應用於植入式葡萄糖生醫感測系統之無線雙向傳輸半工器

2-MHz Half Duplex Bi-Directional Wireless Transceivers for Glucose Biosignal Sensing Systems

亞豐碩(Cesar Albason)

指導教授 ： 鍾文耀

中原大學/工學院/電子工程研究所/碩士(2009年)

https://doi.org/10.6840/cycu200900105

摘要

植入式葡萄糖生醫感測系統主要包含讀出模組、電源管理系統、控制單元、藥物釋放系統及無線雙向傳輸系統，植入式系統的電源及資料主要透過無線傳輸及微控制器進行調變傳送。電能還原單元將會透過無線傳輸提供足夠電能至內部電源管理系統中，使得體內二次鋰離子電池獲得電能並進行充電。資料檢測單元將資料解碼後送至微控制器中並透過資料庫的運算處理，將資訊送入藥物釋放的控制系統中，完成藥物釋放之目的。而本研究的主要目的在於實現一植入式葡萄糖感測系統之無線雙向遙傳架構。
一般體內接收端主要採用被動元件做設計，但過多被動元件將造成晶片面積增加，因此論文中提出一減少電容元件的解調方式，並將其應用於植入式生醫微系統中。體外無線傳輸端主要包含感應線圈、高效率Class-E功率放大器和體內資料檢測器，ASK的載波頻率採用2 MHz及2 kbps 資料傳輸率，此系統經實際量測後證實可在3cm的距離下，成功解調資料並傳送1.51 mW功率。而體內接收端線圈，則採用亞鐵柱為核心，並纏繞導線使其成為接收線圈。本研究的體內接收端可達低功率、低面積之效果，其晶片核心面積為113.2 µm x 171.8 µm，平均功率消耗為833.17µW(量測在100 pF電容負載下)。
植入式上傳系統，則採用LSK作為資料回授的設計主軸，傳輸系統同樣採用2 kbps資料率傳輸率，並可在雙線圈距離38cm的情況下達到資料傳輸之效果，而其晶片核心面積大小則為251.7 µm x 139.3 µm，功率消耗為101.40 mW。研究中主要採用TSMC 0.35 µm mixed-signal 2P4M 3.3V/5V製程以及MIMOS 0.35 µm 2P3M AMS 3.3V standard CMOS process作設計，系統晶片整合後，其核心面積為355.3 µm x 171.8 µm，總功率消耗為102.233 mW (電源為3.3V)。

關鍵字

葡萄糖感測 ； 低功率 ； 植入式系統 ； 雙向無線傳輸

並列摘要

An implementation of an implantable glucose sensing biosystem is composed of a readout module, a power management block, an embedded microcontroller unit, an implantable drug delivery section and a wireless downlink transceiver system. Power, data and command to the implantable system will be coming from an external microcontroller module by radio frequency telemetry. A power recovery unit will wirelessly harvest sufficient voltage levels for processing by the internal power management block to recharge the internal battery. Data detected will be forwarded to an embedded microcontroller unit, which is used to drive an implantable drug delivery system. This paper describes a bi-directional wireless transceiver system for implantable glucose sensing systems.
Previous implementations of the implantable receiver make use of passive components, which resulted in large chip area consumption. A novel capacitor-less amplitude-demodulation receiver architecture was used in the design of a downlink transceiver for a wireless implantable glucose sensing biosystem. The transceiver system is composed of a high efficiency class-E power amplifier utilized as an external transmitter and an implantable data detection receiver, communicating through an inductive link. Amplitude shift keying digital scheme was used to modulate the 2 MHz carrier frequency at a data rate of 2 kbps. Transmitter spectral power was measured at 1.51 mW during transmission in air and data was successfully decoded at an effective distance of 3 cm between antennas. Implantable receiver off-chip antenna was implemented using a ferrite core, wire wound coil. A low power, low area consumption implantable receiver module was produced in the research with internal receiver core area measuring at 113.2 µm by 171.8 µm with average power dissipation typically at 833.17 µW measured while driving a 100 pF load capacitance.
An active uplink transceiver, utilizing load shift keying (LSK) as backward data telemetry was designed. Effective uplink transmission at 2 kbps was achieved at a distance of 38 cm between antennas. Implantable transmitter core area measures 251.7 µm by 139.3 µm, consuming 101.40 mW while driving an RF modeled antenna. Integrating both circuits, implantable transceiver core area is 355.3 µm by 171.8 µm, typically consuming 102.233 mW at a 3.3V single rail power supply. Implantable transceiver chip was designed and implemented using TSMC 0.35 µm mixed-signal 2P4M 3.3V/5V and MIMOS 0.35 µm 2P3M AMS 3.3V standard CMOS process.

並列關鍵字

Glucose sensing ； Low power ； Implantable systems ； Bi-directional wireless transceiver

參考文獻

[1] Riccardo Bellazzi, Gianluca Nucci, Claudio Cobelli, “The Subcutaneous Route to Insulin-Dependent Diabetes Therapy”, IEEE Engineering in Medicine and Biology, January/February 2001.

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[9] Nathan Sokal, “Class-E RF Power Amplifiers”, January/February 2001.