Wireless telemetries data telemetry

These applications, by nature, impose serious limitations on power and area in the design of neural-recording systems. Researchers have developed several kinds of neural-recording systems [23-27], and those systems are generally composed of preamplifiers to amplify the small extracellular potentials, low-pass filters to reject the high frequency noise, multiplexers, and analog-to-digital converters (ADCs) followed by the wireless telemetry circuits to transmit data out of the body. 

Figure 30 shows a simplified dual-band wireless power and data telemetry. There are six different coupling coefficients, named Ki2 pw. Ki2 data, Kn, K22, Kdata pw, and Kpw-data between 4 coils. Among these six coefficients, the Ki2 j9w and Ki2 data affect power and data transfer efficiencies, and the others, Kn, K22, Kdata pw. and K -data determine the power interference to the data transmitter and receiver [117]. 

Wang G (2006) Wireless power and data telemetry for retinal prosthesis. Ph.D. dissertation, University of California, Santa Cruz, EE Dept., CA, USA, Mar. 2006. 

Wireless pH measurement systems have been used in clinical studies. Unlike a standalone pH electrode, a power source, control electronics, and a signal transmitter have to be incorporated into a wireless system. Watanabe et al. [138] have reported a wireless pH sensor to record salivary pH continuously. The sensor system transmits pH data via a telemetry system for about 19 hours with a 3V lithium battery (190mAh). The error of transmitted pH data was less than 0.15 pH in the range of pH 5.0 to 9.0. 

Two of the primary applications for wireless data communications systems are to enable mobile or remote connections to a LAN, and to establish wireless communications links between SCADA remote telemetry units (RTUs) and sensors in the field. Wireless card connections are usually used for LAN access from mobile computers. Wireless cards can also be incorporated into RTUs to allow them to communicate with sensing devices that are located remotely. 

Using CT scanners has some advantages like being widely available, having high spatial resolution and showing 3-D information about the prosthesis and the internal tissues of the stump, but the challenge is that they require the subjects to be positioned supine [13]. The use of photoelectric sensor reported to have some limitations because it is not wireless and a cable connects the sensor to data acquisition system. But it is said to be overcome by radiofrequency telemetry systems. [1]. 

Although there are several communication standards for biomedical applications, most of them eannot provide enough bandwidth for simultaneous recording from more than 100 ehannels. For example, MICS band, which is allocated for the unlicensed use of implantable devices, allows only 300 kHz for data transmission. Other wireless technologies such as Wi-Fi and Bluetooth cannot be used directly due to the power and area constraint of the implanted device. Therefore, there is a need for higher-bandwidth data transmission telemetry that consumes low power and occupies less physical area. 

Andre L. C. Araujo was bom in Fortaleza, Brazil, in 1973. He is currently an Associate Professor with the Department of Telecommunications Engineering, Federal Institute for Education, Science, and Technology of Ceara (IFCE), Fortaleza, Brazil. He works toward the Ph.D. degree in Robust Control Theory with the Federal University of Ceara (UFC), Fortaleza, Brazil. His research interests include telemetry, wireless sensor networks, embedded systems, and data communications. 

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