in the drawings , like numerals indicate like elements throughout . certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention . the following describes preferred embodiments of the present invention . however , it should be understood , based on this disclosure , that the invention is not limited by the preferred embodiments described herein . referring to fig1 and 2 , an exemplary light scanning device 20 is illustrated in use to detect an implanted medical device , i . e . a venous access port 50 in fig1 and a catheter 150 in fig2 . the exemplary light scanning device 20 uses a two - axis optical scanner to sweep an infrared ( ir ) or near - infrared ( nir ) laser 22 over a target area 12 of a patient 10 . the sweeping laser 22 defines a two - dimensional field of view 24 . as explained in more detail hereinafter , the implanted medical device 50 , 150 is formed with at least one light affective area which is configured to affect the ir or nir light differently compared to the surrounding tissue and the remaining components of the medical device 50 , 150 . for example , the medical device 50 , 150 may have an area configured to absorb the ir or nir light , such that less of the light is reflected in that area or an area configured to reflect the ir or nir light , such that more of the light is reflected in the area compared to surrounding areas . at the same time , the light scanning device 20 is configured to receive and record the reflected light from the field of view 24 using photodiodes or the like tuned to the wavelength of the laser 22 . the light sensing device 20 includes a processor ( not shown ) which receives signals corresponding to the received reflected light and utilizes digital signal processing or the like to create an image of the sensed field of view . the light sensing device 20 may include a display 28 upon which the image is displayed . additionally , the light sensing device 20 is further configured to reproject the created image onto the skin using a visible laser . in an exemplary embodiment , the ir or nir laser 22 has a wavelength of approximately 785 nm and the visible laser has a wavelength of approximately 642 nm . aligned with the data acquired in the infrared range , the projected image provides the practitioner with direct and immediate feedback on the location and orientation of the implanted medical device 50 , 150 . the light scanning device 20 may have various internal components for generating and detecting the ir or nir light and for generating the projected image using visible light . additionally , the light scanning device 20 may be a stationary device or a portable device . various systems for carrying out such light sensing and image generation are set forth in u . s . pat . nos . 8 , 073 , 531 ; 8 , 255 , 040 ; 8 , 295 , 904 ; 8 , 328 , 368 ; 8 , 380 , 291 ; 8 , 391 , 960 ; 8 , 463 , 364 ; 8 , 478 , 386 ; 8 , 489 , 178 ; and 8 , 594 , 770 , each of which is incorporated herein by reference . as set forth above , the medical devices 50 , 150 are preferably formed with at least one light affective area which is configured to interact differently with the ir or nir light compared to the surrounding tissue and the remaining components of the medical device 50 , 150 . exemplary venous access ports 50 incorporating such a light affective area will be described with reference to fig3 - 11 . referring to fig3 - 7 , a first exemplary venous access port 50 will be described . the port 50 generally has a structure similar to the port structure disclosed in u . s . pat . no . 8 , 257 , 325 , the contents of which are incorporated herein by reference . generally , the venous access port 50 includes a housing 52 and a septum 54 , with a discharge port 56 extending from a distal end 58 of the port assembly 50 to be attached securely and sealingly to the proximal end of a catheter ( not shown ). a passageway 60 extends from the interior reservoir 62 to the distal tip opening 64 of discharge port 56 . with reference now to fig6 and 7 , the interior of the port assembly 50 is shown to provide an interior reservoir 62 . the housing 52 is shown to include a housing base 68 of needle - impenetrable material that includes a well 70 having a bottom floor 72 and side walls 74 that define the interior reservoir 62 beneath septum 54 . a skirt 82 is overmolded about housing base 68 and may be of silicone elastomer or other biocompatible material . a cap 88 is also secured to housing base 68 to in turn secure the septum 54 in position in the port assembly 50 . the housing base 68 includes a septum seat 92 extending into the top of well 70 , into which a flange of the septum will be seated . referring to fig3 and 4 , the cap 88 defines a series of light affective areas 91 , 93 annularly about the septum 54 . with this illustrative port 50 , four darker absorptive areas 91 alternate with four lighter absorptive areas 93 . the darker absorptive areas 91 are configured to absorb more of the ir or nir light 22 such that less reflected light will be received for these areas while the lighter absorptive areas 93 are configured to absorb less of the ir or nir laser 22 light such that more reflected light will be received for these areas . the light affective areas 91 , 93 may be defined utilizing various techniques . as examples , the light affective areas 91 , 93 may be defined to have a color which is absorptively or reflectively distinct from the other areas and other components . alternatively , materials having different ir or nir absorptive or reflective qualities may be selected . for example , all or portions of the cap 88 may be made from absorptively or reflectively distinct material . in another embodiment , the septum 54 itself may be manufactured from an absorptively or reflectively distinct material such that the septum defines the light affective area and appears as a distinctly lighted area of the reprojected image 26 . as another exemplary alternative , the light affective areas 91 , 93 may be defined by coating the areas with materials which are absorptively or reflectively distinct , e . g . materials having different fluorescence . as yet another exemplary alternative , the light affective areas 91 , 93 may have varying configurations , e . g . different concavities or convexities , which cause absorptively or reflectively distinct areas . other mechanisms , for example , light producing leds or light reflective metals , coatings or the like , may be positioned in the light affective areas 91 , 93 . the invention is not limited to these exemplary mechanisms for achieving absorptively or reflectively distinct areas and other mechanisms may be utilized . the received reflected light for this embodiment of the port 50 is illustrated in fig1 , with the areas corresponding to the darker absorptive areas 91 appearing darker than the areas corresponding to the lighter absorptive areas 93 . while this embodiment is described with the light affective areas 91 , 93 as absorptive areas , it is recognized that one or both of the areas may instead be reflective areas . as illustrated , each of the light affective areas 91 , 93 is distinct from the surrounding area and the remainder of the port 50 , including the septum 54 . in this way , the septum 54 is clearly identifiable as it is encircled by the light affective areas 91 and 93 . fig1 illustrates an exemplary reprojected visible image 26 based on the light received as illustrated in fig1 . the light sensing device 20 is preferably configured to process the received signals such that the reprojected visible image 26 corresponds to the received light , but is sharper and clearer at the contrasting areas . as seen , the reprojected image 26 will allow the practitioner to clearly identify the location of the port 50 , but more specifically the target septum 54 . the practitioner can easily insert a needle into the septum 54 without the need to guess its exact location as may be required using the palpation technique . additionally , the sensed light and projected image 26 allow the practitioner to easily determine the orientation of the port 50 . if the port 50 began to turn in the patient , the practitioner would see such change in orientation and corrective measures may be initiated more promptly than with prior techniques . the light affective areas 91 , 93 may also be utilized to provide attributes of the medical device . for example , the port 50 of fig3 - 7 is a power injectable port and the pattern of the light affective areas 91 , 93 ( e . g . four alternating areas ) may be configured to convey that the port 50 is power injectable . contrast this to the port 50 ′ illustrated in fig8 which is generally the same as the port 50 , but which is not power injectable . the cap 88 ′ includes a series of light affective areas 91 ′ and 93 ′ about the septum 54 , however , only three of each light affective area 91 ′, 93 ′ are provided . a standard may be set such that the alternating pattern of three light affective areas 91 ′, 93 ′ corresponds to a non - power injectable port 50 ′. comparing the reprojected visible image 26 ′ of the port 50 ′ in fig1 with the image 26 of the port 50 in fig1 , it would be clear to the practitioner which port is power injectable and which is not . as an alternative , the non - power ports may be made without any absorptive / reflective pattern that by its very absence would be clear to the practitioner that the port is non - power injectable . as illustrated in fig5 , the port 50 may still include radiopaque markings 100 to designate the port 50 as power injectable . a larger outer circle 102 is seen provided on the outermost periphery of bottom base surface 94 and a smaller inner circle 104 is seen provided more centrally . the outer and inner circles or rings 102 , 104 circumscribe radiopaque indicia 110 . other radiopaque markings 100 distinct from the elements shown may also be utilized . inclusion of the radiopaque markings 100 in addition to the light affective areas 91 , 93 allows the attributes of the port 50 to be identified in the event a light sensing device 20 is not available or in the event that the patient is undergoing an x - ray anyway . referring to fig1 , the location / orientation function may be distinct from the attribute identification function . for example , the reprojected image 26 ″ represents a power injectable port 50 ″ in which a single light affective area 91 ″ encircles the septum 54 to provide an indication of the location and orientation of the septum 54 . a second light affective area 95 in the form of an alphanumeric indicia , i . e . “ ct ”, is defined in the middle of the septum 54 and is visible in the reprojected image 26 ″. other standards may be utilized be to convey attribute information . also , additional attribute information other than the power injectability may be incorporated into the information represented by the light affective areas . referring to fig9 - 11 and 16 , another exemplary port 50 ′″ will be described . the port 50 ′″ is similar to the previous embodiments , but provides a dual port with a pair of septums 54 , 54 ′ positioned over respective reservoirs 62 , 62 ′. a respective passageway 60 , 60 ′ extends from each interior reservoir 62 , 62 ′ to the distal tip openings of discharge port 56 . as illustrated in fig9 , a series of light affective areas 91 , 92 may be provided about each septum 54 , 54 ′ such that the two distinct target areas will be visible in the reprojected image 26 ″, as illustrated in fig1 . referring to fig2 and 17 - 18 , use of the light sensing device with an alternative implantable medical device , namely , a catheter 150 , will be described . in the illustrated embodiment , a light affective area 191 is defined at the tip 152 of the catheter tube 154 . the light affective area 191 is similar to the light affective areas described above . while the illustrated embodiment includes light affective area 191 only at the tip 152 , it may be provided over a larger area , at spaced intervals or any other desired configuration . as illustrated in fig1 , the reprojected image 26 . sup . iv will show the position of the tip 152 as the catheter body 154 is advanced through an incision 155 and under the skin of the patient . additionally or alternatively , the configuration of the light affective area 191 may be selected such that it is absorptively or reflectively distinct from a fluid 160 intended to be passed through the catheter 150 such that both the tip 152 and the presence of the fluid 160 in the catheter are visible on the reprojected image 26 . sup . v , as illustrated in fig1 . while the present invention has been described with respect to various venous access ports and catheters , the invention is not limited to such and other medical devices may be formed with light affective areas and a light scanning device may be utilized to determine location , orientation , attributes and other information about the subcutaneously implanted medical devices . these and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification . accordingly , it will be recognized by those skilled in the art that changes or modifications may be made to the above - described embodiments without departing from the broad inventive concepts of the invention . it should therefore be understood that this invention is not limited to the particular embodiments described herein , but is intended to include all changes and modifications that are within the scope and spirit of the invention as defined in the claims .
a method of determining information regarding an implanted medical device . the method includes scanning an infrared or near - infrared laser over a target area wherein a medical device having at least one light affective area defined thereon is implanted ; sensing reflected light from the scanned area ; processing the reflected light and creating an image which indicates the light affective area based on a difference in the sensed light ; and displaying the created image . a system for determining information regarding an implanted medical device is also provided .