Abstract:
An apparatus comprising of a segmented instrument tray, precision scale, image processing system, photoelectric sensors and a Personal Computer (PC) is disclosed. Said apparatus provides an automated and accurate tracking of surgical instruments used during surgical operating procedure by counting and identifying a specific quantity and instrument type, which are removed from a sterilized instrument tray to be used during the procedure and subsequently returned to the tray upon procedure completion, thus preventing an accidental leaving of an instrument inside of a patient and significantly reducing time spent by the operation staff for the instrument accounting.

Description:
RELATED APPLICATIONS  
       [0001]    The present invention is a Continuation of, and was first described in, and claims the benefit of priority of U.S. Provisional Patent No. 60/456,251 filed on Mar. 20, 2003. There are no previously filed, nor currently any co-pending applications, anywhere in the world. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to systems and methods used to automatically track and inventory nonuniform items in real-time, and more particularly to a method and equipment for automated tracking and identification of surgical instruments and consumables in a surgical operating room environment.  
           [0004]    2. Description of the Related Art  
           [0005]    Problems have long existing in maintaining an accurate accounting of tools, parts and components during many types of intricate procedures. These can relate from assembly and maintenance of aircraft engines, to general inventorying of non-uniform parts, and to keeping accurate track of surgical tools during medical procedures. In this last example, the loss of surgical instruments has been one of the major problems for most healthcare facilities for many years. This problem is particularly costly for large size hospitals comprising hundreds of operating rooms, and multimillion dollars of instrument inventory.  
           [0006]    Instruments are lost during transfer from and to surgical processing departments, sterilization process and/or operating room procedures. But perhaps the most dangerous of all, they are lost inside the patients. Some studies indicate that surgical teams accidentally leave clamps, sponges and other tools inside about 1,500 patients nationwide each year.  
           [0007]    There are several computerize solutions available on the market, which provides tracking of surgical instruments sets. Most systems use barcode-scanning technology to facilitate tracking of instruments through the decontamination process; the inspection assembly, and packaging process; and the sterilization cycle. These systems consider any particular set as a unit and provide list of the instruments comprising the set.  
           [0008]    However, verification that set is actually complete is still done manually. Manual counts are performed in surgical processing departments after set assembly and upon return from operating room procedures. It is performed from two to four times by highly trained nurses before, during and after surgery. Manual count is not very reliable. It is destructive and stressful for operating team, open to counting mistakes, leading to multiple re-counts. Additionally, due to nationwide shortage of nurses, other personnel are often understaffed. Finally, and perhaps most importantly, this practice is very time consuming leading to underutilization of operating room resources.  
           [0009]    A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related:  
                                       U.S. Pat. No.   Inventor   Issue Date                   6,581,204   DeBusk et al.   Jun. 17, 2003       6,430,536   Irving et al.   Aug. 6, 2002       6,611,806   Harvey   Aug. 26, 2003       5,573,529   Haak et al.   Nov. 12, 1996       6,384,349   Voll   May 7, 2002       6,617,530   Lin   Sep. 9, 2003       5,650,593   Morris et al.   Jul. 22, 1997       5,923,001   Morris et al.   Jul. 13, 1999                  
 
           [0010]    Accordingly, there exists a need for a method and mechanism to automatically track and inventory nonuniform items in real-time.  
         SUMMARY OF THE INVENTION  
         [0011]    It is therefore an object of the present invention to provide an improved method and apparatus to track and inventory a set of nonuniform items in real-time.  
           [0012]    It is a feature of the present invention to provide a method and equipment that can be utilized for automated tracking and identification of surgical instruments in a surgical room environment.  
           [0013]    Briefly described according to one exemplary embodiment of the present invention, a method of the instrument tracking involves preliminary (prior to sterilization) weighing of the individual instruments belonging to a standardized surgical instrument set and recording weight information in the computer file identifying the set. During a surgical procedure, sterilized instruments are placed on a segmented tray, with the instruments of a specific type being placed within the same segment. Tray is positioned on top of a precision scale. Image Analysis system detects placement or withdrawal of the instruments from a specific segment. Scale measures weigh difference prior to and after placement or withdrawal of any number of instruments from an individual segment. Signal from the scale and the Image Analysis system are collected by PC, and based on a weight differential and the specific segment position, computer program determines number and type of instruments inserted or withdrawn from the tray. For a consumables (sponges for example), scale and image processing system detect number of sponges removed from the sterilized area to be used during the surgical procedure, and photoelectric sensors detects disposal of the individual soiled sponges in the collection bag. Computer program provides visual and audible indication of the quantity and type of the instruments (or consumables) still remaining in the operating field.  
           [0014]    An advantage of the present invention is that its teachings can be applied, within the scope of the present invention, to many different systems that require a real-time tracking of parts, tools, steps or components.  
           [0015]    Advantages of the present invention, as applied to the exemplary embodiment, include increased real-time accounting accuracy of the location of surgical tools in a substantially diminished time span. Such advantages in this particular application are well known to provide numerous benefits associated with decreased surgical times.  
           [0016]    Further, the present invention is anticipated as being capable of being adapted to many different complex systems utilizing a plurality of nonhomogeneous components, a plurality of specialized installation or assembly tools, a plurality of assembly systems, or any combination thereof. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:  
         [0018]    [0018]FIG. 1 is a logic diagram describing a method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  according to the preferred embodiment of the present invention;  
         [0019]    [0019]FIG. 2 is an example of an input screen on a computer during use of the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10 ;  
         [0020]    [0020]FIG. 3 a  is a block diagram of the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  utilizing an image processing system according to the preferred embodiment of the present invention;  
         [0021]    [0021]FIG. 3 b  is a block diagram of the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  utilizing multiple thru beam photoelectric sensors according to an alternate embodiment of the present invention;  
         [0022]    [0022]FIG. 4 is a logic diagram of the counting and identification method used by the image processing system as used with the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10 , and,  
         [0023]    [0023]FIG. 5 is a sample computer screen as used for automatic continuous counting of surgical instruments stored on the back table.  
                                         DESCRIPTIVE KEY                                10   method and equipment for           automated tracking and           identification of surgical           instruments in a surgical room           environment       15   individual surgical instrument       20   complete standardized           surgical instrument set       25   sterilization       30   accurate scale       35   computer data file       40   serial number       45   set completeness       50   setup process       55   operation phase       60   cleaning process       65   final verification phase       70   pictorial representation       75   computer monitor setup           screen       80   instrument name field       85   set name data field       90   assembly instructions data           field       95   instrument quantity data field       100   indication icons       105   platform       110   sterile cloth       115   segments       120   video camera       125   personal computer equipped           with an image processing           application       130   user       135   identifying bracelet       140   consumables       145   disposal bag       150   thru beam detection system       155   multiple proximity detection           system       160   first sensor       165   second sensor       170   computer monitor utilization           screen       175   instrument quantity present           data field       180   status icon                  
 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within the FIGS. 1 through 5.  
         [0025]    1. Detailed Description of the Figures  
         [0026]    Referring now to FIG. 1, a logic diagram describing a method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  according to the preferred embodiment of the present invention is disclosed. The weight of an individual surgical instrument  15  belonging to a complete standardized surgical instrument set  20  prior to sterilization  25  is measured with an accurate scale  30 , envisioned to be accurate within ˜0.1 g resolution. To simplify said procedure to form a complete standardized surgical instrument set  20  from individual surgical instrument  15 , a picture of the individual surgical instrument  15  is displayed on a computer screen with the required number of instruments necessary for the set assembly as will be shown herein below. The individual surgical instrument  15  are placed on the accurate scale  30  one at a time according to screen request. Weights of the individual surgical instrument  15  are stored in a computer data file  35 . A serial number  40  is assigned to the complete standardized surgical instrument set  20 , which allows retrieval of information regarding instrument weights during operation. Set completeness  45  is automatically verified during set assembly, since the computer will automatically count and compare weights of measured pieces with nominal weights of this particular type of individual surgical instrument  15  stored in the database. However, it is further anticipated that in some situations it would be desired to provide an opportunity for single step verification for set completeness. Such a situation can be resolved by simply weighing the set and comparing its weight with the expected weight as stored in the computer date file  35 . If no mismatch occurs, set completeness is verified. If a mismatch does occur, then the combinatoric algorithm defined in greater detail below can interactively point to potentially missing parts. In either case, during formation of the complete standardized surgical instrument set  20 , a restriction is placed that weight of instruments of the same type cannot differ by more than two times (ratio between minimum and maximum weights of the same type instruments) to prevent rounding off error in the subsequent identification routine. After the sterilization  25 , but prior to surgical procedure, sterilized instrument set is delivered to the operating room. Instruments are spread on a platform covered with a sterile cloth as defined by a setup process  50 . Further description of the tracking process during an operation phase  55  will be defined herein below. At the conclusion of the operation phase  55 , a cleaning process  60  occurs prior to a final verification phase  65 , at which point the process would repeat starting with the sterilization  25 , in the case of a repeated complete standardized surgical instrument set  20 . To speed up final verification in the operating room, the present invention would anticipate the benefit of providing a second scale for used instruments for the instances where used, contaminated instruments are not returned to and in order to prevent cross contamination between sterile and non-sterile instruments.  
         [0027]    Referring now to FIG. 2, is an example of an input screen on a computer during use of the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  is shown. A pictorial representation  70  of each individual surgical instrument  15  (as seen in FIG. 1) is presented upon a computer monitor setup screen  75 . Additional information such as the instrument name field  80  of each individual surgical instrument  15 , as well as the set name data field  85  of the complete standardized surgical instrument set  20  (as seen in FIG. 1) being assembled is presented. An assembly instructions data field  90  is also provided to instruct the user on assembly of the complete standardized surgical instrument set  20 , thus reducing training and errors. An instrument quantity data field  95  is provided to instruct the user on the specific quantity of the individual surgical instrument  15  needed in each complete standardized surgical instrument set  20 . Finally, indication icons  100  are provided to alert the user of the respective status of the individual surgical instrument  15 .  
         [0028]    Referring next to FIG. 3 a , a block diagram of the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  utilizing an image processing system according to the preferred embodiment of the present invention is depicted. Individual surgical instrument  15  are spread on a platform  105  platform covered with a sterile cloth  110 . The platform  105  is divided into segments  115  segmented, with the individual surgical instrument  15  of the same type being placed within the same segments  115 . The platform  105  is positioned on top of the accurate scale  30 . A video camera  120  is installed at some distance above the platform  105  or also known as the operating back-table. The video camera  120  is connected to a personal computer equipped with an image processing application  125 . A user  130 , such as a scrub nurse would wear an identifying bracelet  135  such as a color bracelet or a bracelet with a specific shape imprint on it with a color or imprint specifically chosen to differentiate it from the background. It can also be any identifiable mark or symbol on a cloth or surgical glove differentiating it from the background. The accurate scale  30  detects weight change above a specified level, envisioned to be greater than 0.1 grams. A signal is sent to the personal computer equipped with an image processing application  125  and from the acquired image, position of the hand of the user  130  which places or withdraws the individual surgical instrument  15  instruments from the segments  115  of the platform  105  can be identified by detecting the position of the identifying bracelet  135 . Position of the hand of the user  130  provides a location of the segments  115  from which the individual surgical instrument  15  were withdrawn or placed. After the accurate scale  30  stabilizes, the personal computer equipped with an image processing application  125  will acquire a weight differential prior and after placement or withdrawal of the individual surgical instrument  15 . Count of consumables  140 , such as sponges, is accomplished by detecting new or sterile consumables  140  withdrawals by using above-mentioned sequence for removal from the platform  105 . Disposal of the soiled consumables  140  occurs in a disposal bag  145  and is monitored by use of a thru beam detection system  150 , which counts individual soiled consumables  140  returned, with the aid of and a connection to the personal computer equipped with an image processing application  125 . By adding up the weight of unused and used instruments and comparing it with the initial weight, verification of set completeness can be done in a single step. If there is a mismatch, the user can be guided to search for potentially missing parts, or used instruments can be returned and the system will automatically determine missing components.  
         [0029]    Referring now to FIG. 3 b , is a block diagram of the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  utilizing multiple thru beam sensors according to an alternate embodiment of the present invention is disclosed. Identification of the segments  115  where individual surgical instrument  15  were placed or removed can also be accomplished with any type of multiple proximity detection system  155 , which are positioned in each segments  115  segment as shown. Every time, once a single or several individual surgical instrument  15  are placed or removed from the segments  115  on the platform  105 , the segments  115  will generate a signal corresponding to a particular segment, where thru beam was interrupted. For example, as shown in this FIG., a first sensor  160  and a second sensor  165  will generate a signal, thus identifying a specific segment  115  with changed number of individual surgical instrument  15 . Since instrument placement or withdrawal may potentially generate signals from several neighboring segments  115 , a final verification procedure as described in FIG. 1 will be used. Should the segments  115  be comprised of ultrasonic proximity sensors, said sensors will identify hand position at the moments of scale disturbance, and verification procedure will be similar to the one described above.  
         [0030]    Referring next to FIG. 4, and using references from FIG. 3 a , a logic diagram of the counting and identification method used by the image processing system as used with the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  is depicted. The personal computer equipped with an image processing application  125  determines average weight of the individual surgical instrument  15  placed within the same segments  115  based on the stored information according to the serial number  40  (as shown in FIG. 1) This average weight is defined by the formula:  
         X   j     =         ∑     i   =   1     n          x   i       n                           
 
         [0031]    where, Xj is the average weight of the individual surgical instrument  15  placed in a segments  115  identified by number j. n is number of the instruments in segment j. It should be mentioned that relatively large segmented platform  105  placed on top of the accurate scale  30  could generate potential errors in weight determination, since the same individual surgical instrument  15  placed closer or further away from the center of the accurate scale  30  can produce slightly different scale readings. To eliminate these errors, correction factors are assigned to different segments, which will account for weight differentials vs. segment position relative to the scale center. Number of individual surgical instrument  15 , which could have been potentially placed or removed from any segments  115 , is determined by dividing corrected weight differential over average weight within an individual segment identified by the video camera  120  and the personal computer equipped with an image processing application  125 . Result of the division (a fractional number) is rounded off to the nearest integer. As described above, during selection process, individual surgical instrument  15  of the similar type, which weights differ by more than two times are rejected from the set, thus preventing miscount due to rounding error.  
         [0032]    To prevent misidentification, the following procedure is suggested. Since the personal computer equipped with an image processing application  125  provides only an approximate position of the segments  115 , and each type of individual surgical instrument  15  within neighboring segments  115  can overlap, the number of individual surgical instrument  15 , which could have been potentially removed from neighboring segments  115 , is determined by dividing weight differential (prior and after scale stabilization) over average weight in neighboring segments  115  and rounding off to the nearest integer. To prevent wrong counts, based on the estimated number of pieces removed from each segments  115 , combinatory sum of weights for the estimated number of individual surgical instrument  15  is determined in each segments  115  of interest. The combinatory sum is all possible combinations of weights of the estimated number of individual surgical instrument  15  positioned within the segments  115  of interest. If weight differential measured by the accurate scale  30  coincides with the estimated sum of the individual surgical instrument  15  weights in one of the segments  115 , the number count and identification of the individual surgical instrument  15  is considered to be confirmed. If the above-described condition can be met for several neighboring segments  115 , an audio and/or visual message will appear on the computer monitor requesting clarification of the counted number and types of the individual surgical instrument  15  placed or removed from the sterilized area. If no match can be found as which may occur in the case of an accidental disturbance of the accurate scale  30  the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  will be reset and total count of the individual surgical instrument  15  on the platform  105  will not be changed in this particular counting event.  
         [0033]    Referring finally to FIG. 5, a sample computer screen as used for automatic continuous counting of surgical instruments during operating room procedures is depicted. Count information is continuously displayed on a computer monitor utilization screen  170  as used in the operating room. Said screen will automatically update an instrument quantity present data field  175 , dependent on verification procedure aforementioned described. Should the instrument quantity present data field  175  match the instrument quantity data field  95  as provided in the setup process  50  (as shown in FIG. 1), a status icon  180  will be colored as shown. Should said quantities not agree in number, the status icon  180  will be provided in another color. Such color coding, allows the user  130  (as shown in FIG. 3 a ) to instantly account for any and all individual surgical instrument  15  (as shown in FIG. 3 a ) Said individual surgical instrument  15  usage and history is tracked by the personal computer equipped with an image processing application  125 , and should any individual surgical instrument  15  (as shown in FIG. 3 a ) change, a log file on the personal computer equipped with an image processing application  125  will be updated and stored with the identifying type and number of the individual surgical instrument  15  (as shown in FIG. 3 a ) which are placed or removed from the platform  105  (as shown in FIG. 3 a ) along with a time and date stamp reflecting the specific moment.  
         [0034]    It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.  
         [0035]    2. Operation of the Preferred Embodiment  
         [0036]    The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After installation of the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  in general accordance with either FIG. 3 a  or  3   b , and installation of a personal computer equipped with an image processing application  125  configured with suitable programming to monitor described inputs and outputs, the method and equipment for automated tracking and identification of surgical instruments in a surgical room environment  10  is ready for use. Said use in an operating room environment will be generally identically to conventional operating room procedures and typically transparent to the user  130 , with the exception of the addition of a computer monitor utilization screen  170  in the operating room.  
         [0037]    The user  130  would place each individual surgical instrument  15  on the accurate scale  30  one at a time according to screen request. Weights of the individual surgical instrument  15  are stored in a computer data file  35 , provided as part of the personal computer equipped with an image processing application  125 . set completeness  45  is automatically verified during set assembly as part of the personal computer equipped with an image processing application  125 . When complete, surgery proceeds in a conventional manner, and usage is tracked as described in FIG&#39;s.  3   a ,  3   b  and  4 . At the conclusion of the operation phase  55 , or surgery, the individual surgical instrument  15  would be cleaned in a cleaning process  60 , and a final verification phase  65  occurs, which supports or replaces the conventional verification procedure. At this point the abovementioned process can repeat.  
         [0038]    The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is anticipated that the teachings of the present invention, as exemplified by the present disclosure, can easily be applied or converted to any number of applications. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. Therefore, the scope of the invention is to be limited only by the following claims.