- Isha Andankar
In the year 1895, a happy accident led to the discovery of X-rays by Dr Wilhelm Roentgen. This was the birth of the Medical Imaging system, which further grew to incorporate other advancements such as ultrasound (USG), computed tomography (CT), magnetic resonance imaging (MRI), etc. Such techniques provide the physician with 2-D and 3-D reconstructions of medical images thereby, assisting them in the surgery.
However, when a surgeon enters an operation theatre, no matter how well versed he is with the theoretical location of a tumor he has to remove, or the spine he has to mend, or any other tissue he has to repair, locating the exact spot of concern amid the copious veins and blood vessels in our body is a daunting task.
Misquoting Jane Austen today, it is fair to say "It is a truth universally acknowledged that every profession in possession of a troubling problem must be in want of a computer-assisted solution."
Yes, computerizing the process is the SOLUTION. More specifically, Augmented Reality is the Game changer for the way surgery is done!
AR is not limited to the gaming arena. The technology is creating gigantic waves in healthcare too! Let's take a look at how AR is shaping modern surgery.
AR is a fusion of projected computer-generated (CG) images and the real environment. Its objective is the acquisition of real-time information and data visualization. This is achieved by superimposing a computer-generated image on real-world imagery captured by a camera.
Head Mounted Display systems are other convenient means to aid surgery. They use special projectors, head tracking, and depth cameras to display CG images on the glass, effectively creating the illusion of augmented reality. This is a more preferred tool as it ensures no obstruction between the screen and surgeon. The quality of input data and the accuracy of the reconstruction system determine the 3D reconstruct of the medical image. Such a system assists to plan an effective surgical route, explore target areas, and optimize the orientation and navigation in the operative field.
Constructing an HMD
The basic requirement for such a tool is a clear lens to project the hologram. Standard cameras and Depth sensing infrared cameras help to superimpose the virtual image to the real background. Currently, such glasses can provide a 120-degree field of view. Now, it is pretty obvious that a surgeon will move during the course of a surgery. Hence, the reconstructed image must also move relatively to avoid any delay. Accelerometers which sense the rate of change of motion and gyroscope which sense the degree of movement assist the surgeon to know how the world looks like in real time frame.
Image credit - https://sitn.hms.harvard.edu/flash/2019/augmented-medicine-the-power-of-augmented-reality-in-the-operating-room/
The alignment can further be enhanced using specific markers and trackers. These trackers usually track fiducial markers placed on the surface of specific structures, which remain still during the surgery (i.e., iliac crest, clavicles, etc.) and thus providing the system with points of reference. The aseptic conditions are further maintained using voice recognition and touch free handling of the device.
One such HMD was developed by Microsoft, called Hololens, and has been used by the Imperial College London to perform reconstructive surgery on victims with severe leg injuries. More recently, in June 2020, John Hopkins University witnessed its first augmented neurosurgery.
Companies like Proprio, Immersivetouch, Truevision, etc. have already incorporated AR in Surgery Procedures. Although examples of successful surgeries using AR are stimulating, this intertwining of the virtual world with the real one does not come without big roadblocks. Firstly the image reconstruction is a time consuming task, rendering this technique useless in case of emergencies.
Moreover, the cost of set up and training medical staff is still not a feasible option. Nevertheless, technology today is in favor of harnessing the true potential of AR which is set to revolutionize the healthcare system.
Very well written! Interesting read.