Richard J. Hendrick

A multi-arm hand-held robotic system for transurethral laser Prostate surgery.

Benign prostatic hyperplasia is the most common symptomatic disease in men. A new transurethral surgical intervention is available that has been shown to reduce bleeding, catheterization time, and hospitalization time in comparison to traditional Transurethral Resection of the Prostate (TURP). However, this new procedure, Holmium Laser Enucleation of the Prostate (HoLEP), is so challenging to accomplish that only a small number of expert surgeons are able to offer it. Toward facilitating broader use of HoLEP, we propose a new hand-held robotic system for the purpose of making the surgery easier to perform. In current HoLEP, the only way to aim the laser and/or manipulate tissue is to move the entire endoscope, stretching a large quantity of tissue. In contrast, our new robotic approach provides the surgeon with two concentric tube manipulators that can aim the laser and manipulate tissue simultaneously. The manipulators are deployed through a 5 mm working channel in a 26 French (8.66 mm) endoscope clinically used for transurethral procedures. This paper describes the design of the robot and experiments illustrating its ability to perform the motions expected to be useful in HoLEP.

Hand-held transendoscopic robotic manipulators

Natural orifice endoscopic surgery can enable incisionless approaches, but a major challenge is the lack of small and dexterous instrumentation. Surgical robots have the potential to meet this need yet often disrupt the clinical workflow. Hand-held robots that combine thin manipulators and endoscopes have the potential to address this by integrating seamlessly into the clinical workflow and enhancing dexterity. As a case study illustrating the potential of this approach, we describe a hand-held robotic system that passes two concentric tube manipulators through a 5 mm port in a rigid endoscope for transurethral laser prostate surgery. This system is intended to catalyze the use of a clinically superior, yet rarely attempted, procedure for benign prostatic hyperplasia. This paper describes system design and experiments to evaluate the surgeon’s functional workspace and accuracy using the robot. Phantom and cadaver experiments demonstrate successful completion of the target procedure via prostate lobe resection.

Designing snap-free concentric tube robots: A local bifurcation approach

In designing concentric tube robots, it is often desirable to use curvatures that are as high as possible. However, with high curvatures comes the potential for elastic instabilities. This can be addressed by motion planning or by designing the robot to preclude the possibility of instability. In this paper, we pursue the latter. Our primary contribution is to show that local bifurcation theory can be used to predict the existence of elastic instability anywhere in the workspace of robots with arbitrarily many tubes, with straight transmissions. We show how to use these results to design robots that are guaranteed to remain elastically stable at all times.

Elastic Stability of Concentric Tube Robots: A Stability Measure and Design Test

Concentric tube robots are needle-sized manipulators which have been investigated for use in minimally invasive surgeries. It was noted early in the development of these devices that elastic energy storage can lead to a rapid snapping motion for designs with moderate to high tube curvatures. Substantial progress has recently been made in the concentric tube robot community in designing snap-free robots, planning stable paths, and characterizing conditions that result in snapping for specific classes of concentric tube robots. However, a general measure for determining the stability of a given robot configuration has yet to be proposed. In this paper, we use bifurcation and elastic stability theory to provide such a measure, as well as to produce a test for determining whether a given design is snap-free (i.e., whether snapping can occur anywhere in the unloaded robots workspace). These results are useful in designing, planning motions for, and controlling concentric tube robots with high curvatures.

A robot for transnasal surgery featuring needle-sized tentacle-like arms

This paper discusses a new class of robots known as concentric tube robots and their application to transnasal skull base surgery. The endonasal approach has clear benefits for patients, but the surgery presents challenges that strongly motivate the use of robotic tools. In this paper, the concentric tube robot concept is described, and preliminary experimental results for transnasal skull base surgery are reviewed. Just as the da Vinci robot has revolutionized many laparoscopic surgeries, we expect concentric tube robots will enable the advancement of skull base surgery and the development of other minimally invasive procedures that require access through constrained paths.

Toward Improving Transurethral Prostate Surgery: Development and Initial Experiments with a Prototype Concentric Tube Robotic Platform.

INTRODUCTION Despite the potential clinical advantages of holmium laser enucleation of the prostate (HoLEP), there has been reluctance of the urologic community to adopt the procedure, as a result of a perceived steep learning curve. Thus, we sought to design and develop a transurethral endoscopic robotic platform for HoLEP. MATERIALS AND METHODS We developed a novel transurethral, concentric tube robotic platform for HoLEP. We conducted magnetic tracking experiments to compare movements of the end effectors of the robot with those of a rigid endoscope. Additionally, we tested the robot on an HoLEP simulator and with a human cadaveric prostate to assess its ability to maneuver within a small working space. RESULTS In the prostate scanning experiment, the area reached by the robot represents a 65% improvement vs the area accessible by a rigid endoscope without tissue deformation. Additionally, the robot performed well within the confines of the prostatic urethra and was able to successfully complete prostate lobe enucleation, on both the HoLEP simulator and with a human cadaveric prostate. CONCLUSIONS We have developed a concentric tube robotic platform that is passed through a standard endoscope that is capable of producing complex movements of the end effectors. We have shown that these movements of the concentric tube manipulators are capable of performing tasks that may eventually translate into improved ease of performing HoLEP.

Design of an Endonasal Graft Placement Tool for Repair of Skull Base Defects

Poor tools lead to dropped gra7s, decreased surgeon confidence, increased opera<ng <me Forceps: • cannot reliably open and close in 6ght spaces • good grip • poor force applica6on Blunt Tools: • good force applica6on • poor grip • difficulty handling varying gra: size, shape, rigidity Endonasal Approach • Minimally invasive • Limited tool manipulability • Gra: placement can add up to 30 minutes Inadequate Gra7 Placement Complica<ons • CSF leaks that lead to meningi6s, brain hemorrhage, neurological deficits, or death1

An Experimental Comparison of Two User Interface Designs for a Hand-Held Surgical Robot

1 Background There is a trend towards miniaturization in surgical robotics with the objective of making surgeries less invasive [1]. There has also been increasing recent interest in hand-held robots because of their ability to maintain the current surgical workflow [2, 3]. We have previously presented a system that integrates small-diameter concentric tube robots [4, 5] into a hand-held robotic device [3], as shown in Figure 1. This robot was designed for transurethral laser surgery in the prostate. It provides the surgeon with two dexterous manipulators through a 5mm port in a traditional transurethral endoscope. This system enables the surgeon to retract tissue and aim a fiber optic laser simultaneously to resect prostate tissue.

Experiments on the Simultaneous Hand-Held Control of Rigid Endoscopes and Robots Passing Through Them

Concentric tube manipulators have the diameter of needles and are consequently amenable to delivery into the human body through small ports in an endoscope. When this is done, the surgeon must manipulate both the endoscope and one or more concentric tube robots simultaneously. In this paper we explore a hand-held approach to this user interface challenge, in which the surgeon has direct physical control of endoscope pose and can use finger and thumb controls to specify the motion of two concentric tube robots that pass through the endoscope. In experiments with the system, we explore whether the endoscope-robot combination can reach locations in the prostate that are inaccessible to the endoscope alone. We also compare joint space and task space control for three-degree-of-freedom concentric tube robots, and demonstrate experimentally that laser resection of prostate tissue is possible using an anthropomorphic phantom.

Design of a Safer Tracheostomy Tube

During a tracheotomy, the surgeon makes an incision through the front of the patient’s neck (the incision is known as a tracheostomy) to access the trachea and insert a tracheostomy tube (see Figure 1), which serves as an alternative airway to the mouth or nose. After insertion, a balloon is inflated to the diameter of the trachea, which fixes the tracheotomy tube in place, allows for positive pressure ventilation, and creates a seal to the walls of the trachea.