Medical Robotics E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 678

Veröffentlichungsjahr: 2013

Beschreibung

In this book, we present medical robotics, its evolution over the last 30 years in terms of architecture, design and control, and the main scientific and clinical contributions to the field. For more than two decades, robots have been part of hospitals and have progressively become a common tool for the clinician. Because this domain has now reached a certain level of maturity it seems important and useful to provide a state of the scientific, technological and clinical achievements and still open issues. This book describes the short history of the domain, its specificity and constraints, and mature clinical application areas. It also presents the major approaches in terms of design and control including man-machine interaction modes. A large state of the art is presented and many examples from the literature are included and thoroughly discussed. It aims to provide both a broad and summary view of this very active domain as well as keys to understanding the evolutions of the domain and to prepare for the future. An insight to clinical evaluation is also proposed, and the book is finished with a chapter on future developments for intra-body robots.

Leseprobe

Table of Contents

Introduction

Chapter 1. Characteristics and State of the Art

1.1 Introduction

1.2. State of the art

1.3. Conclusion

1.4. Bibliography

Chapter 2. Medical Robotics in the Service of the Patient

2.1. Introduction

2.2. A cycle of medical service growth

2.3. A case study: the ViKY robotic endoscope support system

2.4. Conclusion

2.5. Bibliography

Chapter 3. Inter-operative Sensors and Registration

3.1. Introduction.

3.2. Intra-operative sensors

3.3. Principles of registration

3.4. Case studies

3.5. Discussion and conclusion

3.6. Bibliography

Chapter 4. Augmented Reality

4.1. Introduction

4.2. 3D modeling of abdominal structures and pathological structures

4.3. 3D visualization system for planning

4.4. Interactive AR

4.5. Automatic AR

4.6. Taking distortions into account

4.7. Case Study

4.8. Conclusions

4.9. Bibliography

Chapter 5. Design of Medical Robots

5.1. Introduction.

5.2. From the characterization of gestures to the design of robots

5.3. Design methodologies

5.4. Technological choices

5.5. Security

5.6. Conclusion

5.7. Bibliography

Chapter 6. Vision-based Control

6.1. Introduction

6.2. Sensors

6.3. Acquisition of the measurement

6.4. Control

6.5. Perspectives

6.6. Bibliography

Chapter 7. Interaction Modeling and Force Control

7.1. Modeling interactions during medico-surgical procedures

7.2. Force control

7.3. Force control strategies

7.4. Conclusion

7.5. Bibliography

Chapter 8. Tele-manipulation

8.1. Introduction

8.2. Tele-manipulation and medical practices

8.3. Tele-manipulation with force feedback

8.4. Bibliography

Chapter 9. Comanipulation

9.1. Introduction

9.2. General principles of comanipulation

9.3. Serial comanipulation: intelligent active instrumentation

9.4. Parallel comanipulation

9.5. A human in the loop

9.6. Bibliography

Chapter 10. Towards Intracorporeal Robotics

10.1. Introduction

10.2. Mini-manipulators/tele-operated instrument holders

10.3. Robotized colonoscopes and autonomous capsules

10.4. Active catheters

10.5. Evolution of surgical robotics

10.6. Additional information

10.7. Bibliography

Conclusion

Notations

Medical Glossary

List of Authors

Index

First published 2012 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

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© ISTE Ltd 2012

The rights of Jocelyne Troccaz to be identified as the author of this work have been asserted by her in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Medical robotics / edited by Jocelyne Troccaz.

p.; cm.

Includes bibliographical references and index.

  ISBN 978-1-84821-334-0

  [DNLM: 1. Robotics. 2. Therapy, Computer-Assisted--methods. 3. Computer Simulation. 4. Diagnosis, Computer-Assisted--methods. WB 365]

610.285'63--dc23

2011045045

British Library Cataloguing-in-Publication Data

Introduction

As a physical device endowed with decision-making, perception and action capabilities and connected to the digital world, a robot can intervene in many ways in the context of care.

In a vision closer to the industrial process, the robot – in this case a mobile platform – may contribute to the logistics of a health-care facility by conveying patients and transferring them from the bed to the couch or the operating table. A robot can also serve as an automated transport system for drugs.

Robots can also assist disabled or elderly people. A robotic walker can contribute to keeping an elderly person upright. A fixed or mobile arm, or a humanoid robot can help a disabled person in daily life tasks. A companion that is more or less robotic can act as an assistant for a dependent person. In addition, the robot can be wholly or partially substituted for a defective organ or limb: this includes artificial organs, artificial limbs, prostheses.

A robot can also be a medical or paramedical personnel assistant. For instance, a robotic platform may ease the tasks of rehabilitation staff who help patients to relearn how to walk after spinal cord injuries. An exoskeleton could be used for the rehabilitation of movement after a stroke.

Concerning the more instrumental side of medicine, a robot could hold the “tool” required by the clinician (surgeon, radiologist, radiation oncologist, etc.) to perform a diagnostic or therapeutic gesture. For example, it could perform the machining of a bone cavity for a prosthetic gesture, carry and move a surgical microscope for microsurgery, an endoscope for minimally invasive surgery or a linear accelerator for radiation therapy. A traditional surgical instrument could also be robotic.

It can thus be seen that there are very diverse machines with very different objectives that can be grouped into the “medical robot” term. We will not cover the entire applications spectrum in this book; instead, we will focus exclusively on the “instrument holder” robot or on the “robotic instrument”, which concludes this long list. We call this type of device a medico-surgical robot. As will be discussed in more detail later (see Chapter 1), this type of robot was introduced in the early 1980s. It is part of the general theme of “computer-aided medical interventions” (CAMI). CAMI gives clinicians the hardware and software tools to enable them to fully exploit the available multimodal information (prior knowledge, gestures or organ models, medical images, physiological signals, etc.) in order to plan, simulate and perform a diagnostic or therapeutic gesture that is as minimally invasive and effective as possible. This field is thematically wide and relevant to signal and image processing, data fusion as well as modeling and simulation, biomechanics, biomedical engineering or robotics. In this book, we will focus on the aspects related to robotics: design, monitoring/control and the link to medical imaging and humanmachine interfaces and evaluation.

The book is organized into 10 chapters:

Chapter 1: This chapter introduces the application domain and the potential contributions of a robot to the achievement of a medico-surgical gesture. The specifics of this application domain are introduced and a state of the art traces back the evolution of applications, robot types and their mode of control over the last three decades.

Chapter 2: Beyond the scientific and technical aspects developed in this book, the clinical purpose of the described devices complicates the question of their evaluation. Readers with technical training quite clearly imagine the technical validation of a device. More rarely, the reader is faced with the real constraints of clinical application, for instance asepsy in the operating room (but there are many such examples), and also determining the clinical added value of the device with respect to other medical/surgical techniques. This chapter follows the various stages from conception to the use of the system in the routine of clinical practice and presents the key concepts. It provides an ethical and regulatory framework that is useful for the engineers or scientists involved in the design and implementation of a medical robot.

Chapter 3: Medical robotics is basically an image-guided robotics since the planning elements of the task are often defined in terms of patient imagery. This imagery can be acquired pre-operatively or intra-operatively. This chapter focuses on the techniques enabling us to link the reference frame “tool” of the robot to the reference frames of patient imagery. It makes extensive use of techniques known as registration or matching, which are similar to methods in the field of computer vision.

Chapter 4: Robotic or not, CAMI requires strong interaction with a non computer expert user and the human-machine interface is critical. To facilitate the interaction of the user with its system and information rendering in an intra-operative situation, augmented reality (AR) aims to present useful information to the clinician (invisible anatomical structures, planning elements, etc.) overlaid with the reality. As in the previous chapter, the link between different reference frames should be determined to allow this overlay. This chapter presents some of the key steps of extracting information on pre-operative imaging, the issue of registering for AR and illustrates the different approaches through examples.

Chapter 5: The specifics of medico-surgical robotics have quickly oriented system designers towards achieving specific robotic systems for an intervention or a type of intervention. The criteria governing the selection of robot architecture are both clinical (type of task, workspace, specific constraints of the asepsis or the compatibility with an imager, etc.) and technical (number of degrees of freedom required, sizing, series/parallel architecture, materials, actuation, etc.). Different design approaches that are more or less systematic are presented. The robot has to operate in an environment where human beings are involved, or even move invasive instruments on or within the body (needle, bone cutter, etc.). Safety is at the heart of the design process.

Chapter 6: While Chapter 3 focuses on the issue of linking the robot with an imaging modality (mostly pre-operative), which served for planning via intraoperative data and also to the update this link when it varies during the gesture, this chapter exclusively considers intra-operative imaging used for real-time control of the robot. Although the visual servoing is done on the position of a tool or that of an organ the robust and real-time processing of the image is at the heart of the problem. Part of this chapter addresses the issue of imaging. The second part presents the control laws that exploit them. Laparoscopic applications, among other applications, enable us to illustrate the presented approaches.

Chapter 7: Medical robotics is mostly the robotics of mechanical interaction with living tissues. When the robot is in contact with these tissues, the force control may therefore turn out to be central for the independent, safe and accurate action of the robot. Similarly, it intervenes in the physical interaction with a human operator during tele-surgery (Chapter 8) with force-feedback or comanipulation (Chapter 9). This chapter presents the general context of interaction with the tissues and its modeling, as well as the different types of force control models. A series of examples illustrates these approaches.

Chapter 8: Industrial robotics has accustomed us to the substitution of a human operator with a robot for arduous or repetitive tasks. The complex and highly variable nature of the medical environment, the decision-making required throughout the gesture, the very nature of potential interactions of the robot with a human body – and therefore the safety issues – have guided medical robotics towards sharing expertise and a human/robot complementarity. Tele-operation is one of these modes of interaction between the clinician and the robot. After introducing the context of tele-operation for medical applications, this chapter focuses more specifically on the issue of controlling tele-operated robots with forcefeedback. Different control models are described and their properties are discussed in terms of stability and transparency. An example of a tele-operated robot for performing the puncture in interventional radiology also illustrates the implementation of such an approach.

Chapter 9: While the operator controls the movements of an instrument using a remote device during tele-operation, the comanipulation, which is discussed here, places this operator closer to the surgical action by providing him with an opportunity to act directly on the movements of the instrument. This chapter formalizes two types of comanipulation: so-called parallel comanipulation where the operator acts on the terminal part of the robot that moves the instrument and the socalled series comanipulation where the operator is holding a robotic instrument. The specific control issues of these two types of comanipulation are discussed and illustrated through numerous examples.

Chapter 10: If the idea of introducing into the human body a miniaturized system, autonomous in its movements, capable of perception and action is not new, the technological advances in recent decades have made this fiction a view of our future reality. The capabilities of miniaturization and integration of sensors can now offer robotic tools of very small size, for instance, to supplement a more conventional carrier and compensate the dexterity loss of intracorporeal actions in minimally invasive surgery. Similarly, different means of exploration or action (flexible endoscopes, catheters in particular) see their options expanded and their safety potentially improved through the integration of robotic functions. This chapter draws up a state of the art of these devices and presents the challenges that still stand for the realization of an intracorporeal micro or nanorobot.

The book also includes a glossary of some medical terms that are used throughout the chapters.

Jocelyne TROCCAZ

January 2012

Chapter 1

Characteristics and State of the Art1

1.1 Introduction

The history of medical robotics is recent with the first experiments in the field of neurosurgery dating from the 1980s. The first systems were directly adapted from industrial robotics. Since then, medical robotics have profited from the development of new materials, new sensors and actuators for robotics, along with a rise in the capacity for real-time calculation. Important factors relating to its progress have been the rapid evolution of medical imaging technology, as well as in the medical world a growing interest in robotics, which is today a major and practical form of improving medical practice. An obvious sign of this growth is the use of medical robotics in everyday clinical practice.

1.1.1. Characteristics of medical robotics

Medical robotics is principally distinguishable from classic robotics by the number of specific needs that we can list by considering three main requirements (from here on we will call these the 3 s):

– safety in the vicinity of the patient and their carers;

– sterility or sanitization;

– constraints of the surgical theater.

1.1.1.1. Safety

The issue of safety is of prime importance in medical robotics. It consists not only of the safety of the patient, but also the safety of the medical personnel who set-up and use the robotics system, as they often find themselves in close proximity to it. In effect, in medical robotics, the robotics system is in contact with the patient or the medical personnel which is quite unlike industrial robotics. In addition, in the health sector, every accident has an enormous negative effect for the practitioner as well as for the company marketing the device. Even if, in theory, a no-risk situation does not exist and there are always occupational hazards, it is clearly expected that a procedure assisted by a robotics system should be more safe and accurate than the same procedure carried out without assistance. Engineers here have a responsibility towards the doctor who will direct the robotics system. Even if the robot and its creators do not take the Hippocratic oath, we must at least keep in mind the first law of Asimov for robots. The use of the robotics system Robodoc (initially sold by the ISS company), which provides surgical orthopedic assistance, has thus had to stop in Europe following cases of badly fitted prosthesis reported in the German press. As a result, numerous rules have been enforced in the field of medical robotics regarding safety (see Chapter 5). Robotics systems must have:

– well defined, documented and precise protocols of use with adequate training of medical personnel;

– intuitive man-agent interfaces which are ergonomic and clear;

– automatic initialization procedures;

– procedures for termination and conversion to a conventional technique;

– a doctor in the loop if possible;

– intrinsically safe robotic structures;

– mechanical fuses if forces are high;

– redundant sensors;

– electric fuses;

– a limit on work space, velocity and force;

– procedures using software to test that all components are in good working order;

– procedures to ensure that every step of the medical procedure is executed correctly

– an extension to the medical procedure which does not put the patient’s health in jeopardy, etc.

The set up and the description of all these procedures and their components are necessary in order to obtain the stamp of approval from the EU or an “FDA approval”, which are required for sale on the market

1.1.1.2. Sterility

Another specific constraint encountered in medical robotics is sanitization for surgical procedures. Thus, the parts directly in contact with the patient or manipulated by the surgeon and the operators should be completely sterilized and the parts that could come into contact and cannot be sterilized should be covered in sterilized material (Figure 1.1). Amongst the more recent compact robots, some have been created in order to be totally sterilizable: this is the case for the LERViKY robot (Figure 1.2), which can be put into an autoclave.

Figure 1.1.Surgical robot (DaVinci) and its sterile covering

The common constraints that are encountered in terms of sanitization for a surgical robot are the following:

– the parts in contact with the patient, the surgeon and the operators must be treated by the autoclave or they must be disposable and in sterile packaging;

– the non-disposable parts which cannot be treated by the autoclave should be covered with a sterile packaging following a very accurate procedure so that they will not be soiled;

– the personnel of the unit should be trained.

Figure 1.2.Endoscope holder robot sterilizable in an autoclave (TIMC, Endocontrol Medical

1.1.1.3. Surgical theater

Unlike in industrial robotics where the robotics system functions in a protective cage specially designed for this purpose, a medical robot has to adapt to the specific environment of the operating room. In effect, with the exception of robotized radiotherapy, very few hospital rooms exist which are specially designed to accommodate a robotic system. In addition to certification of medical equipment (EU stamp, FDA approval, etc.), constraints specific to the operation room are mainly dimensional, ergonomic and concerning availability, in particular it is preferable to:

– reduce obstructions as much as possible;

– clear the working area as much as possible (using a SCARA structure for example);

– be able to transport the robotics system and its controller, if possible using only one person;

– be able to easily take the robotics system in and out of the operating unit, unless a room is entirely dedicated to it (as in radiotherapy);

– define specific procedures for storing and maintaining the accessories;

– conduct pre-emptive maintenance;

– put in place effective management in case of failures;

– ensure electric and magnetic compatibility with the other pieces of equipment;

– avoid as much as possible the need to call additional specialized personnel, etc.

1.1.2. Potential advantages of using a robot in a medical procedure

Given the particular constraints of medical robotics in terms of authentication, safety, sterility and the operating room, it is obvious that the road from the laboratory to the robotics system used in surgical procedures is particularly long and difficult. As we will see throughout this chapter, success stories are relatively few. We must also ask ourselves, what should be defined as a success? There is scientific and technological success when a technological feat has been achieved. This is measured by the yardstick of scientific publications and certificates in the field of robotics. There is success for the surgeon who has accomplished something for the first time with a robot, but there is above all the surgical success when a robot improves the quality of treatment for a patient. Finally, there is commercial success when a company successfully puts a medical robotics system onto the market and makes a profit. The engineer or the robotic’s researcher, even if he is an expert in his field, cannot master all the skills needed to guarantee success at all levels. Nevertheless, before commencing a potentially intense, but often long and costly, research and development project, it is important to ask the following questions:

1. Is a medical quality assessment in the field of the project possible so as not to follow false leads out of ignorance of pre-existing good medical practices?

2. Does the laboratory prototype, depending on additional developments, have a reasonable chance of becoming a system which can be used on a patient, that is, could it be certified (EU, FDA) and does it respect the 3 s?

3. Will the robotics system objectively improve the procedure practiced by the doctor?

4. Is this improvement potentially significant for the patient or for the medical personnel?

Although is difficult to respond to the last question without carrying out comparative surgical trials between robotized procedures and manual procedures, it is possible to respond to the other queries at the beginning of a project or during this discussion. A positive response to the second question is necessary in order to be able to carry out clinical validations. A positive response to the third question assumes that we have identified practical advantages of using a robot in comparison to the manual procedure. The possible advantages of using a robot instead of a human are those that we have already encountered in other fields where robotics have been applied, and it is preferable that a few of these advantages be proven to be true, such as:

– velocity;

– accuracy;

– precision;

– automatically following a trajectory;

– capacity to execute position, velocity and force controls;

– compensation for excessive force;

– fusion of multimodal information in real-time;

– automatically record completed commands.

In the case of a tele-operated robotics system these include:

– scaling of movements and effort;

– increase in sensory feedback;

– performance at a distance or in a hostile environment;

– increase in the numbers of degrees of freedom (dof) and dexterity;

– automatic filtering-out of physiological movement and shaking.

The possibility of simulating a surgical command with a dedicated robotic interface can be added to the robot’s superior qualities. However, to be fair, we must also take into account the superior qualities of man over a robot, that is to say:

– the capacity to analyze a situation and make a decision;

– the option of adapting or even “improvisation”;

– the capacity to train and educate;

– the integration of complex information from multiple sources.

Apart from the legal aspects, these superiorities demonstrate the need for the presence of a doctor for as much time as possible when a robot is being used. This must remain above all a medical tool at the service of a doctor.

In addition we must retain the position3 that some of the functions listed above can also be performed by “navigation” systems. These systems function on the principle of GPS; traditionally in these systems a localizer enables us to follow the position and orientation of the objects (surgical instruments, sensors and anatomical structures) in real-time and the system delivers a stream of information to the clinician on the action which is being performed, possibly in relation to a prerecorded plan or according to pre-operative data. These systems, already largely in use, are genuine competition for medical robotics. In order to maximize the chances of success of the latter, we must therefore use robots where they would be of added value in comparison to other options, such as navigators.

1.2. State of the art

Today the principal fields of the application for medical robotics are:

– surgery of the head and neck (neurosurgery, craniofacial surgery, dental surgery);

– orthopedic surgery;

– non-invasive surgery of the thorax and the abdomen (cardiac, cardio-vascular, general, urological, gynecological, etc.);

– interventional radiology;

– remote ultrasound;

– radiotherapy and diagnostic radiology.

Other uses also exist, but we can confirm that medical robotics has advanced in the aforementioned fields. In effect, robotics systems are used in clinical routine and feedback is available. We can thus observe a notable evolution since the first experimental systems.

In the relatively short history of medical robotics (a little over 25 years), we note three important stages. We can consider the creation of medical robotics to be in the middle of 1980s in the field of neurosurgery. Industrial robots, like the former PUMA robot made by Animation, were used for tasks such as accurately positioning surgical tools in relation to the anatomical structures in the brain of a patient. These first developments were followed, at the beginning of the 1990s, by others in the field of orthopedic surgery. Industrial robots have been adapted for accurate positioning of tools or cutting guides, mainly in the area of the hip, knee or spine. We note that this first generation of robots has directly influenced the more recent developments in the field of radiotherapy and radiology which depend to a large extent on large industrial robots for positioning the patient and heavy tools like linear accelerators or imaging devices.

The second age of medical robotics corresponds with the arrival of the stream of robots in the 1990s in the field of mini-invasive surgery. This concerned remotely operated robots holding tools with frameworks tailored to the particular context of the passage of the tools by fixed points in the body of the patient. These robots enable a scaling in the required movements and, above all, more dexterity inside a patient’s body thanks to additional dof in terms of tools. After the euphoria of 2001 regarding the operation performed by Professor Jacques Marescaux from New York on a patient in Strasbourg with the help of a remotely-controlled ZEUS robot [MAR 01], these expensive systems are used today in clinical routines in a number of less common cases where a real advantage – from the point of view of the patient – is hoped for.

Finally, the recent developments in medical robotics in the last few years have coincided with the arrival of small robots, which are more economical, concentrating on precise indications, in contact with the patient in a way that frees us from the problem of compensating for physiological movement. Also being developed today are robotics “inside the patient” for a growing number of medical cases which either use autonomous capsules or flexible systems like active catheters and robotized endoscopes (see Chapter 10).

Figure 1.3.Some important milestones

1.2.1. Surgery of the head and neck

Different surgical treatments are covered in this section: including neurosurgery, stereotactic or conventional, opthalmological surgery, ear-nose-throat (ENT) surgery, craniofacial surgery, dental surgery. We see that most of the surgical gestures in this category require a lot of precision for:

– instrument positioning relative to anatomical structures;

– fragment manipulation (cutting and repositioning).

Microsurgery or endoscopic techniques used in certain surgical specialities increase the difficulties encountered either in terms of the scale of motion accuracy or the amplitude of the force applied, or in terms of accessibility of the target in focus and the motion restrictions of tools.

1.2.1.1. Neurosurgery

Neurosurgery has a long tradition of reducing the invasive nature of operations coupled with a metrological approach to referencing the anatomy, in particular that which concerns stereotactic neurosurgery; this consists of being able to reach a structure which is often deep in the brain thanks to a linear tool, more often than not through a small opening (usually 3 mm in diameter). Thus, Zernov’s cephalometer appeared at the end of the 19th Century, in order to give the surgeon a mechanical reference system. The stereotactic framework, which succeeded it at the beginning of the 20th Century, fulfills three functions: (1) to provide an external reference frame enabling the position definition of an intra-cerebral structure; (2) to immobilize the skull of the patient during the execution of non-invasive procedures which demand millimetric precision; and (3) to serve as a support for a gesture. The link between internal structures and external references has benefited from the development of medical imaging, firstly in using conventional radiology, then 3D images (X-ray, CT scanning then using magnetic resonance imaging). Neurosurgery has been a precursor clinical field in the quantitative use of imaging for the purpose of localization.

Stereotactic neurosurgery is mainly used for biopsies, for the positioning of stimulatory (Parkinson’s disease) or measurement (stereo-electro-encephalographic in epilepsy) electrodes, or for the removal of cysts or the drainage of hematomas.

It is very clear that robots were introduced in this context as a complement, rather than as an alternative, in the stereotactic setting. The first medical robotics treatments therefore had the objective of using the robot to position or guide a tool with regard to the intracranial target in focus on the basis of 3D information stemming from the imaging. We can point to the pioneering work of Kwoh [KWO 88] who used the PUMA260 robot installed in the scanner of the examining room to facilitate the transfer of the data resulting from the imaging for the positioning of a stereotactic tool. The first operation on a patient took place on the 11th April 1985 for a biopsy. A dozen patients were operated on using this system in a survey of feasibility. In the same way, [LAV 92] presented an industrial robot modified for tool positioning, based on imaging with a mechanical guide supporting the actions of the neurosurgeon (Figure 1.4). The modifications made on the robot were aimed at adapting to medical constraints: a reduction in velocity, increasing the reduction ratios making the arm non-backdrivable and enabling one to cut off the power as soon as the tool was introduced into the brain. This robot was used on a patient for the first time in March 1989 and thousands of patients have since been operated on with its assistance and then with its industrial successor: the Neuromate robot (IMMI company, later ISS, then Schaerer-Mayfield, then Renishaw since 2008).

Figure 1.4.Sterotaxic neurosurgical robot (TIMC, CHU Grenoble)

This robot is described as “semi-active” as the surgical action is performed by the clinician who inserts the surgical tool by hand into the pre-positioned mechanical arm of the robot according to a plan. Recently, different systems have taken up this concept: we refer to the Pathfinder of Prosurgics and Rose of MedTech for example.

Burckardt et al. [BUR 95] suggested a totally automated version of this type of gesture. Minerva, the robot developed specifically in this context, was installed in the scanner room and equipped with different tools. It was used for executing the whole procedure including the perforation of the skull and the insertion of the chosen tool relative to CT data. The first two patients were operated on in 1993. [GLA 95] reported 8 cases of biopsies. To our knowledge this system has not been used intensively in a clinic.

All the robots previously mentioned have relatively generic and anthropomorphic structures. In order to make the system more specific and potentially more secure, some teams have also robotized stereotactic frames (for example [KAL 96]).

Towards the end of the 1980s and the beginning of the 1990s, microscope-holder robots also entered into operating units. We can mention Surgiscope (IMMI company, then DeeMed, then Elekta, finally ISIS) created based on a parallel “delta” robot along with the MKM robot (Zeiss company). The idea here is to motorize the surgical microscope holder used in microsurgery (neurosurgery, ophthalmology, ENT) in order to facilitate handling and to equip it with high-level motion functions and augmented reality connected to imaging [PAU 05].

Many of the robots listed above are no longer available. Sterotaxic positioning robots are competing with often more versatile, potentially less dangerous, easier to set-up and often less expensive neuro-navigation systems. In effect, the concept of the navigation system also grew in the context of neurosurgical applications and ENT: we can cite the innovative work of Watanabe and his “neuronavigator” [WAT 87], Mösges [ADA 90] or Reinhardt [REI 96]. In these first systems the mechanical encoded arms served, more often than not, as localizers. More recently, these navigators allowed frameless stereotaxy thanks to optical localizers and to markers stuck to the skin of the patient thus allowing the tracking and updating of data in real-time. As for microscope-holder robots, it is probable that the cost-profit ratio has been too high to make this idea a real surgical and commercial success.

More recently, numerous robots compatible with MRI have been or are being developed: we cite the work of [NAK 98] where the proposed structure can be compared with the stereotactic arciform frames of NeuroArm [SUT 03] of the University of Calgary. We will also mention the use of the Mazor’s Spine Assist robot (see section 1.2.2) as an application of cranial neurosurgery [SHA 05]. This robot was initially created for spinal operations.

The development of an endoscopic and intra-cerebral robot has recently been the subject of increased interest. [MIY 02] presents a remotely operated system with a rigid endoscope and three adjustable tools with 3 dof for an endoscopic surgery. The micro forceps are compatible with the MRI. One experiment with NeuRobot on a patient is reported in [HON 03a]. [OK03] describes a poly-articulate system with 10 dof designed to move inside the brain. More than ever, the question of safety is important in any such approach.

Many of the systems mentioned are at a preliminary stage of development or an experimental, non-clinical stage. Of the new non-surgical treatments transcranial magnetic stimulation (TMS) is also growing; it is in the course of being developed by different teams all over the world (see section 1.2.7.2). The treatments are psychiatric or neurological.

We finally mention a very innovative device for its time, proposed by [NEI 95], [RIT 96], which moves by an intra-cerebral device thanks to an external magnetic field, for example to provide medication non-invasively in-situ or to accurately deliver hyperthermia deep in the brain. One version of the system has been tried on animals. To our knowledge, the system has never been experimented on a patient.

1.2.1.2. Other treatments

Different prototype systems have been developed for similar cases. Thus in ENT surgery, [BRE 95] became interested in robotized stapedotomy: it involved a clinical routine on the ear requiring the partial perforation of the intermediate structure inbetween the inside of the ear and the exterior of the ear; this is needed to install a mechanical device allowing the repair of the line of transmission of mechanical vibrations necessary for hearing. In this type of treatment, it is the coupling of the motions to the measure of the force that makes this approach interesting, but it also makes it complex: we observe in the vast group of patients large variability in mechanical rigidity of the structures concerned; the precision required was equally important. To our knowledge this system has not gone past the stage of validation on specimens. More recently, Ortmaier et al. [MAJ 09] carried out a feasibility study using anatomical specimens for robotized surgery on the cochlea before inserting hearing aids. [MIR 08] describes the design of a specific robot (Robotol) for surgery on the middle ear.

In addition, this ear surgery is cited as a potential application domain for the Steady Handy robot [KUM 00]. This comanipulation system allows filtering the movements of the surgical tool positioned on the robot and manipulated by the surgeon, and the application of a scaling factor between specified and completed forces. It can be applied to numerous clinical applications.

The other treatments of the ENT surgery, such as skull base surgery or endonasal surgery, have more often given way to the development of navigation systems rather than of robots. This is also the case for craniofacial surgery and dental implantology, with a few exceptions. The applications deal with the positioning of bone fragments or prosthetic components along with cutting bone. We note for the record the pioneering work of Taylor et al. [CUT 96], who developed a passive arm for assistance in the manipulation of bone fragments. We also cite the work of [KLE 01] using a modified “Surgiscope” for positioning implants; this system has been used experimentally on patients. Burgart et al. [BUR 99] have also experimented with the use of an RX90 robot in order to achieve bone incisions in cranio-facial surgery. The system used implemented a comanipulation approachcomanipulat (see Chapter 9) to curb the path of the tool according the plan. Animal experiments have been carried out.

As for Ophthalmological surgery, different projects have begun either with the aim of assisting with surgery on the “surface” of the eyeball or for intra-ocular surgery (the retina in particular). Studies by [SMI 99] and [HU 05] have included the robotization of treatments to dissect and stitch the cornea; the evenness of the tension in the stitch thread directly effects the quality of the curve of the eye and how it functions. [DAS 95] reports on experimentation on phantoms by ophthalmologic surgeons carried out with a master-slave system (the RAMS) integrating two compact arms with 6 dof. The relevance of this last system to intraocular surgery is not clear. Intra-ocular surgeries, in effect, present a triple difficulty of endoscopy on the mobile structure and of microsurgery. [HUN 95] describes a remotely operated system for endo-ocular surgery integrating a 5 dof parallel robot. [JEN 97] describes a parallel robot combining one Stewart platform with 6 dof to a hydraulic dof for the motion of a tool. This robot has been specifically created for endo-ocular surgery. The Steady Hand was previously cited as being of equal value for such tasks [KUM 99]. Much more recently [YES 06] proposed the concept of an injectable system in the eye of the patient, which is controlled magnetically from the outside (see Chapter 10).

1.2.2. Orthopedic surgery

Orthopedic surgery is a domain of activity in medical robotics that is at the same time pioneering and still very active. Naturally, orthopedic surgery seems very close, in its essence, to the machining of robotic manufacturing. In fact, a number of operations require the preparation of cavities or of bone surfaces for the placement of prosthesis (hip, knee, shoulder, etc.). The tools frequently used by the orthopedic surgeon are those of a mechanic: a ream, a saw, a drill, etc. Orthopedic surgery concerns the skeleton (limbs, pelvis, spine) and the joints. Because of the aging population in our industrial countries, prosthetic surgery (in particular knee and hip replacements) is a field of treatment that is extremely active.

There are150,0001 (resp. 600,000) hip replacements every year in France (resp. in the USA) and 58,000 (resp. 300,000) knee replacements in France (resp. in the USA). These numbers are constantly going up. The aim of robotization is to make prosthetic surgery more precise, for example aligning more perfectly with the centers of the ankle-knee-hip joint in the example of knee replacement. Being more functional, it should be more stable in the long term. At the moment, around 10% of the operations for artificial knees are prosthesis revisions (the replacement of already implanted prosthesis). The competition is intense between robotized systems and navigators in the field of prosthetic surgery, the robot being preferable for the execution of complex geometric gestures.

1.2.2.1. Beginnings

Historically, the first robot developed in orthopedics was Robodoc (Figure 1.5) initially created for the preparation of femoral cavities in total hip arthroplasty; the robot autonomously machined a bone cavity using a plan based on scanner data registered to the intra-operative situation (see Chapter 3). The point of such robotization was to guarantee better stability of the prosthesis in the long term by a better mechanical fitting to the bone.

Figure 1.5.Robodoc: the first steps (left) and the current version

The first prototype was studied and created from 1986 to 1989 by Yorktown IBM with the University of California, Davis. From 1989 to 1991, 29 dogs were operated on with the assistance of a system to demonstrate its clinical feasibility [PAU 92]. On this basis, and with the creation of the ISS company, the FDA authorized a test run on 10 patients. Later, a randomized multicenter study in the USA compared a group operated on with traditional surgery to a group operated on with robotized surgery. Then an European “post-market” study involving thousands of patients aimed to show the clinical interest of this tool. [BAR 98] retraces the different stages. Robodoc was deployed in Europe and Asia between 1995 and 2002 (EU certification in 1996). Unfortunately, the use of the robot for prosthetics needing a specific surgical approach [HON 03b] created an unusual morbidity and the legal ramifications drove the ISS company to withdraw the robot from use in Europe. At the moment of this withdrawal, Robodoc had not yet shown its superiority in terms of the clinical results compared to conventional techniques, even though the more important geometrical quality of the robotized act was proven and undeniable. That being so, the lifespan of the prothesis was around a dozen years, it was therefore perhaps a little premature to draw definitive conclusions in the absence of the clinical added value of the robot. The product Robodoc was brought back in 2007 by Curexo Technology Corp, which created the eponymous company Robodoc. Robodoc has been approved by the FDA since 2008. It is now used in the USA and in Asia, particularly in South Korea (2,500 operations every year). Its promoters announced that 50 systems have been installed in the world and more than 20,000 operations have been carried out so far. The CASPAR robot developed by Orto-Maquet based on a Staubli RX90 possessed the same functions and had the same clinical objective as Robodoc. Caspar is no longer distributed, faced no doubt with the joint difficulty of demonstrating added value and also the negative media coverage of the problems with Robodoc. These two robots are knows as “active”: they autonomously achieve a part of the surgical procedure under the supervision of a surgeon.

At the beginning of the 1990s numerous projects were also undertaken to help the positioning of intra-pedicular screws in the spine. Such screws served, for example, to fix rigid rods along the spine of scoliotic patients to correct the curve. Clinical tests concerning this surgery in fact reported many cases of badly fitted screws with more or less serious consequences from badly fixed rods to more serious problems such as the penetration of screws into the spinal canal. Navigation approaches were therefore developed and the first systems were experimented on patients towards the middle of the 1990s [LAV 95], [NOL 95]. The difficulty is in transferring a pre-operative plan, defined for instance on CT data, to operating conditions in order to execute a precise gesture on a structure that is not clearly visible, that is the pedicle of the vertebrae.

Contrary to the example of Robodoc where the structure in question is generally immobilized by being fixed externally, the vertebrae itself is mobile during the surgery, due to the simple fact that the patient is breathing and also because of the surgery itself. Tracking the anatomic structure and updating the target trajectory appear in much more simple terms in the case of navigation since the localizer allows us to measure the displacements as the action is executed by the surgeon. This is what motivated this type of development of this kind of system to the detriment of the robot. As we will see (section 1.2.2.3) compact solutions answering this tracking issue have recently been proposed and may modify this tendency.

1.2.2.2. The second generation

Towards the middle of the 1990s, new approaches towards robot/surgeon interaction grew, the idea being that the robot and human operator hold and move the tool at the same time. We are therefore talking about a “synergistic system” or “hands on” system or the “cobots” according to the authors [TRO 98]; but even if the qualifiers and technology used are different, the approach and the inspiration is unchanged. It turns out to be difficult to encode in a numeric model all the complexity of a clinical situation and it could be advantageous to combine in one gesture the robot taking its information from the numeric model, and the operator observing/taking his information from reality. From this approach the Acrobot [HO 95] system was born in the field of orthopedics. In this system the coefficients of the PID controller vary according to the robot position. Depending on whether the robot end-effector is in an area where movement is permitted or where movement is forbidden, the functions vary leaving the operator more or less free (see Chapter 9 for more details). This system was developed for bone surfacing in knee anthroplasty. It requires machining the tibial and femoral extremities along several pre-determined planes to enable the fitting of the prosthetic components to the bones. The choice of the position and the orientation of these planes depends on the anatomy of the patient (the size of the prosthetic elements and the alignment of the center of the joints of the ankle, knee and hip). This clinically used robot [JAK 03] is fabricated by the company Acrobot. More recently, the company Mako Surgical Corp has also put onto the market a robot called RIO® (Robotic Arm Interactive Orthopedic System) functioning on the principle of comanipulation for unicompartmental prosthetic surgery of the knee: this type of surgery only permits minimally invasive access to the bones which complicates the work of the surgeon by limiting the visibility and dexterity; the assistance provided by the robot guarantees that the work on the bone will conform to the plan. The first clinical trials confirm the superior accuracy and precision of the procedure in relation to the manual procedure [C00 10]. However, there has not been enough evaluation time to determine the eventual clinical consequences from this benefit in accuracy.

1.2.2.3. Recently

A new tendency has grown in the field of orthopedic surgery since the beginning of the 2000s with the concept of the portable robot, which is sufficiently compact to be positioned on the bone structure of interest. This type of approach has numerous advantages: a reduction in work space, a better management of safety, the ability to move with the bone structure on which it is fixed, potential reduction in costs. There are equally some disadvantages connected to this approach; the robot is very specific, it needs be to sterilized, the cluttering of the surgical area.

Figure 1.6.Praxiteles robot from the TIMC laboratory and its commercial version iBlock (Praxim)

We cite in the same way the MBARS [WOL 05], Arthrobot [KWO 01] and Praxiteles [PLA 06] robots developed for the purpose of fitting prosthetic knees, along with the Mars [SHO 03] robot initially created and used to fit intra-pedicular screws [BAR 06]. Spine Assist and iBlock were the respective commercial versions of the Mars and Praxiteles robots.

1.2.3. Mini-invasive or laparoscopic surgery

Mini-invasive surgery grew in popularity in the 1970s and was gradually introduced as opposed to open surgery as the procedure of choice for general surgery (digestive, endocrine, visceral), but also in gynecological and urological surgery by numerous guidelines. Mini-invasive surgery in the abdominal cavity is called coelioscopic or laparoscopic surgery. It consists of executing smalls incisions in which trocars are inserted. The first incision of approximately a centimeter allows an optical device, the laparoscope, to be introduced through the trocar. A camera is placed on the extremity of the laparoscope and allows the inside of the abdominal cavity to be viewed on a screen. The optic fibers in the laparoscope, linked to a light, allow the operating area to be lit up. This is cleared by pumping CO2 into the abdominal cavity. The other incisions are equipped with trocars of about 5 mm through which surgical tools are introduced (Figure 1.7). The trocars allow tears to be avoided, to control sterility, but also to regulate the pressure of the CO2.

Figure 1.7.Coelioscopic or laparoscopic surgery

Coeilioscopic surgery has revolutionized surgical practice. It has shown its superiority in terms of the medical service given to the patient in a number of cases: such as an appendectomy, a cholecystectomy, the treatment of hernias, gastroplasty, sigmoidectomy, the treatment of cysts and ovaries, the tying of tubes, the treatment of endometriosis, uterine ablation for fibroids, radical prostatectomy, etc. This procedure reduces post-surgery wounds, the risk of infection, the duration of time spent in hospital and the cost of the treatment.

This technique is, however, more difficult for the surgeon to comprehend. In effect, the tools are long rods with reduced mobility because of the passage in the trocar. In addition, the surgeon has an indirect, 2D view and loses touch because of rubbing owing to the trocar. The surgeon is also fatigued by his posture, standing up over the patient, a tool in both hands, watching the control screen with reversed movements between his hands and the end of the tools. This gives many opportunities for development in robotics, principally to give more comfort to the surgeon and also for more dexterity inside the body of the patient thanks to adjustable and technically-manipulated instruments.

Robotics became involved with this field in numerous ways [KAZ 08], [HAG 08]. One important use is the automatic positioning of the endoscope which enables a more stable image, along with freeing the dedicated person of this task during the clinical routine. Another use which is very important is tele-operated articulated tools which allow ergonomic manipulation at a distance with additional mobility, but also filters the shaking of the doctor and a scaling in the movements needed for the micro-surgical tasks.

1.2.3.1. The first systems

The first systems were developed at the beginning of the 1990s when miniinvasive surgery was in a period of rapid development. In mini-invasive surgery which could last several hours, the endoscope is held by an assistant near to the operating area who must hold it steady, to move it as instructed by the surgeon and to clean it if necessary when the lens is dirty. The first robot approved by the FDA in 1993 was the robotized endoscope AESOP [SAC 94] by the Computer Motion Company, Goleta, CA, which merged with Intuitive Surgical, Sunnyvale, CA in 2003.

This system was a real commercial success with more than 2,000 models sold in approximately 500 hospitals until the end of its sale by Intuitive Surgical. It was a SCARA robot with 4 active axes and 2 passive axes in order to respect the constraint of the trocar, though the patient could be moved in relation to the base of the robot which was fixed to the operating table (see Figure 1.8, left). The first version of the robot was controlled by a pedal at the foot of the surgeon, which then rapidly became a voice command.

Another type of robotic structure was developed in order to take into account the constraint of the trocar which limited the mobility of the tool. It was a structure with a remote center of motion [TAY 95], [ELD 96].

Other commercial systems followed after the arrival of the AESOP robot. The EndAssist robot from Armstrong Healthcare, High Wycombe, UK (which became Prosurgics in 2006) was approved by the FDA in 2005. It had a 3 active dof endoscope-holder robot controlled by movements of the head [AIO 02] with a remote center of motion on an arm with a vertical axis mounted on a moving trolley (see Figure 1.8, right). A comparison between the EndoAssist robot and the AESOP robot has been made [WAG 06].

Figure 1.8.Endoscope-holder robot AESOP by Computer Motion (left) and EndoAssist the Armstrong-Healthcare (right)

The LapMan robot from Medsys, Gembloux, Belgium approved in 2003 by the FDA, is a system with 3 active dof on a mobile stand [POL 04] created for gynecological mini-invasive clinical routines. Finally, the Naviot robot by Hitachi, Japan is an endoscope-holder robot with manual command consisting of 5 parallel bars attached to the operating table [KOB 99], [YAS 03], [YOS 05].

The major event in the field of robotized surgery was the arrival of the ZEUS robot by Computer Motion and of da Vinci by Intuitive Surgical. These are remotely operated robots with a master-slave architecture where the surgeon navigates several arms holding tools, from a distance, using a remote control and the image displayed from the endoscope. The ZEUS robot evolved from the AESOP robot introduced from 1996 and is made up of 3 independent arms with a similar structure to that of the AESOP robot which was fixed to the operating table (see Figure 1.9).

Two arms with 4 active dof hold tools with active joints at the ends of the arms. These are remotely operated with a master interface made up of two 5 dof polyarticulated arms and a screen showing the endoscopic image from the endoscope held by the third arm, which is identical to the voice command operated AESOP robot.

Figure 1.9.ZEUS robot by Compute Motion: master control (left) and command-operated arms (right)

The first mini-invasive coronary bypass surgery was carried out with the ZEUS robot in 1999 [REI 99]. The use of the ZEUS robot was approved by the FDA for laparoscopic surgery in 2002. The ZEUS robot was used by Professor Marescaux of the IRCAD to carry out a cholecystectomy in September 2001 in New York on a patient in Strasbourg [MAR 01]. The commercial exploitation of the ZEUS robot came to an end in 2003 after the takeover of Computer Motion by Intuitive Surgical.

Figure 1.10.Da Vinci by Intuitive Surgical: the old model with 3 arms (left) and the new model with 4 arms (right)

The da Vinci robot by Intuitive Surgical is made up of three or four interdependent arms mounted on a single base. Each arm has a rotating center (remote center of motion (RCM)) in order to respect the constraints of the trocar (see Figure 1.10). The end of the instruments are articulated with three mobile rotations and are remotely operated via an interface with 6 dof arms and two screens showing the stereoscopic image coming from the two channels and two cameras of the stereoscopic endoscope.

The da Vinci robot was the first tele-surgical system approved by the FDA in 1997. The first operation carried out with the da Vinci robot was a laparoscopic cholecystectomy in 1997 [HIM 98]. The first radical prostatectomy was carried out in 2000 [ABB 00]. Studies have shown that a large number of cases of patients recovered better and more quickly with robotized radical prostatectomy compared to the classic approach, with fewer incontinence and impotence problems [MEN 04]. Since these studies, the commercial success of the da Vinci robot has been secured and robotic surgery has become the point of reference in urology for radical prostatectomy. The robot also facilitates the mini-invasive coronary bypass procedure which enables the surgeon to avoid a sternotomy [PRA 01]. It is interesting to highlight that different studies have shown the learning curve for robotic mini-invasive clinical routines has been reduced compared to that of classical manual procedures, in particular for complex tasks such as stitching [ALH 03], [MOO 04].

Robotics systems for mini-invasive tele-surgery have been developed in university laboratories simultaneously. In particular, the Black Falcon robot is a prototype of the arm of a remotely operated endoscopic surgical robot with an articulated tool developed at MIT [MAD 98]. It is a 4 dof mobile arm with a RCM (see Chapter 5), a 3 dof articulated instrument and a system measuring force. A PHANTOM haptic interface is also used as the master arm. The inventors, A. Madhani and J. Salisbury, have acquired numerous patents for their invention for which rights have been given to Intuitive Surgical. A laparoscopic robot, called “Robotic Telesurgical Workstation (RTW)” has been developed at Berkeley University [CAV 99]. It is a man-agent system where the mobile arms holding instruments at 4 dof have a Remote Center of movement, the end of the instruments are articulated with additional dof and the remote control haptic interface is made up of two haptic 6 dof PHANTOM interfaces (Sensable Technologies).

1.2.3.2. Recently

Previously mentioned systems, in particular, the da Vinci robot, are major commercial successes, but their clinical dissemination is still limited mainly because of their cost.

The more recent developments resulted in the apparition of a new generation of small-size robots in contact with the patient. Thus, the endoscope-holder robot LER (“Light Endoscopic Robot”) developed in the TIMC laboratory in Grenoble is a small robot with 3 dof (2 rotations and one translation) which is in contact with the patient nearthe trocar (see Figure 1.11) and which enables us to position and move the endoscope by voice command [BER 03], [LON 07]. A modified version of the LER robot is sold by Endocontrol, Grenoble under the name of ViKy [GUM 07].

Figure 1.11.LER by TIMC (left) and ViKy by Endocontrol (right)

The Prosurgics company in Guilford in the UK, has sold Freehand since 2010. It is a small size endoscope-holder robot attached to a table over the patient and controlled by movement of the head. It has an identical system to that of the EndoAssist robot (see Figure 1.12) [STO 10].

Figure 1.12.Endoscope-holder robot Freehand by Prosurgics

Robots holding light and compact instruments for endoscopic surgery have been developed by different teams. For example, the MC2E robot with 3 dof from the ISIR laboratory in Paris, which is attached to the trocar with a force sensor allowing the measurement of the forces on the tool and which can be comanipulated [ZEM 04]. We must also note the Endobot robot with 4 dof which was developed at RTI [KAN 01].

1.2.4. Interventional radiology and percutaneous procedures

Interventional radiology is a field of medicine that is in full swing, being directly connected with progress in medical imaging. In interventional radiology, the radiologists achieve medical and surgical gestures with the help of needles, probes, catheters or other similar medical tools, whilst being guided during the operation by one or several imaging modalities.

There are two principal types of activity in interventional radiology, namely, vascular operations and percutaneous procedures. The more common vascular operations consist of introducing a catheter or a probe into a vein or an artery in order to carry out an angioplasty (dilating an artery with the help of a small balloon), placing a stent or a filter, putting in place a prosthesis or embolizing a blood vessel to stop the bleeding. These procedures are executed under image control mainly with the help of X-ray. Percutaneous procedures are usually practiced with the help of needles or with probes directly placed inside the anatomical target. The most common percutaneous procedures are biopsies in preparation for a diagnostic, permeations, tumor destruction as a result of high temperature (radio frequencies, micro-waves, lasers, focused ultrasound) by freezing, by injection from an active principle or by brachytherapy (the injection of radioactive seeds, for example Iodine I135). We should also mention vertebroplasty which consists of the injection of cement into the vertebrae for its consolidation or reconstruction.

The intra-operative imaging modalities are mainly ultrasound for soft tissue and superficial anatomic structures, radiography by X-ray which produces a projection image and can be viewed in real-time with the aid of a fluoroscope (C-arm), tomodensitometry with an X-ray scanner (CT-scan) which produces a 3D series of slices or MRI which allows a 3D series of slices in any direction and also has the advantage of not emitting ionizing radiation [ELH 08].

Robotics is relevant in this area in multiple ways [FIC 08]. One important application is the navigation of manually inserted catheters, probes and needles. Another is the positioning and orientation of these instruments by a robotic system, and more recently their tele-operation. Tele-operation allows the surgeon to be protected from X-rays and also allows him to maneuver in a confined space, with limited access.

1.2.4.1. The first systems

The first robotics systems were developed in the field of interventional robotics approximately a dozen years ago. They are principally concerned with procedures guided by X-ray, but also by ultrasound and MRI. These systems are rigidly attached to the table and assume that the target is motionless. They are used for the precise placement of the needle from image information.

We must note the work achieved by the John Hopkins University, in particular the development of the AcuBot robot [STO 03] which allows the technical manipulation of a needle for percutaneous procedures guided by a scanner. The robot is made from a “PAKY” system where a needle injection device is mounted on the arm with a remote center of motion enabling its orientation around the entry point [STO 98]. This “RCM-PAKY” system is fixed onto a passive 7 dof arm attached to a XYZ Cartesian motorized system and fixed to the table of the scanner. This allows the RCM-PAKY system to be positioned on the body of the patient, at the entry point – in particular for kidney operations (Figure 1.13). Positioning at the entry point, orientation and insertion of the needle are remotely controlled.

Figure 1.13.RCM-Paky and AcuBot systems

Amongst the first systems developed for percutaneous procedures under the guidance of a scanner or ultrasound, we must mention the biopsy 7 dof prototypes (B-Rob I and II) by ARC Seibersdorf Research in collaboration with the department of interventional radiology at the University of Vienna [KRO 03] and [CLE 06]. These prototypes are made up of two parts: a 3 dof Cartesian system for approaching the entry point and a 4 dof needle holder allowing for a precise positioning and orientation of the needle. Finally the needle is inserted manually. These first prototypes have been experimented in vitro only.

The first commercial system on the market was the INNOMOTION system from the German company, Innomedic, bought by Synthes in 2008 (Figure 1.14