Abstract: A method of delivering light energy to target matter in a mammalian body is described. The method may include inserting at least a portion of a catheter into a patient's vasculature, wherein the catheter comprises an open distal tip, a lumen extending proximally from the open distal tip, and at least one optical fiber within the lumen, wherein the at least one optical fiber has a distal end. The method may include flowing a liquid light guide medium through the open-ended catheter tip, wherein the liquid light guide medium flows beyond the distal end of the at least one optical fiber, wherein the liquid light guide medium comprises a magnesium chloride solution having an ion concentration that is isotonic with blood and tissue. The method may include forming a fluid optical channel with the liquid light guide medium between the catheter and the target matter. Other methods are described.

Abstract: Systems and methods for optimizing parameters of an orthopaedic procedure for a particular patient, including parameters relating to the anatomic and biomechanic fit of an implant or implant system implanted into the patient's joint. These systems and methods may utilize patient-specific information gathered pre-operatively in conjunction with optimization algorithms to determine an optimal implant design and an optimal position and orientation for implantation of the implant into the particular patient's joint.

Abstract: Disclosed are systems, devices, and methods for planning a procedure for treatment of tissue in a patient's lungs. An exemplary method includes generating a three-dimensional (3D) model of the patient's lungs, displaying the 3D model of the patient's lungs, selecting a target location in the tissue of the patient's lungs as displayed on the 3D model, identifying a point on a pleural surface of the patient's lungs with access to the target location, determining an access path between the target location and the identified point on the pleural surface, calculating a risk of injury to intervening structures between the identified point on the pleural surface and the target location, based on the determined access path, and displaying the access path and the calculated risk of injury for the access path on the 3D model.

Abstract: A process and system for computer assisted orthopedic procedure is provided with a plurality of options to plan, execute, and monitor the creation of a cavity to receive a prosthetic based on clinical needs and pre-operative imaging data. A phantom made of materials of known densities is used to normalize CT image intensity values to estimate bone density. The process and system controls the speed, cutter engagement, orientation, and shape of the cavity so produced based on the normalized bone density values.

Abstract: A method includes acquiring an anatomical image of at least part of a head of a specific patient, the anatomical image capturing at least a selected location in the head. A personalized gripper, which is shaped based on the anatomical image to personally fit an organ of the specific patient at the selected location, and which includes a first position sensor of a position-tracking system, is fitted. The anatomical image is registered with a coordinate system of the position-tracking system, by identifying the selected location in the anatomical image and measuring a first position of the first position sensor using the position-tracking system. A medical device that includes a second position sensor of the position-tracking system, is navigated in the head of the specific patient by displaying a second position of the medical device in the head on the registered anatomical image.

Abstract: A method for guiding resection of local tissue from a patient includes generating at least one image of the patient, automatically determining a plurality of surgical guidance cues indicating three-dimensional spatial properties associated with the local tissue, and generating a visualization of the surgical guidance cues relative to the surface. A system for generating surgical guidance cues for resection of a local tissue from a patient includes a location module for processing at least one image of the patient to determine three-dimensional spatial properties of the local tissue, and a surgical cue generator for generating the surgical guidance cues based upon the three-dimensional spatial properties. A patient-specific locator form for guiding resection of local tissue from a patient includes a locator form surface matching surface of the patient, and a plurality of features indicating a plurality of surgical guidance cues, respectively.

Abstract: A method for identifying a rotational orientation of a lead includes obtaining a radiological image of the lead having a lead body, a distal tip, electrodes, and an asymmetric marker, where the lead defines a lead axis along the portion of the lead extending from the distal tip and including the electrodes and the asymmetric marker; determining, using the set of lead slices and the set of marker slices, a direction vector extending from an estimated lead axis and passing through a determined center of weighted mass of the lead; and providing an indication of a direction of the direction vector on a display.

Abstract: Methods and devices for diagnosing, monitoring, and/or treating tissue through an opening or port through an airway wall are provided herein.

Abstract: A method of supplying flux may include receiving first data at a control system identifying which of a plurality of remotely-controllable kinematic flux delivery structures is operationally coupled to which of a plurality of flux supply pathways and receiving second data at the control system identifying which of the remotely-controllable kinematic flux delivery structures is operationally coupled to which of a plurality of kinematic support structures. A system for supplying flux may include a plurality of flux supply pathways, a plurality of remotely-controllable kinematic flux delivery structures, and a control system receiving first data identifying which of the remotely-controllable kinematic flux delivery structures is operationally coupled to which of the flux supply pathways and receiving second data identifying which of the remotely-controllable kinematic flux delivery structures is operationally coupled to which of a plurality of kinematic support structures.

Abstract: A surgical path setting method, for a surgical robot, comprises the steps of (a) the surgical robot's operating a first surgical path that has been preset with respect to a surgical site of a person to be operated on; (b) the surgical robot's confirming whether or not a surgical path reset command, transmitted from a surgical path setting device, has been received; (c) the surgical robot's stopping if the surgical path reset command has been received; (d) the surgical path setting device's receiving an input of surgical path form information; (e) the surgical path setting device's determining a second surgical path, which is a new surgical path, on the basis of the surgical path form information and then transmitting same to the surgical robot; and (f) the surgical robot's operating along the second surgical path.

Abstract: Robot system which includes a master device configured to receive an operating instruction from an operator, slave arm, storage device configured to store operating sequence information that defines processing carried out by slave arm, and control device configured to control operation of slave arm. Control device includes a receiver configured to receive an input signal, motion controller configured to determine whether operating mode of slave arm is to be automatic, manual or correctable automatic mode and control operation of slave arm in determined operating mode, and continuation determinator configured to determine whether continuation of automatic mode is permitted. In a process at which slave arm is scheduled to operate in automatic mode, after motion controller suspends operation of slave arm in automatic mode at a given step of process, continuation determinator determines whether continuation of automatic mode is permitted based on input signal received by receiver when operation is suspended.

Abstract: A robot main body having a robotic arm, a remote control device which includes a robotic arm operational instruction input part installed outside of a working area and by which an operational instruction for the robotic arm is inputted, and a contactless action detecting part configured to detect a contactless action including at least one given operating condition parameter change instructing action by an operator, a control device communicably connected to the remote control device and configured to control operation of the robot main body.

Abstract: Adjustable surgical drapes are provided for easily modifying the size of fenestrations in the drape to accommodate patients of different sizes.

Abstract: An oropharyngeal measurement device includes a tubular body, a sealed channel, a radial flange member, and a measurement indicator on the outer surface of the tubular body. The tubular body includes a proximal end and a distal end. The sealed channel extends within the tubular body from the proximal end to the distal end and includes a plurality of bends configured to conform with the airway of a user. The measurement indicator is useful for placing alongside the face of a patient from the mouth towards the throat, in order to gauge an approximation for a oropharyngeal airway device to be used during a medical procedure.

Abstract: An adapter for interconnecting a surgical end effector to a surgical device includes: a drive shaft; and a load sensing device disposed about the draft shaft, the load sensing device configured to measure strain imparted on the drive shaft. The load sensing device includes a housing having: a tubular portion having a first end and a second end and defining a cavity therebetween; a first end cap disposed at the first end, the first end cap having a first opening; and a second end cap disposed at the second end, the second end cap having a second opening. The load sensing device also includes a conductive element wrapped at least partially about the tubular portion.

Abstract: A system for intracranial access that includes a support assembly is described. The support assembly has a hub and lobes surrounding a central aperture for introducing a sheathed core that can accommodate an endoscope and/or other devices. Some embodiments include a collar and a ring, each of which can be tightened to secure the sheathed core in place. An accessory device for use during intracranial aspiration procedures is described.

Abstract: Various devices and methods for guiding a biopsy surgical tool are disclosed. One type of surgical device includes a first rotational mechanism, a translational mechanism, and a second rotational mechanism. In some cases, the second rotational mechanism includes a circular frame and an end-effector. The yaw movement of the end-effector is effectuated via the first rotational mechanism. In addition, roll and pitch movements of the end-effector are effectuated via the second rotational mechanism. Furthermore, translational movement of the end-effector is effectuated via the translational mechanism.

Abstract: There is provided an image registration device, method, and program that enable easy initial registration between a target object included in a video and a simulation image. A first registration unit performs first registration that is initial registration between an intraoperative video and a simulation image. At this time, a boundary image showing the boundary of the simulation image is displayed on a display so as to be superimposed on the intraoperative video. An operator performs registration between a target object included in the intraoperative video and the boundary image. After the end of the first registration, a second registration unit performs second registration between the simulation image and the target object included in the intraoperative video based on the result of the first registration.

Abstract: An instrument device manipulator (IDM) is attached to a surgical arm of a robotic system and comprises a surgical tool holder and an outer housing. The surgical tool holder includes an attachment interface that can secure a surgical tool in a front-mount configuration (where the attachment interface is on a face opposite of an elongated body of the surgical tool) or a back-mount configuration (where the attachment interface is on the same face as the elongated body of the surgical tool). The surgical tool holder may rotate continuously within the outer housing. In a back-mount configuration, the surgical tool holder may have a passage that receives the elongated body of the tool and allows free rotation of the elongated body about the rotational axis. A surgical drape separates the IDM and robotic arm from a tool, while allowing electrical and/or optical signals to pass therebetween.

Abstract: A surgical machine comprises multiple machine connectors disposed on its face, and a device detection mechanism located close to the machine connectors. The device detection mechanism is configured to read identification data from device information component when positioned within a predetermined range. A control circuit is configured to: identify, based on a device information read from a device information component brought within the range of the device detection mechanism, a matching machine connector from multiple machine connectors, control a light source corresponding to the matching machine connector to illuminate the corresponding illumination ring with the first color, in response to this identifying, and, control the light source corresponding to each of one or more remaining ones of the machine connectors to provide no illumination or to illuminate the corresponding illumination ring with a second color.

Abstract: A dental tissue treatment apparatus and associated methods includes a feedback-controlled beam guidance system for directing treatment to a defined area of dental tissue.

Abstract: A physical model of a set of teeth, wherein the physical model includes a gingival part in which a cavity comprising a cavity wall is formed; and a removable component having a part shaped as a tooth, where the removable component is configured for fitting into the cavity with a gap at an interface between the removable component and the cavity wall. The removable component or the cavity wall includes one or more supporting elements extending across the gap to establish contact between the removable component and the cavity wall to support and position the removable component in the cavity, and where contact between the removable component and the cavity wall at the interface only is provided by the supporting elements.

Abstract: Systems and methods are disclosed for fabricating a dental or oral appliance utilizing support structures. A three dimensional representation of the dentition of a patient may be captured and reconfigured for correcting one or more malocclusions. The oral appliance may be printed upon an inner structure which supports the oral appliance during fabrication. The inner structure may be subsequently removed once the oral appliance is completed.

Abstract: A method of determining an orthodontic treatment comprising: obtaining a 3D model of a simulated position of upper and lower teeth following a simulated orthodontic treatment, the 3D model comprising a point cloud representation comprising a plurality of vector points; in a 3D grid having cells onto which the plurality of the vector points have been mapped, identifying cells containing vectors points representative of the upper teeth and applying a first mask to these cells; identifying cells containing vectors points representative of the lower teeth and applying a second mask to these cells; determining the simulated orthodontic treatment as the determined orthodontic treatment if the 3D grid does not include at least one cell which includes both the first mask and the second mask.

Abstract: Provided herein are crosslinked polymers useful in orthodontic appliances and light polymerizable liquid compositions and formulations useful for making crosslinked polymers. Also provided are methods of making an orthodontic appliance comprising a cross-linked polymer formed by a direct fabrication technique.

Abstract: A method for generating an aligner configured to be coupled to a tooth, the aligner having a body defining a channel arranged for receiving the tooth and a fixing block arranged for coupling the aligner and the tooth, the method comprising acquiring a tooth model, defining a zone on the tooth model, determining, based on the zone, a tooth-coupling surface for coupling the tooth with the aligner, generating, based on the tooth model, a body model by generating an inner surface of the body model based on the tooth model, generating, based on the determined tooth-coupling surface, a fixing block-coupling surface indicative of an outer surface of the fixing block by extruding the tooth-coupling surface by an interference length to inward of the tooth model so as to generate a block model having the fixing block-coupling surface, generating the aligner model by joining the block model with the body model.

Abstract: A self-ligating orthodontic bracket has a sliding archwire cover that has a top surface congruent with the top surface of an upper body portion having an archwire slot. The cover has a resilient locking tab that slides across the slot, bending upward as it encounters a ridge on the other side of the slot, and latching to the ridge to secure the cover in a closed position. The cover has a modified dovetail shape with flared bottom portions that slideably engage guides for reciprocal opening and closing sliding motion. A groove in the slide support track engages the locking tab in the open position preventing it from disengaging from the upper body portion.

Abstract: A set of osteotomes have conical tips with free end diameters alternately increasing by a constant increment, k, as a step function, beginning with the first osteotome; and working base diameters alternately increases by a constant increment, C, as a step function, beginning with the second osteotome. For seven osteotomes, the first and second diameters respectively are: 1 mm and 2 mm; 1 mm and 3 mm; 2 mm and 3 mm; 2 mm and 4 mm; 3 mm and 4 mm; 3 mm and 5 mm; and 4 mm and 5 mm. In a first mode all seven osteotomes are used to provide very gradual diameter escalations. In a second mode the first, third, fifth, and seventh osteotomes provide conventional Summers' diameter escalations. In third and fourth modes the first, fourth, and seventh osteotomes, and the second, fifth, and seventh osteotomes respectively provide increasingly more aggressive Summers' type escalations.

Abstract: A retainerless orthodontic dental implant system for positioning the mandible forward relative to the maxilla and for facilitating optimal airflow during sleep and a method of using such a system.

Abstract: Embodiments of this invention provide predictability and standardization in the field creating dental models. Embodiments of the invention are capable of accommodating multiple variations and goals of dental impressions, including but not limited to creating dental models for study models, mouth guards, night guards, whitening trays, sleep apnea/snoring devices, etc. Embodiments may incorporate single arch and dual arch impression trays, as well as base model formers and articulators, among other devices of varying shapes, dimensions, sizes and manufacturers. Embodiments of the invention use standard dimensions for accommodating various components. To adapt embodiments of the invention for multiple purposes, and to standardize the process, embodiments of the invention include a shell that allows for standardized dental models to be suspended in the shell during the process of creating dental molds, creating a reservoir for the dental mold.

Abstract: A zirconia ceramic body for use with dental prosthetics has an L* value between 10 and 20 for a sample thickness 011 to 1.3 mm in accordance with CIE L*a*b* colorimetric system. The zirconia ceramic body can have between 6-20 wt % or 7.20 wt % of yttria based on total weight percent of the zirconia ceramic body. The zirconia ceramic body is subsequently finally sinterable to produce a translucent zirconia sintered body. In one aspect, the sintered body has a total light transmittance of at least 36% and less than 50% to light with a wavelength of 400 nm, and less than 55% to light with a wavelength of 600 nm, at a thickness of 0.6 mm, measured using a LAMBDA 35 UV/VIS Spectrophotometer manufactured by Perkin Elmer.

Abstract: Various apparatus and methods for cleaning teeth and gingival pockets are disclosed herein. A fluid platform can include a pressure wave generator configured to propagate pressure waves through a treatment fluid. The pressure waves may be sufficient to remove undesirable dental deposits from a treatment tooth, neighboring gums, and/or spaces between the tooth and gums.

Abstract: A dental prophy angle reduces the ejection of blood, dental polish, and saliva from a patient's mouth during a dental procedure. The dental prophy angle includes a drive head with an airflow generator is positioned within the drive head. The airflow generator produces an airflow pattern that exits from the drive head. A prophy cup is attached to the drive head. The airflow pattern travels over the outer surface of the prophy cup. The air flow pattern reduces the amount of material that builds up on the outer surface of the prophy cup, thereby reducing the ejection of material from the patient's mouth. In certain embodiments, the prophy cup is transparent to enable a dental practitioner to visualize the prophy paste within the prophy cup.

Abstract: An oral care implement including a handle and a replacement head that is detachably coupled to the handle. The oral care implement may include a handle having a longitudinal axis that includes a gripping portion and a stem extending from the gripping portion. The gripping portion may have a shoulder that circumferentially surrounds the stem and an annular rib protruding from the shoulder. The replacement head may have a sleeve portion terminating in a proximal edge that is formed from a resilient material. The replacement head may be detachably coupled to the handle so that the annular rib of the shoulder and the proximal edge of the sleeve portion that is formed of elastomeric material are in contact with one another.

Abstract: A whitening smart pen apparatus (10) for automatically dispensing a teeth whitening substance onto one or more teeth of a user comprises a fluid reservoir (16), a nozzle (18) having an output port (26), a fluid dispenser (20), a sensor (22) and a controller (24). The fluid dispenser dispenses the teeth whitening substance from the fluid reservoir to the nozzle and is output via the output port. The sensor, positioned in an advance dispensing direction of the nozzle, senses a target surface that comprises either (i) a tooth surface (12) or (ii) other surface (14). The controller (24) is configured for (i) controlling a gating of the fluid dispenser (20) to dispense the teeth whitening substance from the fluid reservoir (16) in response to the sensor (22) detecting the tooth surface (12), and (ii) stopping or disabling the gating of the fluid dispenser to stop or disable a dispensing of the teeth whitening substance from the fluid reservoir in response to the sensor (22) detecting the other surface (14).

Abstract: The invention provides a system treating a weak or leaking urinary or other sphincter. The system includes two magnets and one or more devices to immobilize one of the magnets on a first side of the body organ to immobilize the other magnet on the second side of the body organ. The magnets may be positioned around the body organ with opposite poles facing each other. The invention may be used to induce the formation of muscle tissue of a sphincter such as a urethral sphincter or gastroesophageal sphincter, and also for mechanically occluding a leaking urethral or vesicovaginal fistula.

Abstract: Improved methods and apparatus to secure a urethral sling to pubic bone in a sub-urethral location to support the urethra and alleviate incontinence are disclosed. The urethral sling is preferably formed of a flexible sheet material extending between opposed first and second sling ends and bounded by opposed first and second sling sides. The urethral sling is selectively tensioned in a central portion intermediate the first and second sling ends and/or in one or both of end portions bracketing the central portion. In one embodiment, pre-positioned plicating lines in the central portion are selectively drawn and tied to slacken the central portion and tension the end portions. In further embodiments, bone anchor lines passed through locations displaced from the sling ends are drawn and fixed to tension the central portion between the displaced locations and slacken the end portions.

Abstract: Packaging systems and methods are disclosed for storing a bioprosthetic device comprising a bioprosthetic tissue and maintaining a target relative humidity across a temperature range. The packaging system includes a sealed package defining an internal space having an internal volume, and a humidity control device and bioprosthetic device within the internal space. The humidity control device includes a barrier defining an enclosed space and a humidity control solution comprising glycerol in the enclosed space. At least a portion of the barrier comprises a gas-permeable membrane. The target relative humidity is provided within the internal volume of the sealed package and the control device maintains the target relative humidity across the temperature range by selectively liberating and absorbing water vapor.

Abstract: Devices, methods and systems are provided for occluding an opening within the tissue of a body, such as a left atrial appendage. In one embodiment, a medical device includes an occluder portion and an anchor portion. The occluder portion includes a hub that defines an axis, the occluder portion extending between a proximal end coupled to the hub and a distal end defining an occluder eyelet adjacent thereto. The anchor portion extends between a first end and a second end, the first end coupled to an anchor hub and the second end defining an anchor eyelet adjacent thereto and hingeably coupled to the occluder eyelet. With this arrangement, the anchor hub is moveable along the axis to move the anchor portion between a retracted position and a deployed position upon the occluder portion being in an expanded position.

Abstract: A device for assisting in the removal of items endovascularly includes a catheter, an engagement head, and a pull rod. The pull rod has a proximal portion and a distal end connected to the engagement head. The pull rod is movable within the catheter to selectively extend and retract the engagement head from the distal end of the catheter. The engagement head is arranged to grab an item without regard to a particular orientation of the item. The engagement head has a generally cylindrical outer shape that corresponds to an internal surface of the catheter. The engagement head has a serrated proximal edge arranged to grab and hold an item against the distal end of the catheter, and an internal relief area located radially inwardly from said serrated proximal edge to aid in engaging an item.

Abstract: A method of using an implantable device provides an implantable device including a plurality of links (113, 115, 117, 119), a device closure pin (111), a lock-in unit (103) attached and located between two links, and a quick release unit (105) attached and located between two links. The plurality of links (113, 115, 117, 119), lock-in unit (103) and release unit (105) are constructed in a closed contour. The closed contour of the implantable device, in a rigid state (151), is a figure eight comprised of two arcs (125, 127) and two connected interconnecting sections (131, 133).

Abstract: An endoluminal prosthesis comprises a prosthetic trunk having a trunk lumen and a trunk wall, a first prosthetic branch having a first branch lumen and a branch wall, and a second prosthetic branch having a second branch lumen. The first branch lumen and the second branch lumen are both in fluid communication with the trunk lumen through the trunk wall and the second branch lumen is in fluid communication with the first branch lumen through the branch wall. Additional devices, systems, and methods are disclosed.

Abstract: Provided herein are compositions and methods for treating a subject with damaged tissue, such as an injury associated with a tissue to tissue (e.g., a connective tissue-to-connective tissue or tissue to bone) interface. One aspect provides an adhesive film or adhesive layer, optionally comprising a biomaterial, tissue growth factors, including CTGF/CCN2, or cells.

Abstract: The present invention provides for methods and devices suitable for producing a transplantable cellular suspension of living tissue suitable for grafting to a patient. In applying the method and/or in using the device, donor tissue is harvested, subjected to a cell dissociation treatment, cells suitable for grafting back to a patient are collected and dispersed in a solution that is suitable for immediate dispersion over the recipient graft site.

Abstract: An implant includes a hollow biocompatible shell, first and second electrodes, filling material, and circuitry. The hollow biocompatible shell is configured to be implanted in an organ of a patient. The first electrode is disposed inside the shell. The second electrode has at least one surface disposed outside the shell. The filling material, which includes carbon nanotubes (CNT), fills the shell and is configured, in response to a rupture occurring in the shell, to change a spatial orientation of the CNT and thus to cause a change in electrical conductivity of the filling material between the first electrode and the rupture. The circuitry is electrically connected to the first and second electrodes and is configured to detect the rupture by sensing the change in the electrical conductivity of the CNT, and to produce an output indicative of the detected rupture.

Abstract: The present invention provides, in various embodiments, a breast implant with an RFID transponder embedded therein, so that the implant can be conveniently identified while inside the human body, and methods of making the same.

Abstract: A covering layer for a transcatheter heart valve is in various embodiments configured to prevent or reduce damage to the native valve tissue around the site where the prosthetic valve is implanted. In some cases, prosthetic valves are manufactured with the covering layer attached. Other covering layers are stand-alone accessories that can be mounted onto pre-existing prosthetic valves by an end user. Covering layers that can be mounted by an end user are provided with various features that can facilitate easier attachment of the covering layer to the prosthetic valve, which further reduces the possibility of damage to the covering layer or to the valve. Another covering is provided with two layers in order to insulate and protect the native tissue surrounding the implant from damage due to friction or abrasion, and/or other movement driven wear.

Abstract: A prosthetic heart valve (10) which includes a stent (14) having three leaflets (12) attached thereto is provided. The stent (14) is compressible so as to be capable of being introduced into a patient's body through a minimally invasive procedure and has a ring-like body (16) defining in its height three arch-shaped elements (18). Each element (18) includes an arc (20) and a pair of haunches (22) extending from opposite sides thereof, with three commissural posts (26) formed by the haunches (22) of adjacent elements (18). The leaflets (12) each have an attachment edge (28) and a free edge (30) with a belly (32) extending therebetween. The leaflets (12) are movable between a coapted condition, in which the free edges (30) abut and prevent fluid flow through the valve (10), and an open condition, in which fluid flow through the valve (10) is permitted. The leaflets (12) are made from a polymeric material and are moulded directly onto the stent (14) so as to provide for continuous attachment thereof.

Abstract: Valves constructed from low porosity leaflets are disclosed. The valves disclosed herein may be integrated into a variety of structures, such as valved conduits and transcatheter stents, and may be constructed of one or more layers. Embodiments herein are also directed to methods of using the same and methods of making the same.

Abstract: An expandable introducer sheath provided with a steering mechanism is disclosed. The introducer sheath is configured for providing a prosthesis delivery system percutaneous access to a patient's vasculature. The introducer sheath includes a sheath component defining a central lumen and having a longitudinally-extending, radially-expandable portion. The sheath component also includes a steering wire slidably disposed within a wall thereof that longitudinally extends along the radially-expandable portion. When the steering wire is in a slackened configuration, the steering wire permits a width of the radially-expandable portion to increase. When the steering wire is in a taut configuration, the steering wire permits a distal portion of the sheath component to be manipulated or bent in order to align a distal port of the introducer sheath, for instance, with an ostium of a branch vessel.