Utilisation médicale des ultrasons
October 08, 2012 by Charles Quigley
One medical visionary is on a quest to leverage NewTek’s TriCaster and Web streaming technology to train anesthesiologists worldwide on a technique that can reduce complications and improve outcomes.
Despite a prolonged national debate over how healthcare will be paid for and delivered in the United States, it’s hard to argue that continued progress in medicine hasn’t improved care, shortened recovery times and produced better outcomes for millions of patients throughout the country.
Patients, who likely lack a historical perspective, may be unaware of how far medicine has progressed. But most physicians and other healthcare providers could tick off dozens of advancements, such as improvements in various heart treatments that have reduced death due to coronary artery disease by 40 percent since 1998, targeted therapies for cancer like Herceptin used in breast cancer treatment that have produced significant improvements in survival, and combination drug therapy that has dramatically extended the lives of HIV/AIDS patients.
Another cutting-edge medical development for many facing surgery is a technique known as ultrasound-guided regional anesthesia blocks. These blocks allow anesthesiologists with the assistance of ultrasound imaging to administer anesthetic around a desired nerve or nerves and have visual confirmation that the block is being delivered precisely where it is needed. For anesthesiologist, surgeons and patients alike, ultrasound-guided regional blocks can mean fewer complications and improved success.
While these benefits are impressive, there is a problem. Thousands of anesthesiologists around the world have no training whatsoever in performing the procedure. Further, given their demanding schedules, most don’t have the time to travel to a cutting-edge academic hospital and participate in intensive on-site training to become proficient in this advanced technique.
However, at least one physician is addressing this problem head-on through the use of advanced video and Internet streaming technology to make training in ultrasound-guided regional anesthesia procedures available to anesthesiologists worldwide. Shortly after completing his anesthesia residency at Duke University Medical Center in Durham, NC, Brandon Winchester, M.D., learned firsthand how great the desire was by a large number of anesthesiologists to learn how to use ultrasound to help them administer regional blocks.
“I learned how to use ultrasound for anesthesia techniques from some of the world’s leading experts at Duke. They were my mentors. What I realized once I graduated from residency was this was much more of a unique set of techniques than I had realized when I was learning them,” says Winchester. “I realized there are literally thousands of anesthesiologists interested in learning these techniques that I just so happened to have become quite good at by learning from some of the experts just sort of by happenstance by being at Duke.”
At first, Winchester took the traditional approach to continuing education by successfully working his way into the medical teaching circuit and traveling to medical conferences a couple of times a month where he could teach the techniques in person. But Winchester found that approach to be lacking in two ways: first, he could never reach all of the anesthesiologists who wanted the specialized training; second, he questioned if a single in-person seminar was enough training.
“We weren’t able to provide what I felt to be the necessary follow-up education for those attending on-location training to learn these techniques and become proficient themselves,” says Winchester. “In other words, we were basically setting them free in the wild prior to them learning their skills to survive.”
It occurred to Winchester that the Web was the ideal way to provide education to those anesthesiologists who hadn’t been reached in person, as well as a great way to provide ongoing education to ensure training in the technique was thorough enough for the long term.
In summer 2009, Winchester did his first webcast on the ultrasound-guided procedure for a group of physicians in Beijing. “I did it out of my garage, and it was about 100 degrees inside there on that July 3 day,” says Winchester. While his garage wasn’t air conditioned and the heat made things uncomfortable, Winchester was satisfied with the educational experience he was deliver- deliverwas - delivering. Hiring a Chinese interpreter from Raleigh, NC, Winchester streamed a live lecture on the procedure to physicians in China with subtitles and voiceovers in their native tongue. “It went over very well,” recalls Winchester.
Less than a year later, Winchester teamed up with several other physicians to found Docstream.com, a Web video services company that provides the larger medical community with a way to stream live and on-demand video to help doctors learn about the latest advancements and procedures. For Winchester, however, the main focus remained on ultrasound-guided regional blocks and how to leverage webcasting to achieve his goals.
Before ever presenting that first online class to physicians in China, Winchester learned some valuable lessons about doing a webcast that would help him as he proceeded. For instance, an extensive search for the right streaming technology taught him how important reliability is to success. Winchester personally demoed several alternatives and says it soon became clear that the number of system crashes he was encountering disqualified the technology he was considering. “After trying all of these approaches and seeing how often I got a Blue Screen of Death and how often my capture equipment wasn’t working adequately, I realized it was going to be worth it to look at a higher-end solution for webcasting,” he says. “That was when I discovered the NewTek TriCaster.”
Initially, Winchester built his streaming setup around the TriCaster STUDIO, a small, lightweight production powerhouse with support for SD video switching, virtual sets, audio mixing and the other tools needed to produce his webcast and stream it live.
For his Web streaming lecture, Winchester settled on producing a live two-shot show. One prosumer camcorder shoots Winchester on a green screen and feeds the signal to the TriCaster as Input A. The TriCaster places Winchester in a virtual set. Winchester, who recently joined the world-renowned Andrews Institute for Orthopaedics & Sports Medicine, in Gulf Breeze, FL, uses the TriCaster to place a background image of the institute shot in the evening through a window on the virtual set. The TriCaster also overlays a logo of the institute on the virtual desk from which Winchester teaches. Input B on the TriCaster is assigned to Winchester’s Microsoft PowerPoint presentation. Winchester uses the PowerPoint slides full-screen or keyed over his shoulder on the virtual set, depending on whether he wants his audience to see his facial expressions as he explains the technique or he wants them to see all the detail of the procedure presented as a still image on a slide.
“Since it is only a two-shot setup, if I am detailing something that requires full screen on the PowerPoint, I use a USB foot pedal that I programmed to act as the Enter key on my keyboard,” explains Winchester. “I can just hot swap it back and forth controlling the TriCaster with the foot pedal to switch between those two shots.”
To maintain eye contact with his audience, Winchester feeds his PowerPoint presentation to a monitor placed in front of him on which his camera is mounted. “I am always looking at the audience that way,” he says.
Shortly after deploying this type of two-shot setup for his inaugural webcast to the physicians in Beijing, NewTek introduced the TriCaster 300, a more powerful production solution with support for high definition television – a major benefit for someone like Winchester.
“I realized after that first webcast that I not only wanted to do these webcasts and procedure casts, but that I also was interested in trying to capitalize on the emergence — both from an equipment standpoint and a bandwidth standpoint — of the ability to do high definition webcasting. That realization just happened to time very nicely with the introduction of the TriCaster 300, so I quickly upgraded,” says Winchester.
At about the same time he began using the TriCaster 300, Winchester improved his garage-based production studio, adding air conditioning to make it tolerable during the summer heat, carpet to absorb sound and reduce echoes and professional lighting and prosumer Canon Vixia HD cameras to enhance video quality.
Winchester recalls that moving to HD expanded his vision about what was possible with Web-based training. “I basically turned my sights from this regular webcasting that I was doing — just giving PowerPoint talks via the Web — to medical webcasting and multi-camera procedures.”
While he continued to present the online equivalent of medical lectures with slides, Winchester began preparing to stream the procedure live from a pre-operative holding area at Duke University Medical Center. Approaching the design and build of this system presented unique challenges. Unlike the garage studio, a pre-operative room is a busy place. There, an anesthesiologist takes a thorough medical history from the patient, starts IVs, administers pre-operative sedation if needed and ultimately does the ultrasound-guided regional block. So Winchester had to design his streaming system to be as unobtrusive as possible. “Building a system that is able to do this in a guerilla-style manner is very tricky, and I’m still to this day making tweaks,” he says.
Working with fellow physicians and engineers, Winchester converted a common endoscopy cart into a mobile video platform to hold all of the video gear needed to live stream the ultrasound-guided procedure or record it for on-demand playback. Winchester built up his video cart with the NewTek TriCaster 300 serving multiple roles, including as an HD video production switcher, a digital disk recorder and a live video streaming source. He added two prosumer HD camcorders outputting HDMI signals as sources to the TriCaster. The output of one of the cameras, as well as the video output of the ultrasound machine, which is scan converted to 720p HD, are wirelessly transmitted to receivers that feed two TriCaster inputs. The other camera, which is affixed to a six-foot articulating mechanical arm that extends from the cart, positioning a camera overhead to capture a close-up of Winchester’s hands, is hardwired to a third TriCaster input.
The wireless video transmitters and a remote pan-tilt-zoom control system for the camera stationed on the end of the boom, Winchester says, help to minimize the obtrusiveness of the video rig in the pre-operative room. “I approached this with three goals,” says Winchester. “A, to make it wireless; B, to be as portable as possible; and C, to be as maneuverable as possible with as much control as possible to eliminate the need of going around the room and repositioning cameras and having a camera man for each one.”
The goal of a procedure webcast is to allow Winchester’s audience to have a view of the ultrasound-guided regional anesthesia procedure that is as good as, if not better than, viewing the technique in person. To accomplish that, Winchester delivers three HD views: the high-resolution video from the ultrasound machine; a “big picture shot” from an HD camera mounted to the ultrasound machine that conveys how the patient is oriented on the table, where the anesthesiologist is positioned relative to the patient and how Winchester’s equipment is arranged; and a close-up shot of Winchester’s hands showing where he inserts the needle to administer the block and how he positions the ultrasound probe. “After producing some of these webcasts without the close-up, it became obvious that something was missing. Adding the close-up shot of the hands has been critical,” he says.
Unlike the webcasts of the PowerPoint lectures, Winchester leaves performing the actual switching of video sources, adjusting pan-tilt-zoom angles, riding sound levels and ensuring the production is streaming or being recorded to disk to someone other than the anesthesiologist who is performing the procedure. For that task, mouse clicks and the simplest of keyboard commands, such as hitting the spacebar and Enter key to switch between sources, are used. Winchester also has programmed a wireless Microsoft Xbox 360 controller to run the TriCaster, which provides a tactile control surface that can be used without looking at a computer monitor.
At the Andrews Institute where Winchester now works, it is common for two anesthesiologists and a regional fellow to perform the procedure, he says. In these cases, one anesthesiologist performs the procedure or directs the fellow in performing the procedure and the second anesthesiologist runs the video production and moderates the procedure for the online audience. In other instances, there may be only the regional fellow or a resident and an anesthesiologist. In this setup, the anesthesiologist only runs the switcher in so far as directing and teaching the fellow or resident, who has a view of the program output of the TriCaster. In either case, says Winchester, the primary focus of the doctor performing the procedure remains on the patient and there is no decrease in the quality of care delivered, he adds.
For the time being, Winchester says Docstream.com will continue to focus on providing online video channels for fellow physicians and medical institutions to present their specialties. However, he is confident that a medical video production cart similar to the one he uses to stream and record the ultrasound anesthesia procedure can help other doctors and facilities push the envelope of continuing medical education.
While Winchester doesn’t see himself actually integrating the video gear and marketing and selling the cart as a business model Docstream.com wishes to pursue, he does envision the possibility of a strategic partnership with the right company, should it come along, to offer the rig to other physicians and medical institutions so they too can stream specialized medical procedures to their peers.
Docstream.com’s website quotes a story from news-medical.net as reporting that by 2016 half of all continuing medical education will be done online. With the potential for platforms like Winchester’s TriCaster-based video production cart to be used by specialists in other medical procedures, a lot of that education is likely to be done with live and on-demand video footage of actual procedures.
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