Surgery – Instruments – Electrical application
Reexamination Certificate
2000-06-07
2002-08-06
Dvorak, Linda C. M. (Department: 3739)
Surgery
Instruments
Electrical application
C606S034000, C606S001000
Reexamination Certificate
active
06428535
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a medical apparatus consisting of a terminal instrument for giving certain treatment to the body with electric or electromagnetic output and an apparatus body for activating the terminal instrument. More specifically, the present invention relates to a disposable medical instrument which is activated by electric or electromagnetic output and equipped with a mechanism that prohibits its reuse after a predetermined length of use, as well as to an apparatus body for activating it, and to a medical apparatus consisting of them.
BACKGROUND ART
Many of medical instruments to be brought into direct contact with the body or body fluid are supplied as disposable items for prevention of inter-patient infection. As to an apparatus for coagulation or hemostasis of bio-tissues like a microwave surgical apparatus, too, not a few probes to be brought into contact with the body are supplied as disposable items. In some hospitals or like facilities, however, some cases have been noted where such medical instruments are repeatedly used in order for cost reduction or otherwise. Such a way of use may put patients at risk of infection. Further, as they are instruments designed to be disposable, they may degrade through repeated uses and thereby slump into malfunction just while they are being used.
In order to avoid such problems, it has been attempted to design a medical instrument so that it cannot be used beyond predetermined times or length. For example, an instrument once used will, without doubt, be washed if it is about to be used again. Based on this, a technique is disclosed in Japanese Laid-open Patent Publication H07-95982 by which some element of a probe or a like instrument is made of a material comprising a hydrophilic polymer, which is dissolved, swollen or soften through washing and thereby blocks the reuse of the instrument. Another device is also known with which the reuse of a probe is prevented by forcibly melting down a fuse installed in the probe at the end of its use.
With the method by which some element of the instrument is made of a material comprising a hydrophilic polymer, however, there is a great disadvantage that the instrument could become unusable even during a surgical operation, too, due to its dissolution, swelling or softening when it is brought into prolonged contact with blood, a disinfectant solution or physiological saline. Likewise, with the method relying on a fuse installed in the probe, there is a risk that the body would receive an electric shock, for an electric current, which is not less than 100 mA, for example, must be supplied to the probe by the apparatus body to forcibly melt down the fuse.
Upon the above background, the objective of the present invention is to provide a medical instrument and a medical apparatus equipped with it for microwave surgery, electric knife surgery, laser knife surgery, argon beam coagulation, etc., wherein the medical instrument is made so that it can substantially force itself to be disposed of after use through restricting, without adversely affecting its quality or safety of the apparatus, the length of time during which the use of the medical instrument is allowed by installing in the medical instrument, e.g., a probe, which is brought into direct contact with the body or body fluid of patients a mechanism that limits the operative life span of the instrument.
DISCLOSURE OF INVENTION
Thus, the pre sent invention provides a medical apparatus comprising:
an apparatus body having a terminal-output-generating section which generates predetermined terminal output which may be electric or electromagnetic output and a primary control section which sends an output command to make the terminal-output-generating section generate terminal output, and
a terminal instrument which is removably connected via a cable to the terminal-output-generating section and operates as predetermined while receiving the terminal output wherein:
(1) the terminal instrument is provided with an installed cell of predetermined capacity and further provided with terminals respectively extending from the both poles of the installed cell and electrically connected via a cable to respective cell-voltage-input terminals on the apparatus body, and
(2) the apparatus body is provided with
(a) an allowable-length-of-use-setting/discharging section and an extension-of-time-setting section both of which operate upon receipt of the output command from the primary control section, as well as with a comparison-and-determination section, a standard-voltage-setting section which provides the comparison-and-determination section with standard-voltage information to be referred, and an alarm-generating section, wherein:
(b) the allowable-length-of-use-setting/discharging section is so constructed that it, upon receipt of the output command, provides electrical connection between the cell-voltage-input terminals via a predetermined resistor to form a closed circuit to discharges the installed cell and sends a voltage-information output corresponding to the electromotive force of the installed cell, which is derived based on the voltage between two points within the circuit, to the comparison-and-determination section,
(c) the comparison-and-determination section is so constructed that it compares the voltage-information output with the standard-voltage information received from the standard-voltage-setting section and determines whether the electromotive force of the installed cell is on or above the standard level or it has fallen below the standard level, and transmits the result signal to the extension-of-time-setting section and the alarm-generating section,
(d) the extension-of-time-setting section is so constructed that it, upon receipt of the signal from the comparison-and-determination section, transmits the output command received from the primary control section to the terminal-output-generating section if the electromotive force of the installed cell is on or above the standard level but can block the output command if the electromotive force of the installed cell is below the standard level,
(e) the alarm-generating section is so constructed that it, corresponding to the result signal received from the comparison-and-determination section, generates an alarm to indicate the result if the electromotive force of the installed cell is lower than the standard level, and
(f) the allowable-length-of-use-setting/discharging section is so constructed that it keeps discharging the installed cell while the output command from the primary control section is transmitted to the terminal-output-generating section and the terminal-output-generating section is generating terminal output.
The present invention with the above features is characterized in that the installed cell is discharged and wasted via the apparatus body while the terminal instrument is in actual use (e.g., by supplying microwave to the electrodes of a microwave surgery apparatus). The electromotive force of the cell installed in the terminal instrument thus falls below the standard level after a certain length of use. When a terminal instrument with an installed cell whose electromotive force is below the standard level is attached to the apparatus body and set to be energized in order to reuse it, the comparison-and-determination section determines that the electromotive force of the installed cell is below the standard level. This result in the output command from the primary control section being blocked and not transmitted to the terminal-output-generating section. Thus, terminal output is not generated and such a improper use therefore is effectively prevented. In addition, the user is notified with an alarm that it would be an improper use. Thus, by preventing reuse of the terminal instrument, the apparatus of the present invention guarantees that the instrument be properly used as a disposable item as originally intended, thereby preventing inter-patient infection via the instrument.
The medical instrument according to the present invention do
Kitada Suminori
Wakikaido Koichi
Azwell Inc.
Dvorak Linda C. M.
Millen White Zelano & Branigan P.C.
Ruddy David M.
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