Orthopedic surgical robots are a type of surgical robot mainly used to assist in orthopedic surgeries. Their core functions include customizing 3D preoperative plans, improving the clarity of images of the surgical site, reducing tremors and improving surgical precision, minimizing damage to healthy bones and tissues, reducing blood loss, protecting nerves, shortening hospital stays, and accelerating recovery.
The composition structure of orthopedic surgical robots can be roughly divided into a control system, a positioning and navigation device, a robotic arm device, and a supporting tool set, which are introduced one by one below.
(1) Control System
This is the core system of the robot. In addition to the integration of various components, the algorithms involved in the image processing software module, surgical planning software module, and robotic arm control module are the core secrets independently developed by various robot companies. The accuracy of image processing, the rationality of surgical planning, and the efficiency of human-computer interaction can all increase the surgeons’ acceptance of the robot. The algorithm of the control module is closely related to the doctor’s operating feel. This is a system that is difficult to evaluate quantitatively and can only be verified through clinical applications.
(2) Positioning and Navigation System
This system forms a 3D model based on the preoperatively imported images, unifies the 3D model with the patient’s actual body position and the real-time position of surgical instruments in space under a single coordinate system. Using a 3D positioning system, it collects and displays the real-time position of surgical instruments in space. Doctors perform navigated surgical treatment on patients by observing the relative positional relationship between the surgical instruments and the lesion in the 3D model. It mainly includes an imaging module, a tracking module, and a display module. Precision is a key indicator of navigation equipment. The key technical points include stereo positioning systems, spatial registration technology, and multi-modal image fusion. Among them, spatial registration technology and multi-modal image fusion are both realized through software algorithms. In terms of stereo positioning systems, optical positioning is currently mainly used for surgical navigation, and some instruments are researching magnetic navigation technology, while robotic arms often use mechanical positioning.
(3) Robotic Arm Device
At present, the robotic arms used in medical robots are mainly divided into two types: wire-driven and gear-motor-driven. The advantages of wire-driven robotic arms are their small size, ability to achieve a certain degree of mechanical backdriving, and less stiffness in operation. The disadvantage is that the steel cable drive is prone to fatigue, which will affect accuracy and require regular replacement. The other is the gear motor drive system, which has the advantage of maintaining accuracy for a long time, but the disadvantage is that it is relatively large in size and has a stiff operating feel.
(4) Tool Set
Accessories include sterile covers, fixators, target kits, and displays, which are used to create a sterile area, stabilize bones, track anatomical landmarks, and monitor movement, respectively.
To sum up, the product development of orthopedic surgical robots, on the one hand, requires software systems suitable for clinical surgical procedures and application habits; on the other hand, it is necessary to break technical barriers in hardware such as robotic arms and optical tracking systems, and realize the independence of core technologies. Only in this way can stronger product competitiveness and more market favor be obtained. Take the development of Puai Medical as an example to see its technological iteration. Founded in 2003, the company focuses on the research and development and production of medical X-ray machines, and has gradually developed into a one-stop supplier of general radiography medical imaging equipment. Relying on 20 years of technical expertise in the medical imaging field, Puai Medical’s independently developed PL300 orthopedic surgical robot was approved for market in 2022. This equipment integrates multiple core technologies such as intraoperative integrated scanning adaptive registration algorithm and robot end multi-dimensional force control technology.
