We present a wearable microfluidic impedance cytometer implemented on a flexible circuit wristband with on-line smartphone readout for portable biomarker counting and analysis. The platform contains a standard polydimethylsiloxane (PDMS) microfluidic channel integrated on a wristband, and the circuitry on the wristband is composed of a custom analog lock-in amplification system, a microcontroller with an 8-bit analog-to-digital converter (ADC), and a Bluetooth module wirelessly paired with a smartphone. The lock-in amplification (LIA) system is implemented with a novel architecture which consists of the lock-in amplifier followed by a high-pass filter stage with DC offset subtraction, and a post-subtraction high gain stage enabling detection of particles as small as 2.8 μm using the 8-bit ADC. The Android smartphone application was used to initiate the system and for offline data-plotting and peak counting, and supports online data readout, analysis, and file management. The data is exportable to researchers and medical professionals for in-depth analysis and remote health monitoring. The system, including the microfluidic sensor, microcontroller, and Bluetooth module all fit on the wristband with a footprint of less than 80 cm2. We demonstrate the ability of the system to obtain generalized blood cell counts; however the system can be applied to a wide variety of biomarkers by interchanging the standard microfluidic channel with microfluidic channels designed for biomarker isolation.
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机译:我们提出了一种在柔性电路腕带上实现的可穿戴式微流控阻抗细胞仪,该腕带具有在线智能手机读数功能,用于便携式生物标记计数和分析。该平台包含一个集成在腕带上的标准聚二甲基硅氧烷(PDMS)微流体通道,腕带上的电路由一个定制的模拟锁定放大系统,一个带有8位模数转换器(ADC)的微控制器组成,以及与智能手机无线配对的蓝牙模块。锁相放大(LIA)系统采用新颖的架构实现,该结构包括锁相放大器,带直流偏移减法的高通滤波器级和减法后的高增益级,可检测出小颗粒使用8位ADC时为2.8μm。 Android智能手机应用程序用于启动系统以及离线数据绘图和峰值计数,并支持在线数据读取,分析和文件管理。数据可导出给研究人员和医学专业人士,以进行深入分析和远程健康监控。该系统,包括微流体传感器,微控制器和蓝牙模块,都可以安装在腕带上,且占地面积小于80 cm 2 sup>。我们展示了该系统获得广义血细胞计数的能力;然而,通过将标准微流体通道与设计用于生物标记分离的微流体通道互换,该系统可以应用于多种生物标记。
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