Bone cutting with high performance material removal is critical for enhancing orthopedic surgery. Ultrasonically assisted cutting (UAC) is an advanced process with the potential to improve the material removal. However, strain and other intermediate variables in bone cutting are difficult to obtain because of the lack of suitable measurement methods, especially for high-frequency vibration-assisted cutting. In this study, digital image correlation (DIC) analysis was applied for the first time to investigate the mechanism of crack development during conventional cutting (CC) and ultrasonically assisted cutting of cortical bone. A novel method for calculating cutting and thrust forces under the mixed fracture mode of bone was also proposed. Extensive experimental results showed that the average strain and strain rate of cortical bone decreased after the application of UAC, but the maximum transient strain rate in UAC was greater than that in CC, and the crack-affected area and shear band width in UAC were smaller than those in CC. In addition, the strain parameters obtained by the DIC analysis were used to calculate the cutting and thrust forces in the hybrid fracture mode. The calculated values of forces matched well with the measured results, indicating the strong feasibility of DIC applications in orthogonal bone cutting research. This study has significant theoretical and practical value since it reveals the fracture mechanism of cortical bone in UAC, demonstrates a non-contact full-field measurement method for tissue strain calculation, and provides inspiration for optimizing the design of innovative orthopedic instruments.
Modern-day microtomy requires high precision equipment to thinly section biological tissues. The sectioned tissue must be of good quality not showing cutting tracks or so-called artefacts. The quality of these sections is dependent on the blade wear, which is related to the hardness of the tissue sample, cutting angle and cutting speed. A test rig has been designed and manufactured to allow these parameters to be controlled. This has allowed for the blade wear to be analysed and quantified, and this has been completed for both ultrasonically assisted and conventional cutting. The obtained results showed a 25.2% decrease in average blade roughness after 38 cuts when using the ultrasonically assisted cutting regime. The data also showed no adverse effect on the quality of the slides produced when using this cutting methodology. Finally, the cutting force measured for both cutting regimes showed that ultrasonically assisted cutting required less force compared to conventional cutting. With the reduction of surface roughness and force, it is possible to state that ultrasonically assisted cutting reduces the wear of the blade, thereby increasing the life of the blades. An increase of just 10% in blade life would yield a cost saving of approximately 25% thereby reducing the environmental and financial impact of microtomy.
To benefit the tissue removal and postoperative rehabilitation, the increased efficiency and accuracy and the reduced operating force are strongly required in osteotomy. A novel elliptical vibration cutting (EVC) has been introduced for the bone cutting compared with the conventional cutting (CC) in this paper. With the assistance of the high-speed micrcope imaging and the dynamometer, the material removals of cortical bone and their cutting forces from two cutting regimes were recorded and analysed comprehensively, which clearly demonstrated the chip morphology improvement and the average cutting force reduction in the EVC process. It also revealed that the elliptical vibration of the cutting tool could promote the fracture propagation along the shear direction. These new findings will be of important theoretical and practical values to apply the innovative EVC process to the surgical procedures of osteotomy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.