Medical be than only understood by digital systemsfor
Medical Implants,Embedded sensing systems, Control and Measurement, DistributedSensor Networks, Hand-held Electronics and a lot of other applications increasinglyusing digital systems such as Microcontrollers or Microprocessors to measure temperature,pressure,light intensity etc,in other words analog variables. Physical analog variablesare measured through electrodes, sensors in form of analog signals which needsto be converted to digital form which can be than only understood by digital systemsfor further processing of data. Analog to digital converters (ADCs) are electronic circuitsthat converts analog signal into digital signals. Thus, Analog to digital converters(ADCs) are necessary part of every digital system to eciently process signals fromphysical world.In medical systems, continuous-time monitoring of the patients is required and thuswe need very large amount of data for processing, storage and transmission. Largeamount of data processing, storage and transmission means more power which in ternsmeans we need large power sources while medical implants are very small and batterypowered. Also Medical Systems and implants are very sensitive to power consumptionas human tissue starts burning after 1 C. Moreover, Low power consumption meanslonger battery life while larger distance between transmitter and receiver in medical implants.Hence major requirements of such circuits are minimum power, processing andacquisition due to which ultra low power circuits in medical electronics are in researchwhich could only be possible with ecient signal processing. Signal is processed by Analogto digital converters (ADC). Thus we always need new improved designs for Analogto digital converters (ADC) as it controls the power consumption of the digital signalprocessing step as well as the amount of transmitted data.To stay ahead in the fast changing world requires the ability to look beyond present.Thus, Institute of Nano- and Medical Electronics of the Technical University Hamburgdeveloped dierent (ADC) approaches in their previous works Christian17, Teyfel16.Thebasic idea is that analog signals can be represented by a certain mathematical modelwith specic parameters described by probability distributions and the signal acquireitself to mathematical model by comparing the value of signal with certain thresholdlevels. Conventional Analog to Digital Converters (ADCs) consumes more power, becauselarge number of samples are required for exact copy of input signal.To solve thisproblem, Adaptive Analog to Digital Conveters (ADCs) is used which samples at certainspecic times, means when new information is available and the rest of time it is idle.This approach increases calculation complexity for control unit but decreases power consumption.5Master thesis of Teyfel Teyfel16 was based on implementing the algorithm in MATLABand C code conversion and hardware was based on Programmable System On Chip(PSOC) .The prototyping kit contains a PSoC 5LP Cyp17a from Cypress semiconductors,which contains microcontroller, analog and digital hardware. A prototype of theadaptive ADC was realized using this chip. Main design goals were reduction of powerconsumption in other words less energy and keeping the algorithm simple and ecient.Following master thesis of Teyfel Teyfel16 Christian Adam Christian17 thesis goalwas to investigate the adaptive (ADC) potential to save energy. Therefore a measurementsetup for the prototype was built to provide detailed information about its powerconsumption.Furthermore presented adaptive ADC was compared to more classical approachcalled Successive Approximation ADC (SA ADC).The problem still faced waslarge number of calculations which was causing main total energy consumption. Butthere is always chance for improvement and thus to have further low power and reducedcomputational complexity the idea of distributed system was developed.The overall goal of this master project work is to show that a system following the conceptof distributed system consumes less total energy for determining the signal modelparameters than a system that uses a conventional (SA ADC). Therefore Measurementsetup for distributed system has to be build and investigated to provide detailed informationregarding the functionality of distributed system as well as to ensure lowpower and low energy consumption. Additionally Comparisons has to be made withConventional ADC in order to ensure that distributed systems reduces computationalcomplexity, moreover it ensures low energy consumption as well.In chapter 2,3 and 4 basic concepts,mathematical fundamentals will be introduced.Chapter 5 will explain Distributed system and related concepts. After covering theory,Simulation Model in chapter 6 will be presented which will be followed by chapter 7hardware implementation of Simulated Design. Chapter 8 will be based on Results,Power and Energy Measurements.Further improvements will be covered in chapter 9.