1. Field of the Invention.
The present invention relates to computer assisted surgery. More particularly, the present invention relates to a method and apparatus for using alternative energy technology which is controlled by a computer assisted surgery system to modify or alter tissues or bones.
2. Description of the Related Art.
Orthopedic implants are commonly used to replace some or all of a patient's joints in order to restore the use of the joints, or to increase the use of the joints, following deterioration due to aging or illness, or injury due to trauma. Accurate altering and resections of bone and soft tissue, such as ligaments, are critical to ensure a proper fit of the orthopedic implants. In a typical joint replacement procedure, a surgeon may employ a computer assisted surgery (CAS) system to facilitate accuracy and precision of the outcome of the procedure.
CAS systems and procedures have been developed for positioning surgical instruments in a predefined position and orientation relative to a patient's anatomical structures. Computer assisted guidance of surgical instruments can be used in orthopedic surgical procedures, for example, to position a cutting instrument in a predefined position and orientation with respect to a bone when preparing the bone to receive a prosthetic implant such as a component of an artificial joint, or to position an alteration instrument in a predefined position and orientation with respect to tissue when cauterizing blood vessels or bonding ligaments to bones. Guidance techniques typically involve acquiring preoperative images of the relevant anatomical structures and generating a database which represents a three-dimensional model of the anatomical structures. The surgical instruments typically have a fixed geometry which is used to create geometric models of the instruments. The geometric models of the instruments can then be superimposed on the model of the relevant anatomical structures.
During the surgical procedure, the position of the instrument(s) being used and the patient's anatomical structures are registered with the anatomical coordinate system of the computer model of the relevant anatomical structures. Registration is the process of defining the geometric relationship between the physical world and a computer model. Registration of the patient with the computer model allows the computer to manipulate the computer model to match the relative positions of various components of the patient's anatomical structure in the physical world. Registration of the instrument(s) used with the computer model allows the computer to display and/or direct the placement of the instrument(s) and prosthetic components relative to the patient's anatomical structure. To assist the registration process, fiducial pins or markers are placed in contact with a portion of the anatomical structure and/or instrument which are also locatable in the computer model. The markers are locatable in space by the computer, thereby providing a geometric relationship between the model and physical anatomical structure. A graphical display showing the relative positions of the instrument and anatomical structures can then be computed in real time and displayed to assist the surgeon in properly positioning and manipulating the surgical instrument with respect to the relevant anatomical structure. Examples of various computer-assisted navigation systems are described in U.S. Pat. Nos. 5,682,886; 5,921,992; 6,096,050; 6,348,058; 6,434,507; 6,450,978; 6,470,207; 6,490,467; and 6,491,699, the disclosures of which are hereby explicitly incorporated herein by reference.
CAS systems typically use a mechanical instrument, such as a rotating drill bit or an oscillating saw blade, to perform bone resection or soft tissue alteration. Some CAS systems are equipped with the ability to recognize the location of the instrument, and allow supply of electrical power to the mechanical instrument when the instrument is in a desired location on or near the body of the patient. The CAS system tracks the movement of the instrument to allow the CAS system to determine whether the instrument is in the desired location. If, for some reason, the instrument moves outside the desired location for alteration of the bone or tissue, the CAS system is able to sense the location and terminate supply of electrical power to the instrument. However, conventional mechanical instruments in CAS systems require a time delay before all mechanical motion of the instrument is completely stopped. For example, after electrical power is removed from a mechanical drill bit, the drill bit may continue to rotate while decelerating. Also, for example, after electrical power is removed from an oscillating saw blade, the blade may continue to oscillate until it comes to a complete stop. An example of such a prior art CAS system which provides guidance to cut a predetermined cut plane includes cutting instrument 15, shown in
The present invention provides a method and apparatus for a computer assisted surgery (CAS) system using alternative energy tissue and bone alteration technology. The CAS system utilizes alternative energy technology which is a directed to a surgical instrument including an alteration or cutting tip. The tip may be in contact with the tissue or bone, or, alternatively, the tip may be distant from the tissue or bone and the energy is projected to the desired cut or alteration site. The CAS system recognizes the location of the tip relative to a desired alteration location or area and de-energizes or varies the energy level when the tip moves away from or out of the predetermined alteration location or path. The CAS system provides a method for altering or resecting bone, for example, in preparation for a prosthetic implant, or a method for altering tissue, for example, cauterizing blood vessels or bonding ligaments to bones.
In one form thereof, the present invention provides a method for altering an anatomical structure of a patient using a computer assisted surgery system including a computer and an alternative energy source, the method including the steps of registering the anatomical structure of the patient with the computer; inputting into the computer a workspace associated with the anatomical structure of the patient; applying energy from the alternative energy source to the workspace with a surgical instrument; and terminating immediately the application of energy under control from the computer when the surgical instrument deviates from the workspace.
In another form thereof, the present invention provides a computer assisted surgery system for altering an anatomical structure of a patient, the system including a computer including a workspace storage memory storing an identified workspace associated with at least one anatomical structure of a patient; an alternative energy source; a surgical instrument connected to the alternative energy source, the instrument convertible between a first, non-enabled condition associated with the instrument not being present in the workspace in which energy is not supplied to the instrument from the alternative energy source, and a second, enabled condition associated with the instrument being present in the workspace in which energy is supplied to the instrument from the alternative energy source; and an energy source controller associated with the computer, the controller controlling conversion of the instrument from the second, enabled condition to the first, non-enabled condition to immediately terminate energy supplied to the instrument.
In yet another form thereof, the present invention provides a computer assisted surgery system for altering an anatomical structure of a patient, the system controlling an alternative energy source, the system including a computer; means for registering the anatomical structure of the patient with the computer; means for identifying a workspace associated with the anatomical structure; means for applying energy from the alternative energy source to the workspace; and means for immediately terminating a supply of energy from the alternative energy source under control from the computer when the applying energy means deviates from the workspace.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings.
The present invention provides a method and apparatus for a computer assisted surgery (CAS) system using alternative energy tissue and bone alteration technology. The CAS system utilizes alternative energy technology which is a directed to a surgical instrument including an alteration or cutting tip. The tip may be in contact with the tissue or bone, or, alternatively, the tip may be distant from the tissue or bone and the energy is projected to the desired cut or alteration site. The CAS system recognizes the location of the tip relative to a desired alteration location or area and de-energizes or varies the energy level when the tip moves away from or out of the predetermined alteration location or path. The CAS system provides a method for altering or resecting bone, for example, in preparation for a prosthetic implant, or a method for altering tissue, for example, cauterizing blood vessels or bonding ligaments to bones.
Referring to
Computer 23, shown in
In one embodiment, method 100, shown in
In step 104, reference arrays 40 (
In step 106, imaging device 32 (
In step 108, the relevant anatomical structures are registered with CAS system 20. Specifically, the combination of data available from reference devices 50 and images of the anatomical structures form a model of the anatomical structure, for example, knee joint 65 shown in
In step 110, a desired workspace is identified and input into memory 57 of computer 23. For the purposes of this document, workspace may be defined as any alteration location, area, or volume, for example, a cutting plane, a drilling axis, a bonding location, a cauterizing location, a resection area, a resection volume, etc. The alteration area may be a desired cutting plane, a drilling axis, a cauterizing location, a bonding location, or any other bone or tissue alteration location, area, or three-dimensional volume. The alteration area may be selected or identified by the surgeon using the information provided from CAS system 20. For example and referring to
Also, workspace 60 may be advantageously limited to a preset array of implant sizes. For example, the surgeon may input into computer 23 known characteristics of an actual implant to be used in the surgical procedure. Computer 23 may then determine the desired size for workspace 60 based on the known characteristics of the implant. Thus, computer 23 may tailor the size of workspace 60. In one embodiment, computer 23 may set either a minimum size or maximum size of workspace 60 and the actual final size of workspace 60 is determined by the discretion of the surgeon.
Although described hereinafter with respect to workspace 60 of a knee joint, the present method is equally applicable to any desired resection, alteration, bonding, or cauterizing location, area, or three-dimensional volume, or any other bone or tissue modification location, area, or three-dimensional volume.
In another embodiment, the surgeon identifies and selects the alteration area using a probe without any prior assistance from CAS system 20, i.e., there is no imaging involved. However, imaging of the anatomical structures of patient 22 may also be used when the surgeon identifies the alteration location, area, or volume using a probe. Referring now to
Alternatively, referring to
In optional step 112, CAS system 20 may use the information about the desired alteration location, area, or volume to simulate an appropriate alteration. Upon accepting the simulated alteration, the surgeon may use the information to provide a plan in computer 23 for altering the anatomy of patient 22. A method for simulating prosthetic implant selection and placement in an anatomical structure using a CAS system is fully described in U.S. pat. application Ser. No. 11/231,156, filed Sep. 20, 2005, entitled METHOD FOR SIMULATING PROSTHETIC IMPLANT SELECTION AND PLACEMENT, assigned to the assignee of the present application, the disclosure of which is hereby expressly incorporated herein by reference.
In step 114 and referring to
In step 116, the surgeon may grasp instrument 75, as shown in
Alternative energy source 80 may be any energy source which provides energy different from mechanical energy such as supplied to typical drill bits and cutting saw blades. For example, alternative energy source 80 may be an ultrasonic energy source, a water jet energy source, a light source such as a laser, a shock wave energy source, a vibratory energy source, or any combination thereof. Exemplary alternative energy sources 80 may be produced by S.R.A. Developments Ltd., of South Devon, United Kingdom (ultrasonic energy sources); Lumenis™ Inc., of Santa Clara, Calif. (light energy sources); Dornier MedTech, of Kennesaw, Ga. (shock wave energy sources); Plexus Technology Group Inc., of Neenah, Wis. and Ethicon Endo-Surgery, of Cincinnati, Ohio (ultrasonic vibratory sources). Some of these energy sources allow tip 77 of instrument 75 to never be required to touch any bone or soft tissue surface of an anatomical structure, and, instead, may allow the energy to be projected from tip 77 towards the anatomical structure. This projection of energy can be focused a defined distance from tip 77 so that computer 23 can precisely monitor where the action is taking place.
Also, alternative energy sources 80 may also allow alteration of soft tissue or bone without ever requiring an invasive procedure. For example, a laser may be tuned to project through tissues without harming the tissues and only have the capability to alter bone. Also, alternative energy sources 80 may be combined to work together either as at least two identical energy sources 80 or at least two non-identical energy sources 80. For example, if more than one identical energy source 80 was used, each energy source 80 by itself is not sufficient to alter any tissue or bone, but, when combined with the second (or third, fourth, etc.) identical energy source 80 focused to a predetermined known location, alteration of tissue or bone is possible. In another example, if two non-identical energy sources 80 were used, one energy source 80, e.g., a laser, may be used to alter the tissue or bone, and a second energy source 80, e.g., a water jet, may be used to remove the removed tissue or bone.
In one embodiment, once tip 77 is near or touching bone within the boundaries of workspace 60, software 58 enables alternative energy source 80 to be energized, i.e., instrument 75 is switched from a non-enabled condition to an enabled condition. In one embodiment, the surgeon may then activate actuation interface 78, e.g., a trigger or button, to cause energy to be supplied to the body of patient 22 (
In one embodiment, instrument 75 must be sufficiently close to the bone to permit energy from energy source 80 to reach the bone, the closeness of which depends upon the particular energy source 80 utilized. Alternative energy source 80 is connected to computer 23 via connection 82. Connection 82 may be a hardwired connection or may be a wireless connection. Computer 23 may be connected to instrument 75 via connection 79 which may be a hardwired or wireless connection. If connection 79 is a wireless connection, instrument 75 may be provided with a plurality of reference devices 50 (
In step 118, if the surgeon moves instrument 75 outside the bounds of workspace 60, or, if workspace 60 is a volume, beyond the three-dimensional boundary of workspace 60, e.g., instrument 75 deviates from workspace 60, computer 23 immediately de-energizes alternative energy source 80. Advantageously, upon de-energization, all emission of energy from tip 77 is immediately terminated to eliminate the potential for surrounding bone or tissue to be contacted or otherwise exposed to energy emitted from tip 77 after alternative energy source 80 is de-energized. In one embodiment, controller 25 (
Alternatively, in step 116, instrument 75 may be guided by robot arm 74, shown in
Once workspace 60 or any other alteration location, area, or volume is altered to a desired extent, the surgeon may complete the surgery, if necessary, by implanting a prosthetic implant. One such implant is a formable implant which is fully described in U.S. pat. application Ser. No. 11/251,181, filed Oct. 13, 2005, titled METHOD FOR REPAIRING BONE DEFECT USING A FORMABLE IMPLANT WHICH HARDENS IN VIVO, assigned to the assignee of the present application, the disclosure of which is hereby expressly incorporated herein by reference. Alternatively, once bonding or cauterizing is complete, the surgery is complete. Advantageously, alternative energy source 80 permits some surgeries to be completed with either a minimally invasive incision in patient 22 or, alternatively, no incision at all.
While this invention has been described as having exemplary designs, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.