A smartphone-enabled wireless and batteryless implantable blood flow sensor for remote monitoring of prosthetic heart valve function

Aortic valve disease is one of the leading forms of complications in the cardiovascular system. The failing native aortic valve is routinely surgically replaced with a bioprosthesis. However, insufficient durability of bioprosthetic heart valves often requires reintervention. Valve degradation can be assessed by an analysis of the blood flow characteristics downstream of the valve. This is cost and labor intensive using clinical methodologies and is performed infrequently. The integration of consumer smartphones and implantable blood flow sensors into the data acquisition chain facilitates remote management of patients that is not limited by access to clinical facilities. This article describes the characteristics of an implantable magnetic blood flow sensor which was optimized for small size and low power consumption to allow for batteryless operation. The data is wirelessly transmitted to the patient’s smartphone for in-depth processing. Tests using three different experimental setups confirmed that wireless and batteryless blood flow recording using a magnetic flow meter technique is feasible and that the sensor system is capable of monitoring the characteristic flow downstream of the valve.

主动脉瓣疾病（Aortic valve disease）是心血管系统主要并发症类型之一。临床中常规通过外科手术，将功能衰竭的自体主动脉瓣替换为生物瓣膜（bioprosthesis）。然而，生物人工心脏瓣膜（bioprosthetic heart valves）的耐用性不足往往需要再次干预（reintervention）。可通过分析瓣膜下游的血流特征评估瓣膜退化情况，但采用临床方法学（clinical methodologies）开展此类分析不仅成本高昂、耗时耗力，且检测频次极低。将消费级智能手机与植入式血流传感器集成至数据采集链路（data acquisition chain），可实现不受临床设施获取限制的患者远程管理。本文阐述了一款针对小尺寸、低功耗优化的植入式电磁血流传感器（implantable magnetic blood flow sensor）的特性，该传感器可实现无电池运行（batteryless operation），其采集的数据可无线传输至患者智能手机以进行深度处理。通过三种不同实验装置（experimental setups）开展的测试证实，采用电磁流量计技术（magnetic flow meter technique）实现无线、无电池血流记录具备可行性，且该传感器系统能够监测瓣膜下游的特征性血流。