1. Technical Field
The invention relates generally to an apparatus and method for tracking surgical supplies and, more specifically, to counting and accounting for all disposable surgical sponges used in a surgical procedure.
2. Related Art
During surgical procedures, absorbent sponges are employed to soak up blood and other fluids in and around the incision site. In a study entitled “The Retained Surgical Sponge” (Kaiser, et al., The Retained Surgical Sponge, Annals of Surgery, vol. 224, No. 1, pp. 79–84), surgical sponges were found to have been left inside a patient following surgery in 67 of 9729 (0.7%) medical malpractice insurance claims reviewed. In those 67 cases, the mistake was attributed to an incorrect sponge count in seventy-six percent (76%) of the cases studied, and attributed to the fact that no count was performed in ten percent (10%) of the cases studied. Typically, a sponge left inside a patient is presumed to indicate that substandard and negligent care has taken place. Clearly, it is in both a patient's and the health care providers' best interest to account for every surgical sponge used in any particular surgical procedure.
As explained in U.S. Pat. No. 5,923,001 entitled Automatic Surgical Sponge Counter and Blood Loss Determination System, sponge counts are an essential step in operating room procedure. Sponge counts are a difficult procedure for a number of reasons. For example, the handling of soiled sponges carries the risk of transmission of blood borne diseases such as hepatitis B virus (HBV) and human immunodeficiency virus (HIV). Therefore, used sponges are handled with gloves and/or instruments and the handling is kept to a minimum. Another difficulty is that the counting process is typically tedious, time-consuming and frustrating.
Sponge counts are typically performed multiple times during a surgical procedure, both at the beginning and throughout the procedure as sponges are added, before closure of a deep incision or body cavity, and during personnel breaks and shift changes. Thus, within all the activity of an operating room, maintaining an accurate sponge is difficult, as evidenced by the error rate mentioned in the Keiter article, quoted above.
There do exist products to make the procedure both simpler and more reliable. For example, various systems facilitate the hand-counting of surgical sponges by arranging the sponges into visually inspectible groups or arrangements (see U.S. Pat. Nos. 3,948,390, 4,364,490, 4,784,267, 4,832,198, 4,925,048 and 5,658,077). These systems are problematic because surgeons and anesthesiologists often determine blood loss by means of visual inspection or a manual weighing of soiled sponges and so soiled sponges are typically kept in one area of an operating room during a surgical procedure, thus creating the possibility that groupings are co-mingled or counted twice. In addition, operating room workers are often too rushed, fatigued and/or distracted to accurately count a large number of soiled sponges lumped together in one or more groups. This method also depends upon the accuracy of an initial count and, if the number of sponges in the original package is mislabeled by the manufacturer, then a missing sponge may be missed during a final count.
A second solution to the surgical sponge tracking problem is the inclusion of a radiopaque thread in the sponges. A radiopaque thread can be identified and located if a sponge is accidentally left inside a patient. Thus, if a patient develops a problem such as an abscess, a bowel obstruction, or internal pain at any time following an operation, a sponge that has been left in the body can be detected by x-ray. Companies that market sponges with radiopaque threads include Johnson & Johnson, Inc. of New Brunswick, N.J., Medline Industries of Mundelein, Ill. and the Kendall Company of Mansfield, Mass.
A third solution to the sponge problem is the inclusion of a radio frequency identification (RFID) tag in each sponge (see U.S. Pat. No. 5,923,001). The RFID tag enables a patient to be scanned to detect the presence of a sponge within a body cavity, but RFID tags may cost several times what a typical surgical sponge costs and are also bulky, impairing the usefulness of the sponge.
Another solution to the sponge problem is a device that counts sponges as they are dropped, one-by-one, into an opening, or “entry gate,” of the device (see U.S. Pat. No. 5,629,498). This solution is restricted by the accuracy of the original count and the precision of operating room assistants as they separate sponges from one another and drop them into the entry gate, one-by-one.
A final, exemplary solution involves attaching a magnetic resonance device, or marker tag, to each sponge, which are then scanned by appropriate equipment (see U.S. Pat. Nos. 5,057,095 and 5,664,582). The problem with this solution is that both the marker tags and the scanning equipment are expensive and do not necessarily work well in an operating room environment. As acknowledged in the '582 patent, the scanner must be essentially parallel to the marker tag inside a wadded up sponge. If the marker tag is bent or folded, a signal from the tag may be difficult to identify. In addition, the scanning equipment may give false counts if the operating room contains objects, other than the marker, that also generate or respond to magnetic energy.
Many other problems and disadvantages of the prior art will become apparent to one skilled in the art after comparing such prior art with the present invention as described herein.