Viscoelastic Characteristics of Porcine Liver

Viscoelastic Characteristics of Porcine Liver

In this post, viscoelastic characteristics of porcine liver are measured using rheological experiments. These data were needed for needle insertion experiments. The contributors of this project are Mahdieh Babaiasl, and Fan Yang under the supervision of Dr. John Swensen. Sample Preparation for Rheological Tests Porcine liver was obtained from the WSU's meat science lab right after slaughter to avoid the changing of tissue properties. No authorization or approval was required since the liver was qualified to be food. The liver is then put in the 0.9% Sodium Chloride solution (9g NaCl was dissolved in 700 ml water in clean container…
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Heat Treatment of Nitinol for Different Stylet Shapes

Heat Treatment of Nitinol for Different Stylet Shapes

In this post you will learn about an approach to fabricate different stylet shapes for our proposed stylet and tube steerable needles using heat treatment of the Nitinol (a Shape Memory Alloy SMA). Our lab developed a new class of steerable needles called Stylet and Tube Steerable Needles in which the direction of the tissue fracture is controlled by the inner Stylet followed by the outer tube to help steer the needle. Stylet and Tube Steerable Needles The shape of the stylet and the step length determine the radius of curvature of the steerable needle. For this reason, we have…
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Resultant Radius of Curvature of Stylet and Tube Steerable Needles

Resultant Radius of Curvature of Stylet and Tube Steerable Needles

Our paper "Resultant Radius of Curvature of Stylet-and-Tube Steerable Needles Based on the Mechanical Properties of the Soft Tissue, and the Needle" is accepted to be published at the proceedings of the International Conference on Intelligent Robots and Systems (IROS) which is scheduled to be held on Sun, Oct 25, 2020 – Thu, Oct 29, 2020 at Las Vegas, NV (most likely it will be virtual because of the Pandemic). The contributors of this project are Fan Yang, and Mahdieh Babaiasl who conducted the research under the supervision of Dr. John Swensen. Stylet-and-Tube Steerable Needles. The combined radius of curvature…
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Fracture-directed Waterjet Needle Steering: Design, Modeling, and Path Planning

Fracture-directed Waterjet Needle Steering: Design, Modeling, and Path Planning

Our paper on fracture-directed waterjet needle steering is accepted to be presented at BioRob 2020 and also to be published in IEEE. The contributors of this paper are Mahdieh Babaiasl, Stefano Bocelli, and Fan Yang under the supervision of Dr. John Swensen. The abstract of this paper is: Steerable needle technology has the promise of improving outcomes by enhancing the accuracy of different therapies and biopsies, as they can be steered to a target location around obstacles. Achieving small radius of curvature and being able to control both radius of curvature and tip travel are of paramount importance in steerable…
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Duty Cycling of Waterjet Can Improve Steerability and Radius-of-Curvature (ROC) for Waterjet Steerable Needles

Duty Cycling of Waterjet Can Improve Steerability and Radius-of-Curvature (ROC) for Waterjet Steerable Needles

Our paper on curvature control of waterjet steerable needles is accepted to be presented at ISMR 2020 and also to be published in IEEE. The contributors of this paper are Mahdieh Babaiasl, and Fan Yang under the supervision of Dr. John Swensen. The abstract of this paper is: Steerable needles are a type of medical devices that can steer around obstacles to reach to a target location and thus can improve the accuracy of medical procedures. Radius-of-Curvature (ROC) is of paramount importance while designing steerable needles and achieving smaller radius and being able to control it is very important in…
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Towards Waterjet Steerable Needles

Towards Waterjet Steerable Needles

This paper measured the waterjet needle's insertion forces and compared them with a traditional needle with no waterjet running through. It is shown that incorporating waterjet reduces the insertion force and thus buckling of the needle. The contributors for this project are Mahdieh Babaiasl, and Fan Yang under the supervision of Dr. John P. Swensen. Abstract of the Paper Towards Waterjet Steerable Needles Water-jet technology has been used extensively for decades industrially for many applications including mining, plastic, metal, stone, wood, and produce cutting. The use of water-jet in medical applications has been developed more recently and it is used…
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Fracture-Directed Steerable Needles

Fracture-Directed Steerable Needles

Our paper entitled "Fracture-Directed Steerable Needles" is published in the Journal of Medical Robotics Research. The authors of this manuscript are Fan Yang, Mahdieh Babaiasl, and John Swensen. Abstract of the "Fracture-Directed Steerable Needles" Steerable needles hold the promise of improving the accuracy of both therapies and biopsies as they are able to steer to a target location around obstructions, correct for disturbances, and account for movement of internal organs. However, their ability to make late-insertion corrections has always been limited by the lower bound on the attainable radius of curvature. This project involves a new class of steerable needle…
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Predictive mechanics-based model for depth of cut (DOC) of waterjet in soft tissue for waterjet-assisted medical applications

Predictive mechanics-based model for depth of cut (DOC) of waterjet in soft tissue for waterjet-assisted medical applications

Our new paper entitled "Predictive mechanics-based model for depth-of-cut (DOC) of waterjet in soft tissue for waterjet-assisted medical applications" is recently accepted to be published in Medical & Biological Engineering & Computing journal and is now online at the following address: Click HERE! This paper solves the fundamental physics problem of the interaction of the waterjet with the surrounding soft tissue for waterjet-assisted cutting in medical and surgical applications. Mahdieh Babaiasl, Stefano Bocelli, Yao Chen, and Fan Yang conducted this research under the supervision of Dr. John P. Swensen, and Dr. Jow-Lian Ding.  Watch a short video of the experiments below:…
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