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1

Unique micro system stimulator with high data rate and efficient power recovery circuit

Alghrairi M. K., Sulaiman N. B., Sidek R., Mutashar S.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 11

213--220

EN

This paper present an efficient micro-system stimulator to transfer data and power in biomedical implanted device by using Amplitude shift keying (ASK) modulation technique. The proposed system operates with low frequency 6.78MHz accordance to the industrial-scientific-medical (ISM) bands to avoid the biological tissue damage. The system design include new ASK modulator, class-E power amplifier, half wave rectifier, voltage regulator (LDO) and new ASK demodulator structure without passive elements to transfer 500Kb/s of data with modulation index 12.5%. The efficient inductive coupling link with 74.47% of efficiency is driven by class-E power amplifier with high efficiency up to 94.5%. Adequate and stable 1.8V DC are generated by the modified rectifier and voltage regulator to power the implanted electronics which occupies small area and does not have a thermal protection circuit or passive elements. The proposed ASK demodulator structure is developed to collect a synchronised demodulated signal that has minimum error without using delay-locked loops (DLL) circuits and clock recovery circuit. This system designed by using OrCAD Pspice 16.6 software, which employed 0.35 μm CMOS technology as a basis.

PL

W artykule opisano mikrosystem używany w stymulatorach biomedycznych przeznaczony dpo transferu danych i zasilania. System wykorzystuje kodowanie ASK z częstiotliwością 6.78 MHz. System składa się z modulatora ASK, wzmacniacza mocy klasy E, prostownika, regulatora napięcia LDO I dempodulatora ASK.

2

Power Amplifier Frequency Controller Using feedback control techniques for Bio-implanted Devices

Hussein H. A., Hannan M. A., Mutashar S., Samad S. A., Mikdad A.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 12

34-37

EN

Switch mode power amplifier is used in biomedical devices widely. The power amplifier supplies the required operating power to the implanted devices. Zero voltage switching (ZVS) operation of class-E power amplifier leads to convert DC voltage to AC with high efficiency and workings frequency. Frequency has a great function in powering most of the biomedical implanted devices. Frequency shift caused by inductors and capacitors used in the circuit can cause load variation or changing in mutual displacement or they may lead to instability and data loss of the implanted devices. So switching-mode frequency control is the key problem in the biomedical device powering system. This paper focused on the design of a frequency controlled power amplifier to improve the controller’s efficiency in terms of speed and better results. The objective of this work is to control the operating frequency. Feedback control method is used by using proportional integral derivative controller (PID), proportional integral (PI) and voltage controlled oscillator (VCO) to reduce the phase shift and settling time. The Bode plot and Nyquist stability criterion analyses show that the developed power amplifier frequency controller is stable and perform well to improve the controller efficiency.

PL

W artykule opisano wzmacniacz mocy używany w technice bio-implantów. Wzmacniacz klasy E z operacją ZVS przekształca stałe napięcie na napięcia AC. Kontrola częstotliwości tego napięcia ma ważne znaczenie ponieważ częstotliwość może się zmieniać przy obecności elementów L, C w układzie. W pracy opisano metode kontroli częstotliwości tego napięcia.

3

Efficient Low-Power Recovery Circuits for Bio-implanted Micro-Sensors

Mutashar S., Hannan M. A.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 5

15-18

EN

This paper presents a modified sub-electronic circuit with low-power recovery circuits to be implemented in implanted micro-sensor used to stimulate the human and animals’ nerves and muscles. The system based on ASK modulation techniques operated with 13.56 MHz according to industrial, scientific, medical (ISM). The modulation index is 12.6% to achieve minimum power consumption to avoid the tissue heating. The system consists of external part with modified class-E power amplifier efficiency 87.2%, and internal part consists of a voltage doubling rectifier with selfthreshold cancellation and efficient low-dropout voltage regulator based on series NMOST transistor using 0.35 μm technology to offer very stable 1.8 DC V. The produced voltage used to power the sub-electronic implanted device with steady voltage even in any changing with the implanted load resistance. The mathematical model is given. The design is simulated using OrCAD PSpice 16.2 software tools and for real-time simulation, the electronic workbench MULISIM 11 has been used to simulate the class-E power amplifier.

PL

W artykule przedstawiono zmodyfikowany układ pół-elektroniczny do zastosowania w implantowych mikro-czujnikach stymulujących pracę ludzkich i zwierzęcych nerwów i mięśni. Urządzenie posiada obwód odzyskiwania mocy w przypadku obniżonego zasilania w układzie. W proponowanym rozwiązaniu zastosowano modulację ASK o częstotliwości 13.56MHz i indeksie 12.6% w celu minimalizacji zużycia energii. Przedstawiono także model matematyczny urządzenia. Badania symulacyjne przeprowadzono w środowisku OrCAD PSpice 16.2 oraz MULISIM 11 do symulacji w czasie rzeczywistym wzmacniacza mocy klasy E.