Caitlin Regan1,2, Bruce Y Yang1, Kent C Mayzel1,2, Julio C Ramirez-San-Juan1,3, Petra Wilder-Smith1,4, Bernard Choi1,2,4,5. 1. Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, 92612. 2. Department of Biomedical Engineering, University of California, Irvine, California, 92697. 3. Optics Department, Instituto Nacional de Astrofísica, Óptica y Electrónica, Puebla, México, 72840. 4. Department of Surgery, University of California, Irvine Medical Center, Orange, California, 92868. 5. Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, California, 92697.
Abstract
BACKGROUND AND OBJECTIVE: In endodontics, a major diagnostic challenge is the accurate assessment of pulp status. In this study, we designed and characterized a fiber-based laser speckle imaging system to study pulsatile blood flow in the tooth. STUDY DESIGN/ MATERIALS AND METHODS: To take transilluminated laser speckle images of the teeth, we built a custom fiber-based probe. To assess our ability to detect changes in pulsatile flow, we performed in vitro and preliminary in vivo tests on tissue-simulating phantoms and human teeth. We imaged flow of intralipid in a glass microchannel at simulated heart rates ranging from 40 beats/minute (bpm) to 120 bpm (0.67-2.00 Hz). We also collected in vivo data from the upper front incisors of healthy subjects. From the measured raw speckle data, we calculated temporal speckle contrast versus time. With frequency-domain analysis, we identified the frequency components of the contrast waveforms. RESULTS: With our approach, we observed in vitro the presence of pulsatile flow at different simulated heart rates. We characterized simulated heart rate with an accuracy of and >98%. In the in vivo proof-of-principle experiment, we measured heart rates of 69, 90, and 57 bpm, which agreed with measurements of subject heart rate taken with a wearable, commercial pulse oximeter. CONCLUSIONS: We designed, built, and tested the performance of a dental imaging probe. Data from in vitro and in -vivo tests strongly suggest that this probe can detect the presence of pulsatile flow. LSI may enable endodontists to noninvasively assess pulpal vitality via direct measurement of blood flow.
BACKGROUND AND OBJECTIVE: In endodontics, a major diagnostic challenge is the accurate assessment of pulp status. In this study, we designed and characterized a fiber-based laser speckle imaging system to study pulsatile blood flow in the tooth. STUDY DESIGN/ MATERIALS AND METHODS: To take transilluminated laser speckle images of the teeth, we built a custom fiber-based probe. To assess our ability to detect changes in pulsatile flow, we performed in vitro and preliminary in vivo tests on tissue-simulating phantoms and human teeth. We imaged flow of intralipid in a glass microchannel at simulated heart rates ranging from 40 beats/minute (bpm) to 120 bpm (0.67-2.00 Hz). We also collected in vivo data from the upper front incisors of healthy subjects. From the measured raw speckle data, we calculated temporal speckle contrast versus time. With frequency-domain analysis, we identified the frequency components of the contrast waveforms. RESULTS: With our approach, we observed in vitro the presence of pulsatile flow at different simulated heart rates. We characterized simulated heart rate with an accuracy of and >98%. In the in vivo proof-of-principle experiment, we measured heart rates of 69, 90, and 57 bpm, which agreed with measurements of subject heart rate taken with a wearable, commercial pulse oximeter. CONCLUSIONS: We designed, built, and tested the performance of a dental imaging probe. Data from in vitro and in -vivo tests strongly suggest that this probe can detect the presence of pulsatile flow. LSI may enable endodontists to noninvasively assess pulpal vitality via direct measurement of blood flow.
Authors: Caitlin Regan; Sean M White; Bruce Y Yang; Thair Takesh; Jessica Ho; Cherie Wink; Petra Wilder-Smith; Bernard Choi Journal: J Biomed Opt Date: 2016-10-01 Impact factor: 3.170
Authors: Christian Crouzet; Robert H Wilson; Donald Lee; Afsheen Bazrafkan; Bruce J Tromberg; Yama Akbari; Bernard Choi Journal: J Am Heart Assoc Date: 2020-01-04 Impact factor: 5.501