Patent Description:
As another example, <CIT> describes a viewing trocar assembly including a tubular body having a proximal end and a distal end, and an opening provided at the distal end, and at least one external imaging device positioned on an outer wall of the distal end of the tubular body, wherein the at least one imaging device is adjacent to the outer wall of the distal end of the tubular body when in an inactivated position, and wherein the at least one imaging device is extended further away from the outer wall of the distal end of the tubular body when in an activated position than when in the inactivated position.

Different trocars were previously proposed in the patent literature. For example, <CIT> describes a modular trocar system which includes an obturator assembly, and a cannula assembly defining a longitudinal passageway therethrough configured and dimensioned to slidably receive the obturator assembly. A method of assembly is also provided.

As another example, <CIT> describes a kit assembly for use to construct a desired trocar obturator used during a surgical procedure. The kit includes a proximal portion of the obturator and a plurality of different distal end portions. The proximal portion may be releasably attached to a distal portion by virtue of a detent mechanism. Reuse of the proximal portion affords potential cost savings. The plurality of distal end portions affords the surgeon a choice between different trocar tips so that the trocar may be customized for a particularly surgical procedure.

<CIT> relates to a trocar system, having a trocar, an optical channel extending coaxially in the trocar for receiving an optical unit, and a hollow transparent distal tip of the trocar, which can be observed from the interior by means of the optical unit, wherein at least one working channel is constructed in the wall of the trocar surrounding the optical channel, which channel extends continuously and axially parallel from the proximal end of the trocar into the distal tip and opens into an outlet opening in the region of the tip.

<CIT> relates to surgical visualization systems and related methods, e.g., for providing visualization during surgical procedures. Systems and methods herein can be used in a wide range of surgical procedures, including spinal surgeries such as minimally-invasive fusion or discectomy procedures.

<CIT> relates to a medical navigation system. The medical navigation system includes a computing device having a processor coupled to a memory, a wireless communication component and a display for displaying an image. The medical navigation system further includes a sensor module attached to a medical device.

<CIT> relates to a trocar for inserting a surgical instrument in a body, that comprises: a pipe including an outer cylinder relatively slidable in an axial direction, and an inner cylinder; a head located on a proximal end of the pipe; a camera that is journaled in a distal end notch of the pipe inner cylinder so as to be turnable between a development state in which the camera turns to the outside of the pipe and a storage state in which the camera is stored inside the pipe; and a coil spring biasing the camera to the development state.

In some invasive procedures, to insert a medical probe or other tool into the body of a patient, a trocar, which serves as a penetrating portal, is first placed in an entry location. In addition to being a portal for the probe, the trocar, which comprises a cannula, is used for irrigation and to drain bodily fluids, as well as other fluids. Typically, an obturator is first inserted via the cannula, so that the obturator can penetrate the body and create access for the probe.

Such invasive medical procedures typically require the use of dedicated imaging to guide the medical probe to and/or in an organ, such as a brain; for example, using an X-ray system and/or a camera fitted to the probe. In some cases, for example, brain procedures may require navigating a distal end of a probe inserted into the brain via a hole made in the skull. The treating probe has to be advanced via the trocar and be guided to treat the target brain tissue, for example infected or bleeding brain tissue.

Treating probes, however, are limited in space, while often visual guidance of the probe is required regardless of any other probe navigation techniques. Moreover, the trocar itself is conventionally inserted "blind," so that a physician performing the insertion cannot know exactly where the trocar distal end is located. The physician also cannot see tissue that the trocar is contacting.

The present disclosure describes examples that provide a trocar that has a camera to view target tissue and/or a treating probe fitted internally to a wall of the cannula. In some examples, a position sensor is also fitted internally to a wall of the cannula. Sensor wiring, providing location data from the sensor, is passed from the sensor with the camera wiring to a processor that provides the physician with location data for the trocar distal end, for example, to register captured images from the camera with a reference medical image (e.g., an MRI image).

The disclosed internal camera and position sensor within the cannula (e.g., a magnetic position sensor operated with a position-tracking system) therefore enables the physician to see tissue being penetrated by the trocar, and the sensor allows the trocar distal end to be tracked. Subsequently, the camera may be used in visual guidance of a treating probe.

By optimizing visual image acquisition using an internal camera of a trocar, the disclosed technique may enable improved quality of minimally invasive medical procedures.

In general, trocars are relatively expensive, since they typically may also be precision instruments and must be capable of sterilization (by autoclaving or another method). There are many different types of trocars, depending on the tasks they are designed to perform. For example, a trocar with an obturator for penetrating muscle or bone may have a very sharp obturator head, whereas a trocar for penetrating brain tissue will have a smooth obturator head, in order to open access into brain as "gently" as possible. To form each of these different trocars with a camera and location sensor, as described above, would involve considerable expense.

In some examples a modular trocar is provided, wherein the obturator head of the trocar may be selected by the physician according to the required obturator task. The obturator heads are sterilizable, and may be reused. The proximal end, which includes a camera and location sensor, is a low-cost disposable item, though it can be used multiple times during the same procedure by replacing obturator heads, as described below.

<FIG> is a schematic, pictorial illustration of a brain procedure using a surgical apparatus <NUM> comprising a trocar <NUM> comprising a camera <NUM> and a position sensor <NUM>. A brain diagnostics and treatment system <NUM>, which comprises surgical apparatus <NUM>, is configured to carry out a brain procedure, such as treating an infection in brain tissue of a patient <NUM>. In the shown embodiment, trocar <NUM> is used to penetrate the skull so that a physician <NUM> can insert a probe <NUM> into a head <NUM> of patient <NUM> (insertion not shown) to access brain tissue. Subsequently, probe <NUM> may be operated using the trocar-attached camera <NUM>. Typically, treating probe <NUM> may be further operated by a second physician (not shown).

In the shown example, a cable <NUM> enters a proximal end of trocar <NUM> and is electrically coupled on its distal end to camera <NUM> and position sensor <NUM>.

System <NUM> comprises a magnetic position-tracking system, which is configured to track a position of sensor <NUM> in the brain. The magnetic position-tracking system comprises a location pad <NUM>, which comprises field generators <NUM> fixed on a frame <NUM>. In the exemplary configuration shown in <FIG>, pad <NUM> comprises five field generators <NUM>, but may alternatively comprise any other suitable number of generators <NUM>. Pad <NUM> further comprises a pillow (not shown) placed under head <NUM> of patient <NUM>, such that generators <NUM> are located at fixed, known positions external to head <NUM>. The position sensor generates position signals in response to sensing external magnetic fields generated by field generators <NUM>, thereby enabling a processor <NUM> to estimate the position of sensor <NUM> and therefore a position of a distal edge of trocar <NUM> inside the head of patient <NUM>.

This technique of position sensing is implemented in various medical applications, for example, in the CARTO™ system, produced by Biosense Webster Inc. (Irvine, CA) and is described in detail in <CIT>, <CIT>, <CIT>, <CIT>,<CIT> and <CIT>, in <CIT>, and in <CIT>, <CIT> and <CIT>.

In some examples, system <NUM> comprises a console <NUM>, which comprises a memory <NUM>, and a driver circuit <NUM> configured to drive field generators <NUM>, via a cable <NUM>, with suitable signals so as to generate magnetic fields in a predefined working volume in space around head <NUM>.

Console <NUM> may further include additional control elements to assist physician <NUM> to perform the procedure, such as command buttons to capture an image from camera <NUM> and, using a position obtained by the magnetic position-tracking system, to register it with a reference medical image.

Processor <NUM> is typically a general-purpose computer, with suitable front end and interface circuits for receiving images from camera <NUM> and signals from position sensor <NUM> via cable <NUM>, and for controlling other components of system <NUM> described herein.

In some examples, processor <NUM> is configured to register an image produced by camera <NUM> with a medical image, such as an MRI image. Processor <NUM> may further register the position of the distal end that is estimated using position sensor <NUM>. Processor <NUM> is able to register a camera <NUM> image by estimating a position of a distal edge of trocar <NUM> using position sensor <NUM>. Processor <NUM> is configured to register the camera image and the reference medical image in the coordinate system of the magnetic position-tracking system and/or in a coordinate system of the reference medical image.

In some examples, system <NUM> comprises a video display <NUM> that shows an image <NUM> taken by camera <NUM>. In the shown image, a distal end of treating probe <NUM> can be seen engaging brain tissue.

In some examples, processor <NUM> is configured to receive, via an interface (not shown), one or more anatomical images, such as reference MRI images depicting two-dimensional (2D) slices of head <NUM>. Processor <NUM> is configured to select one or more slices from the MRI images, perform registration with a real-time camera image, such as image <NUM>, to produce a combined image, such as an image <NUM>, and display the selected combined slice to physician <NUM> on user display <NUM>. In the example of <FIG>, combined image <NUM> depicts a sectional coronal view of anterior brain tissue of patient <NUM>.

Console <NUM> further comprises input devices, such as a keyboard and a mouse, for controlling the operation of the console, and a user display <NUM>, which is configured to display the data (e.g., images) received from processor <NUM> and/or to display inputs inserted by a user using the input devices (e.g., by physician <NUM>).

<FIG> shows only elements related to the disclosed techniques for the sake of simplicity and clarity. System <NUM> typically comprises additional or alternative modules and elements that are not directly related to the disclosed techniques, and thus are intentionally omitted from <FIG> and from the corresponding description.

Processor <NUM> may be programmed in software to carry out the functions that are used by the system, and to store data in memory <NUM> to be processed or otherwise used by the software. The software may be downloaded to the processor in electronic form, over a network, for example, or it may be provided on non-transitory tangible media, such as optical, magnetic or electronic memory media. Alternatively, some or all of the functions of processor <NUM> may be carried out by dedicated or programmable digital hardware components. In particular, processor <NUM> runs a dedicated algorithm as disclosed herein, including in <FIG>, that enables processor <NUM> to perform the disclosed steps, as further described below.

<FIG> is a schematic, pictorial illustration of trocar <NUM> applied in the brain procedure of <FIG>. Trocar <NUM> comprises a cannula <NUM> and an obturator <NUM>. As seen, trocar <NUM> comprises a channel <NUM> inside cannula <NUM>, channel <NUM> having a distal edge on which camera <NUM> and position sensor <NUM> are mounted. Channel <NUM> further provides a track for routing cable <NUM>.

In an example, camera <NUM> is tilted relative to the longitudinal axis of trocar <NUM>, so as to have a central distal viewing direction pointing at a center of a distal opening <NUM> of cannula <NUM>. At the same time, sensor <NUM> is mounted such that the sensor does not obstruct the field of view of camera <NUM>.

The configuration of trocar <NUM> in <FIG> is depicted by way of example for the sake of conceptual clarity. In other examples, additional elements may be included, such as additional ports in trocar <NUM> to insert medical tools to the target brain location.

<FIG> is a flow chart that schematically illustrates a method and algorithm for registering a visual image from camera <NUM> of trocar <NUM> of <FIG> with a reference medical image. The process begins when physician <NUM> places trocar <NUM> to access the brain, at a trocar placement step <NUM>.

Next, physician <NUM> operates system <NUM> to magnetically track a location in the brain of a distal end of trocar <NUM> using signals from sensor <NUM>, at a trocar position tracking step <NUM>. Next, in an image capturing step <NUM>, physician <NUM> captures an image by camera <NUM>, to register with a reference medical image.

At an image registration step <NUM>, based on the tracked position of trocar's <NUM> distal end (using sensor <NUM>), processor <NUM> registers the captured image (by camera <NUM>) with a respective reference medical image stored in memory <NUM>, such as from an MRI scan, to produce combined image <NUM>. In an example, processor <NUM> is further configured to correct the reference medical images based on the registered images, for example, if the treatment removes brain tissue. In another example, the processor is further configured to alert a user to a detected discrepancy between the visual image and the reference image due to, for example, a larger tumor size detected by camera <NUM> because of tumor growth since the reference image was taken.

Next, at a trocar adjustment step <NUM>, using combined image <NUM>, physician <NUM> adjusts an alignment of trocar <NUM>, e.g., to best allow best access to target brain tissue, such as an infected tissue. Physician <NUM> then inserts a treating probe <NUM>, at a probe insertion step <NUM>, to treat target tissue under visual guidance provided by camera <NUM>.

The example flow chart shown in <FIG> is chosen purely for the sake of conceptual clarity. In alternative examples physician <NUM> may perform additional steps, such as employing additional monitoring steps (e.g., fluoroscopy) to verify the successful outcome of the procedure, and/or apply irrigation to clear view for camera <NUM>.

<FIG> is a schematic, pictorial illustration of trocar <NUM> applied in the brain procedure of <FIG>. Trocar <NUM> includes cannula <NUM> and an obturator <NUM>. As seen, trocar <NUM> includes a modular obturator <NUM> which is comprises an obturator body <NUM> configured to be inserted into cannula <NUM> of trocar <NUM>. An obturator head <NUM> of obturator <NUM> is configured to penetrate the body and create access for the probe.

Obturator body <NUM> of modular obturator <NUM> is constructed such that different obturator heads can be interchangeably fitted to obturator body <NUM>, few heads seen by way of example in inset <NUM>, which can be used during an invasive medical procedure. In inset <NUM>, an obturator head <NUM> has a sharp tip, and is typically used to penetrate muscle or bone. An obturator head <NUM>, on the other hand, has a smooth tip, and may be used to penetrate brain tissue.

As further seen, obturator body <NUM> and interchangeable obturator heads <NUM> and <NUM> are designed with depressions <NUM>, <NUM>, and <NUM> respectively, such that they could be readily fit (e.g., inserted into) cannula <NUM>, where depressions <NUM>, <NUM>, and <NUM> match a profile of channel <NUM> (seen in <FIG>).

The configuration of trocar <NUM> in <FIG> is depicted by way of example for the sake of conceptual clarity. In other examples, additional elements may be included, such as additional types of interchangeable obturator heads.

<FIG> is a flow chart that schematically illustrates a method of using the trocar of <FIG> with interchangeable obturator heads (<NUM>, <NUM>). The process begins with physician <NUM> selecting a brain trocar <NUM> to access the brain, at a trocar selection step <NUM>.

Next, physician <NUM> selects an interchangeable obturator head capable of penetrating bone, such as interchangeable obturator head <NUM>, at an obturator head selection step <NUM>. The physician mounts selected obturator head <NUM> on obturator <NUM>, in obturator preparation step <NUM>.

At a treatment step <NUM>, physician <NUM> uses the assembled obturator to start an invasive procedure, such as using the obturator to penetrate skull bone.

To continue obturator placement in the brain, physician <NUM> selects, at an obturator head selection step <NUM>, obturator head <NUM>, which is configured to enter the brain tissue. At an obturator head replacement step <NUM> physician <NUM> replaces obturator head <NUM> with obturator head <NUM>. Finally, at a treatment step <NUM>, physician <NUM> uses the re-assembled obturator to continue the invasive procedure, by advancing the obturator in brain tissue.

The example flow chart shown in <FIG> is chosen purely for the sake of conceptual clarity. In typical examples physician <NUM> will perform additional steps, such as advancing cannula <NUM>, while tracking a position of the cannula.

Although the examples described herein mainly address brain procedures, the methods and systems described herein can also be used in other applications that require guiding a medical device in other organs, such as located in the abdomen or the chest.

Claim 1:
A system, comprising;
a trocar (<NUM>) for insertion into an organ of a patient, the trocar comprising:
a cannula (<NUM>) having a longitudinal axis;
a channel (<NUM>) inside the cannula, the channel fitted parallel to the longitudinal axis; and
a camera (<NUM>), which is disposed at a distal end of the channel and is configured to provide images in a direction of a distal opening of the cannula; and
wherein the system further comprises an obturator (<NUM>) comprising an obturator body (<NUM>) configured to be inserted into the cannula, wherein the obturator body comprises a depression (<NUM>) configured to match a profile of the channel (<NUM>); and
characterised in that the camera is tilted relative to the longitudinal axis, so as to have a viewing direction that captures a distal opening of the cannula and enables a physician to see tissue being penetrated by the trocar.