Simultaneous X-ray Video-Fluoroscopy and Pulsed Ultrasound Velocimetry Analyses of the Pharyngeal Phase of Swallowing of Boluses with Different Rheological Properties

Abstract

The Ultrasound Velocity Profiling (UVP) technique allows real-time, non-invasive flow mapping of a fluid along a 1D-measuring line. This study explores the possibility of using the UVP technique and X-ray video-fluoroscopy (XVF) to elucidate the deglutition process with the focus on bolus rheology. By positioning the UVP probe so that the pulsed ultrasonic beam passes behind the air-filled trachea, the bolus flow in the pharynx can be measured. Healthy subjects in a clinical study swallowed fluids with different rheological properties: Newtonian (constant shear viscosity and non-elastic); Boger (constant shear viscosity and elastic); and shear thinning (shear rate-dependent shear viscosity and elastic). The results from both the UVP and XVF reveal higher velocities for the shear thinning fluid, followed by the Boger and the Newtonian fluids, demonstrating that the UVP method has equivalent sensitivities for detecting the velocities of fluids with different rheological properties. The velocity of the contraction wave that clears the pharynx was measured in the UVP and found to be independent of bolus rheology. The results show that UVP not only assesses accurately the fluid velocity in a bolus flow, but it can also monitor the structural changes that take place in response to a bolus flow, with the added advantage of being a completely non-invasive technique that does not require the introduction of contrast media.

Texture properties of foods targeted for individuals with limited oral processing capabilities: the elderly, dysphagia, and head and neck cancer patients

“…109 Sensory studies employing panellists with and without swallowing issues are needed to support instrumental methods in evaluating the tactile safety, sensory acceptance, and nutritional adequacy of foods for individuals with limited OPC. 56,101,110…”

“…100 Further studies and methodological innovations are essential to understanding the cross-talk among shear viscosity, extensional viscosity, sensory texture, video fluoroscopic swallowing tests, and ultrasonic measurements. 101 Recent developments have been made in this regard. For instance, Kato et al 9 applied fibreoptic endoscopy and video fluoroscopy to swallowing studies to determine appropriate food textures for elderly patients with eating difficulties.…”

A method for evaluating time‐resolved rheological functionalities of fluid foods

“…To investigate the rheological properties that an ideal swallowed food should have to prevent aspiration, it is necessary to investigate the dynamics of the swallowed food in vivo and identify a causal relationship with the rheological properties of foods evaluated in vitro (Cutler, Morris, & Taylor, 1983; Houska et al, 1998; Hutchings & Lillford, 1988; Nakauma, Ishihara, Funami, & Nishinari, 2011; Shama & Sherman, 1973; Wood, 1968). In recent years, the development of in vivo methods of measurement has been remarkable, as represented by video fluorography (Bangyeekhan, Leelamanit, & Tekasakul, 2013; Nishinari, 2004; Palmer & Hiiemae, 1997; Qazi, Ekberg, Wiklund, Mansoor, & Stading, 2020; Takahashi et al 2002; Zhu, Mizunuma, & Michiwaki, 2014) and ultrasonic pulse Doppler (Gao & Kohyama, 2014; Hasegawa, Nakazawa, & Kumagai, 2008; Hasegawa, Otoguro, Kumagai, & Nakazawa, 2005; Kumagai, Tashiro, Hasegawa, Kohyama, & Kumagai, 2009; Moritaka & Nakazawa, 2009; Nagatoshi et al 2001; Qazi et al, 2020; Tashiro, Hasegawa, Kohyama, Kumagai, & Kumagai, 2010) methods, which have enabled detailed access to the behavior of the bolus in the swallowing process.…”

Remote Sensing of the Nano-Rheological Properties of Soft Materials Using Magnetic Nanoparticles and Magnetic AC Susceptometry

“…To overcome this issue, non-invasive methods are used to monitor the dynamic changes in food, and sensors are attached to subjects to track muscles and organs related to the oral processing of food. For instance, tongue pressure sensing using pressure transducers was used to observe palatal and swallowing pressures [ 3 ], biting pressures and forces were measured using sheet sensors [ 4 ], and ultrasound velocity profiling and X-ray video fluoroscopy were used for the in situ flow mapping of fluids with a focus on bolus rheology [ 5 ]. The complexity of the oral experience and the lack of characterization techniques for real time in vivo characterizations are the two major challenges in understanding food oral processing [ 6 ].…”