Measurement and modelling of sensory-motor interactions between fluid rheology and swallowing biomechanics

吞咽是大多数人认为理所当然的行为。无论我们是在喝一杯水，还是在品尝最喜欢的主菜，我们都在吞咽，没有意识到食物或液体通过口腔和喉咙的成功运输涉及口咽感觉功能和上呼吸道超过38对肌肉的顺序收缩之间的复杂相互作用。吞咽的生物力学必须进行微调，以处理各种不同的食物和液体质地，并依赖于这种微调的感官信息。稀液体可以说是最难安全吞咽的质地，因为它们流动迅速，如果吞咽生物力学不合时宜，很容易被吸入（进入气道）。我实验室研究的长期目标是更好地了解不同粘度液体的吞咽生物力学变化，并确定流体流动特性（流变学）的感官意识如何影响这种变化。在这个过程中的崩溃是吞咽困难（吞咽障碍）的一部分，它对健康和生活质量都有重大影响。在接下来的5年里，我们有以下短期目标：a)测量各种液体刺激的流变（流动）特性，包括用于吞咽障碍评估和管理的液体，如钡造影剂和增稠液体。b)测量人体对流体流变微小差异的感官辨别能力，识别最小的可感知差异。c)测量各种生理吞咽信号（舌腭压力、肌电图、超声、影像透视），以表征人类对流体流动差异的运动变化模式。d)开发和验证放射图像分析技术（以及相关的用户友好工具，如image - j插件），以量化吞咽生物力学的生理差异，以响应流体流变学的差异。e)利用这些先前目标产生的数据来建立一个数学模型，该模型可以准确地解释吞咽生物力学在可感知的流体粘度差异中的变化。该研究项目的组成部分是对来自工程和语言病理学（S-LP）学科的高素质人才进行跨专业培训。我们正在申请资金，以支持这两个学科的学员进行研究和应用培训机会。这将促进对S-LPs的仪器和测量的理解，以及对工程师在生理环境（吞咽损伤）中应用工程和测量技术的理解。最终，该研究项目将为严格的测量和经验证据提供基础，在此基础上，可以建立与吞咽障碍管理相关的几个不同领域的进步。其中包括改进和开发用于评估和管理环境的流变改性流体；客观测量吞咽运动行为的设备和方案的发展；以及培训技术的发展，以支持医疗保健专业人员精确和准确地测量吞咽行为。

The act of swallowing is one that most people take for granted. Whether we are drinking a glass of water, or savouring a favourite main course, we swallow, unaware that the successful transport of food or fluid through our mouths and throats involves a complex interaction between oro-pharyngeal sensory function and the sequenced contraction of more than 38 paired muscles in the upper aerodigestive tract. The biomechanics of swallowing must be fine-tuned to deal with a variety of different food and liquid textures, and rely on sensory information for this fine-tuning. Thin liquids are arguably the most challenging texture to swallow safely, because they flow fast and can easily be aspirated (enter the airway) if swallowing biomechanics are mistimed. A long-term goal of the research in my laboratory is to better understand how swallowing biomechanics vary across liquids with different viscosities and to determine how sensory awareness of fluid flow characteristics (rheology) influences this variation. Breakdowns in this process are part of dysphagia (swallowing impairment), which has significant consequences both for health and for quality of life. Over the next 5 years, we have the following short-term goals: a) To measure the rheological (flow) characteristics of a variety of fluid stimuli, including those used in the assessment and management of swallowing impairment, such as barium contrast media and thickened liquids. b) To measure human sensory discrimination ability for small differences in fluid rheology, to identify the smallest perceivable differences. c) To measure a variety of physiological swallowing signals (tongue-palate pressures, electromyography, ultrasound, videofluoroscopy) to characterize human patterns of motor variation in response to differences in fluid flow. d) To develop and validate radiographic image analysis techniques (and associated user-friendly tools, such as Image-J plug-ins) to quantify physiological differences in swallowing biomechanics in response to differences in fluid rheology. e) To use these data arising from these previous goals to build a mathematical model that accurately accounts for the variation of swallowing biomechanics across perceivable differences in fluid viscosity. Integral to this program of research is the interprofessional training of highly qualified personnel from the disciplines of engineering and speech-language pathology (S-LP). We are requesting funding to support trainees from both disciplines in research and applied training opportunities. This will foster improved understanding of instrumentation and measurement for the S-LPs, and of the application of engineering and measurement techniques to a physiological context (swallowing impairment) for the engineers. Ultimately, this program of research will provide a foundation of rigorous measurement and empirical evidence upon which advancements in several different fields related to the management of swallowing disability can be built. These include the refinement and development of rheologically modified fluids for use in assessment and management contexts; the development of devices and protocols for objectively measuring swallowing motor behaviours; and the development of training techniques to support precise and accurate measurement of swallowing behaviours by healthcare professionals.