"It's like having a vision of x-rays." Rubén Pérez Mañanes describes the experience of operating with the new technology that the Gregorio Marañón Hospital in Madrid has incorporated, where he is an orthopedic surgeon. Help is to conjugate augmented reality Y 3D printing. The first allows having a virtual image of the patient's anatomy. The second is to create both a model of the area that is going to operate to practice or explain the intervention to the patient and to help place the piece that is the key to all this new development: a marker, a piece with a kind of QR code. This will be what allows, when you arrive at the operating room, to fit the virtual images with the vision of the patient's body, so that the surgeon can see both superimposed with virtual reality glasses (in this case, some Microsoft HoloLens). The work was published in Healthcare Technology Letters in September, and yesterday the center of Madrid presented it.
The process has several steps before arriving at the operating room. First, by means of imaging techniques (CT, X-rays, magnetic resonance), a virtual model of the anatomy of the patient to be operated is elaborated. In the first trial in people, it was a 22-year-old woman with an Ewing's sarcoma, a type of tumor that affects the bones and soft tissues that surround them and which are typical of children and young people.The cancer was in the right leg. That model, therefore, has the patient's bones, but also the tumor mass. In a first trial in people, a 22-year-old woman with an Ewing's sarcoma, a tumor that affects the bones and soft tissues that affect her, was operated on. surround and that are typical of children and young people. The cancer was in the right leg. In this case, it was a tumor that at first glance can not be seen in the bones. But by superimposing the virtual image you know exactly where to cut. In cancer surgery this is essential, since it involves removing the affected part without leaving tumor cells in the body, because there would be a risk of the cancer reproducing, but extracting as little as possible, to help the patient's recovery. It is what in oncology is called leave the edges clean. But the technique can be used in any other surgery that needs a lot of precision, explains Pérez Mañanes.
The process has several phases before arriving at the operating room. First, by means of imaging techniques (CT, X-rays, magnetic resonance), a virtual model of the anatomy of the patient to be operated is elaborated. That model, therefore, has the patient's bones, but also the tumor mass.
All this reconstruction plus the associated information is loaded into a software which will then be projected onto the glasses that the surgeon will use (or who, on their team, decide to use them, since the system allows several users to access at the same time). In addition, the image of what the surgeon sees is projected in the operating room, so that all the staff can see them.
On the other hand, from those previous image tests, a personalized piece is elaborated by means of a 3D printer that will fit exactly in a part of the patient's body that will not be altered with surgery (in this case, it was adjusted to one of the affected bones of the leg, but in areas free of the tumor). That piece is joined by a marker (it looks like a label that stands out) that must correspond to another equivalent in the virtual reconstruction. When the surgeon is going to operate, the first thing he has to do is place that piece – in this case after making an incision in the leg to get to the bone. Then, with the sterilized glasses already put, will make both markers, virtual and physical, match. Once this recognition between the two fixed signals occurs, the glasses will project the images that the surgeon wants on the part to be operated, adjusting its size to that of the real anatomy. This lace is fundamental, because it is the one that ensures that the glasses always offer the virtual image that corresponds to the part of the anatomy of the patient that the doctor is seeing, even if he has to move it.
In addition, before the actual intervention, it is possible to check the adjustment, since you can compare the virtual image with a 3D of the area to be operated and perform tests prior to the operating room. The hospital has extensive experience in using three-dimensional printing to prepare interventions. He has been reproducing body parts for five years and has his own printers for this.
Pérez Mañanes explained yesterday that there are other hospitals that combine these techniques, but noted that the adjustment between the virtual image and the real one is not done automatically, but manually, which delays the process and subtracts accuracy. The surgeon affirmed that with this new technology designed by the Madrid hospital and the Carlos III University, and that the company has developed the 6DLAB, an adequacy between the projected and real image of less than a millimeter error is achieved, although in the first trials this was less than two millimeters, as published. "In any case, it's enough for the operation," says the article.
This development "does not replace the expertise of the surgeon", warns Pérez Mañanes, but gives more information and precision, "and that is always an aid".