scholarly journals Shifting from postauricular to transcanal microscopic tympanoplasty may have similar frequency-specific improvements with better air-bone-gap closure at low frequencies and a minimal learning-curve effect

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253947
Author(s):  
Ethan I. Huang ◽  
Yu-Chieh Wu ◽  
Hsiu-Mei Chuang ◽  
Tzu-Chi Huang
Keyword(s):  
Learning Curve ◽  
Patient Comfort ◽  
Pain Patient ◽  
Repair Rate ◽  
Low Frequencies ◽  
Similar Frequency ◽  
Hearing Outcome ◽  
Curve Effect ◽  
Microscopic Tympanoplasty ◽  
Successful Repair

The shift from postauricular to transcanal microscopic tympanoplasty brings potential advantages of minimal morbidity, less postoperative pain, patient comfort, and surgical ease and speed, but also uncertainties of unfamiliar grafting material, an inadequate operation view, and an uncertain learning curve. These challenges might affect the successful repair rate and the frequency-specific hearing outcome, which is important for hearing perception. Rare studies reported frequency-specific hearing outcome with the learning curve for shifting from postauricular to transcanal microscopic tympanoplasty. Here, from Jul. 2013 to Nov. 2018, we compared patients in a shift from postauricular approach (35 ears) to transcanal approach (35 ears) of microscopic type-1 tympanoplasty. The results show that both of postauricular and transcanal microscopic tympanoplasties reduced the mean air-bone gap, 0.5k Hz gap, and 1k Hz gap after the surgery. The further analyses on gap change as a function of frequency (0.5, 1, 2, and 4k Hz) show that both of postauricular and transcanal tympanoplasties improved postoperative air-bone gap among the levels of frequency. The post hoc comparisons display a common gap reduction difference between 0.5k and 4k Hz. The successful repair rate did not differ between the 2 groups. There was no correlation between the postoperative mean gap change and the surgery date, suggesting a minimal learning-curve effect. The results of similar frequency-specific improvements and a minimal learning-curve effect may help to ease the concerns of those uncertainties before the shift.

1035 Learning Curve Effect on ‘Step Up Approach’ for Management of Severe Acute Pancreatitis

2016 ◽  
Vol 150 (4) ◽  
pp. S1203 ◽  
Author(s):  
Rajesh Gupta ◽  
Rahul Gupta ◽  
Sunil Shenvi ◽  
Raghavendra B. Yelakanti ◽  
Rohit K. Nimje ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Learning Curve ◽  
Severe Acute Pancreatitis ◽  
Curve Effect

Three-Dimensional Organization of Otolith-Ocular Reflexes in Rhesus Monkeys. III. Responses to Translation

1998 ◽  
Vol 80 (2) ◽  
pp. 680-695 ◽  
Author(s):  
Dora E. Angelaki
Keyword(s):  
Frequency Dependence ◽  
Brain Stem ◽  
Rhesus Monkeys ◽  
Three Dimensional ◽  
Head Orientation ◽  
Frequency Range ◽  
Low Frequencies ◽  
Similar Frequency ◽  
Response Sensitivity ◽  
Torsional Response

Angelaki, Dora E. Three-dimensional organization of otolith-ocular reflexes in rhesus monkeys. III. Responses to translation. J. Neurophysiol. 80: 680–695, 1998. The three-dimensional (3-D) properties of the translational vestibulo-ocular reflexes (translational VORs) during lateral and fore-aft oscillations in complete darkness were studied in rhesus monkeys at frequencies between 0.16 and 25 Hz. In addition, constant velocity off-vertical axis rotations extended the frequency range to 0.02 Hz. During lateral motion, horizontal responses were in phase with linear velocity in the frequency range of 2–10 Hz. At both lower and higher frequencies, phase lags were introduced. Torsional response phase changed more than 180° in the tested frequency range such that torsional eye movements, which could be regarded as compensatory to “an apparent roll tilt” at the lowest frequencies, became anticompensatory at all frequencies above ∼1 Hz. These results suggest two functionally different frequency bandwidths for the translational VORs. In the low-frequency spectrum (≪0.5 Hz), horizontal responses compensatory to translation are small and high-pass-filtered whereas torsional response sensitivity is relatively frequency independent. At higher frequencies however, both horizontal and torsional response sensitivity and phase exhibit a similar frequency dependence, suggesting a common role during head translation. During up-down motion, vertical responses were in phase with translational velocity at 3–5 Hz but phase leads progressively increased for lower frequencies (>90° at frequencies <0.2 Hz). No consistent dependence on static head orientation was observed for the vertical response components during up-down motion and the horizontal and torsional response components during lateral translation. The frequency response characteristics of the translational VORs were fitted by “periphery/brain stem” functions that related the linear acceleration input, transduced by primary otolith afferents, to the velocity signals providing the input to the velocity-to-position neural integrator and the oculomotor plant. The lowest-order, best-fit periphery/brain stem model that approximated the frequency dependence of the data consisted of a second order transfer function with two alternating poles (at 0.4 and 7.2 Hz) and zeros (at 0.035 and 3.4 Hz). In addition to clearly differentiator dynamics at low frequencies (less than ∼0.5 Hz), there was no frequency bandwidth where the periphery/brain stem function could be approximated by an integrator, as previously suggested. In this scheme, the oculomotor plant dynamics are assumed to perform the necessary high-frequency integration as required by the reflex. The detailed frequency dependence of the data could only be precisely described by higher order functions with nonminimum phase characteristics that preclude simple filtering of afferent inputs and might be suggestive of distributed spatiotemporal processing of otolith signals in the translational VORs.

Coding of Stimuli by Ampullary Afferents in Gnathonemus petersii

2010 ◽  
Vol 104 (4) ◽  
pp. 1955-1968 ◽  
Author(s):  
J. Engelmann ◽  
S. Gertz ◽  
J. Goulet ◽  
A. Schuh ◽  
G. von der Emde
Keyword(s):  
Frequency Tuning ◽  
Low Frequency ◽  
Weakly Electric Fish ◽  
Behavioral Experiments ◽  
Low Frequencies ◽  
Similar Frequency ◽  
Linear Feature ◽  
Reconstruction Methods ◽  
Electric Fishes ◽  
Weakly Electric

Weakly electric fish use electroreception for both active and passive electrolocation and for electrocommunication. While both active and passive electrolocation systems are prominent in weakly electric Mormyriform fishes, knowledge of their passive electrolocation ability is still scarce. To better estimate the contribution of passive electric sensing to the orientation toward electric stimuli in weakly electric fishes, we investigated frequency tuning applying classical input-output characterization and stimulus reconstruction methods to reveal the encoding capabilities of ampullary receptor afferents. Ampullary receptor afferents were most sensitive (threshold: 40 μV/cm) at low frequencies (<10 Hz) and appear to be tuned to a mix of amplitude and slope of the input signals. The low-frequency tuning was corroborated by behavioral experiments, but behavioral thresholds were one order of magnitude higher. The integration of simultaneously recorded afferents of similar frequency-tuning resulted in strongly enhanced signal-to-noise ratios and increased mutual information rates but did not increase the range of frequencies detectable by the system. Theoretically the neuronal integration of input from receptors experiencing opposite polarities of a stimulus (left and right side of the fish) was shown to enhance encoding of such stimuli, including an increase of bandwidth. Covariance and coherence analysis showed that spiking of ampullary afferents is sufficiently explained by the spike-triggered average, i.e., receptors respond to a single linear feature of the stimulus. Our data support the notion of a division of labor of the active and passive electrosensory systems in weakly electric fishes based on frequency tuning. Future experiments will address the role of central convergence of ampullary input that we expect to lead to higher sensitivity and encoding power of the system.

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