FIELD OF THE INVENTION

The invention relates to systems and methods for avoiding collisions between elements in a robotic system. More particularly, the invention relates to systems and methods for preventing collisions between robotic arms in multi-arm surgical robotic systems. By extension, the systems and methods of the inventive system relate also to avoiding collisions between robotic end effectors in surgical robotic systems and area and between robotic end effectors and other robotic arms in surgical robotic systems. Most particularly, in spinal surgical robotic systems, as in other surgical applications, multiple robotic arms may be operating in close proximity to each other and in close proximity to OR staff and the patient and also other devices such as cameras and surgical equipment and the current invention relates to systems and methods for preventing such robotic arms from colliding with each other and with other items in the surgical field.

BACKGROUND OF THE INVENTION

Collision avoidance and collision prevention methods are well known in robotic systems and in surgical robotic systems in particular. When robotic systems are used and in particular when utilized in surgical fields, it is important to prevent the robotic arm from colliding with itself, with other robotic arms/elements in the field, with the patient and with the medical staff.

The following invention describes a mobile multi-arm system which may deploy its robotic arms around a patient during surgery. The patient’s position, formation and “surface topology” is random and unknown and also continuously changes during the surgery. Surgical tools like forceps, scalpels etc. are being added and continuously change the patient’s surface and form. Also, in close proximity to the patient and the robotic arms several medical staff are standing and working. These people’s location near the patient and the robotic arms is random and continuously changes. Avoiding collision between robotic elements and between robotic elements and OR staff and the patient is essential, but is made more difficult by this constantly changing environment.

One solution known in the art suggests deploying to this task “cobots” (collaborative robots) to perform such tasks. When a well-designed cobot is colliding with a human or an object, it will sense the collision and will stop. The problem is that even the best cobot will sense a collision and stop only with minimal collision force of one-to-two-kilogram force, for example. In a surgical field when the surgeon is holding a scalpel in hand or when sharp surgical tools are inside the human body, even a minimal collision force much smaller than one kilogram might be lethal and might cause harm to the patient and/or medical staff.

For this reason, it is clear that in a delicate and complex area such as a surgical field with robotic arms which move in close proximity to the patient and medical staff it is imperative to have a much more sophisticated, capable and robust collision avoidance system. This system must dynamically and continuously be updated with the random and continuous changes in the surgical field and provide this information to the central controller which will be able to govern the movement of the robotic arms in relation to the updated situation and will prevent any collision from happening beforehand.

There are several well-established methods in the robotic field to prevent these collisions from happening which includes collision algorithms and also cameras and sensors to track the robotic arms’ position in space and by that detecting possible collision and allowing for prevention in real time. These known solutions are often designed for single-arm robotic systems and don’t have the capability of integrating all of the necessary information (position, trajectory, speed etc.) to avoid collisions in multi-arm systems, either between the arms themselves or between the arms and other objects in the surgical environment.

There is thus a strong need for a multi-arm robotic system that can deploy a collision avoidance system that actively and dynamically works to avoid collisions between the multiple robotic arms and between the robotic arms and other objects in the surgical field, such as the patient, OR staff, cameras or other devices, surgical tools or end effectors attached to the robotic arms. The solution must be robust, dynamic and very precise so as to avoid collisions in delicate surgical situations such as, for example, surgery.

SUMMARY OF THE INVENTION

Accordingly, provided herein are systems and methods for collision avoidance in a multiarm surgical robotic system, such as one used in spinal robotic surgery. In some embodiments, the collision avoidance system and methods incorporate a central controller that knows the location and morphology of the robotic arms and can control their synchronized movement relative to each other. The representative embodiments also provide for one of the robotic arms being a surveillance arm that does not actively participate in the surgical procedure but instead holds one or more cameras and/or sensors and gathers information about the constantly changing surgical environment and feeds that information to the central controller that, in turn, works to avoid collisions between the active surgical arms.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a robotic surgical system with collision avoidance features according to an embodiment of the present invention.

Figure 2 shows a robotic surgical system with collision avoidance features operating to avoid collision between two robotic arms according to an embodiment of the present invention.

Figure 3 shows a robotic surgical system with collision avoidance features operating to avoid collision between a robotic arm and a surgeon according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference now to the figures and several representative embodiments of the invention, the following detailed description is provided. The following novel invention describes a system and method to actively and dynamically prevent collisions in a multi-arm robotic system.

In one embodiment of the invention shown in Figure 1, a surgical multi-arm robotic system with collision avoidance capabilities is shown. The system may be comprised of at least two robotic arms, or optionally more, 101, 102, 103 which share the same rigid mechanical chassis and are controlled by a single controller. At least one arm 101, 102, is dedicated to surgical activities and at least one arm 103 is dedicated for collision avoidance tasks and is holding at least one camera or sensor 104. The current embodiment is describing at least three robotic arms, two are surgical arms 101, 102 and one surveillance arm 103.

The suggested system and methods will integrate the following levels of data collection and methods to prevent collisions of the robotic arms in a dynamic way.

The central controller will be fed upfront (prior to the surgery) with all of the robotic arms’ morphology and location in relation to each other. Thus, the controller will know upfront all the arms’ locations and will be able to move them in space without colliding with each other.

At least one arm 103 in Figure 1 will not participate in the active surgery and will be free 100% of the time only to monitor the surgical surroundings. This “surveillance robotic arm” role and function is to hold at least one camera/sensor and to continuously guard the patient and the robotic arms from colliding with each other and to continuously gather information about the changing environment. It is imperative that this arm will not take part in the surgery and will not conduct surgical tasks, like holding surgical tools etc, because this arm must be 100% available and free to perform this critical task.

The “surveillance arm” can hold more than one camera/sensor in order to provide several layers of diverse data. The multiple arms/sensors can provide data from different angles or data of different types. This surveillance arm and camera and sensors can scan and map the surface of the patient and surroundings at the beginning of the surgery (done by other companies like Mazor robotics- Mazor X) but from the reasons explained above this preliminary scan and mapping is not enough since the surgical environment is changing all the time. With the Mazor X system this camera/sensor is built into the surgical arm and performs the scan at the beginning of the surgery but naturally since this arm is busy with the surgery this scan can’t be performed again and/or continuously during the surgery. In the present inventive system, since this arm is completely available for this surveillance task it can continuously scan the patient and for example, update the surface map with new information, such as for example that now there is a surgical tool in the patient’s body and this area needs to be avoided.

This arm can carry more than one sensor and by that provide additional diverse information. For example, it can carry a navigation camera/sensor and continuously detect navigation markers that are placed on the robotic arms and the patient anatomy. This diversity of information can enhance the robustness of the data collected and can help facilitate a safer environment. Additionally, It can hold and carry sensors that can communicate with other sensors that are embedded in the other surgical robotic arms, surgical table etc. the main advantage is that this arm is free for this task from any surgical task.

The multi arm synchronization with regards to collision avoidance have additional critical implication. The central controller can always actively and dynamically choose an optimal position to position the surveillance arm and improve the probability to detect a possible collision. For example, if the surgeon is using now for a certain task one of the arms of the system, the central controller knows that and will be able to position the surveillance camera in an optimal location wherein the sensors will have a higher likelihood to detect a collision with the patient or the surgeon. Also, in case the surgeon now moves and “surprises the robotic system” the sensors on the surveillance arm will have better chances to detect that, being positioned in an optimal location beforehand. Meaning, the surveillance arm is not only detecting possible collision by chance but the controller is using algorithms to actively and dynamically position it in optimal locations in space wherein it will have higher probability to detect the possible collision. Moreover, with mobile robotic systems the challenge is even greater since the area, or in particular, the operation room can’t always be equipped with fixed cameras/sensors. Preferably, The mobile robotic system must provide all the collision detection capabilities by itself. Of course, if will be possible to place additional fixed sensors on the walls, celling etc. this addition will only assist the said mobile system to be even better, but these additions are not necessary if a mobile system with a capable, dynamic collision avoidance system such as that used in the present invention is deployed.

Lastly, since said system is mobile in its essence, it is important that all the robotic arms will share the same rigid chassis. This will make the central controller’s task of synchronizing the arms much simpler and more reliable. With several different carts on the OR floor, for example, additional synchronization system is required (e.g., navigation system) that will never be as reliable, robust and safe as a unified system as provided herein (due to inherent challenges such as “line of sight” problems, connectivity problems and so forth).

In the embodiment of Figure 2, collision avoidance features as described above operate to avoid collision between two robotic arms 201, 202.

In the embodiment of Figure 3, collision avoidance features as described herein operate to avoid collision between a robotic arm 301 and a surgeon 302.

One of skill in the art will appreciate that all the above can’t be achieved with the current state of the art and must require a system which has a dedicated surveillance robotic arm, equipped with sensors which are synchronized with the other robotic arms and is dynamically and actively monitoring the surgical area, pro-actively and dynamically collecting information about the ever-changing environment. The provided system can provide a much higher level of safety both to patients and for the medical staff around it.

One of skill in the art will also realize that the embodiments provided herein are representative in nature. Departures from the provided embodiments that change, for example, the number and position of sensors or cameras on the surveillance arm, are within the scope and spirit of the present invention.