A fibre optic catheter for simultaneous measurement of longitudinal and circumferential muscular activity in the gastrointestinal tract

Abstract

Diagnostic catheters based on fibre Bragg gratings (FBG's) are proving to be highly effective for measurement of the muscular activity associated with motility in the human gut. While the primary muscular contractions that generate peristalsis are circumferential in nature, it has long been known that there is also a component of longitudinal contractility present, acting in harmony with the circumferential component to improve the overall efficiency of material movement. We report the detection of longitudinal motion in mammalian intestine using an FBG technique that should be viable for similar detection in humans. The longitudinal sensors have been combined with our previously reported FBG pressure sensing elements to form a composite catheter that allows the relative phase between the two components to be detected. The catheter output has been validated using video mapping in an ex-vivo rabbit ileum preparation.

Effect of electrode separation on high‐resolution impedance manometry catheters for ex vivo animal experiments

“…The outside diameter is 3 and 5 mm at the pressure sensors. The custom‐made catheter consists of 35 pressure sensors based on fiber optic sensing technology at 10 mm intervals, with 16 impedance segments, with 10 mm electrode separation (Figure B).…”

Review of fiber-optic pressure sensors for biomedical and biomechanical applications

“…The excellent and significant correlation (r ≥ 0.992) between the FBG based catheter and a reference solid-state catheter (Gaeltec, Dunvegan, Scotland; www.gaeltec.com) suggested one could substitute the other. Meanwhile, further studies have been published confirming FBG potentialities as multipoint or multiparameter sensors, 202,205 and their ability to incorporate new features, such as the measurement of longitudinal and circumferential muscular activity in the gastrointestinal tract. 202 An interesting example of the versatility and applicability of FBG sensors was given by Ferreira et al 17 who proposed a complete system for dynamic evaluation of the women pelvic floor muscle strength.…”

“…Meanwhile, further studies have been published confirming FBG potentialities as multipoint or multiparameter sensors, 202,205 and their ability to incorporate new features, such as the measurement of longitudinal and circumferential muscular activity in the gastrointestinal tract. 202 An interesting example of the versatility and applicability of FBG sensors was given by Ferreira et al 17 who proposed a complete system for dynamic evaluation of the women pelvic floor muscle strength. The lack of muscle action seems to play an important role in development of several pelvic dysfunctions, such as urinary incontinence and genital prolapses.…”

“…Nevertheless, more contributions can be found concerning the use of FOS to sense pressure in other sites of the human body, such as the trachea, 200,201 the gastrointestinal tract, 2,56,202 and the intravaginal, 17 intraocular, 146 and intramedullary spaces. 147 We will explore some of them in the following lines.…”

A composite fibre optic catheter for monitoring peristaltic transit of an intra-luminal bead

“…The composite motility catheter comprises alternate pressure and motion sensing transducers and is similar in concept to the longitudinal strain sensor developed by this team in 2011 . In this instance however, the motion sensors respond to the passage of material along the catheter as opposed to monitoring the frictional contact between luminal wall and the outer surface of the catheter.…”