Universal attachment mechanism for attaching a surgical tracking device to an instrument

An attachment mechanism for attaching a component to an instrument. The attachment mechanism includes a first hoop assembly having a first hoop receiving a first portion of the instrument and a second hoop assembly having a second hoop receiving a second portion of the instrument. Either one of the first hoop assembly or the second hoop assembly may be configured to retain the component thereto. The first and second hoop assemblies are configured to be secured to each other such that the first and second hoops are in tension with, and secured about, the instrument.

BACKGROUND OF THE INVENTION

The present invention relates to a mechanism for attaching a component to an instrument having variable geometry. More particularly, certain embodiments of the present invention relate to a universal attachment mechanism for attaching a surgical tracking device to a surgical instrument.

During surgical operations, it is beneficial to be able to track the direction and progress of a surgical instrument, such as a drill bit, into a patient's body in order to ensure that the instrument is directed into the appropriate point in the body. Therefore, surgical tracking systems have been developed that are able to display and monitor movement of a surgical instrument relative to an image of the patient's body.

One system used for surgical tracking is an electromagnetic tracking system. In a typical electromagnetic tracking system, the area of the patient's body where surgery is to take place is imaged using an imaging technology such as the MRI, X-ray, CT scan or any other appropriate imaging device. The scanned images are stored in a computer system and are displayed on a screen during the surgical procedure. A transmitter that emits an electromagnetic field is then secured to the patient's body proximate the area of the patient's body where surgery is to take place. The instrument that is to be tracked during surgery has a receiver attached thereto that receives the electromagnetic signals from the transmitter. The transmitter and receiver are both connected to the computer that displays the image. The computer translates the location of the transmitter on the patient's body to an equivalent point on the image. Then, by monitoring the signals sent from the transmitter to the receiver as the instrument is used in surgery, the computer is able to track the movement of the instrument relative to the transmitter and transpose the movement to the image. Therefore, medical personnel may closely track the positioning and progress of the instrument within the patient's body during surgery by examining the image.

Alternatively, in some electromagnetic systems, a receiver is placed on the patient and the instrument, and a field transmitter is placed proximate the patient. The receivers and transmitter are connected to the computer, and the computer is then able to track the movements of the instrument on an image similarly to the system using just a single receiver.

There are other surgical tracking systems besides electromagnetic tracking systems, such as optical tracking systems. Optical tracking systems typically use light emitting diodes (LEDs) that are attached to the surgical instrument and to the body portion of the patient on which the surgical procedure is to be performed. The LEDs are tracked by a camera unit (sometimes referred to as a digitizer). The output of the camera unit is used by the computer to recreate the movement of the instrument on the image.

In order for a surgical tracking system to work, the tracking device attached to the instrument, whether it be a receiver, transmitter or an LED, must be secured against movement relative to the instrument. If the tracking device moves relative to the instrument during surgery, the recreation of the instrument's position on the image will be incorrect. An incorrect tracking image may cause a surgeon to misdirect the instrument and possibly endanger the patient's health.

Since most surgical instruments are not provided with an integral tracking device, a separate attachment mechanism is generally used to retain a tracking device to the instrument. Many surgical instruments, such as drills, have traditionally been cylindrical in shape. As a result, a tracking device was often connected to the instrument by a cylindrical clamping mechanism, for example two C-shaped pieces connected at one by a hinge and at another end by a clasp. However, as ergonomic concerns have become increasingly prevalent in instrument design, the instruments have assumed more complex and contoured shapes. Many surgical instruments made today have a complex and variable geometry that cannot be accommodated by attachment mechanisms of such limited versatility as a conventional cylindrical clamp. Therefore, attachment mechanisms are often custom-made for each different kind of surgical instrument. In one common design, a boss is specifically developed for attachment to each surgical instrument, and the tracking device is then secured to the boss.

The practice of custom making surgical tracking attachment mechanisms has several drawbacks. First, the companies that make the attachment mechanisms must custom-design, develop, and market a new attachment mechanism specifically for each new surgical instrument that comes into the market. Thus, a company making attachment mechanisms must devote a significant amount of time and money to keeping up with new designs by the instrument makers. Companies that make the attachment mechanisms may, of course, work closely with the companies that make the surgical instruments in order that the instruments and the attachment mechanisms are compatible when the instruments come to market. However, this obligatory collaboration greatly slows down development and product-to-market time of the surgical instruments. Also, the companies that make the attachment mechanisms may be tied into different contracts with certain instrument makers and may be limited from making inroads into business with other instrument makers. An inability to fully reach into the instrument market is especially frustrating because recently there has been a significant increase in the number of new surgical applications, especially in orthopedics. Furthermore, even in instances where the same company makes the instrument and the attachment mechanism, the company must still invest the time and money into custom-designing and developing a new attachment mechanism for each surgical instrument, and therefore still has a delayed product-to-market time. Additionally, because of collaboration between instrument makers and attachment makers or instances where the same company makes the instrument, attachment mechanism, and tracking system, the end user may be limited to only using the tracking system of the company that makes the attachment mechanism for a particular instrument.

Therefore, a need exists for an improved attachment mechanism compatible for use with as many different instruments and tools as possible.

BRIEF SUMMARY OF THE INVENTION

Certain embodiments of the present invention include an attachment mechanism for attaching a component to an instrument. The attachment mechanism includes a first hoop assembly having a first hoop receiving a first portion of the instrument and a second hoop assembly having a second hoop receiving a second portion of the instrument. Either one of the first hoop assembly or the second hoop assembly may be configured to retain the component thereto. The first and second hoop assemblies are configured to be secured to each other such that the first and second hoops are in tension with, and secured about, the instrument.

Certain embodiments of the present invention include an attachment system. The attachment system includes an instrument having a body and a handle, a tracking device, and an attachment mechanism. The attachment mechanism has first and second hoop assemblies. The first hoop assembly includes a first hoop that receives a first portion of the body proximate a first side of the handle and the second hoop assembly includes a second hoop that receives a second portion of the body proximate a second side of the handle. Either one of the first or second hoop assemblies is configured to retain the tracking device thereto. The first and second hoop assemblies are configured to be secured to each other such that the first and second hoops are in tension with, and secured about, the body.

Certain embodiments of the present invention include an attachment mechanism for securing a component to an instrument. The instrument has a body portion with a first end, a second end, and a cross-sectional dimension that increases between the first and second ends. The attachment mechanism includes a first hoop positionable around the first end of the body portion and a second hoop positionable about the second end of the body portion. The attachment mechanism also includes a mechanism configured to secure the component to one of the first and second hoops. The attachment mechanism includes a connection mechanism configured to draw the first and second hoops toward each other such that the interface between the first and second hoops and the increasing cross-sectioned dimension of the body portion secures the first and second hoops relative to the body portion.

Certain embodiments of the present invention include an attachment mechanism for securing a component to an instrument. The instrument has a body portion with a first end, a second end, and a cross-sectional dimension that decreases between the first and second ends. The attachment mechanism includes a first hoop positionable around the first end of the body portion and a second hoop positionable about the second end of the body portion. The attachment mechanism also includes a mechanism configured to secure the component to one of the first and second hoops. The attachment mechanism further includes a connection mechanism configured to move the first and second hoops away from each other such that the interface between the first and second hoops and the decreasing cross-sectioned dimension of the body portion secures the first and second hoops relative to the body portion.

Certain embodiments of the present invention include a method for securing a component to an instrument where the instrument has a body portion with a first end and a second end. The method includes connecting the component to one of first and second hoops, engaging one of the first and second hoops to the instrument along the body portion from the first end, engaging the other of the first and second hoops to the instrument along the body portion from the second end, and securing the first and second hoops to each other such that the first and second hoops are drawn to each other and secured about the body portion.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is an isometric view of a conventional surgical instrument10. The instrument10has a main body14, a handle18and a working portion22. In the illustrated embodiment, the body portion is barrel-shaped but it can take a variety of other shapes. The body14has a front portion12on the front side of the handle18and a rear portion16on the rear side of the handle18. The working portion22extends from the front portion12and may be removably connected thereto, e.g., via a chuck assembly (not shown). The rear portion16may house pneumatic and electrical components that drive the working portion22and provide irrigation and suction.

The body14and the handle18are contoured to provide an ergonomically desirable geometry and weight distribution such that the instrument10may comfortably be used in a surgeon's hand. The ergonomically motivated design, or variable geometry design, of the instrument10is typical for any number of different surgical instruments, for example, a drill. Furthermore, such a variable geometry design is typical for any number of different tools, instruments, appliances, or utensils, whether they be surgically related or not.

FIG. 2is an exploded isometric view of an attachment mechanism26formed according to an embodiment of the present invention. The attachment mechanism26includes a first or front hoop assembly30, a second or rear hoop assembly34, and an attachment assembly24. The front hoop assembly30includes a ring-shaped first or front hoop42formed with a connector bar46. The front hoop42is shown as a closed ring, but, alternatively, the front hoop42may be non-continuous, for example it may be open ended opposite the connector bar46such that it operates more like a clamp. By way of example and not by way of limitation, the front hoop42may be a ring or a clamp or a flexible, adjustable strap. The front hoop42extends from a bottom side of the connector bar46at a front end58thereof. The front hoop42has a fixed diameter generally large enough to receive the body portion of any number of different surgical instruments. Alternatively, the front hoop42may be adjustable such that the diameter can be varied to allow the front hoop to be tightly secured about a variety of points on an instrument body. The front hoop42has a thin wall such that it may be secured about the body of a surgical instrument and cause minimal interference with operation of the instrument. The front hoop42is made of a strong, flexible material that only minimally affects electromagnetic signals. For example, the front hoop42may be made of 300 series stainless steel, titanium, or certain polymers or composites.

The connector bar46generally extends along an axis perpendicular to the circumference of the front hoop42. The connector bar46has a circular face28located behind an arced cut out32proximate the front end58. A cylindrical threaded hole20extends through the face28. The connector bar46also has a cylindrical, threaded hole (not shown) located at a back end70thereof.

The attachment assembly24includes a cylindrical support beam50that is connected to a cylindrical base36at one end and a tracking device carrier62at another end. The base36has a cylindrical hole40that is configured to receive a screw44. The support beam50has a first portion48that extends upward perpendicularly from the base36and a second portion52that extends from the first portion48to the tracking device carrier62at an obtuse angle. Alternatively, the entire support beam50may be one straight beam that extends from the base36at any angle in any direction. Alternatively, the second portion52may extend from the first portion48at any angle in any direction. The tracking device carrier62has prongs82and a platform86that are configured to securably retain a surgical tracking device (not shown), such as an electromagnetic receiver or an optical tracking component such as an LED. The support beam50includes a hook66extending therefrom that retains a cord (not shown) extending from the tracking device held in the tracking device carrier62. The tracking device carrier62is preferably made of a hard plastic in order to avoid interfering with electromagnetic signals being sent to the tracking device.

In operation, the attachment assembly24is connected to the front hoop assembly30by inserting the screw44through the hole40in the base36and the hole20in the face28and tightening the screw44. When the screw44is completely inserted into the holes40and20, the base36is retained within the cutout32along the face28. The screw44is configured such that the base36may be rotated about the screw44within the cutout32without being loosened from the face28. Thus, the attachment assembly24may be rotated about the front hoop assembly30in either direction along a longitudinal axis60. Alternatively, or additionally, the attachment mechanism26may be configured such that the attachment assembly24may be rotated about the front hoop assembly30in either direction along a transverse axis64. The attachment assembly24may be rotated isocentrically about the attachment mechanism26such that the relative distance does not change, or substantially change, between the tracking device and the longitudinal axis60. Similarly, the attachment assembly24may be rotated isocentrically about the attachment mechanism26such that the relative distance does not change, or substantially change, between the tracking device and a longitudinal axis of the working portion22(FIG. 1) or a longitudinal axis of the body14(FIG. 1). By being able to rotate the attachment assembly24relative to the instrument10in such a way, a surgeon can move the attachment assembly24and the tracking device out of the way of other instruments without affecting the communication between the tracking device and the other surgical tracking components.

The rear hoop assembly34includes a ring-shaped second or rear hoop74formed with a square-shaped connector block78. The rear hoop74extends from a bottom side of the connector block78. The rear hoop74is open at one end and has a fixed diameter generally large enough to receive the body of any number of different surgical instruments. Alternatively, the rear hoop74may be a closed ring like the front hoop42. By way of example and not by way of limitation, the rear hoop74may be a ring or a clamp or a flexible, adjustable strap. Alternatively, the rear hoop74may be adjustable such that the diameter can be varied to allow the rear hoop to be tightly secured about a variety of points on an instrument body. The rear hoop74has a thin wall such that it may be secured about the body of a surgical instrument and cause minimal interference with operation of the instrument. The rear hoop74is made of a strong, flexible material that only minimally affects electromagnetic signals. For example, the rear hoop74is preferably made of 300 series stainless steel, titanium, or certain polymers or composites.

The connector block78has a cylindrical, threaded hole56extending therethrough from a front end94to a back end98. The threaded hole56is configured to receive a fastener screw38. In operation, the fastener screw38is threaded through the back end of the hole56in the connector block78, out of the front end of the hole56, and into a reciprocal threaded hole (not shown) in the back end70of the connector bar46in order to secure the rear hoop assembly34to the front hoop assembly30.

FIG. 3is an isometric view of the attachment mechanism26connected to the surgical instrument10. In order to attach the attachment mechanism26to the surgical instrument10, the front hoop42is slid along the front portion12of the body14with the connector bar46positioned along the top of the body14. The front hoop42is slid along the front portion12toward the handle18until the diameter of the front hoop42prevents it from being slid any further. The rear hoop74is then slid along the rear portion16of the body14with the connector block78positioned along the top of the body14. The rear hoop74is slid along the rear portion16toward the handle18until the diameter of the rear hoop74prevents it from being slid any further. The connector bar46and the connector block78are thus proximate each other, and the holes within the connector bar and block46and78are then aligned with each other. The fastener screw38is then threaded through the hole56(FIG. 2) in the connector block78from the back end98to the front end94and then into the hole at the back end70of the connector bar46. The fastener screw38is threaded into the connector bar46until the connector bar46and the connector block78are tightly secured to each other. As the connector bar46and the connector block78are secured together with the fastener, the front and rear hoops42and74are pulled to each other and are in tension or “hoop stress” about their respective portions of the body14. Thus, the flexible front and rear hoops42and74flex toward each other and are tightly secured to the body14of the surgical instrument10such that the attachment mechanism26, and thus the tracking device, do not move relative to the surgical instrument10.

FIG. 4is an isometric view of the attachment mechanism26carrying a tracking device90in the form of an electromagnetic receiver. Alternatively, the tracking device90may be an optical tracking component such as an LED, for example. An electrical cord94extends from the tracking device90through the hook66to a computer (not shown). The computer communicates with the tracking device90and a transmitter (not shown) positioned relative to the patient's body to recreate on an image of the patient's body the movement of the surgical instrument10relative to the transmitter in a conventional manner. This method of tracking the surgical instrument on the image allows medical personnel to track the progress of the surgical instrument10through the patient's body.

It should be noted that the attachment mechanism26may be used with instruments having a generally constant diameter or cylindrical body shape. The front and rear hoops42and74may both be slid onto the body such that the connector bar46and the connector block78are proximate each other. The connector bar46and the connector block78are then fastened to each other such that the front and rear hoops42and74are pulled toward each other and thus pulled in tension tightly against the body.

In an alternative embodiment, the attachment mechanism may be attached to an instrument body having a geometry that requires the front and rear hoops42and74to be pulled away from each other in order for the attachment mechanism to be secured to the instrument. By way of example and not by limitation, the attachment mechanism26may need to be attached to an instrument having an hourglass shaped body. In order to attach the attachment mechanism26to the surgical instrument10, the front hoop42is slid along a first portion of the body from the center toward a first end until the diameter of the front hoop42prevents it from being slid any further. The rear hoop74is then slid along a second portion of the body from the center toward a second end until the diameter of the rear hoop74prevents it from being slid any further. The connector bar46and the connector block78are configured such that when fastened to each other, the front and rear hoops42and74are moved away from each other and are in tension or “hoop stress” about their respective portions of the body. Thus, the flexible front and rear hoops42and74flex away from each other and are tightly secured to the opposite ends of the hourglass shaped body.

In an alternative embodiment, the front and rear hoops42and74may be adjustable such that their diameters can be altered to accommodate instruments of varying body diameter. By way of example only, the front and rear hoops42and74may be adjustable hose clamps. By being able to change the diameter of the front and rear hoops42and74, less tension is necessary between the front and rear hoop assemblies30and34to securely tighten the front and rear hoops42and74to the body of an instrument. Alternatively, the attachment mechanism26may include more than two hoops that receive a portion of an instrument. Alternatively, the attachment mechanism26may be configured to be attached to portions of an instrument besides the body, for example, the attachment mechanism26may be configured to be attached to the handle. Alternatively, the hoops of the attachment mechanism26do not have to be round or ring-shaped but may be any number of other shapes, for example, square, oval, or cylindrical, so long as the hoops are able to receive a portion of an instrument. Furthermore, the hoops of the attachment mechanism26need not be closed, but may be open ended. For example, the hoops may be open-ended clamps having legs that tightly engage the body of an instrument.

In an alternative embodiment, the support beam50connected to the tracking device carrier62may be connected to the rear hoop assembly34instead of the front hoop assembly30. Also, in an alternative embodiment, the front hoop assembly34may include the short connector block78and the rear hoop assembly34may include the longer connector bar46.

Alternatively, the front and rear hoop assemblies30and34may be secured to each other by a means other than the fastener screw38being inserted into the holes. In alternative embodiments, the front and rear hoop assemblies30and34may be connected by bolts, pins, straps, clamps, or any other number of fastening devices that can be used to secure the front and rear hoop assemblies30and34to each other. For example, in one alternative embodiment, the connector bar46and connector block78may have holes along the sides thereof and be configured to overlap such that the holes are aligned to receive a fastening pin.

Alternatively, the attachment mechanism26may be configured to secure any number of different surgical tracking devices to the surgical instrument10. For example, the tracking device carrier62may be configured to retain an LED for use with an optical surgical tracking system. Further, the attachment mechanism26may be used to secure any component (not necessarily a tracking device) to any number of different tools, instruments, utensils, or appliances, whether they be surgically related or not. In other words, the attachment mechanism26may be configured to be used with any instrument having a variable geometry that is to be securely connected to another component. For example, the attachment mechanism26may be used to connect a component to a power drill or even a scope to a gun barrel.

The attachment mechanism of the different embodiments confers a number of benefits. The two connectable hoops allow the attachment mechanism to be used with instruments of different contours and varying diameters and geometry. The applicability of the attachment mechanism to different instruments of varying geometry can perhaps best be demonstrated with the example of using the attachment mechanism with a football. A football is shaped to have a single maximum radius at the center and a nearly infinite number of radius minima on either side of the center of the football (for example, along the parallel white stripes on the football). That is to say, the football has a cross-sectional dimension that increases between the opposite ends thereof. The variable geometry of the football makes it difficult to secure one clamp on the football, even if the clamp was at the maximum radius at the center, because the clamp could easily slide off. However, two clamps can be placed at equivalent radius minima on opposite sides of the center (such as along the stripes) and pulled or drawn toward each other such that the interface between the clamps and the increasing cross-sectioned dimension of the football secures the clamps relative to the football. In other words, the clamps are in tension at the radius minima and thus secured to the football.

The universal applicability of the attachment mechanism is a significant commercial advantage because attachment mechanisms no longer have to be custom made for every new instrument that comes into the market. One attachment mechanism may be used with all instruments and therefore no collaboration is necessary between different companies making instruments and attachment mechanisms. Additionally, the end user is no longer required to use the surgical tracking device of the same company that makes an attachment mechanism for a specific instrument.