Biomedical transducers

Loivisto, E., Safety Aspects in the Standardization of Electromedical Equipment, Proceedings of the Annual International Conference on Biomedical Transducers, 1975, pp. 457-462. 

T. Togawa, T. Tamura, P.A. Oberg, Biomedical Transducers and Instruments, CRC Press, 1997. 

Poly(vinylidene fluoride) has become an attractive material for use in uhrasook biomedical transducers because trf its large bandwidth, low acoustic impedance (about 4.5 MRayl, which is fairly close to human tissue long stability with time, conformability to shape, and low cost. This makes the material intrinsically broadband and permits construction of transducers with short impulse responses without the need for matching layers. The low electromechanical coupling factor is partially oftet by the use of time-delay spectrometry (16j. This technique allows a sig -to-noisc ratio (SNR) of at least 60-7S dB to be maintained in the frequency range from 1 to 40 MHz. 

Cobbold, R. S. Transducers for Biomedical Measurements, p. 349, New York, Wiley 1974... 

The very large absorption cross-sections of Au nanoparticles give rise to photothermal effects, that is, an increase in local temperature upon plasmon resonance excitation. The concept of Au nanoparticles as photothermal transducers has inspired numerous efforts to develop biomedical applications such as localized hyperthermal therapy,63-65 photothermal contrast agents,66 and optothermally controlled drug release,67-69 and also novel platforms for information storage.70... 

Watson, J. D., Gilman, M., Witkowski, J., and Zoller, M., Recombinant DNA, 2nd ed., W. H. Freeman, New York, 1992. Zweiger, G, Transducing the Genome Information, Anarchy, and Revolution in the Biomedical Sciences, McGraw-Hill, New York, 2001. 

W. H. Ko, J. Hynecek, S.F. Boettcher, Development of a miniature pressure transducer for biomedical applications, IEEE Trans. Electron Devices 1979, ED-26, 12, 1896-1905. 

SOURCE From R S C Cobbold, Transducers for Biomedical Measurements 1974, Wiley. 

Figure 2.16 (a) A differential three-terminal capacitor, (b) A capacitance bridge circuit with output proportional to fractional difference in capacitance, (c) A transformer ratio arm bridge. (From R S C Cobbold R S C Transducers for Biomedical Measurements Principles and Applications, copyright 1974, John Wiley and Sons, Inc.)... 

Lion K S 1959 Instrumentation in Scientific Research (New York McGraw-Hill) Cobbold R S C 1974 Transducers for Biomedical Measurements (New York Wiley)... 

Lee G-B, Lin Y-H, Lin W-Y, Wang W, Guo T-F, (2009) Optically-induced dielectrophoresis using polymer materials for biomedical applications. In Proceedings international conference on solid-state sensors, actuators and microsystems, Transducers 09, Denver, CO, 21-25 June 2009, pp 2135-2138... 

There is a clear trend today within the bioanalytical and biomedical fields toward more frequent use of cell-based studies. The dimensions of microfluidic systems are well matched to meet the demand on cell-based systems. Still, new methods are needed that can efficiently handle and manipulate cells in those formats. Examples have already been given in this chapter where acoustic forces are used to trap and manipulate cells. The device in Figure 44.22 has been forther developed for use in cell-based bioassays. The temperature characteristics of the device have been examined to be able to control the temperature during the cell experiments. The major source of heat in the acoustic resonance systems presented here is the power dissipation in the transducer itself. The power dissipation follows a... 

Since sensors generate a measurable material property, they belong in some grouping of transducer devices. Sensors specifically contain a recognition process that is characteristic of a material sample at the molecular-chemical level, and a sensor incorporates a transduction process (step) to create a useful signal. Biomedical sensors include a whole range of devices that may be chemical sensors, physical sensors, or some kind of mixed sensor. 

An important aspect in the development of sensor technology is the need for mass-produced and low-cost disposable transducers [48]. This is especially relevant for environmental and biomedical analysis. For electrochemical sensors, screen-printed electrodes fulfill this need, and the ease of preparation and low cost of MIPs make them attractive as recognition elements for such devices. A first report on this topic demonstrated that an imprinted polymer could be coated onto screen-printed carbon electrodes, and the resulting devices could be used as an amperometric sensor [33]. 

Zweiger, Gary. Transducing the Genome Information, Anarchy, and Revolution in the Biomedical Sciences. McGraw-HiU, New York, 2001. 

The IRRAS method can be used to obtain information about ultrathin films not only at metals but also on semiconductor and dielectric (including liquid) substrates. This class of problem is applicable to many areas, including thin-fihn optics, electronic and electroluminescent devices [27] (Chapter 5), sensors and transducers [28], flotation technology [29] (Section 7.4.4), and biomedical problems [30, 31]. Although the sensitivity is much lower than when metallic substrates are used, the waiving of the metal selection rule allows both s- and /7-polarized spectra to be measured and thus a more thorough investigation of molecular orientation within the layer. 

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