This invention relates to a laser surgical apparatus for use in surgical operations.
In modern surgical operations in hospitals, so-called laser surgical knife apparatus utilizing a laser beam are taking the place of steel surgical knives which have long been used. FIG. 1 shows, in schematic form, a prior art laser surgical apparatus wherein a laser beam generated from a laser oscillator 1 is transmitted through an optical path 2 and irradiated on an affected part 4 by manipulating a hand piece 3 carrying the optical path in order to perform a surgical operation for incision and/or blood-coagulation.
For the laser surgical knife, a YAG (Yttrium Aluminum Garnet; Y.sub.3 Al.sub.5 O.sub.12) laser or a carbon dioxide (CO.sub.2) laser may be used. The former type laser generates a laser beam of a wavelength of 1.06 .mu.m and the latter type laser generates a laser beam of a wavelength of 10.6 .mu.m, these wavelengths being invisible to naked eyes of the surgical operator. Accordingly, with the prior art laser surgical knife apparatus, the operator could not observe the emission of a laser beam from the forefront hand piece. Such a disadvantage is prone to an erroneous irradiation which may cause an erroneous operation or danger of the operator or the assistant operator, raising serious problems in securing safety in surgical operations. The operator often feels uneasy about these problems and cannot devote himself to an intended medical treatment.
In view of the above problems, use of laser surgical knife apparatus is regulated by the safety standard called ANSI (American National Standard Institute) Z 1361 - 1973. This standard rules that when operating a laser apparatus, an alert system using, for example, sound or alarm lamp should be used. Pursuant to this standard, it is possible to confirm whether the laser is emitting an invisible laser beam. To watch the alarm lamp, however, the operator must avert his eyes from the part to be operated and he cannot devote himself to the surgical operation. Also, the sound alert is generally noisy and may prevent proper communication of the operator's instructions to the assistant operator during the operation.