scholarly journals Stimulation efficiency of an actuator driven piston at the biological interface to the inner ear

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susan Busch ◽  
Mohammad Ghoncheh ◽  
Thomas Lenarz ◽  
Hannes Maier
Keyword(s):  
Bone Conduction ◽  
Input Voltage ◽  
Piston Motion ◽  
Stapes Fixation ◽  
Biological Interface ◽  
Piston Displacement ◽  
Stapes Footplate ◽  
Stimulation Efficiency ◽  
The Relationship ◽  
Motion Amplitude

AbstractDirect acoustic cochlear stimulation uses piston motion to substitute for stapes footplate (SFP) motion. The ratio of piston to stapes footplate motion amplitude, to generate the same loudness percept, is an indicator of stimulation efficiency. We determined the relationship between piston displacement to perceived loudness, the achieved maximum power output and investigated stapes fixation and obliteration as confounding factors. The electro-mechanical transfer function of the actuator was determined preoperatively on the bench and intraoperatively by laser Doppler vibrometry. Clinically, perceived loudness as a function of actuator input voltage was calculated from bone conduction thresholds and direct thresholds via the implant. The displacement of a 0.4 mm diameter piston required for a perception equivalent to 94 dB SPL at the tympanic membrane compared to normal SFP piston displacement was 27.6–35.9 dB larger, consistent with the hypothesis that the ratio between areas is responsible for stimulation efficiency. Actuator output was 110 ± 10 eq dB SPLFF @1Vrms ≤ 3 kHz and decreased to 100 eq dB SPLFF at 10 kHz. Output was significantly higher for mobile SFPs but independent from obliteration. Our findings from clinical data strongly support the assumption of a geometrical dependency on piston diameter at the biological interface to the cochlea.

scholarly journals Estimation of High-Speed Liquid-Jet Velocity Using a Pyro Jet Injector

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Naohisa Takagaki ◽  
Toru Kitaguchi ◽  
Masashi Iwayama ◽  
Atsushi Shinoda ◽  
Hiroshige Kumamaru ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Liquid Jet ◽  
Liquid Density ◽  
Liquid Viscosity ◽  
Ejection Velocity ◽  
Piston Motion ◽  
Ansys Fluent ◽  
Piston Displacement ◽  
Jet Velocity

AbstractThe high-speed liquid-jet velocity achieved using an injector strongly depends on the piston motion, physical property of the liquid, and container shape of the injector. Herein, we investigate the liquid ejection mechanism and a technique for estimating the ejection velocity of a high-speed liquid jet using a pyro jet injector (PJI). We apply a two-dimensional numerical simulation with an axisymmetric approximation using the commercial software ANSYS/FLUENT. To gather the input data applied during the numerical simulation, the piston motion is captured with a high-speed CMOS camera, and the velocity of the piston is measured using motion tracking software. To reproduce the piston motion during the numerical simulation, the boundary-fitted coordinates and a moving boundary method are employed. In addition, we propose a fluid dynamic model (FDM) for estimating the high-speed liquid-jet ejection velocity based on the piston velocity. Using the FDM, we consider the liquid density variation but neglect the effects of the liquid viscosity on the liquid ejection. Our results indicate that the liquid-jet ejection velocity estimated by the FDM corresponds to that predicted by ANSYS/FLUENT for several different ignition-powder weights. This clearly shows that a high-speed liquid-jet ejection velocity can be estimated using the presented FDM when considering the variation in liquid density but neglecting the liquid viscosity. In addition, some characteristics of the presented PJI are observed, namely, (1) a very rapid piston displacement within 0.1 ms after a powder explosion, (2) piston vibration only when a large amount of powder is used, and (3) a pulse jet flow with a temporal pulse width of 0.1 ms.

Otosclerotic Involvement of the Cochlea: A Histologic and Audiologic Study

1981 ◽  
Vol 89 (2) ◽  
pp. 343-351 ◽  
Author(s):  
Dennis R. Elonka ◽  
Edward L. Applebaum
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Bone Conduction ◽  
Sensorineural Hearing ◽  
The Other ◽  
Poor Correlation ◽  
Stapes Footplate ◽  
Temporal Bones ◽  
Similar Incidence ◽  
Sensorineural Loss

This study sought correlations between sensorineural hearing loss and otosclerotic endosteal involvement in 29 temporal bones examined histologically. The sensorineural hearing loss of the affected parts of the cochlea was determined by the last antemortum bone conduction audiogram available. There were eight temporal bones with only stapes footplate involvement, six with one discrete focus of otosclerotic endosteal involvement, and 15 with two or more foci of endosteal involvement. Analysis of audiometric data showed that the group of bones with two or more foci of endosteal involvement had a similar incidence of 45 dB sensorineural loss (9 of 15 or 60%) as did the group with no endosteal involvement (5 of 8 or 62%). The group with two or more foci had a greater incidence of 60 dB or greater sensorineural loss (46%) compared with the groups with none (12%) or one focus (16%) involved. Correlation between hearing toss and involvement of cochlear endosteum was poor. Correlation existed in only 2 of 15 ears with two or more foci involving the cochlear endosteum. There was no correlation in the other groups. It appears that cochlear endosteal involvement alone may not be sufficient explanation for the sensorineural hearing loss found with otosclerosis, except in the most severely involved ears.

Stapes fixation surgery: stapedectomy versus stapedotomy

2010 ◽  
Vol 4 (3) ◽  
pp. 429-434 ◽  
Author(s):  
Taweekiat Thamjarayakul ◽  
Pakpoom Supiyaphun ◽  
Kornkiat Snidvongs
Keyword(s):  
Success Rate ◽  
Pure Tone ◽  
Bone Conduction ◽  
Surgical Techniques ◽  
Speech Discrimination ◽  
Stapes Fixation ◽  
Pure Tone Average ◽  
Window Opening ◽  
Hearing Outcomes ◽  
Air Conduction

Abstract Background: Stapedectomy and stapedotomy are the standard techniques for stapes fixation surgery. Both techniques depend on the size of window opening (total, partial stapedectomy and small-hole stapedotomy) and the type of prosthesis used. Outcome of technique and prosthesis are controversy. Objective: Evaluate the outcomes of the two surgical techniques (stapedectomy/stapedotomy) and two sizes of prosthesis (Cawthorn 0.6mm/0.3mm) in terms of effectiveness and safety. Material and methods: Sixty-four medical records of patients undergoing stapedectomy or stapedotomy between the year 1995 and 2005 were reviewed. The subjects were classified into three groups including 0.6-mm stapedectomy, 0.6-mm and 0.3-mm stapedotomy group. The pre and post operative air-conduction threshold (AC) and air-bone gap (A-B gap) were compared for each group. The pre-and post-operative differences in pure tone average of AC, pure tone average of bone conduction threshold (BC), AB gap, AC at 4KHz, BC at 4KHz, AC at 8KHz, and speech discrimination score (SDS) were analyzed. The surgical complications were also compared. Results: Means of post-operative AC, and A-B gap were significantly better in all three groups. The mean of postoperative AC at 4KHz was significantly improved only in stapedotomy groups (0.6-mm and 0.3-mm stapedotomy). To compare the hearing outcomes among the three groups, there were no statistically significant differences between 0.6-mm stapedectomy vs. 0.6-mm stapedotomy, and between 0.6- mm vs. 0.3-mm stapedotomy. The complications were found in all three groups. The 0.3-mm stapedotomy had the lowest rate. Conclusion: Stapedectomy versus stapedotomy yields comparable hearing outcomes but stapedotomy results had a better success rate than the stapedectomy. For 0.6-mm stapedotomy vs. 0.3-mm stapedotomy, the overall results in both groups are not significantly different, in terms of both the hearing outcomes and the success rate. In terms of complication rate, 0.6-mm stapedectomy had the highest rate, while 0.3-mm stapedotomy had the lowest.

Feedback Control of a Flexible Micro-Displacement Manipulator

2011 ◽  
Vol 480-481 ◽  
pp. 1167-1172
Author(s):  
Hua Wei Ji ◽  
Yong Qing Wen ◽  
Chen Ming Fu
Keyword(s):  
Mathematical Method ◽  
Closed Loop ◽  
Input Voltage ◽  
Flexure Hinge ◽  
Output Displacement ◽  
Control Precision ◽  
Hysteresis Nonlinearity ◽  
Vibration Experiment ◽  
The Relationship ◽  
Control Accuracy

Micro-displacement manipulator consists of piezoelectric actuator and flexure hinge is being widely used in precision positioning technology for its high resolution of displacement, high stiffness and fast frequency response. However, the hysteresis nonlinearity of actuator and vibration limited its control accuracy. In order to improve the positioning precision, the relationship between input voltage and output displacement was studied, the hysteresis nonlinearity was described by mathematical method, and a closed-loop controller was proposed to control the hysteresis and vibration. Experiment results revealed the proposed closed-loop controller can enhance the control precision of micro-displacement manipulator.

Retrospective Analysis of Outcomes after Stapedotomy with Implantation of a Self-Crimping Nitinol Stapes Prosthesis

2007 ◽  
Vol 137 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Abraham J. Sorom ◽  
Colin L.W. Driscoll ◽  
Charles W. Beatty ◽  
Larry Lundy
Keyword(s):  
Bone Conduction ◽  
The Self ◽  
Short Term ◽  
Hearing Results ◽  
Intermediate Group ◽  
Stapes Fixation ◽  
Academic Hospitals ◽  
Stapes Prosthesis ◽  
The Mean

OBJECTIVE: To review hearing results after implantation of a self-crimping stapes prosthesis. STUDY DESIGN AND SETTING: Analysis of hearing results in patients implanted with a self-crimping stapes prosthesis at two academic hospitals from 2000 to 2004. RESULTS: Seventy-nine ears were divided into short-term and intermediate follow-up groups. The mean postoperative air-bone gap (ABG), preoperative minus postoperative ABG, and preoperative minus postoperative bone conduction values were 5.7, 21.4, and 4.1 dB, respectively, for the short-term group, and 6.3, 22.3, and 4.7dB, respectively, for the intermediate group. The ABG was <10 dB in 88 percent of the short-term group and in 79 percent of the intermediate group. CONCLUSIONS: The self-crimping Nitinol stapes prosthesis provides excellent short-term and intermediate postoperative hearing results, and may overcome the limitations of stapes prostheses requiring manual crimping. SIGNIFICANCE: This paper provides evidence for the use of a self-crimping Nitinol stapes prosthesis, which may simplify hearing restoration surgery for stapes fixation.

Tympanosclerosis of the middle ear: Late results of surgical treatment

1990 ◽  
Vol 104 (9) ◽  
pp. 685-689 ◽  
Author(s):  
Mirko Tos ◽  
Torben Lau ◽  
Helge Arndal ◽  
Søren Plate
Keyword(s):  
Middle Ear ◽  
Ossicular Chain ◽  
Late Results ◽  
Observation Time ◽  
Type Ii ◽  
Stapes Fixation ◽  
One Stage ◽  
Stapes Footplate ◽  
Two Stages

AbstractThe late results of one stage operation for middle ear tymanosclerosis in 73 patients during the period January 1965 to December 1980 are presented. Mean observation time was 11.2 years (range 3–20.2 years), with a follow-up rate 86 per cent. Among 64 patients with stapes fixation, 59 had removal of tympanosclerotic masses and stapes mobilization, and five cases underwent stapedectomy. The series was divided into six groups and the results analyzed. The best and most stable results occurred in the group with stapes mobilization and an intact ossicular chain followed by the group with stapes mobilization and Type II tympanoplasty with incus interposition. The poorest late results were obtained in ears with lacking stapes crura and stapes mobilization, and in ears subjected to stapedectomy. No case of post-operative sensorineural hearing loss occurred. We recommend that care is taken to preserve an intact ossicular chain at stapes mobilization performed at the same stage as myringoplasty. Also in ears with a defective ossicular chain but intact stapes with tympanosclerotic fixation we recommend stapes mobilization in one stage. In ears with fixation of the stapes footplate and defective crura, we recommend stapedectomy or stapedotomy in two stages.

Tinnitus and otosclerosis surgery

1984 ◽  
Vol 98 (S9) ◽  
pp. 294-298 ◽  
Author(s):  
Mendell Robinson
Keyword(s):  
Beneficial Effect ◽  
Hearing Result ◽  
Stapes Footplate ◽  
The Relationship

AbstractThis study attempts to correlate the relationship between clinical otosclerosis, tinnitus, and stapedectomy surgery. One hundred and thirty-five patients who recently underwent stapedectomy surgery were evaluated to determine the effects upon tinnitus and to determine if there was an association between tinnitus and the pre-operative cochlear reserve, the degree of footplate pathology, and/or the post-operative hearing result.Diminished cochlear reserve and the post-operative audiometric result had no relationship to the tinnitus symptom. A beneficial effect on tinnitus occurred in 25 per cent of the patients requiring drilling of the stapes footplate.

scholarly journals Association Between the Air-Bone Gap and Vibration of the Tympanic Membrane After Myringoplasty

2021 ◽  
pp. 014556132098364
Author(s):  
Ying Zhang ◽  
Jie Wang ◽  
Yu Wang ◽  
Qianjie Fu ◽  
Yongxin Li
Keyword(s):  
Tympanic Membrane ◽  
Bone Conduction ◽  
Hospital Staff ◽  
Contributing Factors ◽  
Important Indicator ◽  
Hearing Status ◽  
Number Of Factors ◽  
The Relationship ◽  
Normal Controls ◽  
Air Conduction

Air-bone gap (ABG) is an important indicator of hearing status after myringoplasty. A number of factors have been associated with ABG, but some patients still have ABG without identifiable cause. This study aimed to evaluate the relationship between tympanic membrane (TM) vibration using laser Doppler vibrometry (LDV) and ABG after myringoplasty. Between January 2013 and January 2015, 24 patients with ABG of unknown cause after myringoplasty were enrolled at the Beijing Tongren Hospital. Thirty normal controls were recruited from the hospital staff. All patients underwent primary overlay myringoplasty. Pre- and postoperative air conduction (AC) and bone-conduction (BC) thresholds, and ABG were measured. Umbo velocity transfer function (UVTF) for vibration of TM was measured with LDV. Air conduction thresholds were significantly reduced after myringoplasty (all P < .05), while BC thresholds were not significantly changed (all P > .05). ABG was significantly reduced after myringoplasty (all P < .05). Air-bone gap was correlated with UVTF at 1.0 kHz (r = −0.46; P = .024). For patients with UVTF >0.08 mm/s/Pa, ABG was correlated with UVTF (r = −0.56; P = .029). For post-myringoplasty ABG without readily observable causes, there was a significant relationship between ABG and TM vibration. These results provide new insights in the understanding of this relationship and may help explain ABG after myringoplasty when there are no clear contributing factors.

scholarly journals EQUIVALENTS OF THE PASSIVE EIGHT-EARTH POLAR WITH THREE INPUT AND FIVE OUTPUT CONCLUSIONS

2019 ◽  
Vol 20 (9-10) ◽  
pp. 109-119
Author(s):  
G. A. Bolshanyn
Keyword(s):  
Electrical Energy ◽  
Input Voltage ◽  
Individual Case ◽  
Output Current ◽  
Current Output ◽  
Input And Output ◽  
Voltage Output ◽  
The Difference ◽  
Output Characteristics ◽  
The Relationship

Eight-poles of various designs, including an eight-terminal network with three input and five output terminals, are needed to replace some power objects. Especially when only the input and output characteristics of electrical energy are of interest. The paper presents the eightterminal network equations with three input and five output terminals, establishing a connection between these characteristics. Equations of the A-form establish a connection between the input and output voltages and currents; the B-form equations establish a connection between the output and input voltages and currents; G-form equations establish a connection between the input current, output voltages and output voltage, output currents; H-form equations establish the relationship between the input voltage, output currents and output current, output voltages; the Yform equations establish a connection between the input and output currents and the input and output voltages; The Z-form equations establish the relationship between the input and output voltages and the input and output currents. When implementing these equations, attention should be paid to the difference in the directions of the currents in each individual case.

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