3 research outputs found
High Data Rate FinFET On-off Keying Transmitter for Wireless Capsule Endoscopy
Wireless capsule endoscopy (WCE) is a painless diagnostic tool used by the physicians for endoscopic examination of the
gastrointestinal track. The performance of the existing WCE systems is limited by high power consumption and low data rate
transmission. In this paper, a 144MHz FinFET On-Off Keying (OOK) transmitter is designed and integrated with a class-E power
amplifier. It is implemented and simulated using 16nm FinFET Predictive Technology Models. The proposed transmitter can
achieve the data rate of 33Mbps with average power consumption of 1.04mWfrom a 0.85V power supply in the simulation. This
design outperforms the current state-of-the-art designs
Development of electronics for microultrasound capsule endoscopy
Development of intracorporeal devices has surged in the last decade due to advancements in the semiconductor industry, energy storage and low-power sensing systems. This work aims to present a thorough systematic overview and exploration of the microultrasound (µUS) capsule endoscopy (CE) field as the development of electronic components will be key to a successful applicable µUSCE device. The research focused on investigating and designing high-voltage (HV, < 36 V) generating and driving circuits as well as a low-noise amplifier (LNA) for battery-powered and volume-limited systems.
In implantable applications, HV generation with maximum efficiency is required to improve the operational lifetime whilst reducing the cost of the device. A fully integrated hybrid (H) charge pump (CP) comprising a serial-parallel (SP) stage was designed and manufactured for > 20 V and 0 - 100 µA output capabilities. The results were compared to a Dickson (DKCP) occupying the same chip area; further improvements in the SPCP topology were explored and a new switching scheme for SPCPs was introduced. A second regulated CP version was excogitated and manufactured to use with an integrated µUS pulse generator. The CP was manufactured and tested at different output currents and capacitive loads; its operation with an US pulser was evaluated and a novel self-oscillating CP mechanism to eliminate the need of an auxiliary clock generator with a minimum area overhead was devised.
A single-output universal US pulser was designed, manufactured and tested with 1.5 MHz, 3 MHz, and 28 MHz arrays to achieve a means of fully-integrated, low-power transducer driving. The circuit was evaluated for power consumption and pulse generation capabilities with different loads. Pulse-echo measurements were carried out and compared with those from a commercial US research system to characterise and understand the quality of the generated pulse. A second pulser version for a 28 MHz array was derived to allow control of individual elements. The work involved its optimisation methodology and design of a novel HV feedback-based level-shifter.
A low-noise amplifier (LNA) was designed for a wide bandwidth µUS array with a centre frequency of 28 MHz. The LNA was based on an energy-efficient inverter architecture. The circuit encompassed a full power-down functionality and was investigated for a self-biased operation to achieve lower chip area. The explored concepts enable realisation of low power and high performance LNAs for µUS frequencies
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Improvements in Image Compression and RF Transmission for Wireless Capsule Endoscopy
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonEndoscopes and colonoscopes are used by many doctors and physicians for diagnoses of pathologies of the
gastrointestinal (GI) track. These methods are painful and dangerous for the life of the patients, due to these
drawbacks: a wireless capsule endoscopy (WCE) is used. The reason is that diagnosing the small intestine is impossible those the WCE improves the overall performance of endoscopy and colonoscopy. The use of these systems provide benefits in the diagnosis of pathologies of the GI such us, cancer, blooding, lymphoma or Cronh’s diseases. WCE has an image sensor that captures images. The amount of data produced by the image sensor is huge. Also, there is the need of wireless transmission of this data. In order to power these systems by a single battery, the system should use compression of this data and an extra low power transmitter with high data rate transmission. The energy of this battery is currently not sufficient to keep the system working for more than 8 hours continuously with conventional compression algorithms and wireless transmitters. For these reasons, mainly, the use of a novel design that can compress and send efficiently this data is needed. In this research, an entirely improved WCE system is proposed. From the perspective of camera lenses that can be used, through camera sensor and compression algorithm, to wireless transmission system. Hundreds of WCE images were used to identify the unique characteristics of them. Statistical analysis was made and finally achieved the best of the performance for the compression algorithm. Additionally, camera lenses where selected to provide a new perspective of view. Traditionally, WCE uses simple lenses to capture the GI track. A 360º degree lenses is proposed to be used. The reason is the fact that the use of them gives the advantage to map the entire GI track and make a virtual reconstruction of the GI outside human body. With this method, the physician/doctor could be able to walk-through in the entire GI track to make a diagnosis. A compression algorithm designed and implemented. Firstly, evaluation of proposed schemes, of the realized by the help of Matlab software. The compression algorithm that was suitable for a medical application like WCE, were implemented in hardware. The implementation in hardware is made with help of an FPGA development board using Hardware Description Language (HDL). Finally, the proposed compression algorithm was designed in Cadence tool-set software in 16nm FinFet technology. The proposed compression algorithm is designed to be able to connect directly to most common commercially available camera sensors. Furthermore, the output of the compression algorithm is not parallel, but the output data is in serial mode. This feature, makes the proposed system to be connected directly to any RF transmitter that is available now. The proposed system except from the compression performance, offers a compact system that can work as it is, without any modifications with most common used camera sensors and RF transmitters. Apart from the compression algorithm, the design and simulation of a low energy wireless transmitter was made. Digital modulation, On-Off Keying (OOK) was used. The selection of the modulation and the working carrier frequency was based in the body characteristics and the performance in the manner of biterror-rate (BER) and low energy usage. A low power design of a specially implemented OOK transmitter is designed and simulated. The wireless transmitter is designed and surface optimized by using fewer internal and external parts, so it can fit inside the capsule. The design and simulation of the proposed wireless transmitter was done with the Cadence tool-set in 16nm FinFet technology. Furthermore, there is another field of research in WCE. Until now, the research in WCE was focused on the internal part of the WCE, the pill. In our research project, the main effort was focused not only on the internal part of the WCE but also in the external part. The external part consists of a receiver, and a recorder, both of them placed in a jacket that the patient wears. In this research work a multi-receiver system is proposed. Existed systems use only one receiver and this introduces the possibility to receive false or corrupted data. For this reason, existing systems use bi-directional RF transmission link. While using bidirectional RF transmission link in the capsule, both transmitter and receiver should be placed. This needs more space and consumes more energy for operation. The proposed multi-receiver system eliminates the need of bi-directional link. Less space and power inside the capsule needed because there is no receiver inside the capsule to operate. Multi-receiver system is used also to increase the BER performance of the wireless link. While using multi-receivers, weak or corrupted reception of RF signal is eliminated because always there will be receivers with good reception that can capture the correct data. Furthermore, error correction algorithm is used that compares the received data of all the receivers which improves the decision making method for the transmitted data. Finally, the entire WCE with a set of special lenses with a 360º degree angle of view is proposed. High resolution images can be captured and transmitted wirelessly. The set of special lens, low complexity and low energy compression algorithm, along with the use of the high data rate, low power transmitter, pushes the WCE technology to the next level