Contact Patterns Using Miniature Radio Transmitters

Ingestible devices for studying the gastrointestinal physiology and their application in oral biopharmaceutics

Ingestible sensor systems are unique tools for obtaining physiological data from an undisturbed gastrointestinal tract. Since their dimensions correspond to monolithic oral dosage forms, such as enteric coated tablets or hydrogel matrix tablets, they also allow insights into the physiological conditions experienced by non-disintegrating dosage forms on their way through the gastrointestinal tract. In this work, the different ingestible sensor systems which can be used for this purpose are described and their potential applications as well as difficulties and pitfalls with respect to their use are presented. It is also highlighted how the data on transit times, pH, temperature and pressure as well as the data from different animal models commonly used in drug product development such as dogs and pigs have contributed to a deeper mechanistic understanding of oral drug delivery.

Perioral force measurement by a radiotelemetry device

A telemetric method was developed to monitor the active and passive perioral forces exerted on the maxillary dental arch. The system consists of intraoral and extraoral units. An electromagnetic coupling between intraoral and extraoral coils supplies the power of the intraoral unit and transmits the signals induced by variations in perioral forces. The force sensor has a diameter of 6 mm, a thickness of 1 mm, and is constructed of an 0.08 mm thick cantilever beam to which semiconductor strain gauges are cemented. Clinical application of the system was tested in four adult subjects. The forces on the labial surface of an upper central incisor were 1.5 gm/cm2 during rest, 10.9 gm/cm2 during swallowing, and 5.0 gm/cm2 during speech; the corresponding lingual forces were 4.0 gm/cm2, 19.1 gm/cm2, and 13.9 gm/cm2, respectively. Lingual forces were always higher than labial forces. The telemetry system can be used to monitor up to 6 hours of continual variations in perioral forces.