Communication Strategies for Various Types of Swallowable Telemetry Capsules

Abstract

In this chapter, introducing some of the ideas, potentialities, and limitations of swalowable telemetry capsule systems. The telemetry systems were widely used for animal research while the subject can do its regular activities [1-9]. Therefore, it is an ideal method to collect the data of migration path and environmental data. In order to collect the data, the telemetry system has to be attached or implanted to the subjects and transmits the signal throughout the antenna. For the human patients, most of physiological signal from outside of the body did not need telemetry systems, because the signal was easily distorted when the patients were moving. Therefore, the telemetry systems are used when the device is implant into the patients and then collect the data. Since the implantation of the device is extremely difficult work, using the telemetry system is limited for scientific researches and a commercial medical telemetry device was not advent. Since the implantable telemetry systems is limited by the regulations and safety issue, the scientists look forward to develop a disposable capsule that resemble a medical pill and automatically measure the various philological data after swallow it. There are many frontier researches about the telemetry capsules. Some of the capsule measured the intraluminal pressure from inside of the gastro intestine while the capsule goes naturally flow toward to aboral direction [10-14]. Since the physician gets the intraluminal data, it was hard to assume a location of the capsule such as the capsule is in the middle of a duodenum or jejunum? Another capsule can measure pH signals from the gastro intestine. This capsule provides the meaningful data to diagnosis many diseases such as the gastroesophageal reflux. These capsules also measure the pH signal while it is naturally flow and does not provide location information. While most of the capsules was measuring the signal when the capsule was naturally flow toward to aboral direction, a bravo capsule can stop at the esophagus and measuring the pH difference [15-19]. Other capsules measures the core temperature [20, 21], which is a bit higher than skin temperature. Unlike above applications, a capsule endoscopy is a revolutionary product that captures inside of the gastro images and transmits it throughout the RF transmitter [22-26]. In order to get clear images, the data rate of the RF transmitter has to be sufficiently high while the power consumption is still low that could be active by small coin batteries. The frontier of this field is Given Image company products and it could monitor not only the small intestine but also the esophagus and colon.