Method and system for optically evaluating drilling proximity to the inferior alveolar nerve in situ
First Claim
1. A surgical drilling system for determining proximity of a surgical drill bit to an artery located within tissue during a drilling procedure, the surgical drilling system comprising:
- at least one of an excitation optical channel and a first collection optical channel of a spectral absorption probe, wherein the excitation optical channel provides excitation light to the tissue, the excitation light having a wavelength configured for absorption by blood chromophores;
further wherein the first collection optical channel of the spectral absorption probe captures diffused back-scattered light from the tissue including the artery, wherein said diffused back-scattered light is modulated by blood flow dynamics in said artery, said blood flow dynamics being a periodic change in blood volume in said artery due to a cardiac cycle;
a first light detector of the spectral absorption probe operatively connected to said first collection optical channel for detecting said diffused back-scattered light modulated by blood flow dynamics including an oscillating signal, a frequency of said oscillating signal being related to said periodic change; and
a first signal processor operatively connected to the first light detector for determining a first distance between the tissue including the artery and the spectral absorption probe based on said back-scattered light using one or more characteristics of the oscillating signal and a value for surrounding tissue attenuation coefficient;
a low coherence interferometry sub-system including a second collection optical channel for capturing low-coherence back-scattered light from said tissue, the sub-system including a second light detector operatively connected to said second collection optical channel; and
a second signal processor operatively connected to the second collection optical channel for facilitating a determination of a second distance between said tissue including the artery and the spectral absorption probe based on said low-coherence back-scattered light received by said second collection optical channel, further wherein the determined first and second distances are indicative of the proximity of the surgical drill bit to the artery.
1 Assignment
0 Petitions
Accused Products
Abstract
A low coherence interferometry probe system for evaluating proximity to a tissue layer, comprising a low coherence light source for generating low coherence excitation light, an excitation optical fiber to bring the low coherence excitation light near the tissue layer and a collection optical fiber for capturing back-scattered light from the tissue layer. The probe system comprises a low coherence interferometry sub-system and a digital signal processor for evaluating a distance to the tissue layer. There is also provided a spectral absorption probe system for evaluating proximity to an artery, comprising a light source excitation light having a wavelength adapted for absorption by blood chromophores, an excitation optical fiber and a collection optical fiber. The probe system comprises a light detector and a signal processor for determining a distance to the artery based on the back-scattered light and on Beer-Lambert law of light absorption using a value for surrounding tissue attenuation coefficient (μeff). A probe system combining low coherence interferometry and spectral absorption is also provided.
133 Citations
11 Claims
-
1. A surgical drilling system for determining proximity of a surgical drill bit to an artery located within tissue during a drilling procedure, the surgical drilling system comprising:
-
at least one of an excitation optical channel and a first collection optical channel of a spectral absorption probe, wherein the excitation optical channel provides excitation light to the tissue, the excitation light having a wavelength configured for absorption by blood chromophores; further wherein the first collection optical channel of the spectral absorption probe captures diffused back-scattered light from the tissue including the artery, wherein said diffused back-scattered light is modulated by blood flow dynamics in said artery, said blood flow dynamics being a periodic change in blood volume in said artery due to a cardiac cycle; a first light detector of the spectral absorption probe operatively connected to said first collection optical channel for detecting said diffused back-scattered light modulated by blood flow dynamics including an oscillating signal, a frequency of said oscillating signal being related to said periodic change; and a first signal processor operatively connected to the first light detector for determining a first distance between the tissue including the artery and the spectral absorption probe based on said back-scattered light using one or more characteristics of the oscillating signal and a value for surrounding tissue attenuation coefficient; a low coherence interferometry sub-system including a second collection optical channel for capturing low-coherence back-scattered light from said tissue, the sub-system including a second light detector operatively connected to said second collection optical channel; and a second signal processor operatively connected to the second collection optical channel for facilitating a determination of a second distance between said tissue including the artery and the spectral absorption probe based on said low-coherence back-scattered light received by said second collection optical channel, further wherein the determined first and second distances are indicative of the proximity of the surgical drill bit to the artery. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification