Indwelling robots for ruminant health monitoring: A review of elements

Maximizing the health, productivity, and sustainability of ruminant animals is an essential societal goal for a variety of reasons including food security, impact on the environment, and global nutrition; however, monitoring the metabolism of ruminant animals is currently a time-consuming and imprecise process. An indwelling robot residing within the ruminant gut would likely revolutionize metabolic monitoring in ruminants by providing a new level of detail into the complex and stratified chemistry of fermentation that goes on hour by hour. Indwelling robots could become an essential tool for ruminant health monitoring because many of the health, productivity, and sustainability challenges experienced by ruminants can be indicated and potentially influenced by changes in biomarkers within the rumen. We believe next-generation ruminant health monitoring will evolve from continuous biomarker measurement, reliable data transmission, and precise locomotion, all of which can be enabled by advances in indwelling ruminal robot design. Within this review, we summarize the requirements of and progress toward engineering advancements necessary to develop field-deployable robots for ruminant metabolic monitoring. The vital elements of an autonomous indwelling medical robot include locomotion, localization, wireless data transmission, and wireless power transfer. The state-of-the-art technologies associated with each element are articulated in this review. The comprehensive techniques of locomotion, the approaches for precise localization, as well as technologies for wireless power and data transmission that will make the indwelling robot entirely autonomous are enunciated, with a special focus on ruminants. The evaluated indices are potentially useful not only to assess the health of the ruminant but also to refine and standardize the assessment protocols. The overview presented in this article on the advances, imperative requirements, and challenges enables the deployment of the ruminal robot for health monitoring in ruminants.