Percutaneous insertion is one of the most common minimally invasive procedures. Compared with traditional straight rigid needles, bevel-tipped flexible needle can generate curved trajectories to avoid obstacles and sensitive organs. However, the nonlinear large deflection problem challenges the bending prediction of the needle, which dramatically influences the surgical success rate. This paper analyzed the mechanism of needle-tissue interaction, and established a mechanics-based model of the needle bending during an insertion. And then, a discretization of the bending model was adopted to accurately predict the large bending of the needle in soft tissue. Insertion experiments were conducted to validate the bending prediction model. The results showed that the large needle bending was predicted with the mean/RMSE/maximumu error of 0.42 mm / 0.26 mm / 1.08 mm, which was clinically acceptable. This proved the rationality and accuracy of the proposed model.
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http://dx.doi.org/10.1016/j.medengphy.2024.104156 | DOI Listing |
Phys Med Biol
December 2024
Harbin University of Science and Technology, No.52 Xuefu Road, Nangang District, Harbin City, Heilongjiang Province, Harbin, 150080, CHINA.
Objective: Due to the limited operating space in the magnetic resonance (MR) environment, there is coupled motion in the insertion mechanism, which not only reduces the flexibility of the robot but also challenges the insertion path planning. Meanwhile, the path planning is also restricted by the bending rule of the flexible needle, thus the bending model of the needle is also essentially built.
Approach: This paper proposes a path planner for the flexible needle based on both the coupled motion kinematics of the insertion robot and the bending model of the flexible needle.
Polymers (Basel)
November 2024
Department of Industrial and Civil Construction Technology, L.N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan.
This study investigates the modification of bituminous mixtures by varying percentages of PET particles (1%, 3%, 5%, 8%, 10%, and 12% PET). The following methods were employed to analyze the samples: the ring-and-ball softening point determination method (ASTM D36/D36M-14), the Fraass breaking point determination method (EN 12593: 2015), the elongation determination method (EN 13589: 2014), and the needle penetration depth determination method (EN 1426: 2015). Optimal bitumen/PET ratios were identified to obtain modified bituminous mixtures (MBMs) with enhanced operational characteristics (5% and 8% PET).
View Article and Find Full Text PDFHeliyon
December 2024
Department of Tissue Engineering and Applied Cell Sciences, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
KTiOPO (KTP) nanoparticles (NPs) are potential materials as biolabels for long-term imaging. Optimizing their properties can lead to higher imaging efficiency and lower cytotoxicity and side effects. In this study, these nanoparticles were synthesized using the co-precipitation method and capping agents of oxalic acid and glycine.
View Article and Find Full Text PDFJ Cutan Aesthet Surg
August 2023
Department of Dermatotherapy and Cosmetology, Maharashtra Medical Foundation's Joshi Hospital, Pune, Maharashtra, India.
Intralesional injections to wide, thick lesions and lesions on curved surfaces are challenging with the syringe and needle unit being held parallel to the skin surface. Bending the needle eases negotiation by lifting the syringe away from the skin surface with the needle entering parallel to the lesion ensuring uniform and optimal drug delivery.
View Article and Find Full Text PDFHealth Technol Assess
December 2024
York Trials Unit, Department of Health Sciences, University of York, York, UK.
Background: Dupuytren's contracture is caused by nodules and cords which pull the fingers towards the palm of the hand. Treatments include limited fasciectomy surgery, collagenase injection and needle fasciotomy. There is limited evidence comparing limited fasciectomy with collagenase injection.
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