前言导读

心力衰竭（heart failure）简称心衰，是指由于心脏的收缩功能和（或）舒张功能发生障碍，不能将静脉回心血量充分排出心脏，导致静脉系统血液淤积，动脉系统血液灌注不足，从而引起心脏循环障碍症候群，此种障碍症候群集中表现为肺淤血、腔静脉淤血。心力衰竭并不是一个独立的疾病，而是心脏疾病发展的终末阶段。

据不完全统计，2018年我国已有1000万心衰患者，2019年全球心力衰竭患病人数达2970万，预计2030年将进一步增加到3870万，即2024年至2030年的复合年增长率为2.5%。

心衰是多种原因导致心脏结构和/或功能的异常改变，使心室收缩和/或舒张功能发生障碍，从而引起的一组复杂临床综合征，关于心衰的原理，笔者通过如下央视的权威介绍向读者进行阐述：

心衰医疗器械

目前，药物是治疗心力衰竭的第一大手段。针对心力衰竭的原因，每种药物的目的是不同的，有些用于缓解心力衰竭症状，而另一些用于减缓心力衰竭的进展并防止并发症。然而，有时仅靠药物不足以减缓心力衰竭，需要额外的治疗。

用于心力衰竭的医疗器械设备分为两大类：诊断和治疗。诊断设备用于监测心力衰竭，可以跟踪恶化的迹象，并且通常可以在发现症状之前发现问题。

雅培（Abbott ）的CARDIOMEMS HF是目前最知名的心衰诊断设备，本篇文章笔者以CARDIOMEMS为例，对心衰诊断医疗器械进行阐述。

认识CARDIOMEMS

CardioMEMS是一种使用微机电系统(MEMS)技术的无线压力敏感器件。该设备由植入式高频传感器、输送导管和电子监测单元组成。采用右心导管插入术(RHC)和局部麻醉，将装置植入远端肺动脉。它由一个线圈和一个电容组成，电容由硅胶覆盖的密封硅胶外壳包裹，形成一个能在特定频率下谐振的电路。施加在传感器上的PAP变化会导致谐振波的频率变化。该设备通过其气压计检测到的周围大气压力变化来测量肺动脉压力。CardioMEMS不含任何电池或导线，由外部天线以射频信号的形式供电。

CardioMEMS示意图

患者在家里时，通过使用便携式电子设备和包含天线的特殊枕头，收集的信息被转换成压力测量值，并传输到安全的服务器进行处理。当天线靠在身体上或患者躺在枕头上时，读数就会出现。这个过程是无痛的，在阅读过程中不会产生任何异常感觉。电子单元每天传输功率放大器测量值。医生可利用这些数据在充血性症状出现之前调整HF治疗(主要是通过调整利尿剂剂量)，最终降低住院率。

系统示意图

临床试验数据证明，CardioMEMS HF系统可降低心力衰竭住院率和死亡率，并改善HFrEF和HFpEF患者的QOL效应。由CardioMEMS HF系统提供的症状前数据允许在心力衰竭症状出现之前对药物治疗进行前瞻性改变。能够单独设置患者阈值，使医生能够个性化和优化每位患者的护理和医疗管理。

CardioMEMS HF在2014年首次获得FDA批准且证明可明显减少住院治疗的心衰监控设备，但是当时只适用于测量NYHA（纽约心脏协会）标准下，III级心衰患者的心率和肺动脉压。近日，雅培宣布FDA批准扩大CardioMEMS HF的适应症---可用于 II 级心衰患者和接受血液检查显示为利钠肽的生物标志物水平升高的患者。

笔者注：HFrEF为射血分数降低的心力衰竭，HFmrEF为射血分数中间值的心力衰竭，HFpEF为射血分数保留的心力衰竭，LVEF为左心室射血分数；利钠肽升高为B型利钠肽（BNP）>35 ng/L和/或N末端B型利钠肽原（NT-proBNP）>125 ng/L。

来源：《中国心力衰竭诊断和治疗指南2018》

专利分析

需要说明的是，本文着重对心衰诊断设备进行阐述，对于CardioMEMS医疗器械相关专利，笔者进行了详细研读和分析，形成了卓有成效的工作成果，基于篇幅原因，本篇文章笔者着重从通讯和传感器两个方面进行简要阐述，同时，对于ICD、CRT、VAD等心衰治疗器械，笔者也完成了相关研究，如若获取完整专利清单与分析报告可以与笔者取得联系，共同交流学习。

1

公开/公告号	US7839153B2	申请日	2009-05-15
发明名称	Communicating with an implanted wireless sensor
解决的技术问题	The resonant frequency of the sensor is a measured parameter that is correlated with the physical parameter of interest. To be clinically useful there must be means to ensure that variations in measurement environment do not affect the accuracy of the sensor. Thus, there is a need for a system and method for communicating with a wireless sensor that considers variations in the measurement environment.
技术方案	The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.
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2

公开/公告号	US6278379B1	申请日	1999-12-06
发明名称	System, method, and sensors for sensing physical properties
解决的技术问题	Sensing technology is currently employed in a number of different environments. Specifically, sensors employed to determine the pressure or temperature of a medium are used in a wide variety of applications. Most such applications involve the use of temperature and pressure sensors in environments of low temperature or in environments of high temperature which require adequate cooling measures or the use of high temperature materials in the construction of such sensors. In such applications, for example, micro-machining techniques exist by which pressure sensors are constructed using silicon as a substrate.
技术方案	Several sensors are provided for determining one of a number of physical roperties including pressure, temperature, chemical species, and other physical conditions. In general, the sensors feature a resonant circuit with an inductor coil which is electromagnetically coupled to a transmitting antenna. When an excitation signal is applied to the antenna, a current is induced in the sensor circuit. This current oscillates at the resonant frequency of the sensor circuit. The resonant frequency and bandwidth of the sensor circuit is determined using an impedance analyzer, a transmitting and receiving antenna system, or a chirp interrogation system. The resonant frequency may further be determined using a simple analog circuit with a transmitter. The sensors are constructed so that either the resonant frequency or bandwidth of the sensor circuit, or both, are made to depend upon the physical properties such as pressure, temperature, presence of a chemical species, or other condition of a specific environment. The physical properties are calculated from the resonant frequency and bandwidth determined.
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