Sharif Digital Repository

In the recent years, medical application of robots has been widely developed. Transforming open surgeries to close surgeries has distinguished this novel method to decrease limitations in this type of surgery. In this procedure, two or three small incisions on the skin are used as guides for robotic instruments to enter the cavity, to improve the surgeon’s manipulation and function in surgery. One of challenges in this field is surgeon’s training for laparoscopic surgery. Surgical simulators are used to solve this problem. Lack of instrument for large organs gripping and tissue palpation loss are existing difficulties in available surgical simulators in such a manner that surgeons has no... 

in laparoscopic surgeries, act zone tissues are not directly palpable for the surgeon. Therefore, evaluating the mechanical behavior of the tissue and distinguishing healthiness or illness of that, are not achievable for the surgeon. In this treatise, the matter of discerning the soft and bulky tissues mechanical properties by a robotic arm during the laparoscopic surgery, is regarded. In first step, a tool like a two finger miniature hand was designed in which either of fingers have utilized a parallelogram mechanism for opening and closing. The dimensional design of the mechanism was undertake in away that the tool has the ability of going through a 10mm diameter path and grabbling and... 

Laparoscopic surgery is a branch of minimally invasive surgery that is implemented in the abdominal cavity. This kind of surgery is conducted using surgical instruments that are inserted into the abdomen through some small incisions created on its wall and the necessary vision is provided for the surgeon using a laparoscope lens that is inserted through the first created incision. In recent years, because of its advantages, controlling and manipulation of the lens is done using some robots instead of surgeon assistant. To facilitate the controlling procedure of these robots for the surgeon, several controlling modes such as keyboard, foot switch, and voice commands are presented. Robolens is... 

Laparoscopic surgery which is categorized under Minimal Invasive Surgery, has many advantages over conventional open surgery. Despite the beneficial effect of this method on patients, surgeons suffer difficulties in utilizing the method. Robotic surgery has been constituted as the answer to remove the difficulties yet retain the advantages.
In the so-called robotic surgery, the tool is handed to a robotic arm, i.e., the slave robot, which is installed and positioned at the bed side. The surgeon sits before a comfortable console and uses a joystick-like robot, i.e., the master robot, to manipulate the slave robot. The vision is also provided by a robotic camera holder and shown in a... 

The Sina robotic surgery setup has been designed and fabricated to simplify the laparoscopic surgery. The second generation of this robot has been designed in order of master and slave by focusing on using surgical wristed laparoscopic tools and utilizing haptic master. The master consists of two distinct mechanism of seven degrees of freedom. The first three degrees are considered for positioning, three of them for direction and one of them is considered for catching the tissue. The first six degrees of freedom (those for movement of haptic) are considered in this research.
To do this, first of all, the cinematic and dynamic relations of the leader mechanism have been derived. Next, the... 

Laparoscopic surgery is one of the Minimally Invasive Surgery (MIS) operations, which has many advantages over the conventional open surgery. However, training the surgeons has been a principal challenge in this type of surgery. In recent years, virtual environments have provided efficient means for MIS education and training. Interfacing surgeons with virtual training environment requires haptic devices. Haptic devices are able to provide force feedback to the surgeon’s hand simulate the sense of real surgery. Telesurgery is another application of haptic devices. In this application, the haptic devices are the master robot which detects the motion of the surgeon’s hand and reflects the... 

The age of minimally invasive surgery has brought forth astounding changes in the health care field. Less pain and quicker patient recovery have been demonstrated with several types of operations that were once performed by an open technique. With these changes have come reports of complications. The decreased sense of touch is just one of several limitations inherent to current techniques of minimally invasive surgery that limit detection of subtle or unapparent lesions on palpation, such as common duct stones and liver lesions. The purpose of this study is to design and implement a bilateral control on a master-slave robotic system for grasping large ogans and demonstrate the ability of a... 

The aim of this project was to design, analyze and fabricate a 4 DOF robotic arm to be used as a slave robot for tool handling in laparoscopic surgery. The mechanism used for this purpose should have a remote center of motion in order to be able to manipulate the tool through the small incision point. The robot should also provide sufficient force to handle endoscopic tools used for large organ manipulation and be capable of measuring these forces. A variety of mechanisms were studied thoroughly, and the best solution was chosen by considering the design parameters such as workspace, manipulability, accuracy, ease of fabrication, etc. The final design consists of a 2 DOF serial spherical... 

Surgical simulation systems facilitate a safe and efficient training process by providing a virtual environment in which the trainee can repeat the surgical procedure unlimitedly at different situations. The present study attempted to provide a real time simulation for the grasping procedure of a large internal organ during laparoscopic surgery. A mass-spring-damper model was employed to simulate the nonlinear viscoelastic large deformations of spleen tissue interacting with a triple-jaw large organ grasper. A novel collision detection algorithm was designed and implemented to determine the contact points between the tissue and the grasper jaws. The boundary conditions imposed at the contact... 

Realistic simulation of tool-tissue interactions can help developing more effective surgical training systems and simulators. In this study we used finite element and meshless modeling approaches to simulate the grasping procedure of a large intra-abdominal organ, i.e., kidney, during laparoscopic surgery. Results indicated that the accuracy of meshless method was comparable with that of the finite element, with the RMS errors in the range of 0.8 to 3.4 mm in different directions. The computational cost of the meshless method however, was much less than that of the finite element model. In order to verify the model, a silicon sample was used with the ship kidney geometry. For determination... 

The actuation mechanism of the tip of the laparoscopic instrument is the main problem in designing the process of miniature scale motorized instruments especially when high level of functionality and multi degrees of freedom (DOF) are concerned. Previous studies suggest local actuation as the best design for this kind of end effectors. In the present study, different actuation methods of needle holders were reviewed, related capabilities and drawbacks were evaluated and a hybrid local actuated design was appointed. The hybrid design included a micro DC motor and a PZT actuator. The main idea behind it was to combine the advantages of DC motors and piezoelectric (PZT) actuators in providing... 

Today, many surgical procedures such, gallbladder, gastric bypass, placement of a ring around the stomach, partial removal of colon, removal of tumors use laparoscopic techniques. In this surgery, a variety of tools to capture and remove the internal organs can be used. Sometimes the surgeon selects the proper tools and replacement during surgery, so the surgeon had to do different things with the operation. These tools generally cannot be used because of the large internal organs device is small and does not have enough degrees of freedom. In laparoscopic surgery, the surgeon operate in the abdominal cavity using a thin instrument that is inserted through the trocar hole would do. If... 

Aside from many advantages of minimally invasive surgery, it has some drawbacks. Surgeons` loss of dexterity dexterity, lack of force feedback and the consequent reduced sensation of forces are some of these drawbacks. Also, surgeons` ergonomically inappropriate posture gets him fatigued, causing hand tremor which is furthermore magnified by the long instruments. Robotic surgery systems have overcome some of minimally invasive surgeries limitations. But still some drawbacks such as high cost of maintenance or lack of haptic force feedback have impeded their widespread application. The high cost of maintenance is mostly caused by instrument changing and sterilization.The main goal of this... 

Sina surgical system is a telesurgery robotic system which is capable of using the conventional laparoscopic tools. In order to provide the wrist degree of freedom and increase the surgical maneuverability, a mechanism is introduced here which enables Sina to use and activate the wristed laparoscopic instrument Laparo-Angle. At first, the kinematics and dynamics characteristics of Laparo-Angle were identified experimentally. This tool contains 4 degrees of freedom, pitch, yaw, grasp and distal Roll. Activation of pitch and Yaw degrees of freedom requires a mechanism which at least has two rotational degrees of freedom to move the tool handle in a cone shape workspace with an apex angle of 36... 

Lack of force feedback during minimally invasive procedures is one of the downsides of such interventions and might result to excessive damage to surrounding tissues. The goal of the present research is to introduce a vision-based approach to estimate contact forces on soft tissues. In this approach, a model was developed in which, image of deformation of a sample soft tissue, under the jaws of laparoscopic gripper, is the input and the output is the gripper force. In this work, a FEM of soft tissue in contact with jaws of a laparoscopic tool is developed. . In the model, the effects of friction between the tool and tissue is considered which was not included in the previous studies. After... 

The main goal of this project is to design and implementation of the tissue auto-grasping algorithm for a wristed laparoscopic instrument. In this algorithm, the difference between the pinch forces of two jaws was taken into account when the pull force direction corresponding to the rod instrument direction was changed. The term ‘Tissue auto-grasping’ means automatic adjustment of the pinch force corresponding to the pull force exerted on the tissue by the robotic surgical instrument, so that slip and exerting excessive force on the tissue are prevented. In this study, obtaining the pinch force is based on the proximal force-sensing technique. For this reason, the force model of wristed...