scholarly journals Effects of Helix Geometry on Magnetic Guiding of Helical Polymer Composites on a Gastric Cancer Model: A Feasibility Study

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1014 ◽  
Author(s):  
Yongju Kim ◽  
Jeong Eun Park ◽  
Jeong Jae Wie ◽  
Su Geun Yang ◽  
Don Haeng Lee ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Flat Surface ◽  
Three Dimensional ◽  
Target Lesion ◽  
Magnetic Flux Density ◽  
Soft Robot ◽  
Cancer Model ◽  
Soft Robots ◽  
Helical Polymer ◽  
Helix Geometry

This study investigates the effects of soft-robot geometry on magnetic guiding to develop an efficient helical mediator on a three-dimensional (3D) gastric cancer model. Four different magnetically active helical soft robots are synthesized by the inclusion of 5-μm iron particles in polydimethylsiloxane matrices. The soft robots are named based on the diameter and length (D2-L15, D5-L20, D5-L25, and D5-L35) with samples having varied helical pitch and weight values. Then, the four samples are tested on a flat surface as well as a stomach model with various 3D wrinkles. We analyze the underlying physics of intermittent magnetomotility for the helix on a flat surface. In addition, we extract representative failure cases of magnetomotility on the stomach model. The D5-L25 sample was the most suitable among the four samples for a helical soft robot that can be moved to a target lesion by the magnetic-flux density of the stomach model. The effects of diameter, length, pitch, and weight of a helical soft robot on magnetomotility are discussed in order for the robot to reach the target lesion successfully via magnetomotility.

scholarly journals An Alternative Method for Calculating the Eddy Current Loss in the Sleeve of a Sealless Pump

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 78
Author(s):  
Tomislav Strinić ◽  
Bianca Wex ◽  
Gerald Jungmayr ◽  
Thomas Stallinger ◽  
Jörg Frevert ◽  
...  
Keyword(s):  
Eddy Current ◽  
Three Dimensional ◽  
Eddy Current Loss ◽  
Theoretical Background ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Pump Impeller ◽  
Current Loss ◽  
Faraday’S Law ◽  
Transient Simulations

A sealless pump, also known as a wet rotor pump or a canned pump, requires a stationary sleeve in the air gap to protect the stator from a medium that flows around the rotor and the pump impeller. Since the sleeve is typically made from a non-magnetic electrically conductive material, the time-varying magnetic flux density in the air gap creates an eddy current loss in the sleeve. Precise assessment of this loss is crucial for the design of the pump. This paper presents a method for calculating the eddy current loss in such sleeves by using only a two-dimensional (2D) finite element method (FEM) solver. The basic idea is to use the similar structure of Ampère’s circuital law and Faraday’s law of induction to solve eddy current problems with a magnetostatic solver. The theoretical background behind the proposed method is explained and applied to the sleeve of a sealless pump. Finally, the results obtained by a 2D FEM approach are verified by three-dimensional FEM transient simulations.

scholarly journals Development of a Novel Orthotopic Gastric Cancer Mouse Model

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Wonyoung Kang ◽  
Leigh Maher ◽  
Michael Michaud ◽  
Seong-Woo Bae ◽  
Seongyeong Kim ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Mouse Models ◽  
Cancer Metastasis ◽  
Soft Tissues ◽  
Tumor Formation ◽  
Cancer Model ◽  
Orthotopic Model ◽  
Cancer Models ◽  
Organotropic Metastasis ◽  
Nsg Mouse

Abstract Background Gastric cancer metastasis is a highly fatal disease with a five-year survival rate of less than 5%. One major obstacle in studying gastric cancer metastasis is the lack of faithful models available. The cancer xenograft mouse models are widely used to elucidate the mechanisms of cancer development and progression. Current procedures for creating cancer xenografts include both heterotopic (i.e., subcutaneous) and orthotopic transplantation methods. Compared to the heterotopic model, the orthotopic model has been shown to be the more clinically relevant design as it enables the development of cancer metastasis. Although there are several methods in use to develop the orthotopic gastric cancer model, there is not a model which uses various types of tumor materials, such as soft tissues, semi-liquid tissues, or culture derivatives, due to the technical challenges. Thus, developing the applicable orthotopic model which can utilize various tumor materials is essential. Results To overcome the known limitations of the current orthotopic gastric cancer models, such as exposure of tumor fragments to the neighboring organs or only using firm tissues for the orthotopic implantation, we have developed a new method allowing for the complete insertion of soft tissue fragments or homogeneously minced tissues into the stomach submucosa layer of the immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mouse. With this completely-closed transplantation method, tumors with various types of tissue may be used to establish orthotopic gastric cancer models without the risks of exposure to nearby organs or cell leakage. This surgical procedure was highly reproducible in generating forty-eight mouse models with a surgery success rate of 96% and tumor formation of 93%. Among four orthotopic patient-derived xenograft (PDX) models that we generated in this study, we verified that the occurrence of organotropic metastasis in either the liver or peritoneal cavity was the same as that of the donor patients. Conclusion Here we describe a new protocol, step by step, for the establishment of orthotopic xenograft of gastric cancer. This novel technique will be able to increase the use of orthotopic models in broader applications for not only gastric cancer research but also any research related to the stomach microenvironment.

Phẫu thuật nội soi 3D cắt bán phần xa dạ dày trong điều trị ung thư dạ dày

2021 ◽  
Author(s):  
Hai Thanh Phan
Keyword(s):  
Gastric Cancer ◽  
Blood Loss ◽  
Operative Time ◽  
Distal Gastrectomy ◽  
Three Dimensional ◽  
Oncologic Outcome ◽  
Intraoperative Blood Loss ◽  
3D Laparoscopy ◽  
Distal Gastric Cancer ◽  
The Mean

TÓM TẮT Đặt vấn đề: Những nghiên cứu gần đây cho thấy phẫu thuật nội soi với kỹ thuật 3D (three - dimensional) đã mang lại nhiều thuận lợi trong điều trị ung thư dạ dày khi so sánh với màn hình 2D truyền thống. Vì vậy chúng tôi thực hiện nghiên cứu này với mục đích đánh giá tính an toàn, kết quả ngắn hạn và kết quả ung thư học của phẫu thuật nội soi 3D trong điều trị ung thư phần xa dạ dày. Phương pháp nghiên cứu: Thực hiện nghiên cứu tiến cứu trên 37 bệnh nhân cắt phần xa dạ dày kèm nạo vét hạch điều trị ung thư dạ dày bằng phẫu thuật nội soi kỹ thuật 3D tại Khoa Ngoại nhi - cấp cứu bụng, Bệnh viện Trung Ương Huế từ 03/2018 đến 09/2021. Kết quả: Phẫu thuật nội soi 3D được thực hiện ở tất cả 37 bệnh nhân, không có trường hợp nào chuyển mổ mở. Thời gian phẫu thuật trung bình là 69,86 ± 20,46 phút, lượng máu mất trong mổ trung bình là 171,22 ± 15,47 ml, số hạch vét được trung bình là 20,49 ± 4,11 hạch và thời gian nằm viện sau phẫu thuật trung bình là 10 ngày (6 - 26 ngày). Tỷ lệ biến chứng là 8,1 % với 1 trường hợp (2,7%) dò mỏm tá tràng, không có trường hợp nào tử vong sớm sau mổ. Tỉ lệ sống còn sau 1 năm là 87,27% và sau 3 năm là 83,31%. Kết luận: Áp dụng phẫu thuật nội soi 3D trong cắt phần xa dạ dày có thể thực hiện an toàn và khả thi. Giúp giảm đáng kể thời gian mổ, lượng máu mất trong mổ và đảm bảo được nguyên tắc an toàn về ung thư học. ABSTRACT EFFICACY USING THREE - DIMENSIONAL LAPAROSCOPY IN THE TREATMENT OF DISTAL GASTRIC CANCER Background: Recent studies have supported that three - dimensional (3D) laparoscopy has advantages in treating gastric cancer compared with conventional two - dimensional (2D) screens. This study investigated the safety, short - term efficacy, and oncological outcome of three - dimensional (3D) laparoscopic distal gastric cancer surgery. Materials and Methods: We prospectively analyzed the clinical data from 37 patients treated with 3D laparoscopic systemic lymphadenectomy for distal gastric cancer at the Hue Central Hospital from March 2018 to September 2021. The effects on operative time, intraoperative blood loss, the number of lymph nodes removed, postoperative recovery time, complications, and oncologic outcome were analyzed. Results: Three - dimensional (3D) laparoscopic distal gastrectomy was successfully carried out in 37 patients. The mean operative time was 69,86 ± 20,46 minutes, mean intraoperative blood loss was 171,22 ± 15,47 ml, the number of harvested lymph nodes was 20,49 ± 4,11, and the mean postoperative hospital stay was 10 (6 - 26 days). The incidence of postoperative complications was 8,1%, with 1 case of duodenal stump fistula. The one - year overall survival rate was 87,27%, and the three - year overall survival rate was 83,31%. Conclusions: 3D laparoscopy distal gastrectomy could be performed safely and feasibly. They reducethe operative time and intraoperative blood loss in distal gastrectomy with a good oncologic outcome. Keywords: Laparoscopic gastrectomy, D2 lymphadenectomy, 3D laparoscopy

A lateral approach to the feline cerebellar fossa: case report and identification of an external landmark for the tentorium ossium

2019 ◽  
Vol 22 (4) ◽  
pp. 358-365
Author(s):  
Marc Kent ◽  
Eric N Glass ◽  
Jordan Schachar
Keyword(s):  
Flat Surface ◽  
Three Dimensional ◽  
Lateral Approach ◽  
Cranial Morphology ◽  
Lateral Aspect ◽  
Temporal Fossa ◽  
3D Reconstructions ◽  
3D Volume ◽  
External Landmark ◽  
Ct Studies

Objectives The aim of this study was to describe the use of an external landmark that defines the attachment of the tentorium ossium for planning a craniectomy to access the cerebellar fossa. The external landmark was defined by a line where the caudal aspect of the convexity of the cranium transitions to a flat surface in the caudal aspect of the temporal fossa. We also aimed to determine if this external landmark was present and readily visualized, and to establish its relationship to the nuchal crest using three-dimensional (3D) volume-rendered CT reconstructions created from cats with normal cranial morphology. Methods First, a case is presented for the description of an approach in a cat with a meningioma located dorsolateral to the cerebellum. Second, CT studies of five cats with normal cranial morphology were selected. Regions of interest (ROIs) were drawn at the attachment of the tentorium ossium to the cranium and nuchal crest. Three-dimensional reconstructions were developed with colored ROI overlays. The external landmark defined the tentorial attachment on all 3D reconstructions. Additionally, using the postoperative CT of the clinical case described herein, ROIs of the tentorial attachment and nuchal crest along with a third ROI, the craniectomy, were drawn and overlaid on the 3D reconstruction to illustrate the position of the craniectomy in relation to the tentorium ossium attachment and nuchal crest. Results The use of the external landmark provided for a craniectomy that enabled adequate visualization for excision of a meningioma. On all 3D reconstructions, the external landmark was present and readily visualized. Conclusions and relevance Between the attachment of the tentorium ossium and nuchal crest exists an area adequately sized for a craniectomy in cats. Clinicians can use an identifiable external landmark on the lateral aspect of the cranium to plan the rostral boundary for a craniectomy to access the cerebellar fossa in cats.

scholarly journals Three-Dimensional Printing of a Hemorrhagic Cervical Cancer Model for Postgraduate Gynecological Training

Cureus ◽  
2017 ◽  
Author(s):  
Michael Bartellas ◽  
Stephen Ryan ◽  
Gregory Doucet ◽  
Deanna Murphy ◽  
Jacqueline Turner
Keyword(s):  
Cervical Cancer ◽  
Three Dimensional ◽  
Cancer Model ◽  
Three Dimensional Printing ◽  
Dimensional Printing

scholarly journals Robotic distal subtotal gastrectomy with D2 lymphadenectomy for advanced gastric cancer: a case report and technical description

2020 ◽  
Vol 2 (1) ◽  
pp. 18-21
Author(s):  
Francesco Giovanardi
Keyword(s):  
Gastric Cancer ◽  
Case Report ◽  
Three Dimensional ◽  
Subtotal Gastrectomy ◽  
Gastric Surgery ◽  
Robotic Systems ◽  
D2 Lymphadenectomy ◽  
Tips And Tricks ◽  
Technical Details ◽  
Three Dimensional Vision

Robotic systems have revolutionized the way we perform minimally invasive surgery and has facilitated the evolution of traditional laparoscopic gastric surgery. Surgeons have several advantages that can overcome some of the well-known limits of laparoscopy: three-dimensional vision, articulated instruments, the absence of tremors. These can give greater dexterity and precision in dissection and suturing movements that are key elements when performing complex and gentle reconstruction to restore digestive continuity. The present case shows the technical details and tips and tricks of a robotic surgical approach for a subtotal gastrectomy.

scholarly journals Self-excited air flow passage changing device for periodic pressurization of soft robot

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Toshio Takayama ◽  
Yusuke Sumi
Keyword(s):  
Mobile Robot ◽  
Rotational Motion ◽  
Air Pressure ◽  
Soft Robot ◽  
Pressure Source ◽  
Large Delay ◽  
Soft Robots ◽  
Flow Passage ◽  
Output Pressure ◽  
Air Chamber

AbstractRecently pneumatic-driven soft robots have been widely developed. Usually, the operating principle of this robot is the inflation and deflation of elastic inflatable chambers by air pressure. Some soft robots need rapid and periodic inflation and deflation of their air chambers to generate continuous motion such as progress motion or rotational motion. However, if the soft robot needs to operate far from the air pressure source, long air tubes are required to supply air pressure to its air chambers. As a result, there is a large delay in supplying air pressure to the air chamber, and the motion of the robot slows down. In this paper, we propose a compact device that changes its airflow passages by self-excited motion generated by a supply of continuous airflow. The diameter and the length of the device are 20 and 50 mm, respectively, and can be driven in a small pipe. Our proposed in-pipe mobile robot is connected to the device and can move in a small pipe by dragging the device into it. To apply the device widely to other soft robots, we also discuss a method of adjusting the output pressure and motion frequency.

scholarly journals Application of a three‑dimensional (3D) breast cancer model to study macrophage polarization

2021 ◽  
Vol 21 (5) ◽  
Author(s):  
Agata Golabek ◽  
Mariusz Kaczmarek ◽  
Ewelina Dondajewska ◽  
Kosma Sakrajda ◽  
Andrzej Mackiewicz ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Macrophage Polarization ◽  
Three Dimensional ◽  
Cancer Model ◽  
Breast Cancer Model

scholarly journals AERODYNAMICS OF JETS INTERACTING WITH A FLAT SURFACE

2019 ◽  
Vol 62 (4) ◽  
pp. 263-269
Author(s):  
I. A. Pribytkov ◽  
S. I. Kondrashenko
Keyword(s):  
Heat Transfer ◽  
Critical Point ◽  
Flat Surface ◽  
Stokes Equations ◽  
Thermal State ◽  
Exchange Process ◽  
Three Dimensional ◽  
Internal Diameter ◽  
Three Dimensional Model ◽  
Aerodynamic Properties

In this paper, the development features of a single free jet of hightemperature nitrogen interacting with a flat surface were studied. Calculation of the heat exchange process during heating by the attacking jets is very difficult to implement analytically due to complexity of the gas-dynamic processes occurring both in a single jet and in a system of jets interacting with the metal. The computational difficulties are aggravated by the fact that when interacting with the surface the jet as such disappears. The flat (fan) flow interacts with the surface: form, aerodynamic properties and thermal state of the flow strongly differ from those of the original jet. The studies were conducted on the basis of numerical simulation in the FloEFD software and computing complex for multiphysical simulation based on solution of the equations of gas dynamics and heat transfer. The solved system of equations consisted of Navier-Stokes equations, equations of energy and continuity and was supplemented by k – ε turbulence model. A three-dimensional model was developed for simulation, the necessary properties, initial and boundary conditions were specified. In the study of aerodynamics of a single high-temperature jet interacting with the surface, the main defining values were: nitrogen flow rate from the nozzle U0 , nitrogen temperature T, internal diameter of the nozzle d0 , distance from the nozzle section to the surface h, distance from the critical point (point of intersection of the jet axis with the surface) along the flow radius r. Data on the gas velocity decrease as the jet develops due to the loss of initial energy to engage the motionless surrounding gas in motion, is presented. The studies have shown that increase in the initial velocity of gas outflow brings the area of higher velocities closer to the surface both in the jet itself and in the fan jet. This factor contributes to heat transfer intensification. In addition, high speeds increase the total thickness of the fan flow and reduce the thickness of hydrodynamic boundary layer, which increases with distance from the critical point.

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