Miniature in vivo robots for remote and harsh environments

Long-term human space exploration will require contingencies for emergency medical procedures including some capability to perform surgery. The ability to perform minimally invasive surgery (MIS) would be an important capability. The use of small incisions reduces surgical risk, but also eliminates the ability of the surgeon to view and touch the surgical environment directly. Robotic surgery, or telerobotic surgery, may provide emergency surgical care in remote or harsh environments such as space flight, or extremely forward environments such as battlefields. However, because current surgical robots are large and require extensive support personnel, their implementation has remained limited in forward environments, and they would be difficult, or impossible, to use in space flight or on battlefields. This paper presents experimental analysis of miniature fixed-base and mobile in vivo robots to support MIS surgery in remote and harsh environments. The objective is to develop wireless imaging and task-assisting robots that can be placed inside the abdominal cavity during surgery. Such robots will provide surgical task assistance and enable an on-site or remote surgeon to view the surgical environment from multiple angles. This approach is applicable to long-duration space flight, battlefield situations, and for traditional medical centers and other remote surgical locations.     

A Perspective on Medical Robotics

This paper provides an overview of medical robotics, from the perspective of a researcher who has been actively involved in the field for 17 years. Like all robot systems, medical robots fundamentally couple information to physical action to significantly enhance humans' ability to perform important tasks-in this case surgical interventions, rehabilitation, or simply helping handicapped people in daily living tasks. Research areas include modeling and analysis of anatomy and task environments, interface technology between the "data world" and the physical world, and study of how complex systems are put together. This paper will discuss these research areas and illustrate their interrelationship with application examples. Although the main focus will be on robotic systems for surgery, it will also discuss the relationship of these research areas to rehabilitation and assistance robots. Finally, it will include some thoughts on the factors driving the acceptance of medical robotics and of how research can be most effectively organized     

Telepresence technology in medicine: principles and applications

Telepresence systems can improve surgeons' performance in minimally invasive surgery (MIS) and microsurgery and also enable them to operate on patients remotely over great distances. In MIS, telepresence technology allows surgeons to experiment surgery as if their hands and eyes were effectively inside the patient's closed abdomen, enabling them to work with improved skill and dexterity. In microsurgery, the technology can scale down the surgeons' motions, forces, and field of view, allowing them to skillfully operate on microscopic anatomy with relative ease. The systems also enable surgeons to treat patients remotely in inaccessible or hazardous locations with great effectiveness, allowing them to operate as if they were present at the remote site. The means for conveying human presence in such systems is through force-reflecting manipulators with digital servo controllers, stereo viewing systems, and communication links. Depending on the application, the surgeon at the telepresence workstation may be across the room from the patient or across the state, connected by a microwave link or communication network     

Generalized approach for modeling minimally invasive surgery as a stochastic process using a discrete Markov model

Minimally invasive surgery (MIS) involves a multidimensional series of tasks requiring a synthesis between visual information and the kinematics and dynamics of the surgical tools. Analysis of these sources of information is a key step in defining objective criteria for characterizing surgical performance. The Blue DRAGON is a new system for acquiring the kinematics and the dynamics of two endoscopic tools synchronized with the endoscopic view of the surgical scene. Modeling the process of MIS using a finite state model [Markov model (MM)] reveals the internal structure of the surgical task and is utilized as one of the key steps in objectively assessing surgical performance. The experimental protocol includes tying an intracorporeal knot in a MIS setup performed on an animal model (pig) by 30 surgeons at different levels of training including expert surgeons. An objective learning curve was defined based on measuring quantitative statistical distance (similarity) between MM of experts and MM of residents at different levels of training. The objective learning curve was similar to that of the subjective performance analysis. The MM proved to be a powerful and compact mathematical model for decomposing a complex task such as laparoscopic suturing. Systems like surgical robots or virtual reality simulators in which the kinematics and the dynamics of the surgical tool are inherently measured may benefit from incorporation of the proposed methodology.     

Dynamic 3-D virtual fixtures for minimally invasive beating heart procedures

Two-dimensional or 3-D visual guidance is often used for minimally invasive cardiac surgery and diagnosis. This visual guidance suffers from several drawbacks such as limited field of view, loss of signal from time to time, and in some cases, difficulty of interpretation. These limitations become more evident in beating-heart procedures when the surgeon has to perform a surgical procedure in the presence of heart motion. In this paper, we propose dynamic 3-D virtual fixtures (DVFs) to augment the visual guidance system with haptic feedback, to provide the surgeon with more helpful guidance by constraining the surgeon's hand motions thereby protecting sensitive structures. DVFs can be generated from preoperative dynamic magnetic resonance (MR) or computed tomograph (CT) images and then mapped to the patient during surgery. We have validated the feasibility of the proposed method on several simulated surgical tasks using a volunteer's cardiac image dataset. Validation results show that the integration of visual and haptic guidance can permit a user to perform surgical tasks more easily and with reduced error rate. We believe this is the first work presented in the field of virtual fixtures that explicitly considers heart motion.     

Haptic-Enabled Telementoring Surgery Simulation

Medical surgery involves a high degree of skill and experience, making the learning curve for medical trainees quite long. For instance, in eye cataract surgery, despite it only taking around seven minutes for a well-trained surgeon to perform and having a success rate of 99 percent, medical residents need months to become proficient in this procedure to avoid its typical complications. Medical trainees traditionally have acquired surgical skills through apprenticeships in which trainees observe senior surgeons, then perform under guidance until they achieve mastery. Training often makes use of cadavers or laboratory animals, but this type of training is becoming increasingly difficult to do in many countries due to ethical reasons. An effective alternative is medical simulation, which can enhance understanding, improve performance, and assess competence; in preoperative settings, it assists surgeons in remaining at a high technical skill level. Surgical simulation can provide high-fidelity training that increases the diffusion of innovative and less- invasive procedures while decreasing the surgeon's learning curve.     

Three‐Dimensional Programmable Assembly by Untethered Magnetic Robotic Micro‐Grippers

Mobile sub‐millimeter micro‐robots have demonstrated untethered motion and transport of cargo in remote, confined or enclosed environments. However, limited by simple design and actuation, they lack remotely‐actuated on‐board mechanisms required to perform complex tasks such as object assembly. A flexible patterned magnetic material which allows internal actuation, resulting in a mobile micro‐gripper which is driven and actuated by magnetic fields, is introduced here. By remotely controlling the magnetization direction of each micro‐gripper arm, a gripping motion which can be combined with locomotion for precise transport, orientation, and programmable three‐dimensional assembly of micro‐parts in remote environments is demonstrated. This allows the creation of out‐of‐plane 3D structures and mechanisms made from several building blocks. Using multiple magnetic materials in each micro‐gripper, the addressable actuation of gripper teams for parallel, distributed operation is also demonstrated. These mobile micro‐grippers can potentially be applied to 3D assembly of heterogeneous meta‐materials, construction of medical devices inside the human body, the study of biological systems in micro‐fluidic channels, 3D micro‐device prototyping or desktop micro‐factories.     

轻型空间遥感器光机系统研究

TMA空间光学系统可以同时实现大视场和轻型化,在目前空间光学遥感器中得到了广泛的应用。本文对焦距1m、视场8.5°的空间遥感器光机系统进行了研究,对遥感器具体结构进行了细致的探讨,利用有限元分析技术对空间遥感器整机结构进行了工程分析。结果表明,采用单点挠性支撑的各反射镜支撑系统、采用环氧/碳纤复合材料的桁架主支撑结构可以很好地保证反射镜在静力学、热环境下镜面具有较高的面形精度和位置精度,而其支撑自身在动力学环境中不会破坏。这种光学遥感器非常适合在重量要求较严格的大视场空间成像小卫星中使用。     

Vision and Task Assistance Using Modular Wireless In Vivo Surgical Robots

Minimally invasive abdominal surgery (laparoscopy) results in superior patient outcomes compared to conventional open surgery. However, the difficulty of manipulating traditional laparoscopic tools from outside the body of the patient generally limits these benefits to patients undergoing relatively low complexity procedures. The use of tools that fit entirely inside the peritoneal cavity represents a novel approach to laparoscopic surgery. Our previous work demonstrated that miniature mobile and fixed-based in vivo robots using tethers for power and data transmission can successfully operate within the abdominal cavity. This paper describes the development of a modular wireless mobile platform for in vivo sensing and manipulation applications. Design details and results of ex vivo and in vivo tests of robots with biopsy grasper, staple/clamp, video, and physiological sensor payloads are presented. These types of self-contained surgical devices are significantly more transportable and lower in cost than current robotic surgical assistants. They could ultimately be carried and deployed by nonmedical personnel at the site of an injury to allow a remotely located surgeon to provide critical first response medical intervention irrespective of the location of the patient.      

Depth-buffer targeting for spatially accurate 3-D visualization of medical images

During interactive image-guided surgery (IIGS), a surgeon uses data from medical images to help guide the surgical procedure. At Vanderbilt University, an IIGS software system called Orion has been developed which is capable of displaying up to four 512 x 512 images and the current surgical position using an active optical tracking system. Orion is capable of displaying data from any tomographic image volume and from any NTSC video image. An additional display module has been implemented to display three-dimensional information as well as the tomographic slices. This provides the surgeon with valuable anatomical information that is not readily obtained from the tomographic slices alone. Before the surgery, a set of rendered images is created, each with a different angular view of the tomographic volume in order to surround the site of surgical interest. The major objectives of the display module are to display the appropriate rendered image from the set, identify the current probe position on the selected image, and provide an indication of distance between the probe and the physical point of the anatomy indicated on the image. This can provide the surgeon with vital information such as distance to blood vessels, tumors, or other critical structures.     

基于RRT算法的无人机路径规划应用研究

经典的路径规划算法大都需要在全局已知空间中对环境进行建模,包括人工势场法、遗传算法、启发式算法、仿生学算法等.由于需要预先构建环境,因此这些方法并不适合解决在高维度空间中的路径规划问题.基于快速扩展随机树(RRT)的路径规划方式其优势在于可以避免对全局环境的构建,通过对状态空间进行随机采样,检测碰撞点,能够有效地解决在...     

Novel Biological Based Method for Robot Navigation and Localization

The capability and reliability are crucial characteristics of mobile robots while navigating in complex environments. These robots are expected to perform many useful tasks which can improve the quality of life greatly. Robot localization and decision-making are the most important cognitive processes during navigation. However, most of these algorithms are not efficient and are challenging tasks while robots navigate through complex environments. In this paper, we propose a biologically inspired method for robot decision-making, based on rat’s brain signals. Rodents accurately and rapidly navigate in complex spaces by localizing themselves in reference to the surrounding environmental landmarks. Firstly, we analyzed the rats’ strategies while navigating in the complex Y-maze, and recorded local field potentials (LFPs), simultaneously. The recorded LFPs were processed and different features were extracted which were used as the input in the artificial neural network (ANN) to predict the rat’s decision-making in each junction. The ANN performance was tested in a real robot and good performance is achieved. The implementation of our method on a real robot, demonstrates its abilities to imitate the rat’s decision-making and integrate the internal states with external sensors, in order to perform reliable navigation in complex maze.     

Supervisory control of remote manipulation

The relatively short distances to be spanned in using the manipulators presently available permit real-time control systems, frequently employing direct linkages. The advent of space flight necessitates the design of manipulation systems that can perform complicated tasks, on the moon and beyond, upon command from earth. Such a design must compensate for the communications time delay due to the distances involved and also for a difference in environment not directly observable by the human operator. The answer to the problem seems to lie in a computer-controlled remote unit, capable of making limited decisions of its own but supervised from home base.     

基于TDRSS应用的远程应急信息传输系统构想

介绍了美军天基通用数据链体系的特点,结合跟踪与数据中继卫星系统(TDRSS)现状和全球远程数据链信息传输需求,分析了TDRSS远程信息传输支持能力,提出了发展基于TDRSS的天基远程应急信息传输系统构想并预测了系统应用前景,以期对未来天基信息系统的发展和应用提供参考.     

基于LabVIEW的无线自动测控系统设计与实现

针对弹药爆炸现场爆压测量难的问题,采用LabVIEW为工具设计了一套无线自动测控系统,主要由传感器网络节点、无线中继站AP和上位机三部分组成。测控系统以LabVIEW为主控软件,利用图形化编程语言和模块化设计实现了对无线传感器网络节点的控制、实验数据的读取、存储和分析。通过系统验证和测试表明,该系统具有数据采集、无线传输和远程控制的能力,完全能够胜任恶劣环境下爆炸现场爆压测量的重任。     

移动Ad Hoc网络技术的分析

移动Ad Hoc网络,它是Mobile Ad Hoc Networks的简称,它不会受到空间与时间的制约,更加快捷和方便,不但能够在危险环境、远距离、战场、会议和救援等环境当中应用,而且还能够扩展末端网络,它的应用具有普遍性。为此,本文论述了移动Ad Hoc网络的基本概念和特点,接着分析了移动Ad Hoc网络设计面临的挑战,最后讨论了它的应用。     

Mechatronic Design of a New Robot for Force Control in Minimally Invasive Surgery

Minimally invasive surgery (MIS) challenges the surgeon's skills due to his/her separation from the operation area, which can be reached with long instruments only. Therefore, the surgeon looses access to the manipulation forces inside the patient. This reduces his/her dexterity when performing the operation. A new compact and lightweight robot for MIS is presented, which allows for the measurement of manipulation forces. The main advantage of this concept is that no miniaturized force sensor has to be integrated into surgical instruments and inserted into the patient. Rather, outside the patient, a standard sensor is attached to a modified trocar, which allows for the undisturbed measurement of manipulation forces. This approach reduces costs and sterilizability demands. Results of in vitro and in vivo force control experiments are presented to validate the concepts     

MARKER-BASED MAPPING BETWEEN MEDICAL IMAGE AND ROBOT SPACE IN ROBOT-ASSISTED SURGERY

This paper focuses on the problems of matching a virtual and a real environments by means of hardware and software tools. The real space is represented by a patient's bone where a set of cuts by means of robot system is to be made. The virtual space is a 3D model of the bone reconstructed from a set of CT slices. Robot system is then not only to machine bones but also to perform the fundamental step of registration between the two spaces. An external force sensor is used to adjust robot stiffness in order to perform the tactile searching necessary for the registration. A simple but reliable software algorithm is used to control the robot for matching between medical image and robot space in robot-assisted surgery. The results show the system proposed is precise enough for application, and tests been made also clarify the way to improve it.     

Compact generic multi-channel plastic joint for surgical instrumentation

With the progress of the miniaturisation, we can expect to integrate new embedded micro-systems such as micro-sensors and micro-actuators into surgical instruments to assist surgeons during minimally invasive surgery (MIS). This paper presents a compact plastic joint with several channels to integrate wires and optical fibres. These wires and fibres will be used to supply and send data from micro-devices inside surgical tools. The aim of our study is to design a biocompatible compact joint with two degrees of freedom and a mobility range close to ±90°. The architecture of this new joint is based on a generic design with biocompatible plastic and super-elastic NiTi wires. Analytical simulation allows to readily suggest different solutions for different scales. Because the surgeon works with a visual feedback, the articulated joint is controlled in an open-loop configuration. Finally, this paper presents two kinds of applications that use the plastic joint: a tele-operated surgical robot and a hand-held surgical instrument.