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... is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with respect to a modulating signal. Fig. 1 shows block diagram of the modulation where the signal is modulated by the carrier signal. There are the three key parameters of the modulation, which is amplitude, phase, and frequency. Typically a high-frequency sinusoid waveform is used as carrier signal, but a square wave pulse train may also occur. Fig. 2 (a) depicts the ...
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... standard way. The real and imaginary components are first converted to the analogue domain using digital-to-analogue converters (DACs); the analogue signals are then used to modulate cosine and sine waves at the carrier frequency, respectively. These signals are then summed to give the transmission signal. Above descriptions are depicted in the fig. 10. Fig. 10. Block diagram of the ...
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... way. The real and imaginary components are first converted to the analogue domain using digital-to-analogue converters (DACs); the analogue signals are then used to modulate cosine and sine waves at the carrier frequency, respectively. These signals are then summed to give the transmission signal. Above descriptions are depicted in the fig. 10. Fig. 10. Block diagram of the ...
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... software-defined radio system (SDR) is a radio communication system where components that have been typically implemented in hardware such as mixer and detectors. The strong advantage of the SDR is that it can modulate/demodulate various type of communication without additional hardware. The fig. 11 depicts the concept of the SDR that it could receive various modulated signal by one hardware. Since the concept of the SDR can directly receive the analog signal from the antenna, the ideal scheme is not completely realized because of limits of the analog to digital conversion (ADC). The ADC speed and resolution is not high enough to ...
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... of the SDR can directly receive the analog signal from the antenna, the ideal scheme is not completely realized because of limits of the analog to digital conversion (ADC). The ADC speed and resolution is not high enough to receiver RF or IF stage signal. Therefore, most of low end SDR use super-heteroine structure and it is depicts in the Fig. ...
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... with low power density which is typically -41 dBm/MHz and does not arrowed to use frequency below 2.6 GHz to reduce possibility of collision. The fig. 13 depicts the FCC indoor mask which is limitation of RF power for the UWB. In order to follow the regulation, most of the UWB signal is generated by nth derivative of the Gaussian pulse shape. The fig. 14 ...
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... the time which the signal is actually transmitting is very short, the power consumption of the UWB is very low and it is easy to achieve the time division multiplex (TDM). Fig. 14. PSD of higher order derivatives of the Gaussian pulse for UWB indoor systems. ...
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... order to design a telemetry system, the RF frequencies have to be chosen based on the attenuation, data rate, maximum permissible exposure (MPE), and antenna efficiency. Since the human body mostly consists of saline, the RF power is attenuated in various parts of the human body. Fig. 16 depicts the attenuation constants for various parts of the human ...
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... endoscopy, and the MPE should be taken into consideration. The MPE is the highest power or energy density of an RF source that is considered safe, i.e. that has a negligible probability for creating damage. Since the MPE is regulated from the outside of the body, it could be used as a guideline for the amount of RF radiation inside the body. Fig. 17. The maximum permissible exposure ...
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... were designed to use the FM method and used a long and flexible antenna. Since early telemetry systems did not require a high data rate, this was sufficient except for the repulsion of its shape. With the advent of capsule endoscopy, the data rate has to be increased so as to be sufficient enough for transmission of gastrointestinal images. Fig. 18 shows an example of capsule endoscopes. The analog type can transmit the National Television Standards Committee (NTSC) format, which is widely used for analog TV transmission, and the physician can monitor the inside of the gastrointestinal tract as if watching an analog television. Since the NTSC uses the analog transmission ...
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... the NTSC uses the analog transmission technology, it could provide a high fame rate (30 frame/s) but it is weak to channel noise; further, restoration of the data is impossible. Fig 18 (b) shows digital type capsule endoscope that could transmit 640×480×8 resolution images by using a digital transmitter. Since a digital receiver can restore the data from environmental noises, the frame rate of the capsule is reduced to 1 frame/s. ...
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... frame/s) but it is weak to channel noise; further, restoration of the data is impossible. Fig 18 (b) shows digital type capsule endoscope that could transmit 640×480×8 resolution images by using a digital transmitter. Since a digital receiver can restore the data from environmental noises, the frame rate of the capsule is reduced to 1 frame/s. Fig. 18 (c) shows images taken from the ileum and esophagus by using a digital type transmitter capsule. In order to transmit at a high data rate, the RF frequency has to be increased so as the make the antenna effective. For capsule endoscopy, the 430 and 1200 MHz the industrial, scientific and medical (ISM) bands are widely used to transmit ...
Citations
... In water, the EM waves attenuate with a rate of 0.2 dB/cm while the US waves attenuate at a rate of 0.002 dB/cm; even though the US waves attenuate much less, it only introduces a difference of 3 dB at 15 cm, which is beyond the maximum range of our experiment. However, when considering the tissue phantom, the EM waves attenuate at a rate of 4 dB/cm while the US waves attenuate only at a rate of 0.7 dB/cm; this introduces a difference of 50 dB at 15 cm when operating in tissue phantom, which is closer to the human body in terms of attenuation and acoustic impedance, hence making the US waves a better fit for intrabody communication [18][19][20] such as in our application with the LN pMUTs. The main concept, to increase the data-rate, is to design devices with a large operation bandwidth. ...
... This bandwidth is higher than pMUTs based on other piezoelectric materials such as AlN and ScAlN-36% as shown in Fig. 8c-e. c Attenuation of electromagnetic (EM) and ultrasonic (US) waves when considering both water and tissue phantom as propagation medium [18][19][20] . The implantation range considered is from 0 to 15 cm. ...
In recent years, there has been an increased interest in continuous monitoring of patients and their Implanted Medical Devices (IMDs) with different wireless technologies such as ultrasounds. This paper demonstrates a high data-rate intrabody communication link based on Lithium Niobate (LN) Piezoelectric Micromachined Ultrasonic Transducers (pMUTs). The properties of the LN allow to activate multiple flexural mode of vibration with only top electrodes. When operating in materials like the human tissue, these modes are merging and forming a large communication bandwidth. Such large bandwidth, up to 400 kHz, allows for a high-data rate communication link for IMDs. Here we demonstrate a full communication link in a tissue phantom with a fabricated LN pMUT array of 225 elements with an area of just 3 by 3 mm square, showing data-rates up to 800 kbits/s, starting from 3.5 cm and going up to 13.5 cm, which covers the vast majority of IMDs.
... telemetria: tecnologia que possibilita a medição remota, o controlo e o relato de informação (Cho & Hyo, 2011). 6, 9 ...
Traditionally the design of human-machine systems is still focused on the ergonomic aspects of the operation, often disregarding other equally important factors such as the way humans learn and use the machines. One of the main reasons which lead to the present situation has to do with the fact that the machine conditions usually do not change, regardless of the human’s skill/dexterity, often requiring an additional operation time and training effort. Besides, one should emphasize that in any manual task under a mechatronic device, the operator always belongs to the closed loop control system, and the human factor should be taken into account.
The work described in this thesis addresses the study and the development of new method- ologies and techniques for improving the operator skills under human-machine devices, exploring several theoretical concepts and strategies, namely the modelling and identification of human- -machine systems, the human-machine control and optimization, the transfer learning/knowledge, the operator assistance and the skill analysis. The efficiency and applicability of these methods is confirmed, and its strengths are exposed. The techniques presented in this thesis are validated experimentally with data obtained from the several interface systems used.
Nowadays, the implications for the development and use of automatic human-machine adap- tation systems are promising, since they lead to the improvement of skills, usability, and security. Examples for such applications can be found in several areas, such as in assistive technology, medicine, teleoperation, entertainment, industrial production, automotive industry and aviation, among others.
Keywords: Human-machine control, Transfer learning/knowledge, Skill analysis, Human-machine interfaces, Electronic assistance devices, Assistive technology.
