Patent Description:
Carpal tunnel syndrome (CTS) is a medical condition caused by compression of the median nerve as it travels through the wrist at the carpal tunnel. CTS can cause pain, numbness, and tingling, typically in the thumb, index finger, middle finger, and the thumb side of the ring fingers. Weak grip strength and loss of manual dexterity may occur, and after a long period of time the muscles at the base of the thumb may atrophy.

While CTS can be treated using splints to limit wrist mobility, or with steroid injections, surgery can also be indicated. Such surgery is known as a carpal tunnel "release" (CTR) or "decompression" surgery, and is shown in <FIG> in a plane view and in <FIG> in a cross sectional view. The goal of CTR surgery is to incise the transverse carpal ligament <NUM> than spans across the base of the palm to alleviate pressure on the median nerve <NUM>. CTR surgery can be performed "openly," essentially by slicing open the skin and fascia of the palm to reveal relevant structures, but <FIG> shows an example of CTR as performed endoscopically.

In endoscopic CTR surgery, a small incision <NUM> is made near the base of palm, and a CTR tool <NUM> is inserted, which allows the surgeon to sever the transverse carpal ligament <NUM> with an incision 10a. CTR tool <NUM> can take many different forms, and is only generically described in <FIG>. As shown, CTR tool <NUM> includes an internal portion (cannula) <NUM> that is insertable into the patient through incision <NUM>, and an external portion <NUM> that operates as a handle for the surgeon. Sometimes incorporated in CTR tool <NUM> is an endoscope <NUM>, which may comprise an instrument separate from the tool and useable in other contexts. In certain CTR tool designs, the endoscope may be positionable within the tool <NUM> and may include a light pipe that proceeds through the cannula <NUM> to allow the surgeon to view relevant anatomical structures to be cut. Commonly, the endoscope <NUM> includes a camera attachment (not shown) allowing the surgeon to view relevant anatomical structures on a display screen <NUM> coupled to the endoscope via a cable <NUM>.

The external portion <NUM> further includes an activator <NUM> to release a blade <NUM> when the cannula <NUM> is in proper position relative to the transverse carpal ligament <NUM>. Activator <NUM> can take many different forms and is only shown here for simplicity as a button on the external portion <NUM>. When the blade <NUM> is released via the activator <NUM>, it can be used to cut (10a) through the transverse carpal ligament <NUM> as shown via the image on the screen <NUM>, and in the cross section of <FIG> also shows in cross section other anatomical structures such as various bones <NUM> of the hand and wrist, and various ligaments <NUM> coupled to the patient's fingers and thumb.

<CIT> shows an endo-surgical tool that includes imaging optics therein. <CIT> shows a cutting apparatus for treating carpal tunnel syndrome with a hollow handle including a forward bent portion. <CIT> shows a surgical instrument for improved viewing of a surgical site by a surgeon from the perspective of a working element of the instrument. <CIT> discloses an improved surgical method for inspecting and manipulating selected tissue in a body cavity, while minimizing the risk of injury to surrounding tissue, and a surgical instrument therefor. <CIT> discloses a wireless endoscopic surgical device used for minimally invasive procedures and comprises a handheld component and a separate power module.

The present invention is defined by the independent claim. Optional embodiments are described in the dependent claims.

The inventors believe that CTR tools such as <NUM> suffer from several drawbacks. First, to the extent that such tools include or incorporate the ability to view the structures being cut, such tools are cumbersome. They can require investment in a completely separate instrument-such as an endoscope <NUM>-and therefore are not complete tool solutions. The endoscope <NUM> may require different components-such as an external video camera, an attachment to connect that camera to the endoscope, and an external light source to illuminate the patient's tissue-to be fully functional in a CTR surgical context. This makes such traditional CTR surgical solutions needlessly expensive and complicated. Further, and as shown in <FIG>, the endoscope <NUM> connects to a display screen <NUM> via a cable <NUM>. This cable <NUM> is cumbersome for the surgeon, as it can get in the surgeon's, or surgical personnel's, way and can otherwise make it difficult to manipulate the tool in the patient.

Second, traditional CTR tools can have replacement parts that are expensive or difficult to replace. In particular, the blade <NUM> at the end of the cannula <NUM> may need replacing. Some traditional tools however require that the entire cannula <NUM> be replaced to replace the blade <NUM>. This needlessly requires replacement of structures that are otherwise perfectly functional, which is wasteful and unnecessarily increases cost of use of the tool.

Third, traditional CTR tools can be difficult to clean and sterilize, or can have too many different components that need cleaning and sterilizing. For example, the CTR tool <NUM> and the endoscope <NUM>, or their components, may each need to be cleaned separately, and the type of cleaning required may be different for different components, which adds complexity and again unnecessary cost. Further, at least certain portions of the CTR tool <NUM> or endoscope <NUM> may be formed of materials that do not permit them to be sterilized in an autoclave. An autoclave comprises a simple sterilization mechanism that uses steam at high temperatures and pressures to sterilize surgical equipment. However, many of the components in traditional CTR tools would be unable to handle the high pressures and temperatures that autoclaving provides. This is regrettable, because autoclaving is generally the cheapest and easiest alternative to more expensive sterilization techniques.

Fourth, the inventors see a need for a CTR tool whose simplicity will not require special resources and support. In some contexts, and depending on the type of tools and techniques used (e.g., open CTR surgery), it may be necessary to perform CTR surgery in an operating room (OR). This may require additional medical personnel to be present, such as one or more surgical nurses or anesthesiologists. In some circumstances, surgery may also require use of a post-surgery recovery room, and its related personnel, which again increases costs.

To address these shortcomings, the inventors have developed an improved CTR tool. The CTR tool is useable to perform CTR surgically endoscopically through a single incision in the patient, which as noted earlier is simpler than open CTR techniques that may require more-traditional and more-expensive surgical resources and support. The CTR tool however lacks a traditional, self-standing endoscope (such as <NUM>, <FIG>), and instead includes all dedicated optical components-including light emitters (e.g., LEDs) and a camera-within the housing of the tool. Preferably, the tool includes wireless communication means-such as a Bluetooth antenna and chip set-to broadcast video images from the camera to an external display in real time to allow the surgeon to see the patient's anatomy, and in particular the transverse carpal ligament to be cut. Because optics in the tool are handled wirelessly, the tool lacks a cable (compare <NUM>, <FIG>), and is thus more convenient to use. The tool also includes a battery for operational power, i.e., to power the optical components and the wireless transfer of the video images.

As will be shown in the figures that follow, the improved CTR tool is also modular, thus allowing different portions of the tool to be replaced if necessary. For example, the cannula includes a blade tip assembly that can be easily replaced after each use of the tool, while leaving otherwise functional portions of the cannula in place. Other aspects of the improved CTR tool can also be easily changed, including (less frequently) its battery and an optical electronics module that may include both the LEDs required for illumination of tissue and the camera used to capture images from the patient. These replaceable portions are simpler and significantly cheaper to replace than in traditional CTR tools, and allow still-functioning portions of the tool to remain unreplaced, which lower costs associated with use of the tool.

Finally, the improved CTR tool is comprised of components manufactured of materials that can be cleaned and sterilized using an autoclave alone. This is significant as it allows the tool to be more easily and cheaply used in subsequent surgeries. This also encourages use of the CTR system in non-traditional contexts, such as minor surgical facilities or facilities that might be more remote and which might otherwise lack the resources and support traditionally necessary for surgery. The CTR system may simply comprise of the tool (and its replacement parts), a monitor (such as a computer, television, or tablet, having wireless display capability), and an autoclave. Use of the CTR tool within such a system is expected to greatly improve the throughput with which, and to reduce the per-patient cost at which, CTR surgery can be performed.

A first view of the improved CRT tool <NUM> is shown in <FIG> in perspective and side views. The tool <NUM> is formed of a lower housing portion 42a and an upper housing portion 42b, and includes a cannula <NUM> emanating from the upper housing portion 42b. As explained in detail later, the end of the cannula <NUM> includes a blade tip assembly <NUM> including a retractable blade <NUM>. Although not yet shown in <FIG>, the blade tip assembly <NUM> also includes an optical window (<NUM>, <FIG>) proximate to the blade <NUM> through which the patient's anatomy can be illuminated and viewed. The tool <NUM> is generally shaped like a handgun, with lower housing portion 42a including a handle <NUM> that can be grasped by the surgeon. A purlicue rest <NUM> is formed at the back of the lower housing portion 42a to allow the tool to rest on the surgeon's purlicue (the portion of the hand between the thumb and index finger) when grasped by the surgeon. The lower housing portion 42a includes an opening <NUM> (<FIG>) through which a trigger <NUM> protrudes and can be manipulated by the surgeon's index finger. As will be explained later, pulling the trigger <NUM> acts to both extend and retract the blade <NUM> from the blade tip assembly <NUM> and to extend and retract the cannula <NUM> from and to the upper housing portion 42b to allow the blade to cut the patient's tissue (e.g., the transverse carpal ligament <NUM>). In other words, the surgeon will be able to cut the tissue without retracting the CRT tool <NUM> relative to the patient (i.e., pulling the tool away from the patient), which minimizes the possibility of an unexpected error.

The cannula <NUM> has a long axis <NUM>, and the upper housing portion 42b has a long axis <NUM> parallel with axis <NUM>. The trigger <NUM> is depressable along an axis <NUM> with is parallel to axis <NUM> along which the cannula <NUM> can move, as explained further below. The lower housing portion 42a also has a long axis <NUM> which, due to the "gun shaped" nature of the tool <NUM>, is not necessarily parallel to axis <NUM>. Instead, axis <NUM> may be said to be substantially perpendicular to axis <NUM>, which may be broadly defined as being between <NUM> to <NUM> degrees relative to the long axis <NUM>. In other designs, axis <NUM> can be parallel with axis <NUM>.

As shown in the side view of <FIG>, the tool <NUM> preferably has one or more internal cavities containing various mechanical and electrical components. A mechanical cavity <NUM> houses an internal actuator <NUM> (<FIG> and <FIG>), with cavity <NUM> spanning both the lower and upper housing portions 42a and 42b. An upper electronics cavity 41b can be formed inside the upper housing portion 42b, and as will be described later, can include supporting electronics for the tool, such as a wireless chip set <NUM> and antenna <NUM> (<FIG>). A lower electronics cavity 41a in the lower housing portion 42a can include a printed circuit board <NUM> and battery <NUM> to provide operational power for the tool. The bottom of the lower housing portion 42a can include a removable hermetic cover <NUM>, thus allowing a user to gain access to, and if necessary replace, the battery <NUM>. The battery <NUM> can be rechargeable or non-rechargeable. Although not shown, the lower housing portion 42a or cover <NUM> can include external contacts or a port allowing the battery to be recharged if it is rechargeable. While two separate electronics cavities 41a and 41b are shown, this is not strictly necessary, and relevant electronic components in the system could be placed in either cavity, or in a single cavity in different designs.

<FIG> shows the upper housing portion 42b removed from the lower housing portion 42a, and shows the actuator <NUM> within mechanical cavity <NUM>. The mechanical cavity <NUM> in the upper housing portion 42b encloses a barrel <NUM> through which various internal components slide when the cannula <NUM> is both retracted into and extended from the upper housing portion. Other aspects of the actuator <NUM> explained later fit into the mechanical cavity <NUM> in the lower housing portion 42a.

<FIG> shows top and bottom views of the lower housing portion 42a in isolation with the upper housing portion 42b removed. From these perspectives, the lower electronic cavity 41a and part of the mechanical cavity <NUM> can be seen. Further shown are rails <NUM> which meet with corresponding rails on the upper housing portion 42b (not shown). Rails allows the upper housing portion 42b to be connected to the lower housing portion 42a by sliding the upper housing portion into position until it locks. As shown, the top of the lower housing portion 42a includes an insert receptacle 54b into which an insert 54a can be fit. This insert 54a can be used to support aspects that slide within the upper housing portion 42b as the cannula <NUM> is retracted and extended into and from the tool, and in particular can be used to support the optical electronics <NUM> (<FIG>) as it moves.

<FIG> shows the actuator <NUM> in isolation from different views. Manufacture of the actuator <NUM> centers around a chassis <NUM>, which is shown in isolation in <FIG>. The chassis <NUM> is held in place within the lower housing portion 42a by retention clips <NUM> which can also support spacers <NUM>. The retention clips <NUM> largely prevent the chassis <NUM> from moving horizontally within the lower housing portion, while the spacers prohibit vertical movement. The chassis <NUM> may also be held in place using pins (not shown) passing though the lower housing portion 42a. Returning to <FIG>, the barrel <NUM> can be seen in isolation, and includes a barrel channel <NUM> or slot at its bottom through which a movable member <NUM> can pass from the mechanical cavity <NUM> in the lower housing portion 42a. The barrel <NUM> does not slide within the upper housing portion 42b, and instead is affixed to the lower housing portion 42a and/or the retention clips <NUM>.

<FIG> shows further details of the actuator <NUM> with the barrel <NUM> removed so that its internal components can be seen. The movable member <NUM> just mentioned is coupled to the trigger <NUM>, such that the movable member <NUM> slides through distance Z as the trigger <NUM> is pushed. To help support such movement, a trigger rod <NUM> is affixed to a left vertical wall of the chassis <NUM> and passes through a hole <NUM> (<FIG>) in the movable member <NUM> and a recess <NUM> (<FIG>) in the trigger <NUM>, such that movement of the movable member <NUM> stops when an end of the trigger rod <NUM> meets with an end of the recess <NUM> (i.e., when the trigger <NUM> is fully pressed in). The trigger <NUM> may be rigidly affixed to the moveable member <NUM> using a pin <NUM> or other securing means.

An extension spring <NUM> coupled to the movable member <NUM> and a right vertical wall of the chassis <NUM> biases the movable member <NUM>, and keeps the trigger <NUM> in its outmost position (to the right as shown) when it is not pressed. Also helping to support movement of the movable member <NUM> are rods <NUM>, which are fixed at both ends to the vertical walls of the chassis <NUM>, and pass through holes (similar to <NUM>, but not shown) in the movable member <NUM>. Thus, when the trigger <NUM> is pressed, the movable member <NUM> slides horizontally over both the trigger rod <NUM> and the rods <NUM>. Other means of biasing the trigger <NUM> can be used. For example, a compression spring <NUM>' may be placed between the moveable member <NUM> and the left vertical wall of the chassis <NUM> that biases the trigger outward to the right. Leaf springs (not shown) may also be used between the moveable member <NUM> and the left vertical wall of the chassis. In short, there are many different ways to bias the trigger <NUM>, and more than one of these means may be used in conjunction with each other.

In <FIG>, an optical electronics module <NUM> is shown which is attached to a circular receptacle <NUM> of the movable member <NUM>. As will be discussed later, this module <NUM> includes electronics necessary for illumination of the patient's tissue, and includes a camera to capture images of the illuminated tissue. The optical electronics module <NUM> slides inside of the upper housing portion 42b (within the barrel <NUM>) as the movable member <NUM> slides, along with other components, as explain further later.

<FIG> shows construction of the movable member <NUM>. In one example, the movable member <NUM> is preferably used to provide power to the optical electronics module <NUM> and other component of the system that may reside in upper electronics cavity 41b (<FIG>). The movable member <NUM> in this example includes two non-conductive outer housings 83a and 83c. Within these housings are a positive conductor <NUM> and a negative conductor <NUM> (or vice versa), which are separated and insulated from each by an insulator 83b. The conductors <NUM> and <NUM> are bent to form tabs 92a and 94a respectively. Conductive contact brushes <NUM> can be placed on the tabs, such that the rods <NUM> are in contact with, but can slide through, the contact brushes <NUM>. In one example, the rods <NUM> may be conductive (e.g., graphite), and used as conductors to route power as well as to provide mechanical support to the movable member <NUM>. In this regard, wires <NUM> can be connected to the conductive rods <NUM> in various fashions. As shown in <FIG>, such wires <NUM> can emanate from the lower electronic cavity 41a, and in particular can be used to carry a positive and negative power supply voltage (i.e., the positive and negative voltages of the battery <NUM>, perhaps as regulated) to the conductive rods <NUM>. Such wires can proceed from the lower electronics cavity 41a via a feedthrough <NUM>, which can be hermetically sealed to separate the lower electronics cavity from the mechanical cavity <NUM> if desired.

Once the wires <NUM> are connected to the conductive rods <NUM> as shown in <FIG>, they can conduct through the contact brushes <NUM> and the tabs 92a and 94a to the positive conductor <NUM> and the negative conductor <NUM>. These conductors terminate at rings 92b and 94b at the top of the movable member <NUM>. Preferably, conductor <NUM> is bent at the top around the insulator 83b so that its corresponding ring 94b resides in the same vertical plane as the does ring 92b. This is accomplished by forming ring 94b with a larger diameter than ring 92b, which allows concentric rings 92b and <NUM> to lie in the same plane without shorting. The rings 92b and 94b are exposed so that they can make electrical contact with the optical electronics module <NUM> (<FIG>) when that module <NUM> is connected to the movable member <NUM>. Further details of how mechanical and electrical coupling occurs between the movable member <NUM> and module <NUM> are explained later with reference to <FIG> and <FIG>. To summarize, power and ground can be provided by the battery <NUM> in lower electronics cavity 41a to the optical electronics module <NUM> and other system components in the upper electronics cavity 42b via the positive and negative rings 92b and 94b of the movable member <NUM>. As will be seen later, the rings 92b and 94b operate similar to a slip ring assembly that allow for power to be transmitted to the cylindrical optical electronics module <NUM> even if that module rotates around the long axis of the cannula.

Note that it is not strictly required that the rods <NUM> be conductive and used in this process of routing power. Instead, rods <NUM> may be non-conductive, in which case the wires <NUM> could be connected directly to the contacts brushes <NUM> or to the tabs 92a and 92b, or can be connected to the conductors <NUM> and <NUM> in other fashions. Note that because the movable member <NUM> is designed to move within the mechanical cavity, wires <NUM> are preferably provided with sufficient slack such that they can stay connected to the movable member <NUM> through its full range of movement.

As noted earlier, pulling the trigger <NUM> horizontally moves the movable member <NUM>, which acts both to retract and extend the cannula <NUM> and to retract and extend the blade <NUM> of the blade tip assembly <NUM>. Components that promote these various movements within the tool <NUM> are shown in further detail starting with <FIG> and <FIG> shows further details of these and other components with the movable member <NUM> removed for easier viewing, and shows the various components in an exploded view so that their shapes can be better appreciated.

A ring slider <NUM> slides horizontally through the barrel <NUM> (<FIG>), and in one example can include notches to accommodate for one or more rollers <NUM> (<FIG>) around its circumference to promote smooth movement along a long axis through the cannula <NUM>. The ring slider <NUM> may also be dimensioned to simply smoothly slide within the barrel <NUM> with the need of rollers. Also present is a central cylinder <NUM>. As will be described in further detail later, the central cylinder <NUM> has an end which is press fit (or glued, sonic soldered, etc.) within a hole <NUM> (<FIG>) of the movable member <NUM>, and thus slides as the member <NUM> moves. Note from <FIG> that this hole <NUM> can be formed in the middle of the inner and outer conductive rings 92b and 94b of the movable member, although the central cylinder <NUM> may also be coupled to the movable member <NUM> in different ways. Press fit (or glued, sonic soldered, etc.) within the other end of the central cylinder <NUM> is a couple <NUM> which connects to a sliding coupling <NUM>, as explained later with reference to <FIG>. A contact beam <NUM> is fixed to the ring slider <NUM>, and is coupled to a fixed coupling <NUM>, again explained with reference to <FIG>. Notice that the central cylinder <NUM> and contact beam <NUM> are formed with interleaved slots <NUM> (three, at <NUM> degree around their circumferences), thus allowing these components to horizontally move with respect to each other without interference.

As best shown in <FIG>, the cannula housing <NUM> includes a rotatable housing <NUM> which includes one or more locks <NUM>. The rotatable housing <NUM> allows the surgeon to rotate the cannula housing <NUM> around its long axis at a position that is most comfortable for the surgeon, which rotating will also change the rotational angle at which a patient's tissue can be viewed and cut. Axial rotation is promoted or prohibited by the locks <NUM>. Preferably there are two such locks <NUM> spaced at <NUM> degrees around the rotatable tip <NUM> (only one is shown). The locks <NUM> are affixed in the rotatable housing <NUM> in a manner that allows them to bend inward towards the long axis of the cannula when pressed at surfaces 108a. So pressing these surfaces 108a will move contact surfaces 108b inward as well. These contacts surfaces 108b are normally in contact with the upper housing portion 42b (<FIG>), and so are normally locked when not pressed to prevent the rotatable housing <NUM> from rotating. When the locks <NUM> are pressed at surfaces 108a, the surfaces 108b move inward allowing rotational movement.

Also relevant to rotation movement is an optional insulator <NUM>, which is press fit (or glued, sonic soldered, etc.) within the ring slider <NUM>, and which receives the central cylinder <NUM> therethrough. As can be seen, the inner diameter of the insulator <NUM> is ribbed where it contacts the outer diameter of the central cylinder <NUM>. The ribbed inner surface of the insulator <NUM> allows the central cylinder <NUM> to pass relatively smoothly horizontally through the ring slider <NUM>, but provides some resistance if the cannula housing <NUM> is rotated using the rotatable housing <NUM> (i.e., when the locks <NUM> are pressed). To summarize, the insulator <NUM>, the rotatable housing <NUM> and the locks <NUM> allow the surgeon to radially turn the cannula <NUM> with some force to change the radial angle at which the tissue can be viewed and cut, and to lock a particular angle into place. In this regard, and jumping ahead, note that an optical assembly <NUM> (<FIG> and <FIG>) will be placed in a center bore <NUM> at the center of the various components and the cannula housing <NUM>.

<FIG> shows the housing <NUM> of the cannula <NUM>, including components that interface with the components just discussed. The cannula housing <NUM> includes a shoulder <NUM>, and includes a fixed coupling <NUM> which is press fit (or glued, sonic soldered, etc.) onto and affixed to the housing <NUM>. Between the fixed coupling <NUM> and the shoulder <NUM> is a sliding coupling <NUM>, which is free to slide along the housing <NUM> between the fixed coupling <NUM> and the shoulder <NUM>. Both the couplings <NUM> and <NUM> have grooves on their outer diameters. The groove on the sliding coupling <NUM> meets with a protrusion on the couple <NUM>, which is in turn press fit (or glued, sonic soldered, etc.) and affixed with the central cylinder <NUM>. The groove on the fixed coupling <NUM> meets with a contact beam <NUM>, which is in turn press fit (or glued, sonic soldered, etc.) onto and affixed to the ring slider <NUM>.

The sliding coupling <NUM> is connected to a wire <NUM> which proceeds slidably through a wire channel <NUM> in the cannula housing <NUM>. This wire <NUM> is connected at its other end to a mechanism in the blade tip assembly <NUM>, which acts to retract or extend the blade <NUM> as the sliding coupling <NUM> moves between the shoulder <NUM> and the fixed coupling <NUM>. Before explaining this movement in further detail, the attachment, construction, and operation of the blade tip assembly <NUM> is discussed.

<FIG> shows the blade tip assembly <NUM> both connected to and disconnected from the cannula housing <NUM>, and shows the wire <NUM> which controls blade <NUM> extension and retraction. The blade tip assembly <NUM> is easily removable from the cannula housing <NUM>, thus allowing the assembly to be easily replaced. It would be expected that the blade tip assembly <NUM> of the tool <NUM> would normally be replaced after each surgery, thus assuring that each new patient benefits from a blade <NUM> that is sharp. Fortunately, the blade tip assembly <NUM> is not constructed of expensive parts, and replacing the assembly <NUM> leaves the cannula <NUM> and other components intact, making component replacement more cost effective.

In one example, the blade tip assembly <NUM> can be connected to the cannula housing <NUM> by using a tab and groove arrangement. Specifically, two tabs <NUM> on the inside of the housing <NUM> can be made to meet with two right-angled grooves <NUM> on the blade tip assembly <NUM>. The assembly <NUM> can then be turned to lock the tabs <NUM> in the grooves. Removal of the assembly <NUM> is the reverse process. It should be noted that this is only an example way in which the blade tip assembly <NUM> can be connected to or disconnected from the cannula housing <NUM>, and other means could be used as well (clamps or clips, press fit arrangements not requiring rotation, etc.) When attaching or removing the blade tip assembly <NUM>, the wire <NUM> is attached or removed from a wire hole <NUM> in a component of the assembly <NUM>, as explained shortly with respect to <FIG> and <FIG>. In this regard, the wire <NUM> terminates at a right angle at an end of the cannula housing <NUM>, as shown in <FIG>, which allows for connection to and disconnection from the wire hole <NUM>.

<FIG> shows the blade tip assembly <NUM> in further detail. The assembly <NUM> includes a blade tip housing <NUM>, which is also shown in isolation in <FIG>, which housing may include a blade housing bottom <NUM> to ease the assembly's construction. The housing <NUM> includes the grooves <NUM> discussed earlier to attach or remove the assembly <NUM> from the end of the cannula housing <NUM>. Also present in the blade tip housing <NUM> is an optical window <NUM>. As will be discussed later with reference to <FIG>, the optical window <NUM> provides an opening to accommodate an end of an optical assembly <NUM>, which allows the surgeon to illuminate the patient's tissue and receive images of the tissue that can be wirelessly broadcast to a display screen.

<FIG> shows components within the blade tip assembly <NUM> with the blade tip housing <NUM> removed for easier viewing. The blade tip assembly <NUM> includes supports 164a and 164b which may comprise thicker grade wire. The supports 164a and 164b are preferably bent into shape and molded into the plastic material used to form the blade tip housing <NUM>. Support 164a provided a hard back stop for the blade <NUM> when it is in the fully retracted position, as perhaps best shown in <FIG>. When in this position, the blade <NUM> is recessed within the blade tip housing <NUM>, thus allowing the surgeon to introduce the cannula <NUM> into the patient, and to extend or retract the cannula, without risk of inadvertently cutting the patient. Support 164b restrains a pin 160a that passes through the bottom of the blade <NUM> to assist in extending and retracting the blade, again as explained in detail with respect to <FIG>.

As shown in <FIG> and <FIG>, the blade <NUM> is bounded by a lever <NUM>. A pin 160c passes through a rotational point in the blade <NUM> to fasten the blade <NUM> to an upper portion of a lever <NUM> while still allowing the blade to rotate. A center of the lever <NUM> is itself rotatably fastened to the sides of the blade tip housing <NUM> (and possibly to support 164a) by pins 160b. A lower portion of the lever <NUM> is attached to a link <NUM>, which is in turn attached to a bracket <NUM>, perhaps as best seen in <FIG>. Bracket <NUM> is in turn connected to another bracket <NUM>, which protrudes proximally from the blade tip housing <NUM> and includes the wire hole <NUM> to which the wire <NUM> is attached. Brackets <NUM> and <NUM> may be press fit together. It is preferable to use two different brackets for safety reasons explained later, but a single integrated bracket piece (<NUM>/<NUM>) could also be used, and is assumed for purposes of discussion.

Now that the components of the blade tip assembly <NUM> have been introduced, <FIG> shows how these components work to extend the blade <NUM>. Again, the blade tip housing <NUM> and other structures have been removed for easier viewing. As noted earlier, wire <NUM> is connected to bracket <NUM>/<NUM>, and so pulling wire the left <NUM> (by pulling trigger <NUM>) will pull the bracket <NUM>/<NUM> to the left within the blade tip housing <NUM>. This motion is transferred by link <NUM> to the lower portion of the lever <NUM>. Because the lever <NUM> is rotatably fastened to the blade tip housing <NUM> by pins 160b, the lever <NUM> will begin to rotate clock-wise as shown. Because pin 160a through the lower end of the blade <NUM> is restrained by support 164b, this rotational motion will pull pin 160a to the right. Because pin 160c through the center of the blade <NUM> continues upwards as the lever <NUM> rotates, blade <NUM> begins to rotate counter-clockwise and thus extends away from the assembly <NUM>, and thus can now be used to cut the patient's tissue. When the wire <NUM> is pulled to the right (i.e., when the trigger <NUM> is released), wire <NUM> will push the bracket <NUM>/<NUM> to the right to reverse the motions just described, thus retracting the blade <NUM> safely back into the blade tip housing <NUM>.

As noted above, it is preferable to use separate brackets <NUM> and <NUM> to provide a useful safety feature-namely the ability to automatically retract the knife <NUM> to keep it from cutting if it is experiencing too much force. This could occur for example if the blade <NUM> is inadvertently in contact with harder tissue, such as bone, that would indicate a problem. In this regard, and as shown in <FIG> and <FIG>, bracket <NUM> is formed with a flexible tab <NUM> which meets with a ledge <NUM> on the bracket <NUM> when the two brackets are fastened together. When trigger <NUM> is pressed and wire <NUM> is pulled to the left, force is transferred from bracket <NUM> and bracket <NUM> at the flexible tab <NUM>. Normally, the moves bracket <NUM> to the left, and extends the blade <NUM> as just described, and if the trigger <NUM> is pulled further, the blade can begin to cut the patient tissue, as described in detail later with respect to <FIG>. However, if the blade <NUM> encounters hard tissue, such resistance will be transferred back to bracket <NUM>, which will now place an excessive force between its ledge <NUM> and the flexible tab <NUM> on bracket <NUM>. If this force exceeds a threshold, the flexible tab <NUM> will pass over the top of the ledge <NUM> to relieve the pressure. When this occurs, force from the wire <NUM> will no longer place sufficient force on the bracket <NUM> to allow for blade <NUM> extension, and the blade <NUM> will fall safely back into the blade tip housing <NUM>. Note that if this occurs, the blade tip assembly <NUM> will need to be replaced, but as explained earlier, this is easily and inexpensively accomplished.

Now that attachment, construction, and operation of the blade tip assembly <NUM> has been discussed, operation of the tool <NUM> is further explained with reference to <FIG>, which show structures within the tool <NUM> that are important to understand its movement (other structures have been omitted for clarity).

<FIG> shows the tool at rest, i.e., before pressure has been placed on the trigger <NUM>. At this point, the spring <NUM> (<FIG>) pulls the movable member <NUM> and the trigger <NUM> to which it is coupled to its right most point. The movable member <NUM> contacts a left edge of the ring slider <NUM>, and so pushes the ring slider <NUM> to the right as well (as it slides though barrel <NUM>; <FIG>). The ring slider <NUM>, as described earlier, is connected to contact beam <NUM> which is in turn connected to a groove on the fixed coupling <NUM>, which is connected to the end of the cannula housing <NUM>. Therefore, the cannula housing <NUM> and the blade tip assembly <NUM> are also pushed to their right most extent. Because the central cylinder <NUM> is connected (hole <NUM>; <FIG>) to the movable member <NUM>, it also is biased to the right by the spring <NUM>, and slides within the ring slider <NUM> and the insulator <NUM> (not shown). The other end of the central cylinder <NUM>, again as described earlier, is connected to a couple <NUM>, which has a protrusion that meets with a groove on the sliding coupling <NUM>. Therefore, this sliding coupling <NUM> is also drawn to its right-most point, i.e., to the point where it hits the shoulder <NUM> on the cannula housing <NUM>. As noted earlier, the sliding coupling <NUM> is affixed to wire <NUM>, which is likewise forced to the right. As explained earlier with reference to <FIG>, moving the wire to the right retracts the blade <NUM> within the blade tip assembly <NUM>, as shown in <FIG>. To summarize, in the rest position of <FIG>, the blade <NUM> is retracted and the cannula <NUM> is extended from the tool.

Note at rest that the sliding coupling <NUM> is spaced at a distance X from the fixed coupling <NUM> at the end of the cannula housing <NUM>. Note also that an edge <NUM> of the central cylinder <NUM> is likewise spaced at a distance X from a right edge of the ring slider <NUM>. Finally, note also that the optical electronics module <NUM> is also coupled to the movable member <NUM>, as noted earlier and described further later with reference to <FIG>. Thus, and as shown in subsequent <FIG>, the optical electronics move <NUM> will also move with the tool as the trigger <NUM> is moved. Specifically, the optical electronics <NUM> will slide within the barrel <NUM> (<FIG>).

<FIG> shows the position of the components after the trigger <NUM> has been pulled to the left by distance X. As the trigger <NUM> is pulled through this distance, the movable member <NUM> moves as does the central cylinder <NUM>. Note that the central cylinder <NUM> slips though the ring slider <NUM>, which remains in a constant position within the tool. Therefore, by virtue of contact beam <NUM> and fixed coupling <NUM>, the cannula housing <NUM>'s position doesn't change, and it is still in a fully extended state. (The dotted line in <FIG> show a fixed reference point in the tool so that the relative movement of the components can be better appreciated). Movement of the central cylinder <NUM> and its couple <NUM> transfer to the sliding coupling <NUM>, which similarly slides distance X until it hits the fixed coupling <NUM>. At this point, edge <NUM> of the central cylinder <NUM> may also make contact with the right edge of the ring slider <NUM>. As the sliding coupling <NUM> is pulled left, it pulls the wire <NUM> to the left, which as explained earlier extends the blade <NUM> from the blade tip assembly <NUM>, as shown in <FIG>. Preferably, the blade tip assembly <NUM> has at this point been placed by the surgeon in a position relative to tissue to be cut, such as the transverse carpal ligament <NUM>. Such proper placement can be assisted by use of the optical capabilities of the tool <NUM>, which are described in detail later. To summarize, in <FIG>, the blade <NUM> is extended and the cannula <NUM> remains extended from the tool as it has not moved. Notice in this position that the left edge of the ring slider <NUM> is now spaced a distance X from the movable member <NUM>.

At this point, and with the blade <NUM> fully extended, the trigger <NUM> can be pulled further through an additional distance Y, as shown in <FIG>. Distance Y can comprise a maximum distance at which the trigger <NUM> can be pulled, which as noted earlier, may be determined by how far trigger rod <NUM> can pass within the recess <NUM> of the trigger (<FIG>) before it bottoms out. At the start of distance Y, the couplings <NUM> and <NUM> are in contact, as is the edge <NUM> of the central cylinder <NUM> and the right edge of the ring slider <NUM>. Thus, the ring slider <NUM> at this point also starts to move to the left as it slides within the barrel <NUM>. This causes the cannula housing <NUM> (via <NUM>, <NUM>) to move left as well. This also pulls the blade tip assembly <NUM> to the left, thus allowing the already extended blade <NUM> to cut through the patient's tissue 10a. To summarize, in <FIG>, the blade <NUM> is extended and the cannula <NUM> is retracted within the tool <NUM>. Notice in this position that the left edge of the ring slider <NUM> is still spaced a distance X from the movable member <NUM>. Notice further that because the cannula housing <NUM> is retracted into the housing of the tool grasped by the surgeon (i.e., upper and lower housing portions 42a and 42b), the housing does not need to move, and hence the surgeon does not need to pull the tool away from the patient in order to make the cut.

Release of the trigger <NUM>, and the corresponding movement of the components within the tool, is shown in <FIG> is the same drawing as <FIG>, showing the condition of the components when the trigger <NUM> is fully pressed, and is provided for reference and easy comparison to <FIG>.

In <FIG>, the trigger <NUM> is released distance X to the right. The bias of the spring <NUM> will pull the movable member <NUM> to the right, which in turn moves the central cylinder <NUM>, couple <NUM>, and sliding coupling <NUM> to the right, until the sliding coupling <NUM> again contacts the shoulder <NUM> of the cannula housing <NUM>. Because the wire <NUM> is connected to the sliding coupling <NUM>, the wire is biased to the right, which as explained earlier retracts the blade <NUM> within the blade tip assembly <NUM>. Because the central cylinder <NUM> slides through the ring slider <NUM>, the ring slider <NUM> stays in its previous position, and hence so does the contact beam <NUM>, the fixed coupling <NUM>, the cannula housing <NUM>, and blade tip assembly <NUM>. To summarize, in <FIG>, the blade <NUM> is retracted and the cannula <NUM> remains retracted within the tool <NUM>. Notice in this position that there is no longer a space between the left edge of the ring slider <NUM> and the movable member <NUM>.

Further release of the trigger <NUM> through distance Y to its rest position is shown in <FIG>. At this point, the movable member <NUM> is in contact with the ring slider <NUM>, and therefore the spring <NUM> will bias both the movable member <NUM> and the ring slider <NUM> to the right. Movement of the ring slider <NUM> also moves the cannula housing <NUM> and the blade tip assembly <NUM> through distance Y to the right. Because the position of the sliding coupling <NUM> on the cannula housing <NUM> hasn't changed, the blade remains retracted. To summarize, in the rest position of <FIG>, the blade <NUM> is retracted and the cannula <NUM> is extended from the tool <NUM>. Notice further that because the cannula housing <NUM> is extended from the housing of the tool grasped by the surgeon (i.e., upper and lower housing portions 42a and 42b), the housing does not need to move, and hence the surgeon does not need to push the tool towards the patient to arrive at the rest position.

Optical details of the tool <NUM> are discussed next, starting with <FIG>. As shown in <FIG>, the central cylinder <NUM>, the fixed coupling <NUM>, the cannula housing <NUM>, and the blade tip housing <NUM> are formed with a central bore <NUM>. As shown in <FIG>, an optical assembly <NUM> can be slid into this bore <NUM>. Preferably, the optical assembly <NUM> will be slidably held within the central bore <NUM> in the cannula housing <NUM>. This allows the optical assembly <NUM> to be axially rotated around the long axis of the cannula housing <NUM> as described previously (using rotatable housing <NUM>).

Holding the optical assembly <NUM> slidably with the central bore <NUM> also permits the optical assembly <NUM> to slide horizontally along the long axis in accordance with the various positions just described with respect to <FIG>. Such movement of the optical assembly <NUM> occurs because the proximal face 170b of the optical assembly <NUM> is affixed to the moveable member <NUM> and the optical electronics module <NUM>, as explained in detail later.

When the trigger <NUM> is at rest (<FIG>), a distal angled face 170a of the optical assembly <NUM> will extend slightly relative to an angled optical window <NUM> formed in the blade tip housing <NUM>, as shown in <FIG>.

When the trigger <NUM> is first pulled and moves through distance X (from <FIG>), the moveable member <NUM>, the optical electronic module <NUM> and the optical assembly <NUM> (which again are all affixed) are pulled to the left relative to the extended cannula housing <NUM>. This pulls optical assembly <NUM> to the left by this same distance X through the housing <NUM>. This preferably brings the distal angled face 170a of the optical assembly <NUM> flush with the angled optical window <NUM>, as shown in <FIG>.

When the trigger <NUM> is pulled further through distance Y (from <FIG> to 16C1), the moveable member <NUM>, the optical electronic module <NUM> and the optical assembly <NUM> are pulled to the left in unison with the cannula housing <NUM> (which now retracts). Therefore, the position of the distal angled face 170a of the optical assembly <NUM> remains flush with the angled optical window <NUM>, as shown in <FIG>.

When the trigger <NUM> is partially release through distance X (from <FIG> to 16D), the moveable member <NUM>, the optical electronic module <NUM> and the optical assembly <NUM> are pushed to the left relative to the retracted cannula housing <NUM>. This pushes optical assembly <NUM> to the right by this same distance X through the housing <NUM>, which again extends the distal angled face 170a of the optical assembly <NUM> from the angled optical window <NUM>, as shown in <FIG>.

When the trigger <NUM> is further fully release through distance Y (from <FIG>), the moveable member <NUM>, the optical electronic module <NUM> and the optical assembly <NUM> are pushed to the right in unison with the cannula housing <NUM> (which now extends). Therefore, the position of the distal angled face 170a of the optical assembly <NUM> remains extended with respect to the angled optical window <NUM>, as shown in <FIG>.

It should be noted that horizontal movement of the optical assembly <NUM> within the cannula housing <NUM> (between the states shown in <FIG>) do not significantly affect operation of the tool <NUM>. The angled distal face 170a will move slightly which will slightly move the field of view <NUM>. This is however not problematic, and if necessary, the surgeon can compensate by pushing or pulling the cannula housing <NUM> through the patient's tissue to adjust the horizontal view of the tissue as necessary.

<FIG> shows the optical assembly <NUM> in cross section. In one example, the optical assembly <NUM> includes at its center an image-receiving pathway, and includes along its perimeter a light-transmitting pathway. The light-transmitting pathway preferably comprises a plurality of fiber optical cables <NUM>. As will be explained in detail with reference to <FIG> and <FIG>, the cables <NUM> receive light from the light emitters (e.g., Light Emitting Diodes, or LEDs) in the optical electronics module <NUM> at a terminated ends 180b of the cables <NUM> at the proximal end of the assembly <NUM>, and transmit this light to terminated ends 180a at the distal end of the assembly <NUM>. The distal end of the optical assembly <NUM> passes through the optical window <NUM> of the blade tip housing <NUM>, where the terminated ends 180b can illuminate the patient's tissue.

The image-receiving pathway preferably comprises a sequence of silica rods <NUM>, which form a light pipe that transmit images of the illuminated tissue from a prism 178a at the distal end of the assembly <NUM> to a terminal silica rod 178b at the proximal end of the assembly <NUM>, where such images can be captured by a camera in the optical electronics modules <NUM>. A sequence of a plurality of silica rods <NUM> is preferred because a single rod may be too fragile and easily broken, and further may be subject to cracking under thermal expansion, particularly when the tool is autoclaved. The prism 178a at the distal end is angled as shown, which operates to capture images generally along an axis <NUM> that is not parallel to axis <NUM> of the cannula, but instead point above the blade tip assembly <NUM>. More generally, the angle end 170a of the optical assembly <NUM> forms a field of view <NUM> that is above the blade tip housing <NUM> and proximate to where the extended blade <NUM> and tissue to be cut can be seen. As noted earlier, the cannula housing <NUM> can be rotated to adjust the rotation angle of the field of view, thus allowing the surgeon more flexibility to see structures of interest.

The optical assembly <NUM> is preferably formed as a solid piece without air gaps, and may comprise an inner jacket <NUM> surrounding the silica rods <NUM>, and an outer jacket <NUM> which surrounds the fiber optic cables <NUM> such that they are between the outer and inner jackets. The inner and outer jackets may be formed of a single layer or a combination of engineering thermoplastics, such as polysulfone (PSU), polyether ether ketone (PEEK), polyetherimide (PEI), etc. Otherwise empty spaces <NUM> in the assembly <NUM> (around the cables <NUM> between the jackets <NUM> and <NUM>, and around the rods <NUM> within the jacket <NUM>) may be filled with polymethyl methacrylate (PMMA). Note that given its optical clarity, the PMMA may be used to couple images from one silica rod <NUM> to the next without significant loss. After the optical assembly is formed, its proximal and distal faces, shown in <FIG>, are preferably polished to allow for good optical transfer.

<FIG> and <FIG> show details concerning the formation of the optical electronics module <NUM>, and how the optical electronics module <NUM> can be coupled to the optical assembly <NUM> and to other electronics in the upper electronics cavity 41a (<FIG>). As mentioned earlier, the optical electronics module <NUM> includes one or more light emitters such as LEDs <NUM> used to provide light to the fiber optic cables <NUM>, and a camera <NUM> to receive images from the silica rods <NUM>. The optical electronics module <NUM> can also include an image-receiving path, which like the optical assembly <NUM> can include one or more silica rods <NUM>. Additionally, one or more corrective lenses <NUM> may intervene between the silica rod(s) <NUM> and the camera <NUM>. Note that the camera <NUM> can comprise any number of small camera devices, such as those commonly used in cellular telephones to capture images. While the optical electronic module <NUM> is shown as integrating both illumination and image capture functionality, reality that these functions can be separated into different modules. For example, a first module can include the LEDs <NUM>, and a second module can include the camera <NUM>.

As shown in the picture of the face of the optical electronics module <NUM> in <FIG>, components can be arranged such that the LEDs <NUM> match up with the terminated ends 180b of the fiber optical cables <NUM> at the proximal end of the optical assembly <NUM>, and such that a terminated end of the silica rod <NUM> matches up with the terminal silica rod 178b at the proximal end of the optical assembly <NUM>. Although not shown, the optical electronics module <NUM> may include light-blocking structures to prevent light from the LEDs <NUM> from reaching the image-receiving path formed by the silica rod <NUM>, lenses <NUM> and camera <NUM>.

The optical electronic module <NUM> further includes conductive pins 182a and 182b. Conductive pins 182a and 182b are preferably pogo pins which include spring tips at their terminations to allow the pins to be pressed in when in contact with another conductive surface. As will be explained shortly, pins 182a and 182b can be used to route power (i.e., power and ground voltages) to electronics in the upper electronics cavity 41a, and to the camera <NUM> and LEDs <NUM>. In this regard, electrical terminations, such as the pins of the camera <NUM>, the terminals of the LEDs <NUM>, and the pins 182a and 182b, can meet with an electrical connector 192a at the end of a cable <NUM>. Cable <NUM> (e.g., a ribbon cable) can pass necessary signals from these electrical components to another connector 192b at its other end, which can in turn be connected to a printed circuit board (PCB) <NUM> in the upper electronics cavity 41a. In this way, the PCB <NUM> in the upper electronics cavity 41a can receive power from pins 182a and 182b via cable <NUM> and its connectors. Further, such power can be routed back from the PCB <NUM> to components in the optical electronics module <NUM>, such as the camera <NUM> and the LEDs <NUM>. Preferably, the LEDs <NUM> are electrically connected in series within the body of the optical electronics module <NUM> (not shown), and thus only terminate at two ends at the connector 192a.

The optical electronics module <NUM> may generally resemble a cylinder, with its various components integrated and held together by mold injecting a material <NUM> around them. In one example, this material <NUM> may comprise PMMA or another transparent material, which as noted earlier is good to promote optical coupling in the module <NUM>'s image-receiving path.

As noted above, the optical electronics module <NUM> is coupled to the movable member <NUM>, and so moves in the barrel <NUM> as the movable member <NUM> moves. The manner of this coupling is shown in <FIG> and <FIG>. As shown, the movable member can include a recess <NUM> to receive the module <NUM>, which recess <NUM> can be formed in the movable housing member 83c (<FIG>). Also inside this recess <NUM> are the inner and outer conductive rings 92b and 94b described earlier, i.e., the positive and negative power supplies (<FIG>). When the module <NUM> is seated in the recess <NUM>, and as shown in <FIG>, pin 182a makes electrical contact with outer conductive ring 94b, which as noted earlier can carry the negative power supply voltage (e.g., ground). Pin 182b similarly makes electrical contact with inner conductive ring 92b, which as noted earlier can carry the positive power supply voltage. Note that because the module <NUM> moves as the trigger <NUM> is pulled, care should be taken to ensure that cable <NUM> has sufficient slack to allow for such movement. Notice that the conductive rings 92b and 94b make electrical contact to pins 182a and 182b of the optical electronic module <NUM> even if that module <NUM> rotates around the long axis through the cannula.

Further, when the optical electronics module <NUM> is seated, the proximal face 170b of the optical assembly <NUM> is brought into contact with the opposing face of the module <NUM>. Because these opposing faces are smooth, light from the LEDs <NUM> transfers to the fiber optic cables <NUM>, and images from the silica rods <NUM> transfer to the silica rod <NUM>, lenses <NUM>, and ultimately to the camera <NUM>.

<FIG> shows electronic components that can be housed in the upper electronics cavity 41a on PCB <NUM>. Significantly included is a wireless chip set <NUM> and an antenna <NUM>. As image data comes into the PCB <NUM> from the camera <NUM>, it may be stored (buffered) in memory if necessary (not shown), and if necessary encoded <NUM> with a suitable video encoding format, such as H. Ultimately the image data is provided to the chip set <NUM>, which includes a transmitter, and wirelessly broadcast in accordance with a short-range RF communications protocol, such as Bluetooth, WiFi, Zigbee, Medical Device Radiocommunications Service (MedRadio), Medical Implant Communication Service (MICS), and the like, or other proprietary protocols. The antenna <NUM> can be formed in different manners within the housing, and may comprise a wire, slot, patch, or coil antenna, and which may operate as a dipole or monopole antenna. Chip set <NUM> may also include a receiver to wirelessly receive data at the tool, which may be beneficial to update its programming for instance.

As mentioned earlier, it is not necessary that such electrical components be located in the upper electronic cavity 41a in the upper housing portion 42a. Instead, necessary electronics could be included in the lower electronics cavity 41b of the lower housing portion 42b as well (<FIG>). In this case, image data from the camera <NUM> can be routed by cabling through feedthrough <NUM> (<FIG>) to the lower electronics cavity 41a, with PCB <NUM> including necessary memory, video encoders <NUM> and the antenna <NUM>. Similarly, lower electronics cavity 41a may be unnecessary, and instead the battery <NUM> could be included in the upper electronics cavity 41b. This would simplify tool design, and may make the inclusion of positive and negative conductors <NUM> and <NUM> (<FIG>) in the movable member <NUM> unnecessary.

Because the CTR tool <NUM> is designed to be cleaned and sterilized using autoclave technology, the electronics may be treated in a manner to withstand the high temperatures and pressure provided by the autoclave. For example, the PCBs and their various circuitry could be overcoated with a high-temperature plastic. Note that the battery <NUM> is preferably removed before autoclaving the tool <NUM>, because batteries will typically be unable to withstand the high heat autoclaving provides.

<FIG> shows components of the CTR tool <NUM> system, and shows the wireless transfer of real-time video image data <NUM> from the tool <NUM>. In this example, a receiver/decoder device <NUM> is coupled to a display <NUM>, such as to one of its ports. The receiver/decoder device <NUM> includes an antenna <NUM> for wirelessly receiving the wireless data <NUM>, a chip set <NUM> compliant with the communications standard used (e.g., Bluetooth), and a video decoder <NUM> to remove the video encoding (<NUM>) used to format the data <NUM>. Raw video images <NUM> may then be provided to the display <NUM> to allow the surgeon to visualize the tissue being cut by the blade <NUM> in real time. (In reality, the "real time" images may be provided to the display with some small amount of latency, but this would not significantly hamper the surgeon and may not even be noticeable). Note that modern-day displays <NUM> may include all or parts of the receiver/decoder <NUM>. In this case, a separate receiver/decoder <NUM> may not be necessary.

Also shown in <FIG> as part of the system is an autoclave <NUM> used to sterilize the tool <NUM>. In this regard, after use of the tool with a particular patient, the battery <NUM> can be removed by removing the cover <NUM> (<FIG>) from the lower housing portion 42a. In this regard, the battery <NUM> may fit into the lower electronics cavity 41a like a cartridge, similar to what occurs in pocket cameras for example, which allows the battery <NUM> can easily slide out of the cavity. Further, the used blade tip assembly <NUM> can be discarded prior to autoclaving. (Alternatively, the blade tip assembly <NUM> could be subject to autoclaving sterilization as well, but this might distort its plastic and metal components due to unexpected thermal expansion).

Thereafter, the tool <NUM> (including the housing, the cannula, the at least one optical electronic module, the optical assembly, and the wireless transmitter and antenna still in an assembled state) may be cleaned of remnants (e.g., blood) and rinsed with water. Because the tool <NUM> at this stage (minus the battery and the blade tip assembly) is made of high temperature materials, the tool can then be placed in the autoclave <NUM> without further disassembly, where it can be heated to <NUM> degrees Celsius in the presence of pressurized steam for <NUM> minutes. Afterwards, the tool <NUM> may be placed in a sterilized bag until its ready for its next use, at which time the battery <NUM> can be reinserted and a new blade tip assembly <NUM> coupled to the end of the cannula <NUM>. Care should be taken when introducing these components to the tool <NUM> after autoclaving to ensure proper sterility. For example, the possibly unsterile battery should not contact the outer shell of the tool, and a new blade tip assembly <NUM> (presumably already in a sterilized bag) should be affixed with gloves to avoid contamination.

While disclosed to this point as useful in Carpal Tunnel Release (CTR) surgery, it should be understood the use of the tool is not so limited. The tool could be used in other contexts in which it is necessary to cut tissue within a patient, for example in cubital tunnel release surgery, other types of nerve decompression surgeries, or in endoscopic surgery more generally.

Claim 1:
A surgical tool, comprising:
a housing comprising one or more housing portions (42a, 42b), wherein the housing comprises a handle (<NUM>) graspable by a surgeon, wherein the handle includes a trigger (<NUM>);
a cannula (<NUM>) emanating from the housing and defining a first long axis (<NUM>), wherein the cannula is configured for insertion within a patient, wherein a distal end of the cannula comprises a blade tip assembly (<NUM>), wherein the blade tip assembly includes an optical window (<NUM>);
at least one optical electronics module (<NUM>) within the housing, where the at least one optical electronics module comprises one or more light emitters (<NUM>) configured to provide illumination, and a camera (<NUM>);
an optical assembly (<NUM>) within the housing having a proximal end coupled to the at least one optical electronics module and a distal end proximate to the optical window, wherein the optical assembly includes at least one first optical path configured to provide the illumination to the patient's tissue proximate to the optical window, and at least one second optical path configured to transmit images of the patient's tissue proximate to the optical window to the camera;
further comprising an actuator within the housing, wherein the actuator is responsive to depressing and releasing the trigger;
wherein the at least one optical electronics module and the optical assembly are configured to move within the housing parallel to the first long axis as the trigger is depressed and released;
a wireless transmitter (<NUM>) and antenna (<NUM>) within the housing, wherein the wireless transmitter is configured to wirelessly transmit via the antenna the images received at the camera to a display; and
a battery (<NUM>) within the housing configured to provide power to the light emitters, the camera, and the wireless transmitter.