Mohamad Sawan - Academia.edu (original) (raw)
Papers by Mohamad Sawan
Proceedings of the 2003 International Symposium on Circuits and Systems, 2003. ISCAS '03.
We present a wireless cortical stimulator comprising a plurality of multi-channel micro-stimulato... more We present a wireless cortical stimulator comprising a plurality of multi-channel micro-stimulators allowing flexible placement of electrodes. These devices perform stimulation, and allow measurement of voltage or stimulating current at any electrode. Power and bi-directional data are managed by an Interface Module. Decoding of the ASK modulated carrier uses a low-power digital technique. A data rate higher than I Mbps
CCECE 2003 - Canadian Conference on Electrical and Computer Engineering. Toward a Caring and Humane Technology (Cat. No.03CH37436)
ABSTRACT
CCECE 2003 - Canadian Conference on Electrical and Computer Engineering. Toward a Caring and Humane Technology (Cat. No.03CH37436)
In this paper, we simulate small recurrent pulsed neural networks (up to a dozen of neurons) of l... more In this paper, we simulate small recurrent pulsed neural networks (up to a dozen of neurons) of leaky integrate-and-fire (LI&F) neurons and we train them thanks to general optimisation methods: genetic algorithm and taboo search; in a way inspired by the training of artificial neural networks (ANN). Unlike the taboo search, the genetic method succeeds in our training procedure. Yet,
Proceedings of the 8th IEEE International NEWCAS Conference 2010, 2010
Implantable sensor network becomes nowadays an important area of research. Sensors are implanted ... more Implantable sensor network becomes nowadays an important area of research. Sensors are implanted inside the patient body to measure its physiological changes and send them wirelessly to an external close-by device. Such network is called IWBSN (Implantable Wireless Body Sensor Network). The life time of the embedded batteries associated with these tiny sensor nodes is too short. Hence power consumption
Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 'Magnificent Milestones and Emerging Opportunities in Medical Engineering' (Cat. No.97CH36136)
Presents a new implantable functional electrical stimulation (FES) system specially designed for ... more Presents a new implantable functional electrical stimulation (FES) system specially designed for the purpose of selective stimulation of the bladder in spinal cord injured patients. This system, composed of an external controller and an implantable microstimulator (implant), is used to induce low-pressure micturition. After receiving both energy and the stimulation parameters via radio-frequency coupling from the controller, the implant starts
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2010
We describe in this paper cells sensing and manipulation methods, as well as platforms based on L... more We describe in this paper cells sensing and manipulation methods, as well as platforms based on Lab-on-chip devices. Among other contributions, new circuit and microfluidic techniques, and packaging methods are proposed for efficient cells manipulation and detection. The proposed devices include high-sensitivity sensing circuits (200 mV/fF), low-pressure liquid injection interfaces (< 0.65 psi), low-voltage manipulation signals, direct-write microfluidic fabrication technique on top of CMOS based capacitive sensors. In addition, several types of electrode arrays (square and L-shaped) are used for the manipulation of various types of cells and particles.
IEEE Journal on Emerging and Selected Topics in Circuits and Systems, 2011
2011 IEEE International Symposium of Circuits and Systems (ISCAS), 2011
This paper concerns the design of a Se lf-Strobed Delay Line Analog-to-Digital Converter (SSDL AD... more This paper concerns the design of a Se lf-Strobed Delay Line Analog-to-Digital Converter (SSDL AD C) which is dedicated to digitally controlled Switched Mode Power Supply (SMPS) in implantable devices. The proposed windowed-based ADC can be adapted for different input signal levels. A n ew single slow delay cell is use d to r educe power consumption, silicon area and hardware complexity. In i mplantable devices, further to low -power consumption an d small area, the ADC is required to op erate in continuously decreasing power supply. Consequently, a new current sink circuit is utilized to eleminate the need to redesign its controller if the characteristics of the supply devices change. The ADC is designed in AMS 0.35 µm CMOS process and it c an operate at high s witching frequency. Spectre simulations of this ADC show a current consumption as low as 10µA/MHz, and the circuit can provide a wide operating range from z ero to 1.5 V with quantization steps smaller than 1% of Vref.
2011 24th Canadian Conference on Electrical and Computer Engineering(CCECE), 2011
In this paper, a new Frequency Shift Keying (FSK) modulation scheme is proposed to implement the ... more In this paper, a new Frequency Shift Keying (FSK) modulation scheme is proposed to implement the transmitter section of a transceiver for wireless interface of ultra low-power medical sensor networks. The FSK modulation technique is implemented and simulated using TSMC 90 nm CMOS technology to validate its functionality in terms of power consumption and output signal generation. Using the proposed
2013 29th Southern Biomedical Engineering Conference, 2013
2013 IEEE International Symposium on Medical Measurements and Applications (MeMeA), 2013
ABSTRACT In this paper, we present a responsive drug delivery system (DDS) that is capable of dir... more ABSTRACT In this paper, we present a responsive drug delivery system (DDS) that is capable of directly injecting antiepileptic drugs at electrographic seizure onset. This may result in better controlling the epileptic seizures. This miniaturized prototype consists of a preamplifier, a seizure detector, a micro-pump unit and a wireless control module; however in this paper we will only focus on micropump prototype. The proposed micropump is composed of a deflectable membrane which is made of polydimethylsiloxane (PDMS). An electromagnetic method is used to actuate the PDMS membrane in a frequency of 143 Hz in order to provide a maximum flow rate of 2.9 ml/min. The experimental results demonstrate a high accuracy and low power dissipation suitable for implantable responsive drug delivery.
2007 IEEE Biomedical Circuits and Systems Conference, 2007
The electrode-tissues interface (ETI) is one of the key issues for the safety, reliability and ef... more The electrode-tissues interface (ETI) is one of the key issues for the safety, reliability and efficiency of implantable devices such as stimulators and sensors. The aim of this paper is to report an implantable telemetry device, based on a full custom integrated circuit (IC) to monitor the ETI. The proposed system performs various types of measurements, such as impedance spectroscopy,
Proceedings. 7th International Conference on Solid-State and Integrated Circuits Technology, 2004.
... Ecole Poly technique de Montreal. Montreal (Quebec) Canada mohamad.sawan@polymll. ca .-\hSlI·... more ... Ecole Poly technique de Montreal. Montreal (Quebec) Canada mohamad.sawan@polymll. ca .-\hSlI·;lct - This invited pap&quot;I&#39; c(,,&#39;ers circuit trchniqurs and ... In all th(&#39;S devin&#39;s, spl&quot;ci:ll &quot;t[&lt;&quot;ntion is paid to low pm&quot;,,!, Illallag.&#39;m&quot;,nt of i!l\&#39;&quot;ln&#39;d S)&#39;st&quot;&#39;IIlS and to th .... ...
Wiley Encyclopedia of Electrical and Electronics Engineering, 1999
During the last few decades, implantable medical devices (IMDs) changed the landscape of modern m... more During the last few decades, implantable medical devices (IMDs) changed the landscape of modern medicine. Combining many technologies and employing smart medical devices within the human body, they allowed a continuous and automatic management of numerous health issues, such as pacemakers and implantable cardiac defibrillators, cochlear implants, bladder controllers, endoscopic capsules, nerve stimulators, lab-on-a-chip, and artificial retinal prosthesis. Due to their continuously increasing potential, IMDs are getting more complex, thus requiring more energy to operate. Most of these advanced implantable devices are extracorporeally powered or battery charged through wireless power transfer (WPT) mechanisms. Following the basic principle of IMD power supplies, we introduce various power transfer techniques, and then focus on the inductive links and various methods to maximize the energy transferred to implantable devices and the calibration methods of these WPT techniques. Keywords: Inductive power sources; prostheses; implantable devices; sensors; actuators
The 3rd International IEEE-NEWCAS Conference, 2005.
In this paper, the authors described a novel class AB opamp based on dynamic threshold voltage tr... more In this paper, the authors described a novel class AB opamp based on dynamic threshold voltage transistors (DTMOS) for low voltage (1-V), low power and low noise applications. The opamp is used to build the front-end receiver part of a near infrared spectroreflectometry (NIRS) device. The opamp has a two-stage configuration; DTMOS pseudo pMOS differential input pairs are used for input common-mode range enhancement, followed by a single ended class AB output. Experimental measurements from previous designs confirm the usage of a DTMOS device to build a 1-V opamp, using standard 0.18-μm CMOS technology. The performed post-layout simulation results show an input referred noise of 107 nV/√Hz at 1 kHz, and a power consumption of 33.1 μW under 5 pF and 10 kΩ loads. The dc open loop gain is 60 dB, and a unity frequency of 2.73 MHz. The opamp has a CMRR of 100 dB, and input and output swings of 0.6 V and 0.8 V respectively.
2003 46th Midwest Symposium on Circuits and Systems, 2003
... 4 M3 vIn CMN K Vo Cz ... The schematic of the proposed CMOS CFOA with its offset compensation... more ... 4 M3 vIn CMN K Vo Cz ... The schematic of the proposed CMOS CFOA with its offset compensation circuit is shown in Figure 2. The compensation technique consists of a voltage averaging circuit (M21 - M23), two voltage substractors (M24 - M27), and a pseudo negative input ...
Analog Integrated Circuits and Signal Processing - ANALOG INTEGR CIRCUIT SIGNAL, 2003
This paper concerns the design, the implementation and the validation of a fully integrated front... more This paper concerns the design, the implementation and the validation of a fully integrated front-end receiver for a portable ultrasonic system. This front-end receiver includes a logarithmic preamplification circuit and followed by a programmable-gain compensator. The proposed building blocks largely amplify small amplitude signals, and moderately the large amplitude ones. They also compensate signal attenuation due to its traveling of several human body tissues. The ultrasonic receiver is implemented in CMOS 0.35 µm technology. Spectre simulations of the front-end receiver show unity gain bandwidth higher than 100 MHz when driving a load of 1 pF. The expected measurements of the fabricated chip are reported. This chip operates at 3.3 V supply voltages, while maintaining wide common mode rejection ratio, high gain and low input offset voltage. The total power consumption is 15.6 mW and the total chip area is 7.2 mm2 including the digital part needed to program the TGC.
IEEE Transactions on Biomedical Circuits and Systems, 2007
This paper presents the design of a system intended to be used as a prosthesis allowing profoundl... more This paper presents the design of a system intended to be used as a prosthesis allowing profoundly visually impaired patients to recover partial vision by means of microstimulation in the primary visual cortex area. The main component of the system is a bio-electronic device to be implanted inside the skull of the user, composed of a plurality of stimulation modules, whose actions are controlled via an interface module. Power and data are transmitted to the implant wirelessly through a bidirectional inductive link, allowing diagnosis of the stimulating device and its environment after implantation, as well as power delivery optimization. A high level of flexibility is supported in terms of stimulation parameters, but a configurable communication protocol allows the device to be used with maximum efficiency. The core of an external controller implemented in a system on a programmable chip is also presented, performing data conversion and timing management such that phosphene intensity can be modulated by any parameter defining stimulation, either at the pulse level or in the time domain. Measured performances achieved with a prototype using two types of custom ASICs implemented in a 0.18-mum CMOS process and commercial components fulfill the requirements for a complete visual prosthesis for humans. When on/off activation is used with predefined parameters, stimuli measured on an electronic test bench could attain a rate in excess of 500 k pulses/s.
Proceedings of the 2003 International Symposium on Circuits and Systems, 2003. ISCAS '03.
We present a wireless cortical stimulator comprising a plurality of multi-channel micro-stimulato... more We present a wireless cortical stimulator comprising a plurality of multi-channel micro-stimulators allowing flexible placement of electrodes. These devices perform stimulation, and allow measurement of voltage or stimulating current at any electrode. Power and bi-directional data are managed by an Interface Module. Decoding of the ASK modulated carrier uses a low-power digital technique. A data rate higher than I Mbps
CCECE 2003 - Canadian Conference on Electrical and Computer Engineering. Toward a Caring and Humane Technology (Cat. No.03CH37436)
ABSTRACT
CCECE 2003 - Canadian Conference on Electrical and Computer Engineering. Toward a Caring and Humane Technology (Cat. No.03CH37436)
In this paper, we simulate small recurrent pulsed neural networks (up to a dozen of neurons) of l... more In this paper, we simulate small recurrent pulsed neural networks (up to a dozen of neurons) of leaky integrate-and-fire (LI&amp;F) neurons and we train them thanks to general optimisation methods: genetic algorithm and taboo search; in a way inspired by the training of artificial neural networks (ANN). Unlike the taboo search, the genetic method succeeds in our training procedure. Yet,
Proceedings of the 8th IEEE International NEWCAS Conference 2010, 2010
Implantable sensor network becomes nowadays an important area of research. Sensors are implanted ... more Implantable sensor network becomes nowadays an important area of research. Sensors are implanted inside the patient body to measure its physiological changes and send them wirelessly to an external close-by device. Such network is called IWBSN (Implantable Wireless Body Sensor Network). The life time of the embedded batteries associated with these tiny sensor nodes is too short. Hence power consumption
Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 'Magnificent Milestones and Emerging Opportunities in Medical Engineering' (Cat. No.97CH36136)
Presents a new implantable functional electrical stimulation (FES) system specially designed for ... more Presents a new implantable functional electrical stimulation (FES) system specially designed for the purpose of selective stimulation of the bladder in spinal cord injured patients. This system, composed of an external controller and an implantable microstimulator (implant), is used to induce low-pressure micturition. After receiving both energy and the stimulation parameters via radio-frequency coupling from the controller, the implant starts
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2010
We describe in this paper cells sensing and manipulation methods, as well as platforms based on L... more We describe in this paper cells sensing and manipulation methods, as well as platforms based on Lab-on-chip devices. Among other contributions, new circuit and microfluidic techniques, and packaging methods are proposed for efficient cells manipulation and detection. The proposed devices include high-sensitivity sensing circuits (200 mV/fF), low-pressure liquid injection interfaces (< 0.65 psi), low-voltage manipulation signals, direct-write microfluidic fabrication technique on top of CMOS based capacitive sensors. In addition, several types of electrode arrays (square and L-shaped) are used for the manipulation of various types of cells and particles.
IEEE Journal on Emerging and Selected Topics in Circuits and Systems, 2011
2011 IEEE International Symposium of Circuits and Systems (ISCAS), 2011
This paper concerns the design of a Se lf-Strobed Delay Line Analog-to-Digital Converter (SSDL AD... more This paper concerns the design of a Se lf-Strobed Delay Line Analog-to-Digital Converter (SSDL AD C) which is dedicated to digitally controlled Switched Mode Power Supply (SMPS) in implantable devices. The proposed windowed-based ADC can be adapted for different input signal levels. A n ew single slow delay cell is use d to r educe power consumption, silicon area and hardware complexity. In i mplantable devices, further to low -power consumption an d small area, the ADC is required to op erate in continuously decreasing power supply. Consequently, a new current sink circuit is utilized to eleminate the need to redesign its controller if the characteristics of the supply devices change. The ADC is designed in AMS 0.35 µm CMOS process and it c an operate at high s witching frequency. Spectre simulations of this ADC show a current consumption as low as 10µA/MHz, and the circuit can provide a wide operating range from z ero to 1.5 V with quantization steps smaller than 1% of Vref.
2011 24th Canadian Conference on Electrical and Computer Engineering(CCECE), 2011
In this paper, a new Frequency Shift Keying (FSK) modulation scheme is proposed to implement the ... more In this paper, a new Frequency Shift Keying (FSK) modulation scheme is proposed to implement the transmitter section of a transceiver for wireless interface of ultra low-power medical sensor networks. The FSK modulation technique is implemented and simulated using TSMC 90 nm CMOS technology to validate its functionality in terms of power consumption and output signal generation. Using the proposed
2013 29th Southern Biomedical Engineering Conference, 2013
2013 IEEE International Symposium on Medical Measurements and Applications (MeMeA), 2013
ABSTRACT In this paper, we present a responsive drug delivery system (DDS) that is capable of dir... more ABSTRACT In this paper, we present a responsive drug delivery system (DDS) that is capable of directly injecting antiepileptic drugs at electrographic seizure onset. This may result in better controlling the epileptic seizures. This miniaturized prototype consists of a preamplifier, a seizure detector, a micro-pump unit and a wireless control module; however in this paper we will only focus on micropump prototype. The proposed micropump is composed of a deflectable membrane which is made of polydimethylsiloxane (PDMS). An electromagnetic method is used to actuate the PDMS membrane in a frequency of 143 Hz in order to provide a maximum flow rate of 2.9 ml/min. The experimental results demonstrate a high accuracy and low power dissipation suitable for implantable responsive drug delivery.
2007 IEEE Biomedical Circuits and Systems Conference, 2007
The electrode-tissues interface (ETI) is one of the key issues for the safety, reliability and ef... more The electrode-tissues interface (ETI) is one of the key issues for the safety, reliability and efficiency of implantable devices such as stimulators and sensors. The aim of this paper is to report an implantable telemetry device, based on a full custom integrated circuit (IC) to monitor the ETI. The proposed system performs various types of measurements, such as impedance spectroscopy,
Proceedings. 7th International Conference on Solid-State and Integrated Circuits Technology, 2004.
... Ecole Poly technique de Montreal. Montreal (Quebec) Canada mohamad.sawan@polymll. ca .-\hSlI·... more ... Ecole Poly technique de Montreal. Montreal (Quebec) Canada mohamad.sawan@polymll. ca .-\hSlI·;lct - This invited pap&quot;I&#39; c(,,&#39;ers circuit trchniqurs and ... In all th(&#39;S devin&#39;s, spl&quot;ci:ll &quot;t[&lt;&quot;ntion is paid to low pm&quot;,,!, Illallag.&#39;m&quot;,nt of i!l\&#39;&quot;ln&#39;d S)&#39;st&quot;&#39;IIlS and to th .... ...
Wiley Encyclopedia of Electrical and Electronics Engineering, 1999
During the last few decades, implantable medical devices (IMDs) changed the landscape of modern m... more During the last few decades, implantable medical devices (IMDs) changed the landscape of modern medicine. Combining many technologies and employing smart medical devices within the human body, they allowed a continuous and automatic management of numerous health issues, such as pacemakers and implantable cardiac defibrillators, cochlear implants, bladder controllers, endoscopic capsules, nerve stimulators, lab-on-a-chip, and artificial retinal prosthesis. Due to their continuously increasing potential, IMDs are getting more complex, thus requiring more energy to operate. Most of these advanced implantable devices are extracorporeally powered or battery charged through wireless power transfer (WPT) mechanisms. Following the basic principle of IMD power supplies, we introduce various power transfer techniques, and then focus on the inductive links and various methods to maximize the energy transferred to implantable devices and the calibration methods of these WPT techniques. Keywords: Inductive power sources; prostheses; implantable devices; sensors; actuators
The 3rd International IEEE-NEWCAS Conference, 2005.
In this paper, the authors described a novel class AB opamp based on dynamic threshold voltage tr... more In this paper, the authors described a novel class AB opamp based on dynamic threshold voltage transistors (DTMOS) for low voltage (1-V), low power and low noise applications. The opamp is used to build the front-end receiver part of a near infrared spectroreflectometry (NIRS) device. The opamp has a two-stage configuration; DTMOS pseudo pMOS differential input pairs are used for input common-mode range enhancement, followed by a single ended class AB output. Experimental measurements from previous designs confirm the usage of a DTMOS device to build a 1-V opamp, using standard 0.18-μm CMOS technology. The performed post-layout simulation results show an input referred noise of 107 nV/√Hz at 1 kHz, and a power consumption of 33.1 μW under 5 pF and 10 kΩ loads. The dc open loop gain is 60 dB, and a unity frequency of 2.73 MHz. The opamp has a CMRR of 100 dB, and input and output swings of 0.6 V and 0.8 V respectively.
2003 46th Midwest Symposium on Circuits and Systems, 2003
... 4 M3 vIn CMN K Vo Cz ... The schematic of the proposed CMOS CFOA with its offset compensation... more ... 4 M3 vIn CMN K Vo Cz ... The schematic of the proposed CMOS CFOA with its offset compensation circuit is shown in Figure 2. The compensation technique consists of a voltage averaging circuit (M21 - M23), two voltage substractors (M24 - M27), and a pseudo negative input ...
Analog Integrated Circuits and Signal Processing - ANALOG INTEGR CIRCUIT SIGNAL, 2003
This paper concerns the design, the implementation and the validation of a fully integrated front... more This paper concerns the design, the implementation and the validation of a fully integrated front-end receiver for a portable ultrasonic system. This front-end receiver includes a logarithmic preamplification circuit and followed by a programmable-gain compensator. The proposed building blocks largely amplify small amplitude signals, and moderately the large amplitude ones. They also compensate signal attenuation due to its traveling of several human body tissues. The ultrasonic receiver is implemented in CMOS 0.35 µm technology. Spectre simulations of the front-end receiver show unity gain bandwidth higher than 100 MHz when driving a load of 1 pF. The expected measurements of the fabricated chip are reported. This chip operates at 3.3 V supply voltages, while maintaining wide common mode rejection ratio, high gain and low input offset voltage. The total power consumption is 15.6 mW and the total chip area is 7.2 mm2 including the digital part needed to program the TGC.
IEEE Transactions on Biomedical Circuits and Systems, 2007
This paper presents the design of a system intended to be used as a prosthesis allowing profoundl... more This paper presents the design of a system intended to be used as a prosthesis allowing profoundly visually impaired patients to recover partial vision by means of microstimulation in the primary visual cortex area. The main component of the system is a bio-electronic device to be implanted inside the skull of the user, composed of a plurality of stimulation modules, whose actions are controlled via an interface module. Power and data are transmitted to the implant wirelessly through a bidirectional inductive link, allowing diagnosis of the stimulating device and its environment after implantation, as well as power delivery optimization. A high level of flexibility is supported in terms of stimulation parameters, but a configurable communication protocol allows the device to be used with maximum efficiency. The core of an external controller implemented in a system on a programmable chip is also presented, performing data conversion and timing management such that phosphene intensity can be modulated by any parameter defining stimulation, either at the pulse level or in the time domain. Measured performances achieved with a prototype using two types of custom ASICs implemented in a 0.18-mum CMOS process and commercial components fulfill the requirements for a complete visual prosthesis for humans. When on/off activation is used with predefined parameters, stimuli measured on an electronic test bench could attain a rate in excess of 500 k pulses/s.