{"title":"用于频率多路穿戴式传感器的低功耗阻抗频率转换器","authors":"Weilun Li;Junyi Zhao;Yong Wang;Chuan Wang;Shantanu Chakrabartty","doi":"10.1109/TBCAS.2024.3362329","DOIUrl":null,"url":null,"abstract":"We propose a low-power impedance-to-frequency (I-to-F) converter for wearable transducers that change both its resistance and capacitance in response to mechanical deformation or changes in ambient pressure. At the core of the proposed I-to-F converter is a fixed-point circuit comprising of a voltage-controlled relaxation oscillator and a proportional-to-temperature (PTAT) current reference that locks the oscillation frequency according to the impedance of the transducer. Using both analytical and measurement results we show that the operation of the proposed I-to-F converter is well matched to a specific class of sponge mechanical transducer where the system can achieve higher sensitivity when compared to a simple resistance measurement techniques. Furthermore, the oscillation frequency of the converter can be programmed to ensure that multiple transducer and I-to-F converters can communicate simultaneously over a shared channel (physical wire or virtual wireless channel) using frequency-division multiplexing. Measured results from proof-of-concept prototypes show an impedance sensitivity of \n<inline-formula><tex-math>$19.66 \\,\\mathrm{Hz}$</tex-math></inline-formula>\n/\n<inline-formula><tex-math>$\\Omega$</tex-math></inline-formula>\n at \n<inline-formula><tex-math>$1.1 \\,\\mathrm{k}\\Omega$</tex-math></inline-formula>\n load impedance magnitude and a current consumption of 128 μ\n<inline-formula><tex-math>$\\mathrm{A}$</tex-math></inline-formula>\n. As a demonstration we show the application of the I-to-F converter for human gesture recognition and for radial pulse sensing.","PeriodicalId":94031,"journal":{"name":"IEEE transactions on biomedical circuits and systems","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A Low-Power Impedance-to-Frequency Converter for Frequency-Multiplexed Wearable Sensors\",\"authors\":\"Weilun Li;Junyi Zhao;Yong Wang;Chuan Wang;Shantanu Chakrabartty\",\"doi\":\"10.1109/TBCAS.2024.3362329\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We propose a low-power impedance-to-frequency (I-to-F) converter for wearable transducers that change both its resistance and capacitance in response to mechanical deformation or changes in ambient pressure. At the core of the proposed I-to-F converter is a fixed-point circuit comprising of a voltage-controlled relaxation oscillator and a proportional-to-temperature (PTAT) current reference that locks the oscillation frequency according to the impedance of the transducer. Using both analytical and measurement results we show that the operation of the proposed I-to-F converter is well matched to a specific class of sponge mechanical transducer where the system can achieve higher sensitivity when compared to a simple resistance measurement techniques. Furthermore, the oscillation frequency of the converter can be programmed to ensure that multiple transducer and I-to-F converters can communicate simultaneously over a shared channel (physical wire or virtual wireless channel) using frequency-division multiplexing. Measured results from proof-of-concept prototypes show an impedance sensitivity of \\n<inline-formula><tex-math>$19.66 \\\\,\\\\mathrm{Hz}$</tex-math></inline-formula>\\n/\\n<inline-formula><tex-math>$\\\\Omega$</tex-math></inline-formula>\\n at \\n<inline-formula><tex-math>$1.1 \\\\,\\\\mathrm{k}\\\\Omega$</tex-math></inline-formula>\\n load impedance magnitude and a current consumption of 128 μ\\n<inline-formula><tex-math>$\\\\mathrm{A}$</tex-math></inline-formula>\\n. As a demonstration we show the application of the I-to-F converter for human gesture recognition and for radial pulse sensing.\",\"PeriodicalId\":94031,\"journal\":{\"name\":\"IEEE transactions on biomedical circuits and systems\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-02-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"IEEE transactions on biomedical circuits and systems\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://ieeexplore.ieee.org/document/10423236/\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE transactions on biomedical circuits and systems","FirstCategoryId":"1085","ListUrlMain":"https://ieeexplore.ieee.org/document/10423236/","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
我们为可穿戴传感器提出了一种低功耗阻抗-频率(I-F)转换器,这种传感器会随着机械变形或环境压力的变化而改变电阻和电容。拟议的 IF 转换器的核心是一个定点电路,包括一个压控弛豫振荡器和一个根据传感器阻抗锁定振荡频率的比例温度(PTAT)电流基准。我们利用分析和测量结果表明,所提出的 IF 转换器的操作与特定类别的海绵机械传感器非常匹配,与简单的电阻测量技术相比,该系统可以实现更高的灵敏度。此外,还可以对转换器的振荡频率进行编程,以确保多个传感器和 I-to-F 转换器可以通过使用频分复用技术的共享信道(物理有线或虚拟无线信道)同时进行通信。概念验证原型的测量结果显示,在 1.1 kΩ 负载阻抗幅值下,阻抗灵敏度为 19.66 Hz/Ω,电流消耗为[公式:见正文]。作为演示,我们展示了 IF 转换器在人体手势识别和径向脉冲感应方面的应用。
A Low-Power Impedance-to-Frequency Converter for Frequency-Multiplexed Wearable Sensors
We propose a low-power impedance-to-frequency (I-to-F) converter for wearable transducers that change both its resistance and capacitance in response to mechanical deformation or changes in ambient pressure. At the core of the proposed I-to-F converter is a fixed-point circuit comprising of a voltage-controlled relaxation oscillator and a proportional-to-temperature (PTAT) current reference that locks the oscillation frequency according to the impedance of the transducer. Using both analytical and measurement results we show that the operation of the proposed I-to-F converter is well matched to a specific class of sponge mechanical transducer where the system can achieve higher sensitivity when compared to a simple resistance measurement techniques. Furthermore, the oscillation frequency of the converter can be programmed to ensure that multiple transducer and I-to-F converters can communicate simultaneously over a shared channel (physical wire or virtual wireless channel) using frequency-division multiplexing. Measured results from proof-of-concept prototypes show an impedance sensitivity of
$19.66 \,\mathrm{Hz}$
/
$\Omega$
at
$1.1 \,\mathrm{k}\Omega$
load impedance magnitude and a current consumption of 128 μ
$\mathrm{A}$
. As a demonstration we show the application of the I-to-F converter for human gesture recognition and for radial pulse sensing.