Variable stiffness methods of flexible robots for minimally invasive surgery: A review

Abstract

With high flexibility and slim body, flexible robots have been widely used in minimally invasive surgery because they can safely reach the lesion deep inside the human body through small incisions or natural orifices. However, high stiffness of robot body is also required for transferring force and maintaining the motion accuracy. To meet these two contradictory requirements, various methods have been implemented to enable adjustable stiffness for flexible surgical robots. In this review, we first summarize the anatomic constraints of common natural tracts of human body to provide a guidance for the design of variable stiffness flexible robots. And then, the variable stiffness methods have been categorized based on their basic principles of varying the stiffness. In the end, two variable stiffness methods with great potential and the moving strategy of variable stiffness flexible robots are discussed.

Keywords

Minimally invasive surgery / Continuum robot / Variable stiffness

CRediT authorship contribution statement

Botao Lin: Investigation, Writing - original draft. Shuang Song: Data curation, Project administration, Validation. Jiaole Wang: Conceptualization, Funding acquisition, Investigation, Project administration, Supervision, Writing - original draft, Writing - review & editing.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work was suported in part by Talent Recruitment Project of Guangdong (2021QN02Y839), and in part by the Science Technology Innovation Committee of Shenzhen (JCYJ20220818102408018 and GXWD20231129103418001).

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