The present application relates to hardware components of surgical robot arms used in robotized computer-assisted surgery.
Robot arms have become prominent equipment in surgical rooms, often in assistance to operating staff. In a particular application, commonly but not exclusively used in orthopedic surgery, the robot arm supports instruments, e.g., known as guides, relative to a body part of a patient, while the operating staff such as a surgeon manipulates the tools using the guides to perform bone alterations. The characteristics of a robot arm, such as its stiffness and capacity to hold its position and orientation, combined with the precision of robot arm position tracking, may benefit the operating staff and the patient by contributing to the success of a surgical procedure.
Indeed, a primary advantage of surgery assisted by motorized robots is the precision. Usually, robotic surgery assistance systems use, among other things, calibrated mechanical instruments, laser optical systems. Since these instruments are installed at the end of the robot to obtain optimum precision, the patient registration operation can only be carried out before the surgical procedure. Accuracy may then rely on the ability to keep the patient and the robot perfectly still.
In robot assisted surgery, the surgical robot arms do not necessarily interact directly with the patient's body, but rather serve as a collaborative tool used to assist the operating staff. Nevertheless, it may be desired to increase the functionalities associated with such surgical robot arm, as its end effector is in close proximity to the surgical site and thus at a unique point of view thereof.
Moreover, some surgical robots are commonly used with a navigation system incorporating a camera. It is therefore possible to continuously monitor the position of the instruments, the robot stand and the patient. The navigation system is usually located at a distance of about a meter or more. Consequently, there may be an accumulation of errors that may be proportional to the distances, to the various changes of reference frames, to the cumulative calculation times.
In accordance with a first aspect of the present disclosure, there is provided an interface for a robotic arm comprising: a body having a first axial face adapted to be connected to a distal face of a link of a robotic arm, a second axial face adapted to be connected to a proximal face of an end effector, the second axial face having a geometry differing from a geometry of the proximal face of the end effector so as to define a peripheral band in the second axial face, the peripheral band facing distally; a connection configuration for the interface to be fixed to the link and for the end effector to be fixed to the interface; circuitry embedded in the body; and at least one light source in the peripheral band, the at least one light source connected to the circuitry to produce light in a distal direction of the robotic arm.
Further in accordance with the first aspect, for instance, the peripheral band extends around the proximal face of the end effector for at least 270 degrees.
Still further in accordance with the first aspect, for instance, the peripheral band extends around the proximal face of the end effector for 360 degrees.
Still further in accordance with the first aspect, for instance, the interface has a plurality of the light source, at least one of the light sources being located in each quadrant of the peripheral band.
Still further in accordance with the first aspect, for instance, at least one lens of a vision system may be in the peripheral band, the at least one lens capturing images in a distal direction of the robotic arm.
Still further in accordance with the first aspect, for instance, electric insulation may be provided in the body.
In accordance with a second aspect, there is provided an interface for a robotic arm comprising: a body having a first axial face adapted to be connected to a distal face of a link of a robotic arm, a second axial face adapted to be connected to a proximal face of an end effector; a connection configuration for the interface to be fixed to the link and for the end effector to be fixed to the interface; circuitry embedded in the body; a circumferential surface defined between the first axial face and the second axial face; and at least one light source in the circumferential surface, the at least one light source connected to the circuitry to produce light.
Further in accordance with the second aspect, for instance, at least one of the light sources is in a lower portion of the circumferential surface so as to produce light in a downward direction.
Still further in accordance with the second aspect, for instance, at least one lens of a vision system may be in the circumferential surface.
Still further in accordance with the second aspect, for instance, the at least one lens is in a lower portion of the circumferential surface so as to capture images below the end effector.
Still further in accordance with the second aspect, for instance, the circumferential surface defines a flat surface, at least one of the lens being in the flat surface.
Still further in accordance with the second aspect, for instance, further including at least one interface button in the circumferential surface.
In accordance with a third aspect, there is provided a robot comprising: a robotic arm; an interface as described above, the interface being between the distal arm and an end effector.
Further in accordance with the third aspect, for instance, the end effector is a non-powered tool support.
Still further in accordance with the third aspect, for instance, the interface is non-electrically connected to the end effector.
Referring to
Other components, devices, systems, may be present, such as surgical instruments and tools T, interfaces I/F such as displays, screens, computer station, servers, and like etc. Secondary robotized CAS systems may also be used for redundancy. The interfaces I/F may include one such interface as part of the base or station supporting the robot arm 20, as shown in
Referring to
Any of the links 22, including a wrist or like distal-most link 22′ (
In a variant, the tool head 23 of robot arm 20 may be defined by a chuck or like tool interface, that is non-powered and that serves as a guide and/or support for tools T manipulated and/or supported by the operator (e.g., a surgeon, physician or like medical professional). Nevertheless, it is considered to equip the robot arm 20 with powered tools as tool head 23, such as a reamer (e.g., cylindrical, tapered), a reciprocating saw, a retractor, a laser rangefinder or light-emitting device (e.g., the indicator device of U.S. Pat. No. 8,882,777), laminar spreader depending on the nature of the surgery. The various tools may be part of a multi-mandible configuration or may be interchangeable, whether with human assistance, or as an automated process. The installation of a tool in the tool head may then require some calibration in order to track the installed tool in the X, Y, Z coordinate system of the robot arm 20. The tool head 23 of the robot arm 20 may also be a universal instrument adapter, which can be positioned by robot arm 20 relative to the surgical area in a desired orientation according to a surgical plan, such as a plan based on preoperative imaging. The universal instrument adapter may include a tool base, an extension arm, at the end of which a cutting guide is located. The cutting guide may be known as a cutting block, adapter block, etc. In an embodiment, the extension arm may have a first segment and second segment, though fewer or more segments may be present, so as to give a given orientation to the cutting guide relative to the tool head. The cutting guide may have a body defining a guide surface (e.g., cut slot), and pin holes. In an example, the cutting guide can be configured as a talus resection block for use in a total knee arthroplasty. Other configurations of the cutting guide may be used, such as with or without pin holes. Again, calibration steps may be performed if required to calibrate any end effector instrument.
In order to position the tool head 23 or like end effector of the robot arm 20 relative to the patient, the CAS controller 50 can manipulate the robot arm 20 automatically by the robot driver 70, or by a surgeon manually operating the robot arm 20 (e.g. physically manipulating, via a remote controller through the interface I/F) to move the end effector of the robot arm 20 to the desired location, e.g., a location called for by a surgical plan to align an instrument relative to the anatomy. When the surgeon manually operates the robot arm 20, it may be in a collaborative mode in which the robot arm 20 may sense forces applied to the robot arm 20 and actuate its joints 21 as a function of force vectors. Once aligned, a step of a surgical procedure can be performed.
The robot arm 20 may include sensors 25 in its various joints 21 and links 22. The sensors 25 may be of any appropriate type, such as rotary encoders, optical sensors, position switches, for the position and orientation of the end effector, and of the tool in the tool head 23 (e.g., cutting block) to be known. More particularly, the tracking module 60 may determine the position and orientation of the robot arm 20 in a frame of reference of the robot arm 20, such as by obtaining the position (x,y,z) and orientation (phi, theta, ro) of the tool from the robot driver 70 using the sensors 25 in the robot arm 20. Using the data from the sensors 25, the robot arm 20 may be the coordinate measuring machine (CMM) of the robotized CAS system 10, with a frame of reference (e.g., coordinate system, referential system) of the procedure being relative to the fixed position of the base of the robot 20. The sensors 25 must provide the precision and accuracy appropriate for surgical procedures. The coupling of tools to the robot arm 20 may automatically cause a registration of the position and orientation of the tools in the frame of reference of the robot arm 20, though steps of calibration could be performed. For example, when a cutting guide is coupled to the robot arm 20, a position and orientation of the guide surface may be registered for its subsequent tracking as the robot arm 20 moves in space. The geometry of the cutting guide is thus known, as well as the manner by which the cutting guide is coupled to the robot arm 20, to allow this automatic registration. Additional steps may be performed to register/calibrate the cutting guide, such as the contact with a probe, image processing, data entry, etc. The sensors 25 may include force/torque sensors for three axis of torque and three directions of forces, for example. Such sensors may be useful as part of the operation of a collaborative mode.
Referring to
The peripheral surface 40B may be said to be a distal surface, as it is located toward the distal end of the robot arm 20. Moreover, the peripheral surface 40B may be normal to a rotational axis of the wrist 20′ as a possibility. Accordingly, the peripheral surface 40B faces distally, toward the tool head 23. In an embodiment, the peripheral surface 40B is substantially flat, though this is optional.
Depending on the nature of the tool head 23, the electrical interface 40 may have a mating connector 41 as part of a connection configuration. The mating connector 41 is shown as being a male connector, and/or may have cylindrical shape or any other projecting shape, but other configurations are possible, including a female connector. Moreover, even though the geometry of the mating connector 41 is regular and uniform, the mating connector 41 could have a clocking feature to ensure a unique complementary positioning of the tool head 23 on the electrical interface 40.
Attachment bore(s) 42, such as threaded bores, may be circumferentially distributed around the mating connector 41 if present, or may be at other locations, and may also be part of the connector configuration. The attachment bore(s) 42 may be used to secure a tool such as the tool head 23 to the electrical interface 40. Accordingly, some compatibility is required between the mating connector 41 and/or attachment bore(s) 42, for tools to be attached to the electrical interface 40. Moreover, different patterns and configurations of attachment bores 42 may be present as part of the connector configuration, for the electrical interface 40 to be compatible with different tool types.
Alignment features 43 may optionally be present, for example if no other clocking feature is present, and may be part of the connector configuration. The alignment features 43 may be circumferentially distributed around the mating connector 41 if present, or may be at other locations. In the illustrated embodiment, the alignment features 43 may be conical holes and/or conical projections, matingly engaged with complementary features on the tool head 23. The alignment features 43 are used to ensure a precise positioning engagement of the tool head 23, for example by removing any possible play between the tool head 23 and the electrical interface 40 once connected, provided the fastener(s) received in the attachment bore(s) 42 is suitably tightened, such as threaded members with knobs 23D on the tool head 23 (
Light source(s) 44 may be located on the peripheral surface 40B. For example, the light sources 44 are embedded in the disc body 40A so as not to project beyond a surface of the peripheral surface 40B, but this is merely optional. As the light sources 44 are on the peripheral surface 40B, their light is projected in a distal direction, generally along an axis of the wrist 22′. As the wrist 22′ is in the vicinity of the surgical site, and as the wrist 22′ may often support a tool (e.g., tool head 23) that is along the rotation axis of the wrist 22′, the light source(s) 44 is (are) strategically positioned to assist in providing light at the surgical site. As observed, there may be more than one light source 44, with some of the light sources 44 located in a lower half of the disc body 40A, and some of the light sources 44 located in an upper half of the disc body 40A. Depending on the source of ambient light projected onto the surgical site, the location of the light sources 44 on the lower half and upper half may ensure that a zone that is otherwise shaded by the tool head 23 is illuminated (lights may be in all four quadrants if the peripheral surface 40B extends for more than 270 degrees. In a variant, the light source(s) 44 is (are) light-emitted diodes, and may be selected based on light spectrum requirements. Other types of light sources could be used. Thus, the light source(s) 44, if present, enable the electrical interface 40 to provide focused lighting on the operated area.
Still referring to
Referring to
The electrical interface 40′ has any appropriate body shape. The electrical interface 40′ resembles the electrical interface 40 in that it is generally disc-shaped (disk-shaped) body 40A, but with truncated portions in the outer periphery 40C, defining optional flat support surfaces 40D in the outer periphery 40C. As observed, the support surfaces 40D may face downwardly. The body 40A may also have width dimensions greater than that of a base of the tool head 23, so as to define the peripheral surface 40B that projects beyond the base 23C of the tool head 23. The body 40A may thus be viewed as a flange relative to the wrist 22′. The body 40A may serve as a support or interface for a drape. In a variant, a drape is connected to a rear surface of the body 40A.
The electrical interface 40′ may be powered via the robot arm 20, or by wires internally routed into the robot arm 20 or exterior to the robot arm 20. The wiring may be proximally located relative to the drape, if present. As an alternative, the electrical interface 40′ may include a battery, so as to be wireless and battery operated. Accordingly, the electrical interface 40 may include a telecommunications unit, using any appropriate telecommunications protocol (e.g., wi-fi, Bluetooth®, etc).
The peripheral surface 40B may be said to be a distal surface, as it is located toward the distal end of the robot arm 20. Moreover, the peripheral surface 40B may be normal to a rotational axis of the wrist 20′ as a possibility. Accordingly, the peripheral surface 40B faces distally, toward the tool head 23. In an embodiment, the peripheral surface 40B is substantially flat, though this is optional.
Depending on the nature of the tool head 23, the electrical interface 40′ may have a mating connector 41, as part of a connector configuration. The mating connector 41 is shown as being a male connector, or cylindrical shape, but other configurations are possible, including a female connector. Moreover, even though the geometry of the mating connector 41 is regular and uniform, the mating connector 41 could have a clocking feature to ensure a unique complementary positioning of the tool head 23 on the electrical interface 40′. This is visible in the various embodiments in the form of a keyway on the mating connector 41.
Attachment bore(s) 42, e.g., threaded bores, may be circumferentially distributed around the mating connector 41 if present, or may be at other locations, and may be part of the connector configuration. The attachment bore(s) 42 may be used to secure a tool such as the tool head 23 to the electrical interface 40′. Some compatibility is required between the mating connector 41 and/or attachment bore(s) 42, for tools to be attached to the electrical interface 40′. Moreover, different patterns and configurations of attachment bores 42 may be present, for the electrical interface 40′ to be compatible with different tool types.
Alignment features 43 may optionally be present, as part of the connector configuration. The alignment features 43 may be circumferentially distributed around the mating connector 41 if present, or may be at other locations. The alignment features 43 may be in a non-symmetrical pattern, to create a unique orientation connection correspondence between the electrical interface 40′ and the tool head 23 (or any other tool to be connected to the electrical interface 40′. In the illustrated embodiment, the alignment features 43 may be conical holes and/or conical projections, matingly engaged with complementary features on the tool head 23. The alignment features 43 are used to ensure a precise positioning engagement of the tool head 23, for example by removing any possible play between the tool head 23 and the electrical interface 40′ once connected, provided the fastener(s) received in the attachment bore(s) 42 is suitably tightened, such as threaded members with knobs 23D on the tool head 23 (
Light source(s) 44 may be located on the peripheral surface 40B. For example, the light sources 44 are embedded in the disc body 40A so as not to project beyond a surface of the peripheral surface 40B, but this is merely optional. Other light sources 44′ may be provided on the peripheral surface 40C and/or on the flat support surfaces 40D, and may be selectively turned on an off (such light sources 44′ may also be in the electrical interface 40). These light sources 44′ may be in every quadrant of the electrical interface 40. As the light sources 44 are on the peripheral surface 40B, their light is projected in a distal direction, generally along an axis of the wrist 22′. As the wrist 22′ is in the vicinity of the surgical site, and as the wrist 22′ may often support a tool (e.g., tool head 23) that is along the rotation axis of the wrist 22′, the light source 44 and 44′ are strategically positioned to assist in providing light at the surgical site. As observed, there may be more than one light source 44, with some of the light sources 44 located in a lower half of the disc body 40A, and some of the light sources 44 located in an upper half of the disc body 40A. Depending on the source of ambient light projected onto the surgical site, the location of the light sources 44 and 44′ on the lower half and upper half may ensure that a zone that is otherwise shaded by the tool head 23 is illuminated. In a variant, the light source 44 and/or 44′ are light-emitted diodes, and may be selected based on light spectrum requirements. Other types of light sources could be used. Thus, the light sources 44 and 44′, if present, enable the electrical interface 40 to provide focused lighting on the operated area.
Referring to
Buttons 47 may be provided on the electrical interface 40′ (and also in the electrical interface 40 though not shown). The buttons 47 may be mechanical and thus connected to switches within the electrical interface 40′. Other technologies can be used, include capacitive sensing. The buttons 47 may strategically be positioned on the periphery 40C of the body 40A, so as to be readily accessible. In a variant, the buttons 47 may be configured by a user of the robot arm 20 to perform selected functions, such as some functions related to the operation of the electrical interface 40′ (e.g., turning lights 44 on/off), or optionally functions associated with the surgical workflow, in a manner similar to a keyboard, mouse, etc. The buttons 47 may be taught some functions.
Accordingly, the electrical interface 40′ may use the vision system to perform various functions. For instance, the electrical interface 40′ may be used to facilitate patient landmark registration, by capturing images of such bone landmarks in proximity to the patient. For example, the captured images of the vision system of the electrical interface 40′ may be used to monitor the relative position of the patient in relation to the instrumentation in real time throughout the surgery, from a privileged proximal point of view, which may result in enhanced accuracy.
Both electrical interfaces 40 and 40′ are configured to be placed in between a link of the robotic arm 20, such as the wrist 22′, and the end effector (including any passive or active component, tool) that is at the distal end of the robotic arm 20. Accordingly, the electrical interfaces 40 and 40′ may be retrofitted to existing systems, and their connector configurations may be disposed depending on the type of robotic arm 20/end effector. Moreover, their thinness gives the electric interfaces 40 and 40′ a small footprint, for example in comparison to other interfaces and tracking camera.
Referring to
The tracking device 30 (including the vision system of the electrical interface 40′) may produce structured light illumination for tracking objects with structured light 3D imaging. In structured light illumination, a portion of the objects is illuminated with one or multiple patterns from a pattern projector or like light source. Structured light 3D imaging is based on the fact that a projection of a line of light from the pattern projector onto a 3D shaped surface produces a line of illumination that appears distorted as viewed from perspectives other than that of the pattern projector. Accordingly, imaging such a distorted line of illumination allows a geometric reconstruction of the 3D shaped surface. Imaging of the distorted line of illumination is generally performed using one or more cameras (including appropriate components such as e.g., lens(es), aperture, image sensor such as CCD, image processor) which are spaced apart from the pattern projector so as to provide such different perspectives, e.g., triangulation perspective. In some embodiments, the pattern projector is configured to project a structured light grid pattern including many lines at once as this allows the simultaneous acquisition of a multitude of samples on an increased area. In these embodiments, it may be convenient to use a pattern of parallel lines. However, other variants of structured light projection can be used in some other embodiments.
The structured light grid pattern can be projected onto the surface(s) to track using the pattern projector. In some embodiments, the structured light grid pattern can be produced by incoherent light projection, e.g., using a digital video projector, wherein the patterns are typically generated by propagating light through a digital light modulator. Examples of digital light projection technologies include transmissive liquid crystal, reflective liquid crystal on silicon (LCOS) and digital light processing (DLP) modulators. In these embodiments, the resolution of the structured light grid pattern can be limited by the size of the emitting pixels of the digital projector. Moreover, patterns generated by such digital display projectors may have small discontinuities due to the pixel boundaries in the projector. However, these discontinuities are generally sufficiently small that they are insignificant in the presence of a slight defocus. In some other embodiments, the structured light grid pattern can be produced by laser interference. For instance, in such embodiments, two or more laser beams can be interfered with one another to produce the structured light grid pattern wherein different pattern sizes can be obtained by changing the relative angle between the laser beams.
The pattern projector may emit light that is inside or outside the visible region of the electromagnetic spectrum. For instance, in some embodiments, the emitted light can be in the ultraviolet region and/or the infrared region of the electromagnetic spectrum such as to be imperceptible to the eyes of the medical personnel. In these embodiments, however, the medical personnel may be required to wear protective glasses to protect their eyes from such invisible radiations. As alternatives to structured light, the tracking device 30 may also operate with laser rangefinder technology or triangulation, as a few examples among others.
The tracking device 30 may consequently include the cameras to acquire backscatter images of the illuminated portion of objects. Hence, the cameras capture the pattern projected onto the portions of the object. The cameras are adapted to detect radiations in a region of the electromagnetic spectrum that corresponds to that of the patterns generated by the light projector. As described hereinafter, the known light pattern characteristics and known orientation of the pattern projector relative to the cameras, are used by the tracking module 60 to generate a 3D geometry of the illuminated portions, using the backscatter images captured by the camera(s). Although a single camera spaced form the pattern projector can be used, using more than one camera may increase the field of view and increase surface coverage, or precision via triangulation.
The tracking device 30 may also have one or more filters integrated into either or both of the cameras to filter out predetermined regions or spectral bands of the electromagnetic spectrum. The filter can be removably or fixedly mounted in front of any given camera. For example, the filter can be slidably movable into and out of the optical path of the cameras, manually or in an automated fashion. In some other embodiments, multiple filters may be periodically positioned in front of a given camera in order to acquire spectrally resolved images with different spectral ranges at different moments in time, thereby providing time dependent spectral multiplexing. Such an embodiment may be achieved, for example, by positioning the multiple filters in a filter wheel that is controllably rotated to bring each filter in the filter wheel into the optical path of the given one of the camera in a sequential manner.
More specifically, the filter can be used to provide a maximum contrast between different materials which can improve the imaging process and more specifically the soft tissue identification process. For example, in some embodiments, the filter can be used to filter out bands that are common to backscattered radiation from typical soft tissue items, the surgical structure of interest, and the surgical tool(s) such that backscattered radiation of high contrast between soft tissue items, surgical structure and surgical tools can be acquired. Additionally, or alternatively, where white light illumination is used, the filter can includes band pass filters configured to let pass only some spectral bands of interest. For instance, the filter can be configured to let pass spectral bands associated with backscattering or reflection caused by the bones, the soft tissue while filtering out spectral bands associated with specifically colored items such as tools, gloves and the like within the surgical field of view. Other methods for achieving spectrally selective detection, including employing spectrally narrow emitters, spectrally filtering a broadband emitter, and/or spectrally filtering a broadband imaging detector, can also be used.
Referring to
The tracking module 60 may be a subpart of the CAS controller 50, or an independent module or system. The tracking module 60 receives from the tracking device 30 (if present) the video feed of the surgical scene, e.g., as backscatter images of the objects. In an embodiment, as the system 10 performs real-time tracking, the video images and the orientation data are synchronized, as they are obtained and processed simultaneously. Other processing may be performed to ensure that the video footage and the orientation data are synchronized.
The tracking module 60 processes the video images to track one or more objects, such as a bone, an instrument, etc. The tracking module 60 may determine the relative position of the objects, and segment the objects within the video images. In a variant, the tracking module 60 may process the video images to track a given portion of an object, that may be referred to as a landmark.
The tracking module 60 may also be provided with models of the objects to be tracked. For example, the tracking module 60 may track bones and tools, and hence uses virtual bone models and tool models. The bone models may be acquired from pre-operative imaging (e.g., MRI, CT-scans), for example in 3D or in multiple 2D views, including with 2D X-ray to 3D bone model technologies. The virtual bone models may also include some image processing done preoperatively, for example to remove soft tissue or refine the surfaces that will be exposed and tracked. The virtual bone models may be of greater resolution at the parts of the bone that will be tracked during surgery, such as the knee articulation in knee surgery. The bone models may also carry additional orientation data, such as various axes (e.g., longitudinal axis, mechanical axis, etc). The bone models may therefore be patient specific. It is also considered to obtain bone models from a bone model library, with the data obtained from the video images used to match a generated 3D surface of the bone with a bone from the bone atlas. The virtual tool models may be provided by the tool manufacturer, or may also be generated in any appropriate way so as to be a virtual 3D representation of the tool(s).
In a variant, the tracking module 60 may generate 3D models using the video images. For example, if the tracking module 60 can have video images of a tool, from 360 degrees, it may generate a 3D model that can be used for subsequent tracking. This intraoperative model may or may not be matched with pre-existing or pre-operative model of the tool.
Additional data may also be available, such as tool orientation (e.g., axis data and geometry). By having access to bone and tool models, the tracking module 60 may recognize an object in the image processing and/or may obtain additional information, such as the axes related to bones or tools. The image processing by the tracking module 60 may be assisted by the presence of the models, as the tracking module 60 may match objects from the video images with the virtual models.
Accordingly, the electrical interface 40 and 40′ may be generally described as being an interface for a robotic arm that may have a body having a first axial face adapted to be connected to a distal face of a link of a robotic arm, a second axial face adapted to be connected to a proximal face of an end effector, the second axial face having a geometry differing from a geometry of the proximal face of the end effector so as to define a peripheral band in the second axial face, the peripheral band facing distally; a connection configuration for the interface to be fixed to the link and for the end effector to be fixed to the interface; circuitry embedded in the body; and at least one light source in the peripheral band, the at least one light source connected to the circuitry to produce light in a distal direction of the robotic arm.
The electrical interface 40 and 40′ may alternatively be described as An interface for a robotic arm having a body having a first axial face adapted to be connected to a distal face of a link of a robotic arm, a second axial face adapted to be connected to a proximal face of an end effector; a connection configuration for the interface to be fixed to the link and for the end effector to be fixed to the interface; circuitry embedded in the body; a circumferential surface defined between the first axial face and the second axial face; and at least one light source in the circumferential surface, the at least one light source connected to the circuitry to produce light.
The present application claims the priority of U.S. Patent Application No. 63/498,665, filed on Apr. 27, 2023 and incorporated herein by reference.
Number | Date | Country | |
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63498665 | Apr 2023 | US |