Robot Guided Sheaths (RoGS) for Percutaneous Access to the Pediatric Kidney: Patient-Specific Design and Preliminary Results

2013 ◽  
Author(s):  
Tania K. Morimoto ◽  
Michael H. Hsieh ◽  
Allison M. Okamura
Keyword(s):  
Three Dimensional ◽  
The Body ◽  
Surrounding Tissue ◽  
Patient Specific ◽  
Three Dimensional Model ◽  
Specific Design ◽  
Surgical Access ◽  
Minimally Invasive Surgical ◽  
Area Of Interest ◽  
Ct Data

Robot-guided sheaths consisting of pre-curved tubes and steerable needles are proposed to provide surgical access to locations deep within the body. In comparison to current minimally invasive surgical robotic instruments, these sheaths are thinner, can move along more highly curved paths, and are potentially less expensive. This paper presents the patient-specific design of the pre-curved tube portion of a robot-guided sheath for access to a kidney stone; such a device could be used for delivery of an endoscope to fragment and remove the stone in a pediatric patient. First, feasible two-dimensional paths were determined considering workspace limitations, including avoidance of the ribs and lung, and minimizing collateral damage to surrounding tissue by leveraging the curvatures of the sheaths. Second, building on prior work in concentric-tube robot mechanics, the mechanical interaction of a two-element sheath was modeled and the resulting kinematics was demonstrated to achieve a feasible path in simulation. In addition, as a first step toward three-dimensional planning, patient-specific CT data was used to reconstruct a three-dimensional model of the area of interest.

scholarly journals Spatial Sensitivity of ECG Electrode Placement

2021 ◽  
Vol 7 (2) ◽  
pp. 151-154
Author(s):  
Andra Oltmann ◽  
Roman Kusche ◽  
Philipp Rostalski
Keyword(s):  
Three Dimensional ◽  
Signal Propagation ◽  
Cellular Level ◽  
The Body ◽  
Electrode Placement ◽  
Patient Specific ◽  
Three Dimensional Model ◽  
Circular Pattern ◽  
Spatial Gradients ◽  
The Impact

Abstract The electrocardiogram (ECG) is a well-known technique used to diagnose cardiac diseases. To acquire the spatial signal characteristics from the thorax, multiple electrodes are commonly used. Displacements of electrodes affect the signal morphologies and can lead to incorrect diagnoses. For quantitative analysis of these effects we propose the usage of a numerical computer simulation. In order to create a realistic representation of the human thorax including the heart and lung a three-dimensional model with a simplified geometry is used. The electrical excitation of the heart is modelled on a cellular level via the bidomain approach. To numerically solve the differential equations, describing the signal propagation within the body, we use the finite element method in COMSOL Multiphysics®. The spatial gradients of the simulated body potentials are calculated to determine placement sensitivity maps. The simulated results show that the sensitivity is different for each considered point in time of each ECG wave. In general, the impact of displacement is increased as an electrode is more closely located to the signal source. However, in some specific regions associated with differential ECG leads the placement sensitivity distribution deviates from this simple circular pattern. The results provide useful information to enhance the understanding of placed specific effects on classical ECG features. By additional consideration of patient-specific characteristics in the future, the used model has the ability to investigate additional body-related aspects such as geometrical body shape or composition of various tissue types.

Design and operation of a tripod walking robot via dynamics simulation

Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Conghui Liang ◽  
Hao Gu ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone
Keyword(s):  
Mechanical Design ◽  
Low Cost ◽  
Three Dimensional ◽  
The Body ◽  
Dynamics Simulation ◽  
Walking Ability ◽  
Walking Robot ◽  
Three Dimensional Model ◽  
Software Environment ◽  
Leg Mechanisms

SUMMARYA mechanical design and dynamics walking simulation of a novel tripod walking robot are presented in this paper. The tripod walking robot consists of three 1-degree-of-freedom (DOF) Chebyshev–Pantograph leg mechanisms with linkage architecture. A balancing mechanism is mounted on the body of the tripod walking robot to adjust its center of gravity (COG) during walking for balancing purpose. A statically stable tripod walking gait is performed by synchronizing the motions of the three leg mechanisms and the balancing mechanism. A three-dimensional model has been elaborated in SolidWorks® engineering software environment for a characterization of a feasible mechanical design. Dynamics simulation has been carried out in the MSC.ADAMS® environment with the aim to characterize and to evaluate the dynamic walking performances of the proposed design with low-cost easy-operation features. Simulation results show that the proposed tripod walking robot with proper input torques, gives limited reaction forces at the linkage joints, and a practical feasible walking ability on a flatten ground.

Accuracy of Patient-Specific 3D Printed Drill Guides in the Placement of a Canine Coxofemoral Toggle Pin through a Minimally Invasive Approach

2020 ◽  
Author(s):  
Brett G. Darrow ◽  
Kyle A. Snowdon ◽  
Adrien Hespel
Keyword(s):  
Minimally Invasive ◽  
Three Dimensional ◽  
Bone Tunnel ◽  
Patient Specific ◽  
Exit Point ◽  
Minimally Invasive Approach ◽  
Invasive Approach ◽  
Post Procedure ◽  
Drill Guide ◽  
Ct Data

Abstract Objective The aim of this study was to evaluate the accuracy of patient-specific three-dimensional printed drill guides (3D-PDG) for the placement of a coxofemoral toggle via a minimally invasive approach. Materials and Methods Pre-procedure computed tomography (CT) data of 19 canine cadaveric hips were used to design a cadaver-specific 3D-PDG that conformed to the proximal femur. Femoral and acetabular bone tunnels were drilled through the 3D-PDG, and a coxofemoral toggle pin was placed. The accuracy of tunnel placement was evaluated with post-procedure CT and gross dissection. Results Coxofemoral toggle pins were successfully placed in all dogs. Mean exit point translation at the fovea capitis was 2.5 mm (0.2–7.5) when comparing pre- and post-procedure CT scans. Gross dissection revealed the bone tunnel exited the fovea capitis inside (3/19), partially inside (12/19) and outside of (4/19) the ligament of the head of the femur. Placement of the bone tunnel through the acetabulum was inside (16/19), partially inside (1/19) and outside (2/19) of the acetabular fossa. Small 1 to 2 mm articular cartilage fragments were noted in 10 of 19 specimens. Clinical Significance Three-dimensional printed drill guide designed for coxofemoral toggle pin application is feasible. Errors are attributed to surgical execution and identification of the borders of the fovea capitis on CT data. Future studies should investigate modifications to 3D-PDG design and methods. Three-dimensional printed drill guide for coxofemoral toggle pin placement warrants consideration for use in select clinical cases of traumatic coxofemoral luxation.

Three-dimensional modelling of wheelchair contrived with lower limb exoskeleton for right hemiplegic dysfunction

2020 ◽  
Vol 234 (7) ◽  
pp. 651-659
Author(s):  
AN Nithyaa ◽  
S Poonguzhali ◽  
N Vigneshwari
Keyword(s):  
Lower Limb ◽  
Computer Aided Design ◽  
Age Groups ◽  
Three Dimensional ◽  
The Body ◽  
Three Dimensional Model ◽  
Design Quality ◽  
Lower Limb Exoskeleton ◽  
Repeated Exercise ◽  
Aided Design

Hemiplegia is a type of paralysis that affects one side of the body due to stroke, characterizing severe weakness or rigid movement. Many people of different age groups are affected by this condition which cannot be completely cured but can be minimized through proper physiotherapy. A continuous and repeated exercise has to be given to the hemiplegic subjects to regain their motor function. To serve this purpose, a three-dimensional model of wheelchair contrived with lower limb exoskeleton is designed and motion analysis is done using SolidWorks. This virtual model of the object is created with the assistance of computer-aided design software. Professionals can be able to do the experiment on what-if scenarios with their three-dimensional designs, which helps to validate their devices and identify any snags with design quality. The pattern of behaviour of lower limb exoskeleton is predicted using SimMechanics in MATLAB.

The Effects of Large Blood Vessels on Three-Dimensional Tissue Temperature Distributions During Electromagnetic Induced Nano-Hyperthermia: Numerical Simulation

2008 ◽  
Author(s):  
Zhong-Shan Deng ◽  
Jing Liu
Keyword(s):  
Blood Vessels ◽  
Tumor Cells ◽  
Three Dimensional ◽  
The Body ◽  
Thermal Therapy ◽  
Tissue Temperature ◽  
Surrounding Tissue ◽  
Temperature Profiles ◽  
Hyperthermia Treatment ◽  
Tumor Hyperthermia

As is well known, the blood flowing through large blood vessels acts as a heat sink and plays an important role in affecting temperature profiles of heated tissues [1]. In hyperthermia, heating is usually limited to the tumor and a small margin of the surrounding tissue. Since the temperatures in the rest of the body remain normal, the blood that supplies the tumor will be relatively cold. Consequently, the blood flow inside a large vessel will represent a sink which cools the nearby heated tissues and then limits heating lesion during tumor hyperthermia. Under this adverse condition, a part of vital tumor cells may remain in the thermally lethal area and lead to recurrence of tumors after hyperthermia treatment. More specifically, tumor cell survival in the vicinity of large blood vessels is often correlated with tumor recurrence after thermal therapy. Therefore, it is difficult to implement an effective hyperthermia treatment when a tumor is contiguous to a large blood vessel or such vessel transits the tumor. How to totally destroy tumor cells in the vicinity of large blood vessels has been a major challenge in hyperthermia [2].

scholarly journals Two-Phase Non-Newtonian Pulsatile Blood Flow Simulations in a Rigid and Flexible Patient-Specific Left Coronary Artery (LCA) Exhibiting Multi-Stenosis

2021 ◽  
Vol 11 (23) ◽  
pp. 11361
Author(s):  
Abdulgaphur Athani ◽  
Nik Nazri Nik Ghazali ◽  
Irfan Anjum Badruddin ◽  
Abdullah Y. Usmani ◽  
Sarfaraz Kamangar ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Left Coronary Artery ◽  
Solid Wall ◽  
Three Dimensional ◽  
Patient Specific ◽  
Maximum Pressure ◽  
Three Dimensional Model ◽  
Two Phase ◽  
Pressure Drops

Coronary artery disease (CAD) is stated as one of the most common causes of death all over the world. This article explores the influence of multi stenosis in a flexible and rigid left coronary artery (LCA) model using a multiphase blood flow system which has not yet been studied. Two-way fluid–solid interaction (FSI) is employed to achieve flow within the flexible artery model. A realistic three-dimensional model of multi-stenosed LCA was reconstructed based on computerized tomography (CT) images. The fluid domain was solved using a finite volume-based commercial software (FLUENT 2020). The fluid (blood) and solid (wall) domains were fully coupled by using the ANSYS Fluid-Structure Interaction solver. The maximum pressure drops, and wall shear stress was determined across the sever stenosis (90% AS). The higher region of displacement occurs at the pre-stenosis area compared to the other area of the left coronary artery model. An increase in blood flow velocity across the restricted regions (stenosis) in the LCA was observed, whereas the recirculation zone at the post-stenosis and bifurcation regions was noted. An overestimation of hemodynamic descriptors for the rigid models was found as compared to the FSI models.

scholarly journals Three-Dimensional Model Extraction and Parameter Measurement of Cerebral Hemangioma Based on Mimics

2022 ◽  
Vol 2160 (1) ◽  
pp. 012012
Author(s):  
An Qu ◽  
Tianmin Guan ◽  
Tianxiang Gan ◽  
Yuanyuan Li ◽  
Zhuang Lin ◽  
...  
Keyword(s):  
Therapeutic Effect ◽  
Cerebral Angiography ◽  
Structural Design ◽  
3D Model ◽  
Three Dimensional ◽  
The Body ◽  
Model Reconstruction ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
3D Model Reconstruction

Abstract In this paper, Mimics is using to reconstruct the 3D model of hemangioma from 2D cerebral angiography images. The process of 3D model reconstruction is formulated. The hemangioma model is extracted and the parameters of the hemangioma are measured, which provided a model basis for the structural design of the spring coil. The shape and structure of the coil are very important for the therapeutic effect. During the treatment, the coil is implanted into the hemangioma from outside the body through a catheter.

scholarly journals Computational Fluid Dynamics Characterization of Two Patient-Specific Systemic-to-Pulmonary Shunts before and after Operation

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Neichuan Zhang ◽  
Haiyun Yuan ◽  
Xiangyu Chen ◽  
Jiawei Liu ◽  
Qifei Jian ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Pulmonary Artery ◽  
Energy Loss ◽  
Three Dimensional ◽  
Left Pulmonary Artery ◽  
Postoperative Recovery ◽  
Patient Specific ◽  
Wall Shear ◽  
Ct Data

Studying the haemodynamics of the central shunt (CS) and modified Blalock–Taussig shunt (MBTS) benefits the improvement of postoperative recovery for patients with an aorta-pulmonary shunt. Shunt configurations, including CS and MBTS, are virtually reconstructed for infants A and B based on preoperative CT data, and three-dimensional models of A, 11 months after CS, and B, 8 months after MBTS, are reconstructed based on postoperative CT data. A series of parameters including energy loss, wall shear stress, and shunt ratio are computed from simulation to analyse the haemodynamics of CS and MBTS. Our results showed that the shunt ratio of the CS is approximately 30% higher than the MBTS and velocity distribution in the left pulmonary artery (LPA) and right pulmonary artery (RPA) was closer to a natural development in the CS than the MBTS. However, energy loss of the MBTS is lower, and the MBTS can provide more symmetric pulmonary artery (PA) flow than the CS. With the growth of infants A and B, the shunt ratio of infants was decreased, but maximum wall shear stress and the distribution region of high wall shear stress (WSS) were increased, which raises the probability of thrombosis. For infant A, the preoperative abnormal PA structure directly resulted in asymmetric growth of PA after operation, and the LPA/RPA ratio decreased from 0.49 to 0.25. Insufficient reserved length of the MBTS led to traction phenomena with the growth of infant B; on the one hand, it increased the eddy current, and on the other hand, it increased the flow resistance of anastomosis, promoting asymmetric PA flow.

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