Accepted for presentation at The Fourth International
Syposium Medicine Meets Virtual Reality: 4 Health
Care in the Information Age: Future Tools for Transforming Medicine.
San Diego, California - January 17-20, 1996
ABSTRACT- Resource allocation, including manpower and other expenses, have limited the evolution of minimally invasive surgical procedures to provide humanism and to improve surgical care for patients. Robotic enhancement has been proposed as a mechanism to improve the cost-benefit relationship for patients. To this end, we have used the robotic arm enhancement to minimize resource and personnel utilization during minimally invasive procedures. Phase I of our study has included the use of the robotic arm in 24 laparoscopic hernia repairs, cholecystectomies, and nissen fundoplications with the surgeon as a solo-surgeon, i.e., the primary surgeon is the only participant in the operative sterile field. The scrub nurse did not participate in the procedures. During this study, there were no technical mishaps, no complications related to the solo-surgeon - robotic arm concept, and the operative times were statistically similar to equivalent procedures utilizing multiple personnel. The hernia repair is least complex and most amenable to solo-surgery due to the use of only three access ports; cholecystectomy occasionally requires four access ports increasing its complexity to a measurable degree. Nissen fundoplication, however, requires five access ports and proved to be the most complex of the procedures to adapt successfully to solo-surgery utilizing robotic arm enhancement.
Phase II of our study has involved the use of a combination of technologically complex and sophisticated technology to improve outcomes in complex laparoscopic procedures. The Head-Mounted Display, AESOP, the robotic arm, and the Harmonic Scalpel have been used in 140 complex minimally invasive procedures; the procedures were laparoscopic spine surgery (24 cases), laparoscopic gastric surgery (28 cases), and laparoscopic colon resection (88 cases). The use of these sophisticated technologies added safety, improved versatility, and did not increase the length of the operative procedures. The use of multiple technologies had an additive effect on the benefits. There were no experiences in which the technologies contributed to a technical complication or an adverse result for the patients. However, the successful use of these technologies requires an in-depth educational experience for the surgeon and for the operating room team.
In a further effort to improve efficiency and control of the visual fields during minimally invasive surgery, we have tested a new prototype voice activation and instrument tracking control method for the robotic arm in order to create a nearly seamless method to control the visual field. Prototype voice activation and deactivation also allows instruments to be used in the visual field for the surgical procedure while not being used for tracking of the visual field. Tracking with the instrument utilizing a color-coded tracking system has been 100% effective in our hands, has not induced errors in technical performance of procedures, and has shortened the time required for performance of specific procedural tasks. Further, this process improves versatility for the surgeon, increases concentration, reduces fatigue and does not interfere with the position of the surgeon. Areas for improvement which have been observed utilizing these techniques are (1) the use of appropriate and consistent voice activation terminology, and (2) the proper positioning of the instrument tracking unit in the most appropriate locations on the video screen and on the instrument within the visual field.
We have concluded from these experiences that the robotic technology will continue to reduce costs and minimize risk for patients undergoing minimally invasive surgical procedures; moreover, safety, versatility, and diminished use of resources will accrue utilizing the additive benefit of sequential sophisticated technologies requiring a simultaneous educational investment in team development. Further, we conclude that with further development that voice activation and instrument tracking of robotically enhanced minimally invasive surgical procedures will improve efficiency, effectiveness, and will diminish risk, resource utilization and cost.
Surgical care of patients has heretofore enjoyed improved quality of care and diminished risk to patients due to continuous technological advancements and similar improvements for the operating room environment. Improvement associated with sophisticated technology has, however, historically been associated with an increase in resource utilization (most often measured by increased cost). The current medical economic environment, however, tends to slow the progress elucidated by technology due to the intense focus on minimizing cost and resource utilization in the healthcare environment. As a result, new and evolving technology carries a new burden; not only must the technology improve the efficiency and productivity of the surgeon and simultaneously decrease risk to the patient but it must also reduce cost and/or resource utilization in order to be considered a viable product for the current surgical operating theater.
In an attempt to address this issue, we have chosen to use robotic arm enhancement as the key technology to reduce cost in the operating theater while simultaneously diminishing patient risk and improving productivity and quality of patient care. The robotic arm is most often used in minimally invasive surgery to hold the laparoscope and camera. It moves the visual surgical field with precision under the direct control of the surgeon1. Thus, one personnel resource (a physician's assistant or assistant surgeon) is no longer required for the operative procedure allowing the individual to provide health care for other patients. Further, control of the visual field by the surgeon diminishes the need for communication between personnel and improves the focus and concentration of the surgeon. Moreover, the robotic arm maintains the optical field stable and motionless providing the surgeon with an environment for improved precision and efficiency during the surgical task(s). A further benefit of the stable, motionless image occurs in conjunction with the use of the robotic arm and 3-D technology for minimally invasive procedures. The motionless image improves the quality of the 3-D image dramatically when compared to the hand-held 3-D image. Thus, the cumulative benefit of two technologies enhances the visual field with resultant improved quality and efficiency by the surgeon as well as a concomitant diminution in the risk of error during the procedural tasks. Other sophisticated technologies which synergistically improve efficiency and thereby diminish risk as well as shorten operating time (with a commensurate decrease in costs or operating room utilization) include the Head-Mounted Display (HMD), the Harmonic Scalpel, and the Zoom Camera Lens.
The HMD provides the surgeon with a relaxed position and binocular vision thus further improving the stability of the visual surgical image2. The HMD specifically allows the surgeon to always work in a normal hand-eye axis thus avoiding inefficient and dangerous paradoxic motion3. It also enhances the benefits of 3-D technology with the addition of binocular vision4 providing a circumstance to further improve efficiency and decrease risk thus improving outcome.
The Harmonic Scalpel is a versatile laparoscopic instrument which cuts, coagulates, acts as a retractor, grasper, pointer, sharp dissector, and blunt dissector5. Its use diminishes instrument exchanges and thereby increases the focus of the surgeon, diminishes the need for intermittently changing operative visual fields for instrument exchange, with resultant cumulative benefits in the areas of efficiency, operative time, patient risk, and ultimate resource utilization.
The zoom camera lens adds the opportunity for the surgical operative field to be a fish-eye panoramic view versus a very close detailed view being under the direct control of the surgeon and changeable by the turn of a switch. This added versatility in the size of the visual field adds a magnitude of versatility to the use of the robotic arm.
The robotic arm technology currently is controlled by the surgeon with a foot pedal. While the foot pedal provides reasonable control by the surgeon, other foot pedals compete for space and attention in the operating theater. Other forms of control and activation of the robotic arm and subsequent control of the visual field would seem to be beneficial.
To address these issues, we have designed a three-part
study; the first is the performance of solo-surgeon procedures
(solo-surgery) using robotic enhancement6 as the aid;
the second is the cumulative and synergistic benefits of multiple
sophisticated technologies (along with the robotic arm) to enhance
efficiency in complex minimally invasive procedures; and the third
phase is to investigate the use of prototype instrument tracking
and voice activation to control the robotic arm and subsequently
control the visual laparoscopic field of view.
Phase I: We performed solo-surgeon surgery for 24 patients who were electively undergoing either laparoscopic hernia repair, laparoscopic cholecystectomy, or laparoscopic nissen fundoplication. In all cases, solo-surgery was defined as "performance of the operative procedure without the help of an assistant, a nurse, or another surgeon." The scrub nurse did not help the surgeon during the procedure. In all cases, the time of the operative procedure, operative technical mishaps, and the number of occasions that the laparoscope was removed from the abdomen to clean the tip were recorded. The laparoscope was affixed to the robotic arm in all cases and control of the robotic arm, the laparoscope, and the subsequent optical surgical field of view were controlled by the surgeon using a foot pedal control. These data were compared to similar data collected from patients undergoing these three minimally invasive procedures in circumstances in which robotic arm enhancement was not used and the surgery was not performed by solo-surgeon.
During each of the laparoscopic solo-surgeon procedures, a second surgeon or a Physician's Assistant was immediately available to help the solo-surgeon in circumstances of necessity.
Phase II: To assess the cumulative benefits of the robotic arm plus other sophisticated technologies in improving efficiency during highly complex minimally invasive surgical procedures, we utilized robotic arm enhancement plus a combination of HMD, 3-D Optics, the fish-eye Zoom Lens, the Harmonic Scalpel, and the ergonomic sitting position during 140 elective procedures. The procedural experiences were laparoscopic anterior spine surgery (24 cases), laparoscopic gastric surgery (28 cases), and laparoscopic colon resection (88 cases). The number of operative technical mishaps, the category of the first assistant (surgeon vs. physician's assistant), and the number of times the scope was removed to clean the tip were recorded. These data were compared to comparable data recorded for patients undergoing these procedures in the absence of sophisticated technologies.
Phase III: The porcine model was used to study instrument
tracking and voice activation of the robotic arm in order to move
the operative field of view by the surgeon. For instrument tracking,
computer activation of a color sensor by a blue tape on the shaft
of the surgeon's instrument in the operative field was used. Once
the field of view was moved to a new location by the device tracking
the blue shaft on the surgeon's instrument, the tracking was de-activated.
Complex laparoscopic skills were performed including running the
bowel, suturing, tying, and dissecting adhesions using the instrument
tracking device. The ability or inability to move the visual field
appropriately during the performance of complex skills was recorded.
To determine the ability of voice activation to control the operative
field of view using the robotic arm, the surgeon imprinted the
following words on the voice activation device: "in",
"out", "left", "right", "up",
"down", "stop". The use of each command activated
the robotic arm to move the visual field in the direction described
by the command. The command "stop" de-activated the
robot resulting in a stable motionless field of view. Complex
laparoscopic tasks were again used during activation and de-activation
using voice commands.
Solo-Surgery: The 24 patients who underwent solo-surgery using robotic arm enhancement and minimally invasive approach all experienced successful completion of their operative procedures. There were no incidents of technical mishap in any of the procedures. The cholecystectomy procedures had an average operating time of 54 minutes compared to 61 minutes for other laparoscopic cholecystectomy patients. The solo-surgery laparoscopic herniorrhaphy procedures had an operative time of 76 minutes compared to 84 minutes for non-solo surgeon laparoscopic herniorrhaphy procedures. The solo-surgery laparoscopic nissen fundoplication procedures had an average operating time of 112 minutes compared to an operating time of 160 minutes for comparable non-solo surgery operative procedures. The number of times the laparoscope required cleaning per 60-minute interval for cases involving solo-surgery and the robotic arm were 1.4 compared to 9.1 per 60-minute interval for comparable cases when the robotic arm was not used.
Complex Laparoscopic Procedures Using Cumulative Sophisticated Technologies: Of the 140 patients undergoing complex minimally invasive surgery utilizing a combination of robotic arm enhancement, the Harmonic Scalpel, the Head-Mounted Display, 3-D technology, and the ergonomic sitting position all were successfully completed utilizing the minimally invasive approach. There were no technical mishaps either related or unrelated to the technologies. Operating times were 155 minutes for gastric procedures, 153 minutes for colectomy procedures, and 125 minutes for anterior spine procedures. Each being comparable to operative times for comparable procedures when not using the additive benefits of these technologies. The average number of times the laparoscope was removed to clean its tip per 60-minute interval during these procedures was 1.0 compared to 7.7 per 60-minute interval for comparable procedures when not using the robotic arm technology.
Instrument Tracking and Voice Activation: The use of the instrument tracking mechanism to move the visual operative field by a color-coded instrument shaft was entirely successful utilizing motions to the left, to the right, in an upward direction, or a downward direction. However, the ability of the instrument tracking mechanism to move the field inward and outward was less successful. Further, the use of complex skills with instrumentation all were successfully accomplished when the tracking was inactivated. However, if the surgeon required movement of the visual field during the performance of a complex skill utilizing this instrumentation, then instrument tracking was unable to accomplish movement of the visual field.
Voice activation of the robotic arm to accomplish
movement of the visual operative field of view was entirely successful.
Motions to the right and left, up and down, as well as in and
out, were all successfully accomplished with ease. However, two
voice commands were always necessary; the command to start the
motion of the robotic arm and the command to "stop".
Further, the use of voice activation as a mechanism to move the
visual field in small increments when necessary - especially during
performance of laparoscopic complex skills, provided a solution
to movement of the visual field during the performance of skills
with the surgeon's instruments.
The use of the robotic arm to enhance minimally invasive operative procedures is identified and delineated in these studies in a variety of ways. Use of robotics to enhance the opportunity for a surgeon to perform solo-surgery without increasing the length of the operative procedures is delineated in Phase I of our study using laparoscopic cholecystectomy, laparoscopic hernia repair, and laparoscopic nissen fundoplication. Further, there were no technical mishaps and no technical complications either related or unrelated. This data diminishes cost and resource utilization by allowing either a surgeon-first assistant or a physician's assistant to not be utilized, thus allowing these medical personnel to be free to perform other healthcare interventions for other patients. It should be noted that no additional equipment was required to perform solo-surgery, thus the resource "trade-off" is the robotic arm in exchange for versatile medical personnel.
In circumstances in which laparoscopic nissen fundoplication and cholecystectomy were performed utilizing the solo-surgeon methodology, the procedures usually involve four ports (cholecystectomy) or five ports (nissen fundoplication). In these circumstances, there are often three personnel participating in the operative procedure. These include the surgeon, the first assistant and the camera holder. As a result, these latter two procedures may actually be modified by the solo-surgeon concept in order to exchange two medical personnel for a modified preoperative setup and robotic arm enhancement.
The solo-surgeon experiences have raised two important issues to the surgeon's consciousness. The first is that the use of the robotic arm diminishes the number of occasions per 60-minute interval that the laparoscope must be removed and cleaned at the tip. Since each occasion of removal and defogging uses time and also defocuses the surgeon, then the reduction in these cleaning maneuvers should result in a shortening of the operative time as well as diminishing risk due to defocusing of the surgeon's attention during a procedure. Further, since the robotic arm holds the position of the scope and the surgeon's optical field of view motionless and perfectly stationary, it allows for a much more stable and concentrated field of view for the surgeon to work. This phenomenon would seem to eventually translate into shortened operating time, increased concentration, decreased fatigue, and a diminution in risk of operative error.
The use of the robotic arm to enhance the efficiency and safety of complex minimally invasive procedures along with the synergistic benefits of other sophisticated technologies clearly is practical and imminently possible. In our series, the addition of multiple complex technologies did not lengthen the operative procedures and did not result in technical mishaps. Further, the reduction of medical personnel from three individuals to two personnel invariably occurred diminishing cost and human resource utilization. The robotic arm itself maintained a stable and motionless operative field for the surgeon throughout the cases and minimized the number of scope cleaning events. Both of these factors increased the concentration and focus of the surgeon providing continuity to the procedure without interruption. The use of the HMD in all circumstances allowed the surgeon to maintain a normal hand-eye axis allowing the work to be in front of the surgeon with his/her visual field exactly in the same plane as the laparoscopic procedure being performed. This benefit diminished fatigue, accommodated a non-paradoxical approach to the procedural tasks and eliminated the risks and inefficiencies associated with paradoxical motion (either related to a disparity in the location of the visual monitor or a disparity in the location of the relationship between the surgeon and his work7).
A further benefit perceived by the surgeon when using the HMD is the binocular vision which occurs because of the dual liquid crystal displays in the HMD. The left-sided display provides a visual field for the left eye and the right-sided display provides a visual field for the right eye. This binocular vision gives the surgeon a perception of depth and allows the eyes to fix on a very distant focal point to reduce eye fatigue. When coupled with 3-D technology, the HMD brings the surgeon binocular vision and depth. As a result, a "normal" three-dimensional field is perceived as opposed to an "exaggerated" three-dimensional field as perceived when the active 3-D glasses are used along with the 3-D active monitor. It might also be noted that the cost of the HMD in exchange for the active 3-D glasses and the 3-D monitor provides a major savings as well as technical safety and efficiency.
Three-dimensional technology itself adds depth to the visual operative field diminishing the risk of technical error inherent when working in a two-dimensional field. Further, the surgeon is not required to spend time and excess motions developing tactile clues to accommodate for the lack of depth in the two-dimensional field. This phenomenon can be translated into shorter operating times.
The Harmonic Scalpel (LCS) adds a subsequent degree of increased efficiency and diminished risk to the aforementioned technologies during complex minimally invasive surgical procedures. The LCS is a highly versatile instrument which cuts, coagulates, retracts, grasps, and bluntly dissects8. Therefore, its versatility diminishes cost in three separate ways: it eliminates the need for a variety of other instruments; it diminishes the number of instrument exchanges performed during a complex procedure, and it uses ultrasonic energy to cut and coagulate rather than using monopolar cautery. The use of the LCS eliminates the need for endoscopic scissors, endoscopic multiple clip applier, monopolar cautery, cautery line, and grounding pad. Elimination of these items reduced direct costs. The reduction in instrument exchanges maintains the surgeon's focus on the procedure and diminishes the waste of time and loss of concentration which occurs to the operating team during instrument exchanges. Lastly, the elimination of the risk of monopolar cautery when using the LCS may be translated to decreased cost due to decreased risk.
The use of a foot pedal to control the robotic arm and the subsequent operative field of view laparoscopically in complex minimally invasive surgical procedures presents a rather unique experience. At one extreme, many complex procedures (subtotal colectomies, gastric resections, trauma cases) require movement of the surgeon from one portion of the torso to another. The necessity of surgeon mobility detracts from the effectiveness and efficiency of the robotic foot pedal. On the other hand, many long complex minimally invasive procedures are benefited from placing the surgeon in the ergonomically beneficial sitting position which diminishes the effective use of the foot pedal. Further, most surgeons have other foot pedals as part of their procedure including either the Harmonic Scalpel foot pedal or the cautery foot pedal. The potential for increased complexity involving the robotic foot pedal tends to diminish efficiency and effectiveness. Therefore, we have attempted to utilize computerized instrument tracking and voice activation as alternative methods to direct the surgical field of view by way of the robotic arm. These experiences have delineated that the use of a blue color activated tracking system on the shaft of an instrument accomplishes efficient movement of the field of view to left and right as well as up and down. However, a number of movements are not successfully accomplished by instrument tracking. First, the "in" and "out" positions require a command other than instrument tracking. Secondly, an additional command is required to de-activate instrument tracking in order for the surgeon to utilize his instrument for a technical task while simultaneously holding the field of view steady. In addition, once the instrument tracking system has been de-activated and the surgeon is using his instruments for a technical task, the requirement for a small or moderate alteration in the visual field to accommodate the surgeon cannot be accomplished by instrument tracking because the instruments are being used for the surgical task. Therefore, an additional command is necessary in this latter circumstance. The addition of a prototype voice activation system allows the surgeon to move the field of view inward and outward. It also provides the opportunity to deactivate and reactivate the instrument tracking system. Finally, the voice activation and voice command may be used to accomplish fine movements while performing a delicate surgical task with the instruments. We believe this combination of control devices will further improve efficiency and versatility of the robotic arm to enhance minimally invasive surgical procedures.
These data delineate that each of the technologies
described improve safety, diminish resource utilization, improve
efficiency and versatility for the surgeon, and are clearly usable
synergistically together to maximize the benefits for the patient.
The authors strongly believe that further investigations to study
the details of each of these technologies and their respective
benefits are urgent and necessary.
1. Sackier, J and Wang, Y: Robotically Assisted Laparoscopic Surgery: from Concept to Development. Surg Endosc 8:63-66, 1994.
2. Geis, WP: Head-Mounted Video Monitor for Global Visual Access in Mini-Invasive Surgery: An Initial Report. Surg Endosc In Press, 1995.
3. Birkett, DH, Josephs, LG and Este-McDonald, J: A New 3-D Laparoscope in Gastrointestinal Surgery. Surg Endosc 8:1448-1451, 1994.
4. Satava, RM: 3-D Vision Technology Applied to Advanced Minimally Invasive Systems. Surg Endosc 7:429-431, 1993.
5. Amaral, JF: Laparoscopic Cholecystectomy in 200 Consecutive Patients Using an Ultrasonically Activated Scalpel. Surg Laparosc Endosc 5:255-262, 1995.
6. Wang, Y: The Concept and Need for Solo-Surgery. Proceedings of Virtual Reality in Medicine and Developers Expo Cambridge, MA, June 1995.
7. Geis, WP and Kim, HC: Use of Laparoscopy in the
Diagnosis and Treatment of Patients with Surgical Abdominal Sepsis.
Surg Endosc 9:178-182, 1995.
