AN INTRODUCTION TO VIRTUAL REALITY IN SURGERY
By Mr B.R.Prashanth M.B, MS, MCh(Orth), MRCS Ed, FACSM
INDEX
Introduction Top
Virtual reality as described by Dr Joseph Rosen, is a computer generated technology which allows information to be displayed in a simulated but life like environment. Although it sounds like something out of a science fiction movie, virtual reality has been around for several years. In the 1940s virtual reality type simulation programs were used to train, evaluate and certify military and commercial pilots. Over the past decade virtual reality and computer simulation have expanded into other domains including the medical field.
Virtual reality is perhaps being used more in Medicine than in any other industry, because its applications have such far-reaching benefits. It promises to bring one of the most dramatic changes to the practice of medicine over the next decade.
In terms of computer literacy and competence, there are all levels of expertise in the population. In terms of computer comfort, however, there are only two groups: younger people, who find the technology easy to use and the rest who were raised in the age of the magical knowledge system called books.
At the present time, we are becoming more and more dependent on computerised information, the Internet, e-mail and CD-ROM instructional systems.
CD Technology can put an enormous amount of information in a highly presentable manner to get ideas across much more effectively. It is a portable, highly interactive and inexpensive medium for distribution of information.
John Hunter applied a scientific approach to surgery 200 years ago "Evidence Based Surgery". Surgical training is an ongoing process and these factors have played a major part in the rise of evidence-based surgery:
In Surgical training there is often a short fall in the number of desired operations performed. One consequence is that trainees may have less practice and feel less confident about many surgical procedures and techniques. With the increasing level of difficulty of surgical procedures it has become imperative that trainees have an arena in which to learn their trade that is forgiving. With the advent of Virtual reality, this has become a reality. Advances in modelling compete with virtual reality.
Applications of Virtual reality Top
Education: Virtual reality patients can be used to create an environment for learning Anatomy. The advantage over traditional dissection would be that the exercises can be easily reversed allowing the models to be repeatedly taken apart and examined from multiple points of view.
Simulation for Surgical training: Virtual reality can teach surgeons new procedures and determine their level of competence before they operate on patients. It allows the trainee to practise a skill several times as a refresher course. One example of applying this is in the field of Laparoscopic surgery. The first application of laparoscopic surgical procedure by virtual reality was in the virtual clinic where a prototype of a laparoscopic cholecystectomy was performed. The results were favourable and now several other projects of minimal access surgeries are being developed. Below are several new simulators that are allowing surgeons to learn and practice the skills of their trade:
Project Hippocrates: Project Hippocrates uses virtual reality to simulate, plan and execute Orthopaedic surgeries. The goal of this system is to allow the surgeons to simulate operations and then alter their approach to them based on the results of the simulated surgical procedure. The program allows the surgeon to plan his or her surgery.
ERCP: Georgia Tech’s Biomedical interactive centre has produced the Endoscopic retrograde cholangio-pancreatography surgical simulator. This simulator replicates an endoscopic procedure in a virtual environment. Its job is to train physicians to perform ERCP procedures by using photo realistic and tactile environments.
The Karlsruhe Endoscopic Surgery Trainer: This is a virtual reality based training system for minimally invasive surgery, which imitates the operation area and provides a real-time synthetic endoscopic view. The viewer can interactively manipulate the modelled objects and execute surgical tasks.
Telemedicine: Telemedicine is a system of electronically communicating data from one site to a distant site for the purpose of medical diagnosis, patient care and as a medium for delivering medical services over long distances. An example would be transferring a patient record from a doctor in London to a surgeon in Lancaster to provide expert patient care. Virtual telemedicine can enhance telemedicine by superimposing data that is patient specific directly on to that patient. This is called data fusion. Telemedicine is improving lives by spreading medical information to remote areas around the world.
Teleprescence Surgery: This is the performance of surgical procedures where the patient and the surgeon are in different locations. Using audio and/or visual the surgeon is able to use his expertise and guide the procedure. An example of this emerging technology is the Green Teleprescence Surgery System, which consists of two components, the surgical work station and the remote work site. At the remote site are a 3-D camera system and responsive manipulators with sensory input. At the work station are a 3-D monitor and dexterous handles with force feedback. (((At the present time this is an experimental tool not currently used in practice.))) - taken out
Advantages of virtual reality Top
Efficiency: Virtual reality simulators are more efficient than training on real patients. It eliminates the risk of harming the patient while trying to learn a new skill. It also eliminates the time restraints on waiting for types of cases to come up and allows the trainee to practise independently.
Objectivity: Virtual reality can objectively evaluate and measure technical competence rather than traditional subjective measure of trainee and mentor.
Ethical: Using virtual patients to train on is less expensive and less offensive than training on animal models.
Disadvantages of virtual reality Top
Cost: New technology is expensive. The cost of developing hardware and software for the application of virtual reality technology is too great for many institutions to implement at this time. Computer instrumentation is expensive after introduction but has always decreased over time; so I suspect as this occurs virtual reality will eventually become more commonplace in Medicine.
Restraint: Presently the equipment used to create a virtual environment is restrictive and uncomfortable to its users. This would have to be overcome for more convenient uses in surgical procedures.
Looking to the future Top
Robotic Surgeons: The first generation of surgical robots are already being installed in a number of operating rooms around the world. These are not true autonomous robots that can perform surgical tasks on their own, but they are lending a mechanical helping hand to surgeons. These machines still require a human surgeon to operate them and input instructions. Remote control and voice activation are the methods by which these surgical robots are controlled. The three surgical robots that have been recently developed are:
1. Da Vinci surgical system
2. Zeus robotic surgical system
3. AESOP robotic system
Da Vinci system is presently in clinical trials in the United States for applications with in cardiac surgery. This system is also being currently used in London. (see the video library where this robot is seen in rectopexy and management of achalasia)
Researchers are currently trying to incorporate surgery and robotics in the form of teleprescence surgery. The great attraction of this system is that it would allow surgeons to observe, assist or perform surgical procedures from some distance.
Conclusion Top
Just as simulators are now standard in the fields of aviation and aerospace, soon surgical simulators will be standard in the medical field. These simulators will allow instruction of correct surgical technique without the need for live patients. With the advent of virtual reality, surgeons get the opportunity to learn and practise the skills of their trade. It is a tool that has many potential applications. I predict that, as technology continues to advance and the cost of manufacturing decreases, virtual reality will become a dominant tool for training future surgeons.
References Top
1. A tutorial on Surgical simulation: Past, Present and future; Medicine meets virtual reality (MMVR) journal, January 24, 2002.
2. Medical simulation for Surgical training; Medical image computing and computer- Assisted intervention (MICCAI) journal, October 14, 2001.
3. A computer-based simulator for diagnostic peritoneal lavage, Alan liu, Christoph Kaufmann, Thomas Ritchie, Medicine meets Virtual reality, 2001.
4. An architecture for simulating needle-based surgical procedures, Alan liu, Christoph Kaufmann, Daigo Tanaka, Medical image computing and Computer-assisted intervention (MICCAI), 2001.
5. From virtual reality to surgical performance, Medical Simulation and training, Vol(1), 24-25, 1996.
6. M. Bro-Nielsen and S. Cotin: Real-time volumetric deformable models for surgery simulation using finite elements and condensation, Computer graphics forum, 15(3): 57-66, 1996.
7. M. Bro-Nielsen: Soft tissue modelling in surgery simulation for prediction of results of craniofascial operations & step towards virtual reality training systems, Medicine and computer assisted surgery, 1995
8. virtual reality-multimedia synthesis: next generation learning environment for medical education, Journal of Bio communication 22(3): 2-7, 1995.
9. Virtual reality and The New world Order of Medicine, Journal of Image Guided Surgery, 1(1): 12-16, 1995.
10. Virtual reality in Laparoscopic surgery, BJS 81, 1709-1711, 1994.