精度、低功耗等显著特点，后续主要的发展趋势是更低功耗、小型化、更高信息安全性，以及达到临床级的检测精度。这些特点和趋势对三大功能单元中的元器件都提出了很高的要求，并推动便携式医疗设备和可穿戴设备的深度融合，进一步提升了设备的渗透率。现在很多人配戴的智能手表便能够提供医疗级的血氧检测和准医疗级的血压检测等功能。

Due to the specificity of product functions, high precision is always the primary design consideration for medical equipment among all features and trends. The same is true for portable medical equipment. The quality and integrity of measurements directly affect users' evaluation of related equipment and future market growth.

Here we recommend an analog front end (AFE) that can be used to build clinical-grade portable medical equipment from the manufacturer TI. The part number of the device on the Mouser Electronics website is AFE4960YBGT .

Figure 4: AFE4960 analog front end

(Source: Mouser Electronics)

The AFE4960 is a dual-channel ECG analog front-end with integrated respiratory and pacing signal detection that can be configured as a 2-channel ECG receiver, 1-channel ECG receiver, or respiratory impedance channel. All signal chain outputs are converted into well-defined time slots by an ADC and stored as 24-bit words in a 128-sample FIFO that can be read out via the SPI or ^{I2C interface.}

In terms of the ECG signal chain, the AFE4960 analog front-end supports single-channel ECG acquisition up to 2.048kHz and 2-channel ECG acquisition up to 1.36kHz/channel; in terms of the Bio-Z signal chain, the AFE4960 analog front-end supports an excitation frequency range of 30kHz to 100kHz. To measure bioimpedance, use sine wave excitation or square wave excitation.

除了高性能和高精度，如下图所示，高集成也是AFE4960模拟前端一大显著优势。作为一套高集成度解决方案，该器件可以灵活连接多达4个电极，可用于实现3引线ECG系统，如果两个并联AFE同步运行则可用于实现5引线ECG。此外，该器件还提供SPITM、I ² C接口等接口资源。

Figure 5: AFE4960 analog front-end block diagram

(Source: TI)

Outstanding performance enables the device to be used to create clinical-grade wearable devices such as wireless patches for inpatient and outpatient monitoring, handheld ECG monitors, portable multi-lead ECG, and IEC60601-2-47:2012/(R )2016 and IEC60601-2-27:2011(R)2016 compatible systems. In addition, the AFE4960 analog front end can also be used to build telemedicine equipment, allowing patients to monitor their health status at home.

As mentioned in the block diagram of portable medical equipment we gave, wireless transmission devices are an important part of it.

无线连接极大地丰富了便携式医疗设备的应用场景。通过无线网络，设备能够和智能手机上的App互联，方便用户查询指标以及解读指标；通过无线网络和大数据平台互联，设备也能够接入到远程医疗平台，可以显著提升医生和患者的沟通效率，并扩大相关设备适用疾病的范围。

However, we have also mentioned that portable medical devices need to continuously optimize power consumption to improve the user experience, so wireless communication solutions need to have both low power consumption and high performance. Here, we recommend the CC2651R3 SimpleLink ^™ 2.4GHz wireless MCU to everyone, which is still from the manufacturer TI. You can find it by searching for the part number CC2651R31T0RKPR on the official website of Mouser Electronics .

Figure 6: CC2651R3 SimpleLink ^™ 2.4GHz Wireless MCU

(Source: Mouser Electronics)

CC2651R3 can well meet the high performance and low power consumption characteristics we mentioned above. In terms of high performance, this wireless MCU uses the powerful 48MHz Arm Cortex-M4 as the main processor, combined with 352KB flash program memory and 32KB ultra-low leakage current SRAM, with a receiving sensitivity as high as -104dBm (when low-power Bluetooth is 125kbps) ), with output power up to +5dBm and temperature compensation. The device supports Zigbee, Bluetooth 5.2 Low Energy, SimpleLink TI 15.4-stack and other proprietary 2.4GHz protocols.

Figure 7: CC2651R3 system block diagram

(Source: TI)

In terms of low power consumption, CC2651R3 has been specially optimized and has a software-defined radio powered by Arm Cortex-M0, supporting multiple physical layer and radio frequency standards. As a result, its MCU consumes only 2.91mA in active mode, consumes 61µA/MHz when running CoreMark, and is able to provide RTC and 32KB RAM retention in 0.8µA standby mode. In terms of radio power consumption, the device performs at 7.1mA TX (at 0dBm) and 9.5mA TX (at +5dBm).

As shown in the system block diagram, CC2651R3 is also a highly integrated device with rich system peripherals, such as 12-bit ADC, 8-bit DAC, UART, SSI, I ² C, etc. Of course, it must also be mentioned that this device has an extremely long life cycle, 10 to 15 years or more.

Sensors are the first step in accurate information collection for portable medical equipment. Devices with different functions require different sensors to capture information. For example, ventilators require flow sensors, blood pressure monitors require pressure sensors, forehead thermometers require temperature sensors, etc.

Judging from the development trend of portable medical equipment, there are three main requirements for sensors, namely high precision, low power consumption and small size. TE's Measurement Specialties TSYS03 digital temperature sensor is such a device. The part number of the device on Mouser Electronics' official website is 20011957-00 .

Figure 8: TSYS03 digital temperature sensor

(Source: Mouser Electronics)

TSYS03 is a miniature digital sensor that provides factory-calibrated high-precision (±0.5°C at 0°C to +60°C) temperature data and supports adjustment of the high-precision temperature range as required. Although available in small packages such as TDFN8 (2.5mm x 2.5mm) and XDFN6 (1.5mm The I ² C interface manages data communications. TSYS03 has excellent low power consumption characteristics, with operating current <5μA and standby current <0.3μA.

Figure 9: TSYS03 accuracy characteristics

(Image source: TE)

In addition to being used in medical probes and patient monitoring equipment, TSYS03 can also be used in a variety of scenarios such as consumer products and appliances, industrial control and food monitoring, and vehicle battery monitoring.

In the above content, we mainly focus on the design issues and usage experience of portable medical devices, so we have discussed aspects such as high performance, low power consumption, small size and wireless transmission.

However, we must also be aware that as portable medical devices move from the clinic into ordinary people's homes, and as devices and big data are deeply integrated, data security issues will be a serious challenge that the industry needs to face. In this regard, in addition to solution providers making enhancements in terms of software and hardware, policies, laws and regulations are also needed to adapt to the new industrial form.

The General Office of the State Council pointed out in the "Opinions on Further Improving the Medical and Health Service System" (released in March 2023) that the construction of the health and medical data security system should be accelerated, data security monitoring and early warning should be strengthened, and the data security protection capabilities of medical and health institutions should be improved. Strengthen the protection of important information.

At the hardware level, electronic components can provide an isolated and secure operating environment for sensitive data through security solutions such as encryption and decryption, key generation, credential protection, and hardware root of trust, and play an important role in the information processing, transmission, and storage of portable medical devices. Provides all-round protection. In order to promote the rapid, stable and healthy development of the portable medical equipment industry, Mouser Electronics will work with everyone to ensure data security and continue to propose more comprehensive hardware protection solutions.