Abstract: An apparatus for detecting a surgical implement in human or animal tissue comprises a battery powdered marker. The marker is secured to the surgical implement and positioned within a surgical wound. A detection means has an antenna disposed in close proximity of the tissue. Means are provided for capacitance coupling of both the marker and the antenna to the tissue. A field generating means generates an electromagnetic field having a predetermined frequency band within the tissue and a signal generating means generates a signal having a predetermined frequency band ranging from about 10 MHz to 1 GHz. The signal generated by the signal generating means causes the field generating means to generate the electromagnetic field providing the marker with signal identity.

Abstract: A radiographic film packet is adapted to be placed in a patient's mouth for exposing a sheet of dental film to x-rays generated by an x-ray tube. The packet includes a light-proof and moisture resistant envelope having a first side and a second side defining a pocket for receiving the film sheet.Disposed within the pocket are a sheet of lead and a sheet of film, the lead sheet being located adjacent the second side and the film sheet being located between the lead sheet and the first side. An indicator affixed to the first side expressly designates the edge of the film packet appointed to be uppermost in the mouth during radiographic exposure. A film marker is affixed to said film sheet along a periphery and proximate a corner thereof. The film marker has a constant orientation relative to the indicator, and identifies the orientation of the film sheet during exposure.

Abstract: A radiographic film cassette exposes a sheet of film to X-rays projected along an X-ray path by an X-ray tube. The cassette has an inner surface defining a recess for receiving the film sheet. A base having an inner surface is adapted to close upon the cover for securing the film sheet. A key is permanently mounted to the cover and disposed within the recess to provide the recess with chiral asymmetry. The sheet of film has a cutout adapted to engage the key. A marker is permanently fixed along at least one edge of the film. The key is so mounted that its disposition within the recess permits engagement with the cutout in only one orientation of the film sheet therein. The marker has chiral asymmetry and cooperates with the key and the cutout to identify the side of the film sheet facing the X-ray tube during exposure.

Abstract: An apparatus for detecting a surgical implement in human or animal tissue has means for defining a transmitting zone encompassing a surgical wound in the tissue. A battery powered marker is secured to a surgical implement positioned within the wound. Field generating means are provided for generating within the transmitting zone an electromagnetic field having a predetermined frequency band. A signal generating means generates a signal having a predetermined frequency band. The signal generating means is operative to cause the field generating means to generate the electromagnetic field, providing the marker with signal identity. A detecting means having an antenna located within the transmitting zone of the marker detects the marker signal irrespective of the marker's orientation therewithin.

Abstract: An apparatus for detecting a surgical implement in human or animal tissue comprises a battery powered marker. The marker is secured to the surgical implement and positioned within a surgical wound. A detection means has an antenna disposed in close proximity of the tissue. Means are provided for capacitance coupling of both the marker and the antenna to the tissue. A field generating means generates an electromagnetic field having a predetermined frequency band within the tissue and a signal generating means generates a signal having a predetermined frequency band ranging from about 10 MHz to 1 GHz. The signal generated by the signal generating means causes the field generating means to generate the electromagnetic field providing the marker with signal identity.

Abstract: The present invention provides an X ray film cassette with a permanent marking means for identifying the side of the radiographic film that faced the X ray tube during exposure. Such identification is achieved irrespective of whether the film is exposed through the cover or base of the cassette and does not require any separate action by the X ray technologist, eliminating the element of human error. In a preferred embodiment, the working means is comprised of chirally asymmetric X ray opaque and/or light-opaque letters or markings permanently mounted in the film cassette. A user friendly apparatus is described, for installing the light-opaque markers on the intensifying screens of the X ray film cassette.

Abstract: Apparatus for detecting a surgical implement in human or animal tissue comprises a detector responsive to the presence, within an interrogation zone, of a surgical implement to which a marker is secured. The marker is adapted to produce identifying signal characteristics within a frequency band generated in the interrogation zone. Variations in the phase and or direction of the interrogating field and changes in the electromagnetic coupling between markers and receiver optimize coupling therebetween.