Robotic aided surgery is particularly suitable to invasive surgical procedures that require delicate tissue manipulation and access to areas with difficult exposure. It is achieved through complex systems that translate the surgeon's hand movements into smaller, precise movements of tiny instruments that can generally bend and rotate far more than a human hand is capable of doing inside the patient's body. In addition, those systems are usually able to filter out hand tremor and therefore allow more consistent outcomes for existing procedures, and more importantly the development of new procedures currently made impractical by the accuracy limits of unaided manipulation.
A typical robotic setup for telesurgery can be depicted as follows.
The robot and the surgeon's console can be co-located in the same operating room in which case they communicate through a NPN, or, in another deployment option, when specialists and patients are far from each other (hundreds of kilometres) they can exchange data through communication services delivered by PLMNs. The depicted medical application can be instantiated at either side or in the Cloud. Its role consists in:
Generating appropriate haptic feedback based on instrument location, velocity, effort measurements data and images issued by surgical instruments and 3D pre-operative patient body model. This allows to provide tactile guidance by constraining where the instruments (scalpel, etc.) can go.
Filtering motion control commands for better closed loop stability
Typical surgery robotic systems can have around 40 actuators and the same number of sensors which allows to compute the data rate requires in each direction in order to execute a given movement.
Human sensitivity of touch is very high, tactile sensing has about 400 Hz bandwidth, where bandwidth refers to the frequency of which the stimuli can be sensed. This is why, in general, haptic feedback systems operate at frequencies around 1,000 Hz. This rate naturally applies to the update of all information used in the generation of the haptic feedback, e.g. instruments velocity, position … Therefore, the robot control process involves:
The surgeon console periodically sending a set of points to actuators
Actuators executing a given process
Sensors sampling velocity, forces, positions… at the very same time and returning that information to the surgeon console at the rate of 1 kHz
As opposed to machine to machine communication, robotic aided surgery implies there is a human being in the middle of the control loop, which means that the console generates new commands based on the system state collected in the previous 1 kHz cycle and also on surgeon's hand movement.
Each equipment involved in a robotic telesurgery setup (endoscopes, image processing system, displays, motion controller and haptic feedback systems) is synchronized thanks to a common clock either external or provided by the 5G system. The synchronization is often achieved through dedicated protocols such as e.g. PTP version 2 and allows to e.g. guarantee the consistency of the haptic feedback and displayed images at the master console, or enable the recording and offline replay of the whole procedure.