應用於智慧型居家看護系統心電訊號擷取之超高頻自動辨識標籤晶片

A UHF RFID Tag SOC with ECG Acquisition for Intelligent Healthcare Systems

賴韋志(Lai Wei-Jhih)

指導教授 ： 朱元三 ； 李順裕

國立中正大學/工學院/電機工程學系/碩士(2013年)

摘要

本論文為設計一個應用於心電訊號(ECG)擷取的傳送接收系統，提出利用射頻自動辨識(RFID)的新穎檢測方式對病人心跳即時檢測，達到低功率、低成本的目的，系統晶片內容主要分為四大塊，分別為射頻前端電路(RF-Front-End)、電源管理電路(Power Management)、數位控制(Digital Control)和類比前端電路(Analog-Front-End)，論文內容主要包含其中兩部分，第一部分為射頻前端電路設計，包含了電壓幫浦、振幅移鍵解調變器，啟動電路，第二部分為電源管理電路設計，涵蓋了線性穩壓器、上電復位電路以及能隙差參考電壓產生電路。
論文提出了利用RFID半被動式標籤讀取ECG訊號的系統，首先，高頻訊號經由天線接收進入貼片標籤(Tag)，射頻前端電路會將925MHz的載波訊號解調變為數位訊號，接著數位訊號會傳送給數位控制電路處理，同時會把啟動電路打開，啟動電路會將整個電源管理電路開啟，供給晶片內部電壓，上電復位電路也會產生脈波訊號將所有數位邏輯閘重置，此時AFE(Analog-Front-End)開始擷取心電訊號，並將心電訊號以反向散射的技術回傳訊號；此論文晶片為實現射頻前端以及電源管理電路，主要為利用電容陣列與距離偵測電路，解決當製程漂移時所產生解碼錯誤的問題，並且使用限壓器的切換，解決讀取器(Reader)與標籤(Tag)距離過近時解碼器所產生的問題，同時讓電源電路提供系統穩定的電壓使用。
本論文晶片採用TSMC 0.18um 1P6M CMOS製程實現，整體的晶片面積為0.965 x0.965(mm2)，從量測結果說明解調變器能正常解調出數位訊號提供給數位電路處理，未來會將校正解碼錯誤的演算法整合進晶片完成ECG訊號擷取之RFID系統晶片。

關鍵字

心電訊號 ； 標籤

並列摘要

In this thesis, A wireless transceiver system for ECG acquisition has been implemented. We propose a novel method using Radio Frequency Identification(RFID) to detect the heartbeats of patients immediately. The target of our system is to achieve the purpose of low-power, low-cost. The system chip is composed of four parts which are a RF-Front-End、a power management、a digital control and a analog-front-end(AFE). This thesis mainly consists of two parts of the RFID system. The first part is the RF front-end that contains a charge pump, an ASK demodulator, and a start-up circuit. The second part is the power management that covers a low-dropout regulator, a power-on-reset circuit, and a bandgap reference circuit.
We propose the semi-passive RFID system to acquire ECG signals. First of all, the high-frequency signal is received by the antenna into the Tag. The RF-Front-End circuit would demodulate the 925Mhz carrier into digital signal. The start-up circuit is turned on at the same time, and the power circuit will supply the voltage to the RFID chip. Moreover, the POR would produce a pulse signal to reset all the logic circuits. After the system is turned on, the ECG signals is acquired by AFE instantly and the tag would transmit the signals to Reader by backscattering. The RF-Front-End and power management circuits are implemented in this thesis. The capacitor array and DDC(Distance-to-Digital) circuits are used to correct the error bit caused by the process variation and to solve the demodulation issue by limiter switches as the tag is too close to Reader. And the power circuit can also provide stable voltages to our chip.
The overall circuit with core area of 0.965x0.965(mm2) has been implemented in TSMC 0.18μm 1P6M CMOS process technology. Measurement results show that the carier signal can normally be demodulated to digital core. In the future we will also make correction decoding algorithm integrated into the chip to handle the communication better.

並列關鍵字

Tag ； ECG Acquisition ； RFID

參考文獻

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