Patent Abstract:
A method comprising (a) illuminating a blood vessel in a relatively low-light surgical field by inserting a subcutaneous light source into tissue near the blood vessel and to a first location in the tissue underlying the blood vessel, and causing emission of light from the subcutaneous light source while the subcutaneous light source is at the first location, so that light from the subcutaneous light source passes through the tissue near the blood vessel, toward an observer; (b) drawing a portion of the tissue near the blood vessel through an incision in the skin; and (c) illuminating the drawn portion of tissue by activating an external light source in a hands-free manner, thereby facilitating determining whether the drawn tissue is the blood vessel.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/174,631 filed on May 1, 2009 and entitled “METHODS AND SYSTEMS FOR ILLUMINATION DURING PHLEBECTOMY PROCEDURES,” which is hereby incorporated herein by reference in its entirety and is to be considered a part of this specification. 
     
    
     BACKGROUND 
       [0002]    The disclosed embodiments relate generally to methods and systems for providing illumination during phlebectomy procedures. Phlebectomy is a standard treatment for varicosities arising from incompetent veins, particularly those below the saphenofemoral and saphenopopliteal junctions. This technique involves the avulsion and removal of the varicose veins through multiple stab incisions made directly over the veins, which are removed using surgical tools, such as hooks and mosquito forceps. Proper location of the veins to be removed is essential for proper situation of the incisions. In general, this is accomplished by preoperative vein location and marking, a procedure generally accomplished with the patient in a standing position so that the veins become engorged with blood due to the action of gravity and thus easily marked; however, the phlebectomy operation is generally conducted with the patient in a supine position. The position of the incompetent veins may shift during the transition from a standing to a supine position, and often further marking is conducted after the patient is placed in the surgical position in an attempt to track these shifts. Once the patient has been marked and incisions have been made along the length of the vein to be removed, the surgeon probes with the surgical implements, such as hooks, to locate the vein. 
       SUMMARY 
       [0003]    In one embodiment, a method comprises (a) illuminating a blood vessel in a relatively low-light surgical field by inserting a subcutaneous light source into tissue near the blood vessel and to a first location in the tissue underlying the blood vessel, and causing emission of light from the subcutaneous light source while the subcutaneous light source is at the first location, so that light from the subcutaneous light source passes through the tissue near the blood vessel, toward an observer; (b) drawing a portion of the tissue near the blood vessel through an incision in the skin; and (c) illuminating the drawn portion of tissue by activating an external light source in a hands-free manner, thereby facilitating determining whether the drawn tissue is the blood vessel. 
         [0004]    In the method, the blood vessel can optionally be a vein, such as a varicose vein, or a superficial leg vein near the skin surface. The surgical field can optionally be an area at least about 20 cm wide and centered on the subcutaneous light source insertion site, extending at least about 20 cm from the skin surface at the subcutaneous light source insertion site toward an observer (e.g. a surgeon). The method can optionally further comprise, prior to drawing the portion of tissue near the vein, selecting the portion of the tissue based on observing the tissue illuminated by the subcutaneous light source. The external light source can optionally be worn on the surgeon&#39;s head and/or activated by a movement of the head (such as a nod of the head). The external light source can optionally be one which is activated without use of the hands or feet, and/or by the surgeon himself or herself without commanding another person to activate an external light source. The external light source can optionally provide broadband or white light in a floodlight fashion in the surgical field. 
         [0005]    In another embodiment, a surgical illumination system comprises a subcutaneous illuminator having an elongate member configured for insertion into subcutaneous tissue. The elongate member has a light emitter near its distal end, and the light emitter is configured to emit light primarily in a generally radial direction, outward and away from a longitudinal axis of the elongate member. The system further comprises an external illuminator configured to illuminate a surgical field in a floodlight fashion. The external illuminator is configured for activation without use of the hands. 
         [0006]    In the system, the external illuminator can optionally be configured to be worn on the surgeon&#39;s head and/or activated by a movement of the head (such as a nod of the head). The external illuminator can optionally include an inertial switch or accelerometer to facilitate such activation. The external illuminator can optionally be one which is activated without use of the hands or feet, and/or by the surgeon himself or herself without commanding another person to activate an external illuminator. The external illuminator can optionally provide broadband or white light in a floodlight fashion in the surgical field. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    In the drawings: 
           [0008]      FIG. 1  is a front view of an exemplary subcutaneous illumination apparatus of an illumination system according to one embodiment. 
           [0009]      FIG. 2  is an enlarged view of the region labeled II in  FIG. 1  showing an electroluminescent device of the subcutaneous illumination apparatus of  FIG. 1 . 
           [0010]      FIG. 3  is a perspective view of an exemplary external illumination apparatus of the illumination system according to one embodiment. 
           [0011]      FIG. 4  is a plan view of the external illumination apparatus of  FIG. 3 . 
           [0012]      FIG. 5  is a perspective view of a switch according to one embodiment from the external illumination apparatus of  FIG. 3 . 
           [0013]      FIG. 6  is a sectional view of the switch of  FIG. 5  in an unactuated condition. 
           [0014]      FIG. 7  is a sectional view similar to  FIG. 6  with the switch in an actuated condition. 
           [0015]      FIG. 8  is an exemplary electrical circuit for the external illumination apparatus of  FIG. 3 . 
           [0016]      FIG. 9  illustrates the external illumination apparatus of  FIG. 3  worn on the head of a user and actuation of the switch via movement of the head of the user. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Methods and systems for providing illumination during phlebectomy procedures are disclosed. The methods and systems can provide subcutaneous illumination for visualization of veins and surrounding tissue and external illumination of material removed through the incisions for identification thereof. More particularly, after the patient has been marked and at least one incision has been made during the phlebectomy procedure, the surgeon attempts to locate the vein through the incisions, which can be difficult when the vein has shifted from the marked positions upon movement of the patient to the supine position. To facilitate vein location, the surgeon can employ an illumination device, such as a subcutaneous illumination device, that provides internal illumination for visually distinguishing the vein from the surrounding tissue. The subcutaneous illumination device can emit light at wavelengths selected to render the appearance of the vein dark, such as black, against a highlighted background of surrounding tissue. The illumination source can be relatively small and concentrated, and the region illuminated by the subcutaneous illumination device can often be viewed best when the room is relatively dark, which can be achieved by turning off or dimming the room lights. After location of the vein inside the body, the surgeon pulls a hook or other surgical implement from the incision and visually inspects material removed therewith for identification of the vein. However, this visual inspection can be difficult when the room is relatively dark for optimized efficacy of the subcutaneous illumination device, and the surgeon can employ an external illumination device that provides external illumination to facilitate the visual inspection. 
         [0018]    One embodiment of the system comprises a subcutaneous illumination apparatus  10 , an example of which is illustrated in  FIG. 1 , and an external illumination apparatus  30 , which will be described in detail below. Referring to  FIG. 1 , the exemplary subcutaneous illumination apparatus  10  comprises a handle  12  and an illuminator portion  14  housing an electroluminescent device  16 . The handle  12  includes a switch  18  operatively coupled to the electroluminescent device  16  for selectively providing power to the electroluminescent device  16 . The illuminator portion  14  comprises an elongated shaft  20  and a flattened blade or bladelike member  22  at the distal end of shaft  20 . In certain embodiments, the shaft  20  can be of sufficient stiffness to permit the dissection of tissue or the avulsing of veins using the blade  22 . The blade  22  can be sized for insertion into the subcutaneous surgical space through the small stab incisions typically employed in phlebectomy. The blade  22  can optionally be omitted and instead the shaft  22  can comprise a tube or cylinder of less than or equal to 7 French (2.33 mm) diameter along its length, with an insertable length of about 13-14 cm. 
         [0019]    In the illustrated embodiment, the blade  22  or shaft  20  incorporates the electroluminescent device  16 , which is configured to both generate and emit light in a generally radial direction, outward and away from a longitudinal axis of the illuminator portion  14 . Any suitable type of electroluminescent lighting apparatus that can be accommodated within the blade  22  or shaft  20  can be employed as the electroluminescent device  16 . Examples of electroluminescent devices include LED elements and other solid state light emitters. Individual light emitting elements  24  can be assembled into a linear array to form the device  16 , as seen in the enlarged plan view of the electroluminescent device  16  in  FIG. 2 . In certain embodiments, the light emitting elements are configured to emit red or yellow light. In other embodiments, the light emitting elements are configured to emit light having a wavelength of less than 610 nm, or in the range of 630 to 670 nm. In other embodiments, the light emitting elements are configured to emit light substantially only in a wavelength or wavelength range that tends to highlight a blood vessel against surrounding tissue when the light is passed through the blood vessel and tissue. In other words, the incident light can cause the vein to appear darker than the surrounding tissue. The light emitting elements can be powered by batteries or other energy storage devices that are housed within the handle  12 , or by an external power supply to which the apparatus  10  can be connected, such as a wall outlet. 
         [0020]    The subcutaneous illumination apparatus  10  shown in  FIGS. 1 and 2  and described above is one exemplary embodiment of the apparatus  10  that can be employed with the illumination system. Other types of subcutaneous illumination apparatuses can be employed with the illumination system and for the corresponding methods, including those described in U.S. Patent Application Publication No. 2007/0244371, published Oct. 19, 2007, and the corresponding U.S. patent application Ser. No. 11/732,771, filed Apr. 4, 2007, which are incorporated herein by reference in their entireties; the &#39;371 publication is attached in the Appendix to the present application. Further, the system can employ other types of apparatuses for illuminating or otherwise identifying veins, such as a transdermal illumination apparatus (e.g. the VEINLITE™ available from TransLite LLC of Sugar Land, Tex.), in combination with or instead of the subcutaneous illumination apparatus. 
         [0021]    As mentioned above, the illumination system comprises the external illumination apparatus  30  in addition to the subcutaneous illumination apparatus  10 . While the subcutaneous illumination apparatus  10  provides internal illumination (i.e., illumination internal of the body of the patient) for identifying veins, the external illumination apparatus  30  provides external illumination (i.e., illumination external to the body of the patient) for inspection of the material removed from the patient&#39;s body. The external illumination apparatus  30  provides the external illumination without the use of the hands of the surgeon so that the hands remain free for manipulating the subcutaneous illumination apparatus  10 , hooks, and/or other surgical instruments. The illustrated embodiment of the external illumination apparatus  30  achieves hands-free operation via mounting the apparatus  30  on the surgeon&#39;s head and actuation of the apparatus  30  in response to movement of the surgeon&#39;s head. 
         [0022]    Referring now to  FIG. 3 , an exemplary embodiment of the external illumination apparatus  30  comprises a head mount  32  adapted to be worn on the head of the surgeon. The head mount  32  includes a generally circular headband  34  having a front portion  36  corresponding to the surgeon&#39;s forehead region, a rear portion  38  corresponding to the back of the surgeon&#39;s head, and an adjustable closure  40  for sizing the headband  34  according to the circumference of the head of the surgeon. The headband  34  can further incorporate one or more pads, such as a forehead pad  42  oriented for placement against the forehead that provide cushioning and facilitate a secure fit of the headband  34  around the head of the surgeon. The head mount  32  also comprises a harness  44  in the form of a band coupled to the front portion  36  and the rear portion  38  of the headband  34  and having an arcuate configuration so as to extend over the crown of the surgeon&#39;s head. Pads, such as crown pads  46 , can be positioned on the underside of the harness  50  to facilitate a comfortable fit of the harness  44  against the crown of the surgeon&#39;s head. 
         [0023]    The headband  34  supports an illumination assembly  50  at the front portion  36  and a power source  52  for the illumination assembly  50  at the rear portion  38 . The illumination assembly  50  comprises an illumination source  54  provided within an illumination source housing  56  and a lens  58  positioned at the front end of the housing  56 . The lens  58  protects the illumination source  54  within the housing  56  and can optionally function as a filter for light emitted by the illumination source  54 . An adjustable mount  60  couples the housing  56  to the headband  34  and includes a pivotable joint  62  at which the housing  56  connects to the mount  60  and about which the housing  56  can pivot for moving the housing  56  and, thereby, the illumination source  54 , in up and down directions. In some embodiments, the mount  60  can be configured for additional adjustment of the housing  56  and/or the illumination source  54  in other directions, such as lateral or side-to-side movement. In certain embodiments, the mount  60  can be configured for adjustment of the housing  56  and/or the illumination source  54  in any direction, such as via a universal or U-joint. The adjustment of the housing  54  and/or the illumination source  54  in the illustrated embodiment is accomplished manually, and other embodiments employ other adjustment methods, such as verbal/speech recognition adjustment to further render the external illumination apparatus  30  hands-free. 
         [0024]    The illumination source  54  can be any suitable device that provides desired external illumination during a phlebectomy procedure. In one embodiment, the desired external illumination is a broad field of white light that sufficiently illuminates a relatively dark room to allow the surgeon to perform the visual inspection of the material removed from the patient. Such light can be provided by any suitable illumination source, including, but not limited to, electroluminescent illumination sources, such as LEDs, and conventional light bulbs, such as fluorescent and incandescent light bulbs. In other embodiments, the desired external illumination can be a broad field of colored (i.e., not white) light that facilitates the visual inspection of the material or a narrow, focused field of white or colored light. In one embodiment, the wavelength(s) of light provided by the illumination source  54  can be selected to aid the surgeon in distinguishing the vein from surrounding tissues, such as fat tissue. 
         [0025]    The power source  52  that provides power to the illumination source  54  in the illustrated embodiment comprises a portable power source in the form of a battery. The battery can be any suitable battery, including replaceable and/or rechargeable batteries. In one embodiment, the battery can be rechargeable and removed from the head mount  32  for coupling to a charger. In another embodiment, the entire external illumination apparatus  30  can be coupled to a charger, such as via a docking station or a cord that connects the battery to a power outlet. The power source  52  can also include a cord or other physical connection that couples the illumination source  54  to an external source of power, either to replace the portable power source or to be used as a back-up in the event that the portable power source becomes depleted during use of the external illumination apparatus  30 . 
         [0026]    A set of wires  70 ,  72  electrically connects the power source  52  to the illumination source  54 , and a switch  80  controls the supply of electricity from the power source  52  to the illumination source  54 . As best viewed in  FIG. 4 , which is a top view of the external illumination apparatus  30 , the harness  44  of the head mount  32  supports the wires  70 ,  72  and the switch  80 . The wire  70  electrically couples the power source  52  to the switch  80 , and the wire  72  electrically couples the switch  80  to the illumination source  54 . 
         [0027]    In the illustrated embodiment, the switch  80  is an inertial switch in the form of an acceleration switch responsive to the movement of the surgeon&#39;s (or other wearer&#39;s) head. The switch  80  is partially located within a switch housing  82  mounted to the harness  44 . Referring now to  FIG. 5 , which is a perspective view of the switch  80 , and  FIG. 6 , which is a sectional view bisecting the switch  80  along its longitudinal axis, the switch  80  comprises a casing  84  having, at its rear end, a vent  86  for an interior chamber  88  that receives a ball  90  and a compression spring  92  and, at its front end, a bore  94  that slidably receives a plunger  96 . The plunger  96  extends from within the chamber  88  and through the bore  94  to project beyond the front end of the casing  84 . The compression spring  92  surrounds the portion of the plunger  96  within the chamber  88  and spaces the ball  90  from the plunger  96  when the compression spring  92  is in its natural extended condition shown in  FIGS. 5 and 6 . The front end of the plunger  96  functions as a first electrical contact  98  and is electrically coupled to the wire  70  by a conductive leaf spring  100 . The switch  80  further includes an L-shaped arm  102  extending from the front end of the casing  84  and terminating at a second electrical contact  104  linearly aligned with and facing the first electrical contact  98 . The conductive arm  102  couples the wire  72  with the second electrical contact  104 . The switch  80  is normally in an unactuated condition where the compression spring  92  is in its extended condition, and the plunger  96  is in a retracted position such that the first and second electrical contacts  98 ,  104  are spaced from each other with no electrical communication therebetween, as shown in  FIGS. 5 and 6 . 
         [0028]    Actuation of the switch  80  results from movement of the ball  90  within the chamber  88 . When the switch  80  undergoes sufficient movement for the ball  90  to accelerate forward and overcome the bias of the compression spring  92 , the moving ball  90  compresses the compression spring  92  and eventually contacts the plunger  96 . The moving ball  90  applies a linear force to the plunger  96 , which responds by moving linearly through the bore  94  to an extended position whereby the first electrical contact  98  on the plunger  96  contacts the second electrical contact  104  on the arm  102 , as illustrated in  FIG. 7 , for momentarily closing an electrical circuit, which is described in detail below. The compression spring  92  at this point is completely or near completely compressed, and the forward movement of the ball  90  ceases. Because the forward acceleration of the ball  90  terminates, the compression spring  92  expands and returns to its extended condition, thereby pushing the ball  90  to the rear end of the chamber  88  and spacing the ball  90  from the plunger  96 . Upon removal of the linear force applied by the ball  90 , the plunger  96  slides rearward within the bore  94  due to the bias of the leaf spring  100  and returns to its retracted position. The retraction of the plunger  96  spaces the first electrical contact  98  from the second electrical contact  104 , thereby opening the electrical circuit. 
         [0029]    The electrical circuit can be any suitable electrical circuit that functions to turn the illumination source  54  on and off upon actuation of the switch  80 , and  FIG. 8  illustrates a diagram of an exemplary embodiment of the electrical circuit. The switch  80  is a momentary switch implemented, by example, through a NAND gate  110 , such as a CD4011B gate, and a D-type flip-flop  112 , such as a CD4013B flip-flop. When the contacts  98 ,  104  are closed upon actuation of the switch  80 , the output at pin  3  of the gate  110  is sent to the input CLK at pin  11  of the flip-flop  112 . At an initial state with the illumination source  54  off, the input D at pin  9  of the flip-flop  112  and the output Q-bar at pin  12  are HIGH. When the contacts are closed, the input CLK at pin  11  goes from HIGH to LOW. Data from the input D at pin  9  is shifted to output Q at pin  13 , which makes the output Q at pin  13  HIGH and turns the illumination source  54  on and makes Q-bar at pin  12  of the flip-flop  112  LOW. The next actuation of the switch  80  shifts the data from the input D at pin  9 , which is now LOW, to the output Q at the pin  13  to turn the illumination source  54  off. This cycle repeats with subsequent actuations of the switch  80 . 
         [0030]    Referring now to  FIG. 9 , which shows the external illumination apparatus  30  worn on the head of a surgeon, the switch  80  in the illustrated embodiment is positioned forward of the apex of the harness  44  to facilitate actuation of the switch  80 . The switch position preferably corresponds to forward of the head apex when the external illumination apparatus  30  is worn on the surgeon&#39;s head. In this position, the switch  80  is slightly angled with the ball  90  behind the compression spring  92 . Actuation of the switch  80  occurs when the surgeon quickly nods the head, as indicated by the arrow “A” in  FIG. 9 . Forward and downward movement of the head during the nod (together with a relatively sudden stop and/or momentary reversal of the direction of movement of the head) induces forward movement of the ball  90  against the compression spring  92 . Because the ball  90  is angled, gravity aids forward movement of the ball  90  within the chamber  88  against the compression spring  92 . While the switch  80  has been described and illustrated as being located forward of the harness apex, the switch  80  can be positioned at any desired location on the head mount  32 . 
         [0031]    As just described, movement of the head of the surgeon wearing the external illumination apparatus  30  actuates the switch  80  to turn the illumination source  54  on and off. The switch  80  defaults to the unactuated condition shown in  FIGS. 5 and 6  and must be converted to the actuated condition shown in  FIG. 7  via a quick head nod or other suitable motion to turn the illumination source  54  on or off In particular, to actuate the switch  80 , the surgeon performs a head nod, whereby the ball  90  moves forward to compress the compression spring  92  and push the plunger  96  through the bore  94  and against the bias of the leaf spring  100  to establish momentary contact between the first and second electrical contacts  98 ,  104 . If the illumination source  54  is off prior to the actuation of the switch  80 , then the output Q at pin  13  of the flip-flop  112  in the electrical circuit becomes HIGH upon contact between the first and second electrical contacts  98 ,  104 , as described above, to turn the light on. On the other hand, if the illumination source  54  is on prior to the actuation of the switch  80 , then the output Q at pin  13  of the flip-flop  112  in the electrical circuit becomes LOW upon contact between the first and second electrical contacts  98 ,  104 , as described above, to turn the light off After the momentary contact between the first and second electrical contacts,  98 ,  104 , the compression spring  92  pushes the ball  90  rearward, and the leaf spring  100  retracts the plunger  96 , as described above, to return the switch  80  to the unactuated condition. In short, the surgeon quickly nods to turn the illumination source  54  on and quickly nods again to turn the illumination source  54  off. 
         [0032]    An exemplary method of operation of the above described embodiment of the system for providing illumination during phlebectomy procedures follows. The method comprises providing internal illumination with the subcutaneous illumination apparatus  10  and providing external illumination with the external illumination apparatus  30 . 
         [0033]    Commonly, phlebectomy procedures involve the use of tumescent anesthesia, using, for example, large-volume, low-concentration lidocaine. Subcutaneous application of the tumescing solution elevates the veins closer to the skin surface and increases the field of illumination. Where the standard anesthesia protocol is inadequate to provide the desired conditions for illumination, additional saline solution can be injected. 
         [0034]    The surgeon&#39;s preparation for the phlebectomy procedure includes placing the external illumination apparatus  30  upon the head by positioning the headband  34  around the head with the front portion  36  on the forehead and the rear portion  38  on the rear of the head such that the illumination assembly  50  and power source  52  are located on the forehead and the rear of the head, respectively, as shown in  FIG. 9 . Adjustment of the headband  34  can be accomplished by adjusting the closure  40 . If needed, the surgeon can adjust the position of the illumination assembly  50  so that the light from the illumination source  54  projects in a desired direction. 
         [0035]    During the following portion of the method involving the use of the subcutaneous illumination apparatus  10 , the illumination source  54  of the external illumination apparatus  30  is in the off condition. At the least, the illumination source  54  is in the off condition when the subcutaneous illumination apparatus  10  illuminates the interior of the body for vein identification. Further, lights in the procedure room, such as an operating room, are preferably off or dimmed for optimized performance of the subcutaneous illumination apparatus  10 . 
         [0036]    Holding the handle  12  of the apparatus  10 , the surgeon inserts the illuminator portion  14  through a skin incision made in the vicinity of a vein to be avulsed. The surgeon can engage the electroluminescent device  16  using the switch  18  either before inserting the illuminator portion  14  or after insertion. The handle  12  is manipulated to place the apparatus  10  beneath a vein to be avulsed, with the electroluminescent device  16  facing upward (or radially outward, or otherwise toward the surgeon or observer). The light emitted by the electroluminescent device  16  passes upward through the vein (including the deoxygenated blood in the vein) and the surrounding tissue, thereby enabling the surgeon to better visualize the vein. For example, where the electroluminescent device  16  emits red, yellow or amber light, or light having a wavelength of 630-670 nm, or approximately 610 nm or less, the vein appears black in contrast to the surrounding tissue, which appears red or yellow. When viewed through the skin, the vein appears as a dark shadow, thereby facilitating location and the placement of further incisions, if required. 
         [0037]    For the initial location of the vein, in one embodiment, the surgeon orients the longitudinal axis of the electroluminescent device  16  transverse to the presumed longitudinal axis of the vein. This configuration offers an improved chance that the vein falls within the field of illumination of the electroluminescent device  14 . Once the vein has been located, the surgeon can employ the blade  22  to locally avulse the vein prior to its removal through the skin incisions. Alternatively, a separate surgical implement such as a phlebectomy hook or forceps can be inserted into the incision(s) and employed to hook or grip, and avulse the vein along its length while it is being visualized through the skin. 
         [0038]    When the surgeon removes the vein through the incision, some other material, such as fat and other surrounding tissues, is frequently removed along with or instead of the vein, and the surgeon performs a visual inspection of the removed material for identification of the vein and separation of the vein from the surrounding tissue. Because the procedure room is relatively dark, the surgeon can employ the external illumination apparatus  30  to provide illumination for the visual inspection. In particular, the surgeon, wearing the external illumination apparatus  30  on the head, quickly nods the head to actuate the switch  80 , as described above in detail, to convert the illumination source  54  from the off condition to the on condition. The light provided from the illumination source  54  enables the surgeon to better visualize the removed material for more accurate identification of the removed vein. If surrounding tissue has indeed been removed with the vein, the surgeon can separate the vein from the surrounding tissue. Upon completion of the visual inspection or whenever desired, the surgeon performs another quick head nod to actuate the switch  80  and, thereby, convert the illumination source  54  from the on condition to the off condition. The surgeon can turn the illumination source  54  on and off as needed throughout the phlebectomy procedure. 
         [0039]    The above method can be adapted for use with other types of apparatuses that provide internal illumination. Examples of other operation methods for other types of internal illumination apparatuses are given in the aforementioned and incorporated &#39;371 publication and corresponding application. Further, the above method can be adapted for use with other types of switches that are activated in hands-free (or hands-free and feet-free) manners other than nodding the head. 
         [0040]    While the external illumination apparatus  30  has been described as part of the illumination system for phlebectomy procedures, the apparatus  30  can be employed alone or in other systems for other types of procedures. Further, the external illumination apparatus  30  can be employed with other types of internal illumination devices for phlebectomy or other types of procedures. 
         [0041]    While certain invention(s) have been specifically described herein in connection with certain specific embodiments thereof, it is to be understood that this description is an illustration of useful embodiments of the invention(s) and not a limitation of the scope of the invention(s).

Technology Classification (CPC): 5