Patent NZ-565509-A (NZ)
Title: Method and apparatus using infrared photothermal radiometry (PTR) and modulated laser luminescence (LUM) for diagnostics of defects in teeth
Inventor: MANDELIS ANDREAS
IPC: H01L31/101
Filed: 2006-07-18
Abstract: Disclosed is an apparatus, comprising: at least one laser light source adapted to irradiate a portion of a surface of a dental tissue with a modulated laser beam of effective wavelength of at least about 659 nm such that modulated photothermal radiometric signals and modulated luminescence signals are responsively emitted from said portion of a dental surface; a first detection means for detecting said emitted modulated luminescence signals, and a second detection means for detecting said emitted modulated photothermal radiometric signals; a hand held probe head, and a flexible optical fiber bundle having a distal end connected to said hand held probe head, said optical fiber bundle including one optical fiber having a proximal end in optical communication with said light source and a distal end terminated at said hand held probe head, said optical fiber bundle including a plurality of multi-mode optical fibers having distal ends terminated at said hand held probe head, a first pre-selected number of said multi-mode optical fibers being near-infrared transmitting optical fibers and having proximal ends optically coupled to said first detection means for transmitting said modulated luminescence signals to said first detection means, and a second pre-selected number of said multi-mode optical fibers being mid-infrared-transmitting optical fibers and having proximal ends optically coupled to said second detection means; software based lock-in amplifier programmed for demodulating said emitted modulated photothermal signals into photothermal phase and amplitude signals and said modulated luminescence signals into luminescence phase and amplitude signals; and processing means programmed for comparing said photothermal phase and amplitude signals to photothermal phase and amplitude signals of a reference sample and comparing said luminescence phase and amplitude signals to luminescence phase and amplitude signals of a reference sample to obtain differences, if any, between said portion of said dental tissue and said reference sample and correlating said differences with defects in said dental tissue. Also disclosed is a method for detection of defects in dental tissue including erosive lesions, pit and fissure lesions, interproximal lesions, smooth surface lesions and root carious lesions in dental tissue, comprising the steps of: a) illuminating a portion of a surface of said dental tissue with said apparatus b) detecting emitted modulated luminescence signals from said apparatus c) demodulating signals from said apparatus into photothermal phase and amplitude components and demodulating modulated luminescence signals from said apparatus into luminescence phase and amplitude signals; and d) comparing said photothermal phase and amplitude signals to photothermal phase and amplitude signals of a reference sample and comparing said luminescence phase and amplitude signals to luminescence phase and amplitude signals of a reference sample to obtain differences, if any, between said portion of said dental tissue and said reference sample and correlating said differences with defects in said dental tissue.