Laser Doppler measurements of cochlear blood flow

Miller, Josef M.; Marks, N. J.; Goodwin, Paul C.

doi:10.1016/0378-5955(83)90069-2

Cited by 110 publications

(38 citation statements)

References 15 publications

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“…In small animals, such as guinea pigs and gerbils, the laser beam can be delivered to the capillary bed of the stria vascularis through the promontory bone of the cochlea (Miller et al 1983, Asami et al 1995. In humans and larger animals, such as rabbits, however, whose cochlea is surrounded by dense otic capsule bone, the penetration depth of the laser is greatly attenuated, which decreases the measurement capability and results in unreliable CBF values (Miller et al 1991, Mom et al 1999.…”

Section: Laser-doppler Measurement Techniquementioning

confidence: 99%

Neuromonitoring of cochlea and auditory nerve with multiple extracted parameters during induced hypoxia and nerve manipulation

Bohórquez

Özdamar

Morawski³

et al. 2005

J. Neural Eng.

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A system capable of comprehensive and detailed monitoring of the cochlea and the auditory nerve during intraoperative surgery was developed. The cochlear blood flow (CBF) and the electrocochleogram (ECochGm) were recorded at the round window (RW) niche using a specially designed otic probe. The ECochGm was further processed to obtain cochlear microphonics (CM) and compound action potentials (CAP).The amplitude and phase of the CM were used to quantify the activity of outer hair cells (OHC); CAP amplitude and latency were used to describe the auditory nerve and the synaptic activity of the inner hair cells (IHC). In addition, concurrent monitoring with a second electrophysiological channel was achieved by recording compound nerve action potential (CNAP) obtained directly from the auditory nerve. Stimulation paradigms, instrumentation and signal processing methods were developed to extract and differentiate the activity of the OHC and the IHC in response to three different frequencies. Narrow band acoustical stimuli elicited CM signals indicating mainly nonlinear operation of the mechano-electrical transduction of the OHCs. Special envelope detectors were developed and applied to the ECochGm to extract the CM fundamental component and its harmonics in real time. The system was extensively validated in experimental animal surgeries by performing nerve compressions and manipulations.

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Section: Laser-doppler Measurement Techniquementioning

confidence: 99%

Neuromonitoring of cochlea and auditory nerve with multiple extracted parameters during induced hypoxia and nerve manipulation

Bohórquez

Özdamar

Morawski³

et al. 2005

J. Neural Eng.

View full text Add to dashboard Cite

show abstract

“…With small animals, like guinea pigs and gerbils, the laser beam can be delivered to the capillary bed of stria vascularis through the promontory bone of cochlea (Miller et al, 1983;Asami et al, 1995). In humans and larger animals, such as rabbits, however, where the cochlea is surrounded by dense otic capsule bone, the penetration depth of the laser is greatly attenuated, decreasing the measurement capability and resulting with unreliable CBF values (Miller et al, 1991;Mom et al, 1999).…”

Section: Laser-doppler Measurement Techniquementioning

confidence: 99%

“…Development of LD technique and its successful use in other tissues enabled researchers to measure CBF with accuracy and minimal invasiveness (Stern et al, 1977). LD rapidly became popular for measuring CBF and other physiological parameters in animal models such as guinea pig, rat, gerbil, and rabbit (Miller et al, 1983;Scheibe et al, 1990;Asami et al, 1995;Ren et al, 1995). Generally, the LD probe was placed on the cochlear promontory bone throughout these experiments, resulting in attenuation of measurement penetration depth due to dense bone tissue.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous measurement of electrocochleography and cochlear blood flow during cochlear hypoxia in rabbits

Yavuz¹,

Morawski²,

Telischi³

et al. 2005

Journal of Neuroscience Methods

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In this study, a new monitoring system is developed to measure cochlear blood flow (CBF) and electrocochleography (ECochG) during transient ischemic episodes of the cochlea. A newly designed otic probe was used for the simultaneous recordings of laser-Doppler CBF and ECochG directly from the round window (RW). The probe enabled the recording of high amplitude compound action potentials (CAP) and cochlear microphonics (CM) with few averages. Experiments were conducted on rabbits to generate episodes of cochlear ischemia by using timed compressions of the internal auditory artery (IAA). The computer monitoring system extracted and measured CAP and CM components from ECochG in real-time. Results indicate that CM and CAP generally followed CBF during compressions and releases of IAA. Both CBF values and CAP amplitudes showed an overshoot following the reperfusion. CAP amplitude measures were found to be very sensitive to ischemia showing very rapid amplitude, latency and morphological changes. CM amplitude decreased more slowly than the CAP and CBF. Simultaneous recordings of CBF and ECochG using the otic probe provide a valuable neuromonitoring tool to investigate the dynamic behavior of the cochlea during ischemia.

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“…In addition, the output of the laser Doppler flowmeter is easily influenced by the thickness of the cochlear bony wall [16]. Therefore, we analyzed CoBF and BP using relative changes from the initial value (percent change).…”

Section: Statistics and Analysismentioning

confidence: 99%

Mechanisms of Photoinduced Cochlear Ischemia in the Guinea Pig

Saitô

Ogawa²,

Inoue

et al. 2001

ORL

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An experimental model of cochlear ischemia using the photosensitization reaction of rose bengal (RB) is reported. Ischemia was induced by the systemic administration of RB solution and localized irradiation of the cochlea with a green light of specific wavelength for RB activation. After the RB solution was administered, the cochlear blood flow was temporarily increased and then decreased, and the latency of wave I of the auditory brainstem response increased and the amplitude of wave I decreased after RB injection and finally wave I disappeared completely. A histological study revealed thrombus formation in the vessels of the irradiated cochlea not only in the stria vascularis and the spiral ligament, but also in the modiolus. L-Histidine, a scavenger of singlet oxygen (¹O₂) and hydroxyl radical (·OH), significantly prolonged cochlear dysfunction, but D-mannitol, a specific scavenger of ·OH did not, suggesting that ¹O₂ has an important role in this reaction.

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Laser Doppler measurements of cochlear blood flow

Cited by 110 publications

References 15 publications

Neuromonitoring of cochlea and auditory nerve with multiple extracted parameters during induced hypoxia and nerve manipulation

Neuromonitoring of cochlea and auditory nerve with multiple extracted parameters during induced hypoxia and nerve manipulation

Simultaneous measurement of electrocochleography and cochlear blood flow during cochlear hypoxia in rabbits

Mechanisms of Photoinduced Cochlear Ischemia in the Guinea Pig

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