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Training real doctors on virtual patients: haptic technology improves treatment skills.

Endoscopy and minimally invasive surgery (MIS) now account for more than 25% of all surgeries in developed countries, according to Millenium Reseach Group. Even as these procedures put patients at less risk of complications and post-surgical trauma, they are not tasks assigned to amateur personnel, just as student volunteers typically are not permitted to inoculate a patient. In the future, medical schools may require simulation certification as a mandatory part of the medical residency program.

Hands-on practice in the operating room is an effective way of building skills. However, there is one problem: with a live patient on the table, learning by trial-and-error is simply not an option. As the use of complex, minimally invasive medical procedures continues to rise, simulators that can reproduce the tactile feel of these procedures accurately will play an increasingly important role in medical training. These devices allow healthcare providers to practice procedures in an environment that poses no immediate risks to patients, where mistakes have no dire consequences, animal use is avoided, and performance standards for specific procedures are raised. Haptic technology, often found in the consumer market producing touch-feedback in video game controllers, can be used in medical training systems, allowing healthcare professionals to simulate a range of medical situations while experiencing real-life vision, sounds and touch sensations. Using advanced 3-D computer graphics, high-fidelity sound and sta te-of-the-art tactile feedback, these medical simulations reproduce the real experience.

To this end, Immersion Medical, a subsidiary of Immersion in San Jose, CA, has developed several training simulators.

Bloodless venipuncture

Until the CathSim Vascular Access Simulator was developed, nursing and phlebotomy students had to learn how to start an IV or draw blood using rubber arms, oranges or each other. Healthcare professionals learned only by practicing on patients. Now, both groups are using CathSim for practice, skills maintenance and IV certification. The device combines cognitive and motor skills training into an integrated learning experience. It provides a variety of patient types -- different ages, skin color and health conditions -- as encountered in real life, and even creates complications. With Immersion Medical's AccuTouch Tactile Feedback device, the student is able to feel the needle and catheter insertion from the "pop" as the needle enters the skin through entry into the vein lumen. Transparent and Side Views show underlying anatomy and angle of needle insertion, while pre- and post-procedure videos demonstrate best practices. The cognitive content reinforces aseptic technique and proper medical waste disposal.

The software for CathSim is tuned not just for patient types, but for responses, as well. The Adult module details simulations of skin stretch, responses to pain, flashback of blood and threading off the catheter. Another module designed for older patients enables the user to practice accessing fragile veins responding poorly to palpation, rolling veins needing greater stabilization and superficial veins requiring a lower angle of insertion. This is also the first Cathsim module to address the use of safety needles.

The company also produces an endovascular simulator. This system allows clinicians to practice endovascular procedures such as pacemaker leads placement, angiography and angioplasty. Endovascular procedures require careful attention to interpretation of the fluoroscopic image as well as the subtle feel transmitted through guide wires, catheters and other interventional devices. An accurate display simulation presents heart electrical activity.

Laparoscopy simulator

By digitally recreating the procedures and environment of abdominal keyhole surgery, LapSim replaces the vulnerable patient with expendable pixels and provides an effective learning experience. The modules include an accurate simulation of the frequently performed laparoscopic cholecystectomy procedure: the dissection of Calot's triangle. Anatomical variations are common in this area. Misidentification of bile ducts and blood vessels is a constant risk. When such errors occur, they may lead to severe complications that are both hazardous to the patient and potentially costly to the clinic performing the procedure.

There is also a virtual laparoscopic surgical workstation that helps developers, researchers, and educators to develop software further for simulating procedures, such as cholecystectomy, tubal ligation, oophorectomy (ovariectomy), endometriosis treatment and Nissen fundoplication. Highspeed optical tracking technology accurately monitors the motions of two surgical instruments, simultaneously enabling developers, researchers, and educators to simulate these procedures.

Endoscopic procedures

Endoscopic procedures are some of the most commonly practiced medical procedures today. The motor skills necessary to perform these are difficult to train and assess. The AccuTouch Endoscopy Simulator is a realistic, computer-based system for teaching and assessing motor skills and cognitive knowledge, enabling novices and experienced physicians to practice in a safe environment. Using real-time computer graphics, including. anatomic models developed from actual patient data and a robotic interface device, force is transmitted through the flexible scope to provide tactile sensations mimicking the actual feel of a procedure.

Immersion Medical's system addresses three types of endoscopic procedures: flexible bronchoscopy, flexible sigmoidoscopy and colonoscopy. A mannequin provides realistic force feedback, allowing the user to experience the feel of the real procedure, while the endoscopes look, feel and handle exactly like the real ones. The modules are case-based, providing increasingly challenging patients to test progress. Again, the digital patients respond in a physiologically accurate manner adding to the level of realism. For bronchoscopy, the modules introduce students to the airways, give them practice using tools with the bronchoscope (including performing a biopsy procedure), and teaches them to deal with pediatric patients. For flexible sigmoidoscopy simulations, the anatomy displayed during the procedure is derived from actual patient data and reacts like real tissue in real time -- the colon expands with air insufflation and collapses with suction. And in the colonoscopy module, students learn to perform biopsies a nd polypectomies with all appropriate tools and responses -- interaction between the forceps and mucosa shows tissue deformation, and complications include uncontrolled bleeding when the polyp head is guillotined, electrocautery-induced perforation, and vasovagal reactions.

Upper GE disorders

Endoscopic retrograde cholangio-pancreatography, referred to as ERCP, is a minimally invasive procedure that allows doctors to diagnose and treat disorders of the gallbladder and pancreas. The ERCP training module for the AccuTouch Endoscopy Simulator helps clinicians acquire, maintain and measure ERCP skills without putting patients at risk. At the end of the simulation, the system generates a detailed performance evaluation for review by users and supervisors..

Immersion Medical's ERCP module accurately replicates the sight, sound and feel of the actual procedure. During an ERCP a doctor's attention is focused on a camera view of the upper gastrointestinal tract, the feel of scope movement during navigation, and the reactions of the patient. The ERCP module gives doctors a view of a realistic three-dimensional model that visibly responds to scope movement in real-time. The feel of performing the procedure is provided by Immersion's haptic (touch) technology, which reproduces the tactile sensations of scope resistance, tissue stretching, and difficult cannulation. Each computerized patient audibly responds to endoscopist's actions by expressing discomfort or pain.

"With the number of endoscopic procedures increasing each year, doctors are looking for better ways to train and perfect their skills," says Richard Stacey, vice president and general manager of Immersion Medical. "With our simulators, residents can perform as many simulated procedures as necessary to achieve the required skill level before ever coming into contact with real patients."

As part of an ongoing study at Rush Presbyterian St. Luke's Medical Center, residents who practiced sigmoidoscopies on Immersion Medical's simulators demonstrated a statistically significant 75% increase in overall competency scores. This study validates the use of the AccuTouch Endoscopy Simulator with Flexible Sigmoidoscopy module in reducing the number of patient-based procedures required to achieve competency in performing flexible sigmoidoscopy. A gastroenterologist objectively scored the residents, monitoring factors such as intubation, retroflexion, pathology and virtual patient discomfort.

"This study validates the use of medical simulators for training doctors in conducting minimally invasive surgeries," said Dr. Michael Brown of Rush Presbyterian St. Luke's Medical Center. "Immersion Medical's simulators are a more effective way of training than the traditional methods, allowing residents to repeat difficult procedures until they feel comfortable. Reducing the number of procedure-related errors during the learning process translates into safer patient care. This technology will have profound effects in improving healthcare education at all levels. Furthermore, this study signifies a big step towards simulation certification."

Circle 150--Immersion, or connect directly to their website via the Online Reader Service Program at

Three Quicktime demos of procedures simulated on Immersion equipment may be viewed at
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Author:Mandel, Richard
Date:Mar 1, 2003
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