A Magnetic Actuated Fully Insertable Robotic Camera System for Single Incision Laparoscopic Surgery

Minimally Invasive Surgery (MIS) is a common surgical procedure which makes tiny incisions in the patients anatomy, inserting surgical instruments and using laparoscopic cameras to guide the procedure. Compared with traditional open surgery, MIS allows surgeons to perform complex surgeries with reduced trauma to the muscles and soft tissues, less intraoperative hemorrhaging and postoperative pain, and faster recovery time. Surgeons rely heavily on laparoscopic cameras for hand-eye coordination and control during a procedure. However, the use of a standard laparoscopic camera, achieved by pushing long sticks into a dedicated small opening, involves multiple incisions for the surgical instruments. Recently, single incision laparoscopic surgery (SILS) and natural orifice translumenal endoscopic surgery (NOTES) have been introduced to reduce or even eliminate the number of incisions. However, the shared use of a single incision or a natural orifice for both surgical instruments and laparoscopic cameras further reduces dexterity in manipulating instruments and laparoscopic cameras with low efficient visual feedback. In this dissertation, an innovative actuation mechanism design is proposed for laparoscopic cameras that can be navigated, anchored and orientated wirelessly with a single rigid body to improve surgical procedures, especially for SILS. This design eliminates the need for an articulated design and the integrated motors to significantly reduce the size of the camera. The design features a unified mechanism for anchoring, navigating, and rotating a fully insertable camera by externally generated rotational magnetic field. The key component and innovation of the robotic camera is the magnetic driving unit, which is referred to as a rotor, driven externally by a specially designed magnetic stator. The rotor, with permanent magnets (PMs) embedded in a capsulated camera, can be magnetically coupled to a stator placed externally against or close to a dermal surface. The external stator, which consists of PMs and coils, generates 3D rotational magnetic field that thereby produces torque to rotate the rotor for desired camera orientation, and force to serve as an anchoring system that keeps the camera steady during a surgical procedure. Experimental assessments have been implemented to evaluate the performance of the camera system

Magnetic Surgical Instruments for Robotic Abdominal Surgery.

This review looks at the implementation of magnetic-based approaches in surgical instruments for abdominal surgeries. As abdominal surgical techniques advance toward minimizing surgical trauma, surgical instruments are enhanced to support such an objective through the exploration of magnetic-based systems. With this design approach, surgical devices are given the capabilities to be fully inserted intraabdominally to achieve access to all abdominal quadrants, without the conventional rigid link connection with the external unit. The variety of intraabdominal surgical devices are anchored, guided, and actuated by external units, with power and torque transmitted across the abdominal wall through magnetic linkage. This addresses many constraints encountered by conventional laparoscopic tools, such as loss of triangulation, fulcrum effect, and loss/lack of dexterity for surgical tasks. Design requirements of clinical considerations to aid the successful development of magnetic surgical instruments, are also discussed

Development of An In Vivo Robotic Camera for Dexterous Manipulation and Clear Imaging

Minimally invasive surgeriy (MIS) techniques are becoming more popular as replacements for traditional open surgeries. These methods benefit patients with lowering blood loss and post-operative pain, reducing recovery period and hospital stay time, decreasing surgical area scarring and cosmetic issues, and lessening the treatment costs, hence greater patient satisfaction would be earned. Manipulating surgical instruments from outside of abdomen and performing surgery needs precise hand-eye coordination which is provided by insertable cameras. The traditional MIS insertable cameras suffer from port complexity and reduced manipulation dexterity, which leads to defection in Hand-eye coordination and surgical flow. Fully insertable robotic camera systems emerged as a promising solution in MIS. Implementing robotic camera systems faces multiple challenges in fixation, manipulation, orientation control, tool-tissue interaction, in vivo illumination and clear imaging.In this dissertation a novel actuation and control mechanism is developed and validated for an insertable laparoscopic camera. This design uses permanent magnets and coils as force/torque generators in an external control unit to manipulate an in vivo camera capsule. The motorless design of this capsule reduces the, wight, size and power consumption of the driven unit. In order to guarantee the smooth motion of the camera inside the abdominal cavity, an interaction force control method was proposed and validated.Optimizing the system\u27s design, through minimizing the control unit size and power consumption and extending maneuverability of insertable camera, was achieved by a novel transformable design, which uses a single permanent magnet in the control unit. The camera robot uses a permanent magnet as fixation and translation unit, and two embedded motor for tilt motion actuation, as well as illumination actuation. Transformable design provides superior imaging quality through an optimized illumination unit and a cleaning module. The illumination module uses freeform optical lenses to control light beams from the LEDs to achieve optimized illumination over surgical zone. The cleaning module prevents lens contamination through a pump actuated debris prevention system, while mechanically wipes the lens in case of contamination. The performance of transformable design and its modules have been assessed experimentally

Monolithic self-supportive bi-directional bending pneumatic bellows catheter

The minimally invasive surgery has proven to be advantageous over conventional open surgery in terms of reduction in recovery time, patient trauma, and overall cost of treatment. To perform a minimally invasive procedure, preliminary insertion of a flexible tube or catheter is crucial without sacrificing its ability to manoeuvre. Nevertheless, despite the vast amount of research reported on catheters, the ability to implement active catheters in the minimally invasive application is still limited. To date, active catheters are made of rigid structures constricted to the use of wires or on-board power supplies for actuation, which increases the risk of damaging the internal organs and tissues. To address this issue, an active catheter made of soft, flexible and biocompatible structure, driven via nonelectric stimulus is of utmost importance. This thesis presents the development of a novel monolithic self-supportive bi-directional bending pneumatic bellows catheter using a sacrificial molding technique. As a proof of concept, in order to understand the effects of structural parameters on the bending performance of a bellows-structured actuator, a single channel circular bellows pneumatic actuator was designed. The finite element analysis was performed in order to analyze the unidirectional bending performance, while the most optimal model was fabricated for experimental validation. Moreover, to attain biocompatibility and bidirectional bending, the novel monolithic polydimethylsiloxane (PDMS)-based dual-channel square bellows pneumatic actuator was proposed. The actuator was designed with an overall cross-sectional area of 5 x 5 mm2, while the input sequence and the number of bellows were characterized to identify their effects on the bending performance. A novel sacrificial molding technique was adopted for developing the monolithic-structured actuator, which enabled simple fabrication for complex designs. The experimental validation revealed that the actuator model with a size of5 x 5 x 68.4 mm3 i.e. having the highest number of bellows, attained optimal bi-directional bending with maximum angles of -65° and 75°, and force of 0.166 and 0.221 N under left and right channel actuation, respectively, at 100 kPa pressure. The bending performance characterization and thermal insusceptibility achieved by the developed pneumatic catheter presents a promising implementation of flexibility and thermal stability for various biomedical applications, such as dialysis and cardiac catheterization

Mechanical Characterization of the Small Intestine for In vivo Robotic Capsule Endoscope Mobility

The state-of-the-art in enteroscopic surgery and therapeutic care continues to minimize invasiveness, cost, surgery time, and patient trauma. To this end, a new class of medical device, called the robotic capsule endoscope, is being pursued by multiple research groups. These potentially swallowable devices will radically expand the capabilities of natural orifice surgery by performing non-invasive tasks within the gastrointestinal tract that are now only possible with enteroscopic, laparoscopic, or open surgery. It is necessary for a robotic capsule endoscope to possess active, controlled mobility, which involves interactions between gastrointestinal tissue and engineering materials. Design challenges stem from the nonlinear and variable mechanical and physiological response of tissue and organs to the robot and from poor understanding of interfacial properties. In this work we initiate a study of the mechanical properties of the small intestine with the goal of accelerating the development of in vivo robotic capsule endoscopes for the gastrointestinal tract. To this end, four investigative devices and testing methods are presented: 1) A novel tribometer that measures the in vivo coefficient of friction between the mucosa and the robot surface; 2) An in vitro biaxial test apparatus and method for characterizing in-plane biomechanical properties of the bowel wall; 3) An in vitro test protocol to characterize the adhesive properties of mucosa; and 4) A novel manometer and force sensor array that measure the in vivo myenteric contact force against a solid bolus. Using these devices and test methods, the tribometry, passive biomechanics, mucosal adhesivity, and contractile response of the small intestinal tissue from multiple porcine models are measured. The results of this study offer crucial yet previously unknown biomechanical properties of the small intestine and have provided a foundation for the development of a unified and comprehensive model of the interactions between a robotic capsule endoscope and the intraluminal environment

Modulated Properties of Fully Absorbable Bicomponent Meshes

Current meshes used for soft-tissue repair are mostly composed of single component, nonabsorbable yarn constructions, limiting the ability to modulate their properties. This situation has left the majority of soft tissue repair load-bearing applications to suffer distinctly from undesirable features associated, in part, with mesh inability to (1) possess short-term stiffness to facilitate tissue stability during the development of wound strength; (2) gradually transfer the perceived mechanical load as the wound builds mechanical integrity; and (3) provide compliance with load transfer to the remodeling and maturing mesh/tissue complex. The likelihood of long-term complications is reduced for fully absorbable systems with degradation and absorption at the conclusion of their intended functional performance. The primary goal of this dissertation was to develop and characterize a fully absorbable bicomponent mesh (ABM) for hernia repair which can modulate biomechanical and physical properties to work with the expected needs of the wound healing process. The first study reviewed the current state of hernioplasty and proposed the subject device. The second study investigated different knitting technologies to establish a mesh construction which temporally modulated properties. To this end, a novel construction using warp knitting was developed where two degradable copolyester yarns with different degradation profiles were coknit into an initially interdependent knit construction. The developed knit construction provided an initial high level of structural stiffness; however, upon degradation of the fast-degrading yarn the mesh comprised of the slow-degrading yarn was liberated and affords high compliance. In the third study, the segmented, triaxial, high-glycolide copolyester used as the fast-degrading yarn was optimized to retain strength for greater than 18 days. As such, the ABM physical and biomechanical transition was designed to temporally coincide with the expected commencement of wound strength. The fourth study investigated the in vivo tissue response and integration of the developed degradable copolyester yarns in a novel construct to simulate the ABM. Results indicated a strong initial inflammatory response which resolved quickly and an integration process that produced a dense, compacted, and oriented collagen capsule around the implant during the transition phase. For the final study, the clinically-relevant biomechanical properties of two different ABM constructions were compared against traditional hernia meshes. Using a novel synthetic in vitro simulated mesh/tissue complex, the ABM were found to provide significantly greater early stability, subsequent biomechanics that approximated that of the abdominal wall, and evidence of restoring endogenous tension to the surrounding tissue. These results were in marked contrast to traditional hernia meshes which showed stress shielding and significantly greater stiffness than the abdominal wall