Vipan Kakkar

A comparative analysis of different vibration based energy harvesting techniques for implantables

Energy harvesting is the process of scavenging electrical energy from energy sources available in the environment. A wide variety of energy sources can be exploited here. Some of the sources include kinetic energy, thermal energy, solar energy etc. With the progress in low power design, the concept of harvesting energy to power electronic circuits has also gained relevance. Electrical energy/power can be harvested by exploiting the human body motion. Different types of transducers can be used for this. Piezoelectric materials, variable capacitors, and inductive generators can be employed here according to the type of harvester. An important and vast area of application of energy harvesting can be the medical implants field. Energy harvesting for the powering of a new generation of medical implants, miniaturized implants (functioning without battery) such as a pacemaker is discussed. Various potential techniques for this energy transduction are studied, surveyed and compared. Also the different types of mechanical energy sources in the implant environment are explored.

Modeling and simulation of an eight-bit auto-configurable successive approximation register analog-to-digital converter for cardiac and neural implants

An analog-to-digital converter (ADC) is a critical block of the sensing unit of all implants and for measurements of various biophysiological signals that cover distinct portions of the frequency spectrum and signal bandwidths. However, the conventional methodology of direct transistor-level implementation of the ADC for any application does not guarantee the accuracy to meet the desired specifications. For this purpose, the behavioral modeling approach facilitates the designer to set up an environment to extract various electric and dynamic parameters with a good level of accuracy. Based on this, behavioral modeling of a new architecture of an eight-bit auto-configurable successive approximation register (SAR) ADC has been proposed in this paper for application in both cardiac and neural implants, such as pacemakers, deep brain stimulators, etc. All the building blocks of the SAR ADC have been modeled in such a way that the ADC can operate either in the voltage mode or the current mode and the various non-idealities, such as clock jitter, clock feedthrough, and thermal and flicker noise, among others, have been incorporated into the design to make it as realistic as possible and estimate the response of the ADC with high accuracy. Based on the simulations for both ideal and non-ideal scenarios, it is observed that the proposed eight-bit auto-configurable SAR ADC works efficiently for applications in both cardiac and neural implants and achieves a signal-to-noise ratio as high as 48.943 dB and effective number of bits of 7.838 bits with very low distortion of only −62.549 dB.

Recent technological advancements in tuberculosis diagnostics – A review

Early diagnosis and on-time effective treatment are indispensable for Tuberculosis (TB) control - a life threatening infectious communicable disease. The conventional techniques for diagnosing TB normally take two to three weeks. This delay in diagnosis and further increase in detection complexity due to the emerging risks of XDR-TB (Extensively drug Resistant-TB) and MDR-TB (Multidrug Resistant-TB) are evoking interest of researchers in the field of developing rapid TB detection techniques such as biosensing and other point-of-care (POC) techniques. Biosensing technologies along with the collaboration with nanotechnology have enormous potential to boost the MTB detection and for overall management in clinical diagnosis. A diverse range of portable, sensitive and rapid biosensors based on different signal transducer principles and with different biomarkers detection capabilities have been developed for TB detection in the early stages. Further, a lot of progress has been achieved over the years in developing various point-of-care diagnostic tools including non-molecular methods and molecular techniques. The objective of this study is to present a succinct review of the available TB detection techniques that are either in use or under development. The focus of this review is on the current developments occurred in nano-biosensing technologies. A synopsis of ameliorations in different non-molecular diagnostic tools and progress in the field of molecular techniques along with the role of emerging Lab-on-Chip technology for diagnosing and mitigating the TB consequences have also been presented.

Miniaturized Resonant Power Conversion for Implanted Medical Devices

The design of a millimetre-sized power converter is proposed which is based on coil coupling that could be integrated into the neural or cardiac implantable medical device (IMD) to provide isolated power or energy transmission by harvesting it from external transmitter device. A special step-up case of transformer coupling to a millimetre-sized receiver coil by a comparatively larger transmitter coil is examined. This paper is expected to increase research efforts to develop the battery-less IMD’s with reduced size, low power, high efficiency, and improved reliability and feasibility. Based on our work, we believe that the inductive coupling link with low loss ferrite material is the suitable method to be used to power the batteryless devices. The converter produces the targeted output power of more than 400

Analog-to-digital converters: A comparative study and performance analysis

\mu \text{W}

A COMPARATIVE ANALYSIS OF THERMAL FLOW SENSING IN BIOMEDICAL APPLICATIONS

with 1 mm3 size of the coil at 2 MHz.

Development of low power buck convertor for enhanced light load efficiency

Analog-to-Digital Converters (ADCs) are critical components of biomedical, communications and signal processing systems which require low power consumption and high conversion efficiency and are used to convert the real world signal to digital signal for the purpose of processing. In this paper various state-of-the-art ADCs including experimental converters, have been explored keeping in mind their application requirements. A comparative study of these ADCs, keeping in mind the various performance parameters like power consumption, resolution, sampling rate has also been presented, providing an insight into their shortcomings.

Improved digital design of BPSK modulator using look-up table technique

Flow sensors have diverse applications in the field of biomedical engineering and also in industries. Micromachining of flow sensors has accomplished a new goal when it comes to miniaturization. Due to the scaling in dimensions, power consumption, mass cost, sensitivity and integration with other modules such as wireless telemetry has improvised to a great extent. Thermal flow sensors find wide applications in biomedical such as in hydrocephalus shunts and drug delivery systems. Infrared thermal sensing is used for preclinical diagnosis of breast cancer, for identifying various neurological disorders and for monitoring various muscular movements. In this paper, various modes of thermal flow sensing and transduction methods with respect to different biomedical applications are discussed. Thermal flow sensing is given prime focus because of the simplicity in the design. Finally, a comparison of flow sensing technologies is also presented.

Optimal Realization of Universality of Peres Gate Using Explicit Interaction of Cells in Quantum Dot Cellular Automata Nanotechnology

Power consumption and device size have been placed at the primary concerns for battery-operated portable applications. Switching converters also known as DC/DC convertors gain popularity in powering portable devices due to their high efficiency, compact sizes and high current delivery capability. Currently, the Synchronous Buck convertor has become much more popular in portable devices due to their very high power efficiency and widely availability. However the portable devices usually operate at light loads (standby mode) most of the time and are required to deliver high current only for very short periods, while the conventional Synchronous Buck converter suffers from low power efficiency at light loads due to the negative value of inductor current at light loads. In this research, a novel technique for designing a buck converter is proposed which automatically senses the zero inductor current and forces the convertor to step from automatically from Continuous Conduction Mode (CCM) to Discontinuous conduction mode (DCM) when the inductor current tries to go negative, thereby preventing the inductor current to go negative and hence improve convertors power efficiency at light loads. A synchronous buck convertor which steps down 1.8V input voltage to 1V output is designed in PSIM software with a switching frequency of 1MHz. The simulation results shows that the proposed convertor has better efficiency than the conventional convertor at light loads whereas at heavy loads both convertors have almost same efficiency.

Lab-on-Chip Technology: A Review on Design Trends and Future Scope in Biomedical Applications

This paper present a new and improved digital design of BPSK (Binary Phase Shift Key) modulator. The generic digital design of BPSK modulator has two carrier signals in the form of sine wave having 0 degree and 180 degree phase shift. Generic design uses two sine wave generators which act like carrier signal and MUX gives out any one of the carrier signal depending upon the input bit (0 or 1). Our main aim in this paper is to reduce the hardware from the previous existing digital architecture of the BPSK modulator. The new architecture of the BPSK modulator with optimized resource utilization is proposed. In this improved design instead of using two sine wave generators for producing two different sinusoidal carrier signals having 0 degree and 180 degree phase shift, we have used a single sine wave generator using LUTs technique to generate both sinusoidal carrier signals (sine wave with 0 degree and 180 degree phase shift). Digital Clock Manager (DCM) is used a control block (DCM) this make our architecture more flexible and can work on large frequency range. This new improved architecture is implemented using VHDL language on the Xilinx ISE 9.2i simulator. VHDL Design and simulation of every block of the new architecture is done. Finally the simulation of whole digital design of BPSK is performed and its gives the satisfactory result which confirms that the new architecture can produce BPSK modulated signal.