The present invention provides a method of verifying a medical impairment, comprising receiving a medical diagnosis of an injury, the numeric permanent impairment rating resulting from an evaluation of a permanent impairment, and comparing that permanent impairment rating to a statistically evaluated probable impairment rating of the injury. Subject to the use of the detachable cover plate to hold down the electrical fan in the fan chamber, the electrical fan can be installed in the fan chamber conveniently without any fastening members, such as screws, or the use of any hand tool, such as screwdriver and, after removal of the cover plate, the electrical fan can be removed from the housing easily. Rolling circle amplification is then carried out with a DNA polymerase. The light source 2 is disposed so that the light from the light source 2 enters into a substantial center of a part of the finger 1 including a first joint on a palm side and that the light source 2 is contacted with the finger 1. A semi-dense upright growth habit is displayed.