The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Monika Kwacz - One of the best experts on this subject based on the ideXlab platform.
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Transmission of the Acoustic Signal through the Middle Ear – An Experimental Study
Mechatronics, 2020Co-Authors: Monika Kwacz, Maciej Mrowka, Jarosław WysockiAbstract:The transmission of the acoustic signal through the middle ear structures was determined on the basis broad-band measurements (400 Hz to 10 kHz) of the Stapes, the round window and the Teflon piston Stapes Prosthesis displacements. The measurements were made in 4 fresh cadaver temporal bones with AC stimulation at 90 dB SPL applied to the external auditory canal. Two conditions in the same specimen were measured: the physiologial and the implanted state. A PSV 400 Scanning Laser Doppler Vibrometer system (Polytec GmbH, Waldbronn, Germany) was used to determine the effect of the Teflon piston Stapes Prosthesis implantation on transmission of the acoustic signal through the middle ear. It was shown that the cochlear stimulation after Stapes piston Prosthesis implantation, in comparison with a physiological specimen was reduced several times.
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Differences in the perilymph fluid stimulation before and after experimental stapedotomy.
Acta of Bioengineering and Biomechanics, 2020Co-Authors: Monika Kwacz, Maciej Mrowka, Jarosław WysockiAbstract:A stapedotomy surgery using a piston Stapes Prosthesis significantly modifies the perilymph fluid stimulation level and always leads to alteration of conditions in sound transmission through the cochlea. This paper shows the results of non-contact measurements of the Stapes head velocity, a Teflon piston Stapes Prosthesis velocity and round window velocity conducted in freshly harvested human cadaver temporal bone specimens. The vibration patterns were measured within the frequency range of 0.4–10 kHz at the sound pressure level of 90 dB administered to the external auditory canal in the same specimen before and after experimental stapedotomy. It was shown that the vibrations of the Stapes Teflon piston Prosthesis and the physiological Stapes are similar and approximately five-fold lower amplitude of the round window membrane vibrations compared to a physiologic situation is caused by piston shape of the Stapes Prosthesis. The results in this report are the part of a larger study designed to develop a new type of chamber Stapes or whole middle ear Prosthesis.
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Round Window Membrane Vibration Measured by Laser Doppler Vibrometer
2020Co-Authors: Monika Kwacz, Maciej Mrowka, Jarosław WysockiAbstract:The paper describes the results of non-contact measurements of the human ear round window (RW) membrane vibration parameters using the scanning Laser Doppler Vibrometer (LDV) in freshly harvested human cadaver temporal bone specimens - a procedure conducted for the first time in Poland. A PSV 400 Scanning Laser Vibrometer system (Polytec, Waldbronn, Germany) was used in the research. The paper presents amplitude-frequency and phase-frequency characteristics of the RW membrane vibrations in an anatomically correct specimen (in its physiological conditions) and in the same specimen after teflon piston Stapes Prosthesis implantation. The characteristics were measured in a 400Hz - 10000Hz frequency range with a 90 dB sound pressure level applied to the external auditory canal. It was indicated that measurements of the round window membrane vibrations may be a tool for evaluating hearing results of surgical ossicular chain reconstruction, especially in case of otosclerosis surgery.
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design of a resilient ring for middle ear s chamber Stapes Prosthesis
Computer Methods in Biomechanics and Biomedical Engineering, 2018Co-Authors: Emilia Anna Kiryk, Konrad Kamieniecki, Monika KwaczAbstract:AbstractThis paper presents the process of designing a new elastic element replacing a membrane in the chamber Stapes Prosthesis (ChSP). The results of the study are volume displacement characteristics obtained for the Prosthesis and physiological Stapes. Simulation tests on a 3D CAD model have confirmed that a properly designed ring can stimulate perilymph with the same or greater efficacy as the physiological Stapes footplate placed on the elastic annular ligament. The ChSP with a new elastic element creates a good chance of improving hearing in patients suffering from otosclerosis.
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Chamber Stapes Prosthesis with an improved fastening of the membrane
ITM Web of Conferences, 2017Co-Authors: Małgorzata Pudlik, Henryk Skarżyński, Monika KwaczAbstract:Stapes prostheses are dedicated to assisting patients with otosclerosis. Currently used Stapes prostheses have the form of a piston and are called piston prostheses. However, the perilymph excitation by piston Prosthesis is not perfect so a new chamber Stapes Prosthesis (ChSP) has been proposed. The ChSP allows for a more effective stimulation of the cochlea than the piston. A crucial element of the ChSP is a flexible membrane. The membrane transmits vibrations from the plate to the fluid that fills the chamber and then to the inner ear. In the first prototype, the membrane was glued to the chamber, which is an unacceptable solution in a real medical device because of a risk to patient's health. Therefore, there is a need to improve the membrane fastening. In this study, we present a new improved method for attaching the membrane to the chamber. A modified 3D model of the ChSP was build and an additional fastening element was designed. The design process of the fastening element was based on the analysis of deformation conducted for elements made of different materials. As a result the optimal geometry of the element was determined. The new fastening has been experimentally tested using the 3D printed model. Fastening the membrane to the Prosthesis was a success and assessed as efficient. The results of the experimental tests confirmed that presented modification can be used in the ChSPs intended for clinical trials.
Glen E J Forton - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous true Stapes fixation and bilateral bony dehiscence between the internal carotid artery and the apex of the cochlea: the ultimate pitfall.
Otology & neurotology : official publication of the American Otological Society American Neurotology Society [and] European Academy of Otology and Neu, 2020Co-Authors: Peter Neyt, Fabienne Govaere, Glen E J FortonAbstract:A dehiscence of a semicircular canal can mimic the audiologic characteristics of otosclerosis. To present a unique case report of a patient presenting with Stapes fixation due to otosclerosis but persisting conductive hearing loss after uneventful laser-assisted stapedotomy with interposition of an àWengen titanium clip Stapes Prosthesis. Eventually, a bilateral bony dehiscence between the apical turn of the cochlea and the internal carotid artery was eventually identified, which explained the persisting postoperative conductive hearing loss. A dehiscence of the semicircular canals was duly ruled out preoperatively. : Caucasian man aged 63 years. Laser-assisted stapedotomy with interposition of an àWengen titanium clip Stapes Prosthesis. Later on, the patient received a Bone-Anchored Hearing Aid. A 63-year-old man presented with a clinical and audiologic bilateral Stapes fixation due to otosclerosis. A possible dehiscence of a semicircular canal was duly ruled out preoperatively by high-resolution computed tomographic scanning. The Stapes fixation was treated lege artis by laser-assisted stapedotomy and subsequent interposition of an àWengen titanium clip Stapes Prosthesis, but the mixed hearing loss persisted. Eventually, a dehiscence between the apical turn of the cochlea and the internal carotid artery was identified. Thereafter, the patient was adequately helped with a Bone-Anchored Hearing Aid. We think that this is the first published case of simultaneous occurrence of radiologically and preoperatively confirmed Stapes fixation and bilateral bony dehiscence between the apex of the cochlea and the internal carotid artery. Preoperative imaging studies therefore should look not only for a possible dehiscence of a semicircular canal, mimicking otosclerosis, but also for a dehiscence between the cochlea and the internal carotid artery.
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Response to "Simultaneous true Stapes fixation and bilateral bony dehiscence between the internal carotid artery and the apex of the cochlea: the ultimate pitfall".
Otology & Neurotology, 2011Co-Authors: Peter Neyt, Fabienne Govaere, Glen E J FortonAbstract:BACKGROUND: A dehiscence of a semicircular canal can mimic the audiologic characteristics of otosclerosis. OBJECTIVE: To present a unique case report of a patient presenting with Stapes fixation due to otosclerosis but persisting conductive hearing loss after uneventful laser-assisted stapedotomy with interposition of an aWengen titanium clip Stapes Prosthesis. Eventually, a bilateral bony dehiscence between the apical turn of the cochlea and the internal carotid artery was eventually identified, which explained the persisting postoperative conductive hearing loss. A dehiscence of the semicircular canals was duly ruled out preoperatively. PATIENT: : Caucasian man aged 63 years. INTERVENTION: Laser-assisted stapedotomy with interposition of an aWengen titanium clip Stapes Prosthesis. Later on, the patient received a Bone-Anchored Hearing Aid. RESULTS: A 63-year-old man presented with a clinical and audiologic bilateral Stapes fixation due to otosclerosis. A possible dehiscence of a semicircular canal was duly ruled out preoperatively by high-resolution computed tomographic scanning. The Stapes fixation was treated lege artis by laser-assisted stapedotomy and subsequent interposition of an aWengen titanium clip Stapes Prosthesis, but the mixed hearing loss persisted. Eventually, a dehiscence between the apical turn of the cochlea and the internal carotid artery was identified. Thereafter, the patient was adequately helped with a Bone-Anchored Hearing Aid. CONCLUSION: We think that this is the first published case of simultaneous occurrence of radiologically and preoperatively confirmed Stapes fixation and bilateral bony dehiscence between the apex of the cochlea and the internal carotid artery. Preoperative imaging studies therefore should look not only for a possible dehiscence of a semicircular canal, mimicking otosclerosis, but also for a dehiscence between the cochlea and the internal carotid artery.
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co2 laser assisted stapedotomy combined with awengen titanium clip Stapes Prosthesis
Otology & Neurotology, 2009Co-Authors: Glen E J Forton, Floris L Wuyts, Kathelijne G Delsupehe, Jan Verfaillie, Robert LonckeAbstract:Objective:To report on the short-term results of CO2-laser assisted stapedotomy combined with the aWengen titanium clip Stapes Prosthesis. A comparison with published series using other prostheses and/or different stapedotomy techniques is made.Study Design:Retrospective case series.Patients:Patient
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co2 laser assisted stapedotomy combined with awengen titanium clip Stapes Prosthesis superior short term results
Otology & Neurotology, 2009Co-Authors: Glen E J Forton, Floris L Wuyts, Kathelijne G Delsupehe, Jan Verfaillie, Robert LonckeAbstract:OBJECTIVE: To report on the short-term results of CO2-laser assisted stapedotomy combined with the aWengen titanium clip Stapes Prosthesis. A comparison with published series using other prostheses and/or different stapedotomy techniques is made. STUDY DESIGN: Retrospective case series. PATIENTS: Patients with a history and audiologic data matching Stapes fixation and computed tomographic imaging excluding other anomalies such as malleus fixation, dehiscent superior semicircular canal, and large vestibular aqueduct that may mimic Stapes fixation-like hearing loss. INTERVENTION: All patients underwent CO2 laser-assisted stapedotomy (Lumenis Co. Israel CO2 laser, Acuspot 712, SurgiTouch 870 scanner) and subsequent reconstruction by means of the aWengen titanium clip Stapes Prosthesis by Heinz Kurz Medizintechnik GmbH (Germany). OUTCOME MEASURES: Comparison and statistical analysis of preoperative and postoperative audiologic data. RESULTS: Sixty-two stapedotomies were performed (61 patients) using the CO2 laser and aWengen titanium clip Stapes Prosthesis. The mean postoperative air-bone gap 3 months postoperatively was 5.1 +/- 0.5 dB (standard deviation [SD], 4.1 dB; 0.5, 1, 2, 4 kHz). Air-bone gap closure less than or equal to 10 dB was achieved in 54 cases (87%). Air-bone gap closure less than 20 dB was achieved in all cases. The average gain was 27.8 +/- 1.5 dB (SD, 12 dB; 0.5, 1, 2, 4 kHz). The average bone-conduction threshold shift or "overclosure" on 2,000 Hz was 13.6 +/- 1.3 dB (SD, 10 dB). There was no postoperative perceptive hearing loss exceeding 15 dB on any measured frequency. The Amsterdam Hearing Evaluation Plots have also been used to evaluate our data. These data were statistically analyzed and compare favorably to other published series. CONCLUSION: The authors conclude that the combination of CO2 laser-assisted stapedotomy and the aWengen titanium clip Stapes Prosthesis is a combination likely to yield superior results in experienced hands.
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co superior short term results2 superior short term results laser assisted stapedotomy combined with awengen titanium clip Stapes Prosthesis superior short term results
Otology & Neurotology, 2009Co-Authors: Glen E J Forton, Floris L Wuyts, Kathelijne G Delsupehe, Jan Verfaillie, Robert LonckeAbstract:Objective: To report on the short-term results of CO2-laser assisted stapedotomy combined with the aWengen titanium clip Stapes Prosthesis. A comparison with published series using other prostheses and/or different stapedotomy techniques is made. Study Design: Retrospective case series. Patients: Patients with a history and audiologic data matching Stapes fixation and computed tomographic imaging excluding other anomalies such as malleus fixation, dehiscent superior semicircular canal, and large vestibular aqueduct that may mimic Stapes fixation-like hearing loss. Intervention: All patients underwent CO2 laser-assisted stapedotomy (Lumenis Co. Israel CO2 laser, Acuspot 712, SurgiTouch 870 scanner) and subsequent reconstruction by means of the aWengen titanium clip Stapes Prosthesis by Heinz Kurz Medizintechnik GmbH (Germany). Outcome Measures: Comparison and statistical analysis of preoperative and postoperative audiologic data. Results: Sixty-two stapedotomies were performed (61 patients) using the CO2 laser and aWengen titanium clip Stapes Prosthesis. The mean postoperative air-bone gap 3 months postoperatively was 5.1 ± 0.5 dB (standard deviation [SD], 4.1 dB; 0.5, 1, 2, 4 kHz). Air-bone gap closure less than or equal to 10 dB was achieved in 54 cases (87%). Air-bone gap closure less than 20 dB was achieved in all cases. The average gain was 27.8 ± 1.5 dB (SD, 12 dB; 0.5, 1, 2, 4 kHz). The average bone-conduction threshold shift or "overclosure" on 2,000 Hz was 13.6 ± 1.3 dB (SD, 10 dB). There was no postoperative perceptive hearing loss exceeding 15 dB on any measured frequency. The Amsterdam Hearing Evaluation Plots have also been used to evaluate our data. These data were statistically analyzed and compare favorably to other published series. Conclusion: The authors conclude that the combination of CO2 laser-assisted stapedotomy and the aWengen titanium clip Stapes Prosthesis is a combination likely to yield superior results in experienced hands.
Alexander M Huber - One of the best experts on this subject based on the ideXlab platform.
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mid term results after a newly designed nitinol Stapes Prosthesis use in 46 patients
Otology & Neurotology, 2013Co-Authors: Christof Roosli, Alexander M HuberAbstract:OBJECTIVE: Analysis of 12-month midterm clinical and audiometric data of patients with otosclerosis who underwent stapedotomy using a newly designed Prosthesis made of nitinol, a shape memory alloy. PATIENTS: Fifty-five ears of 50 consecutive patients who underwent stapetotomy between March 2010 and July 2011 were included. They met the inclusion criteria of primary procedures, a clinical follow-up and absence of nickel allergy. INTERVENTION: Stapedotomy and insertion of a newly designed Stapes Prosthesis. MAIN OUTCOME MEASURES: Preoperative and postoperative (3 and 12 mo) air and bone conduction thresholds were recorded. Pure tone average and air bone gap (difference of air and bone conduction thresholds) were calculated for 500, 1,000, 2,000, and 3,000 Hz. The occurrence of complications was assessed. RESULTS: Air conduction thresholds, pure tone average, and air-bone gap improved significantly 3 and 12 months postoperatively. Bone conduction threshold improved significantly at 2,000 Hz 3 months postoperatively and at 1,000 and 2,000 Hz 12 months postoperatively. A PTA of less than 20 dB was achieved in 96% of ears. No sensorineural hearing loss or other Prosthesis-related adverse effects were observed. CONCLUSION: Postoperative hearing results are comparable to the results obtained with other self-crimping prostheses. No complications or failures related to the Prosthesis occurred. A longer follow-up is necessary to prove long-term stability of hearing results and safety of the new Prosthesis.
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Assessment of a direct acoustic cochlear stimulator.
Audiology and Neuro-otology, 2012Co-Authors: Michail Chatzimichalis, Alexander M HuberAbstract:This study aimed to assess the functional results of a new, active, acoustic-mechanical hearing implant, the Direct Acoustic Cochlear Stimulation Partial Implant (DACS PI), in a preclinical study. The DACS PI is an electromagnetic device fixed to the mastoid by screws and coupled to a standard Stapes Prosthesis by an artificial incus (AI). The function of the DACS PI-aided reconstruction was assessed by determining: (1) the maximum equivalent sound pressure level (SPL) of the implant, which was obtained from measurements of the volume displacement at the round window in normal and implanted ears, and (2) the quality at the coupling interface between the AI of the DACS and the Stapes Prosthesis, which was quantified from measurements of relative motions between the AI and the Prosthesis. Both measurements were performed with fresh temporal bones using a scanning laser Doppler interferometry system. The expected maximum equivalent SPL with a typical driving voltage of 0.3 V was about 115–125 dB SPL up to 1.5 kHz in reconstruction with the DACS PI, and decreased with a roll-off slope of about 65 dB/decade, reaching 90 dB SPL at 8 kHz. The large roll-off relative to a normal ear was presumed to be a relatively high inductive impedance of the coil of the DACS PI actuator at higher frequencies. Good coupling quality between the AI and the Prosthesis was achieved below the resonance (∼1.5 kHz) of the DACS PI for all tested Stapes prostheses. Above the resonance, the SMart Piston, which is composed of a shape-memory alloy, had the best coupling quality.
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clinical evaluation of the nitibond Stapes Prosthesis an optimized shape memory alloy design
Otology & Neurotology, 2012Co-Authors: Alexander M Huber, Thomas Schrepfer, Albrecht EiberAbstract:OBJECTIVE: To prospectively analyze short-term (3 mo) results in patients with otosclerosis who underwent stapedotomy with the newly designed NiTiBOND Prosthesis and compare them with patients that underwent SMart piston stapedotomy. We aimed to assess "noninferiority" for the new Prosthesis. STUDY DESIGN: Prospective controlled trial. SETTING: Tertiary referral center. PATIENTS: Thirty-eight patients were included in the NiTiBOND group (41 ears), and 74 patients were included in the SMart Piston group (75 ears). INTERVENTION(S): Stapedotomy. MAIN OUTCOME MEASURE(S): Pure-tone audiometry 3 months after surgery, intraoperative Prosthesis handling as assessed using a questionnaire, and complications were analyzed. RESULTS: Pure-tone audiometry showed postoperative air-bone gap means (standard deviation) of 8.1 (8.3) and 9.9 (5.4) dB; air-bone gap closure within 10 dB was achieved in 71% and 72% and within 20 dB in 93% and 96% for the NiTiBOND and the SMart piston Prosthesis, respectively. Noninferiority was shown at all frequencies and in the pure-tone average. The NiTiBOND Prosthesis provides excellent intraoperative handling, and no adverse reactions were reported. CONCLUSION: Preliminary short-term results suggest safety and reliability for the new NiTiBOND Stapes Prosthesis.
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the influence of Prosthesis diameter in Stapes surgery a meta analysis and systematic review of the literature
Otology & Neurotology, 2011Co-Authors: Roman D Laske, Christof Roosli, Michail Chatzimichalis, Alexander M HuberAbstract:Objective:To analyze the influence of Stapes Prosthesis diameter on postoperative hearing results after stapedotomy without interposition in otosclerotic patients.Data Sources:PubMed search from 1970 to 2009 using the key words stapedotomy or stapedectomy or otosclerosis or Stapesplasty.Study Select
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biocompatibility of nitinol Stapes Prosthesis
Otology & Neurotology, 2011Co-Authors: Christof Roosli, Philipp Schmid, Alexander M HuberAbstract:OBJECTIVE: Use of the SMart piston, a nitinol-based, self-crimping Prosthesis in Stapes surgery may allow improved functional results because of better sound transmission properties at the incus-Prosthesis interface because of the elimination of manual crimping. Possible disadvantages include thermal damage or strangulation of the incus and its mucoperiosteum or nickel intolerance. The goal of this study was to morphologically assess the fixation of this Prosthesis to the incus, investigate the reaction of the middle ear mucosa to the Prosthesis, identify alterations to the incudal bone, and detect deposits of nickel in the tissue around the Prosthesis. STUDY DESIGN:: Prospective consecutive case analysis. SETTING:: Tertiary referral center. PATIENTS: Four patients with an unfavorable functional result after primary SMart-piston stapedotomy. INTERVENTION: Revision malleostapedotomy with explantation of the incus and Prosthesis for further analysis. MAIN OUTCOME MEASURES: Analysis of intraoperative findings and postoperative examination of the explants using light- and scanning-electron microscopy, energy dispersive x-ray analysis, and atom absorption spectrometry. RESULTS:: The intraoperative, macroscopic, and scanning electron microscopic investigation showed tight circular fixation of the prostheses, whereas a gap between the Prosthesis and the lateral incus was found in 1 case. All prostheses were overgrown by mucosa. Superficial localized erosion of the incudal bone was found in 2 cases. There was no elevation in nickel content in the removed tissue samples. CONCLUSION:: The lateral gap between Prosthesis and incus did not affect fixation of the Prosthesis, neither did covering by a mucosal layer. Bone erosion was most likely caused by laser in one and by the Prosthesis in another explant. No signs of increased nickel deposits could be found on energy dispersive x-ray analysis or atom absorption spectrometry. We conclude that a nitinol Stapes Prosthesis is safe for treatment of stapedial fixation.
Robert Loncke - One of the best experts on this subject based on the ideXlab platform.
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co2 laser assisted stapedotomy combined with awengen titanium clip Stapes Prosthesis
Otology & Neurotology, 2009Co-Authors: Glen E J Forton, Floris L Wuyts, Kathelijne G Delsupehe, Jan Verfaillie, Robert LonckeAbstract:Objective:To report on the short-term results of CO2-laser assisted stapedotomy combined with the aWengen titanium clip Stapes Prosthesis. A comparison with published series using other prostheses and/or different stapedotomy techniques is made.Study Design:Retrospective case series.Patients:Patient
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co2 laser assisted stapedotomy combined with awengen titanium clip Stapes Prosthesis superior short term results
Otology & Neurotology, 2009Co-Authors: Glen E J Forton, Floris L Wuyts, Kathelijne G Delsupehe, Jan Verfaillie, Robert LonckeAbstract:OBJECTIVE: To report on the short-term results of CO2-laser assisted stapedotomy combined with the aWengen titanium clip Stapes Prosthesis. A comparison with published series using other prostheses and/or different stapedotomy techniques is made. STUDY DESIGN: Retrospective case series. PATIENTS: Patients with a history and audiologic data matching Stapes fixation and computed tomographic imaging excluding other anomalies such as malleus fixation, dehiscent superior semicircular canal, and large vestibular aqueduct that may mimic Stapes fixation-like hearing loss. INTERVENTION: All patients underwent CO2 laser-assisted stapedotomy (Lumenis Co. Israel CO2 laser, Acuspot 712, SurgiTouch 870 scanner) and subsequent reconstruction by means of the aWengen titanium clip Stapes Prosthesis by Heinz Kurz Medizintechnik GmbH (Germany). OUTCOME MEASURES: Comparison and statistical analysis of preoperative and postoperative audiologic data. RESULTS: Sixty-two stapedotomies were performed (61 patients) using the CO2 laser and aWengen titanium clip Stapes Prosthesis. The mean postoperative air-bone gap 3 months postoperatively was 5.1 +/- 0.5 dB (standard deviation [SD], 4.1 dB; 0.5, 1, 2, 4 kHz). Air-bone gap closure less than or equal to 10 dB was achieved in 54 cases (87%). Air-bone gap closure less than 20 dB was achieved in all cases. The average gain was 27.8 +/- 1.5 dB (SD, 12 dB; 0.5, 1, 2, 4 kHz). The average bone-conduction threshold shift or "overclosure" on 2,000 Hz was 13.6 +/- 1.3 dB (SD, 10 dB). There was no postoperative perceptive hearing loss exceeding 15 dB on any measured frequency. The Amsterdam Hearing Evaluation Plots have also been used to evaluate our data. These data were statistically analyzed and compare favorably to other published series. CONCLUSION: The authors conclude that the combination of CO2 laser-assisted stapedotomy and the aWengen titanium clip Stapes Prosthesis is a combination likely to yield superior results in experienced hands.
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co superior short term results2 superior short term results laser assisted stapedotomy combined with awengen titanium clip Stapes Prosthesis superior short term results
Otology & Neurotology, 2009Co-Authors: Glen E J Forton, Floris L Wuyts, Kathelijne G Delsupehe, Jan Verfaillie, Robert LonckeAbstract:Objective: To report on the short-term results of CO2-laser assisted stapedotomy combined with the aWengen titanium clip Stapes Prosthesis. A comparison with published series using other prostheses and/or different stapedotomy techniques is made. Study Design: Retrospective case series. Patients: Patients with a history and audiologic data matching Stapes fixation and computed tomographic imaging excluding other anomalies such as malleus fixation, dehiscent superior semicircular canal, and large vestibular aqueduct that may mimic Stapes fixation-like hearing loss. Intervention: All patients underwent CO2 laser-assisted stapedotomy (Lumenis Co. Israel CO2 laser, Acuspot 712, SurgiTouch 870 scanner) and subsequent reconstruction by means of the aWengen titanium clip Stapes Prosthesis by Heinz Kurz Medizintechnik GmbH (Germany). Outcome Measures: Comparison and statistical analysis of preoperative and postoperative audiologic data. Results: Sixty-two stapedotomies were performed (61 patients) using the CO2 laser and aWengen titanium clip Stapes Prosthesis. The mean postoperative air-bone gap 3 months postoperatively was 5.1 ± 0.5 dB (standard deviation [SD], 4.1 dB; 0.5, 1, 2, 4 kHz). Air-bone gap closure less than or equal to 10 dB was achieved in 54 cases (87%). Air-bone gap closure less than 20 dB was achieved in all cases. The average gain was 27.8 ± 1.5 dB (SD, 12 dB; 0.5, 1, 2, 4 kHz). The average bone-conduction threshold shift or "overclosure" on 2,000 Hz was 13.6 ± 1.3 dB (SD, 10 dB). There was no postoperative perceptive hearing loss exceeding 15 dB on any measured frequency. The Amsterdam Hearing Evaluation Plots have also been used to evaluate our data. These data were statistically analyzed and compare favorably to other published series. Conclusion: The authors conclude that the combination of CO2 laser-assisted stapedotomy and the aWengen titanium clip Stapes Prosthesis is a combination likely to yield superior results in experienced hands.
Maciej Mrowka - One of the best experts on this subject based on the ideXlab platform.
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Transmission of the Acoustic Signal through the Middle Ear – An Experimental Study
Mechatronics, 2020Co-Authors: Monika Kwacz, Maciej Mrowka, Jarosław WysockiAbstract:The transmission of the acoustic signal through the middle ear structures was determined on the basis broad-band measurements (400 Hz to 10 kHz) of the Stapes, the round window and the Teflon piston Stapes Prosthesis displacements. The measurements were made in 4 fresh cadaver temporal bones with AC stimulation at 90 dB SPL applied to the external auditory canal. Two conditions in the same specimen were measured: the physiologial and the implanted state. A PSV 400 Scanning Laser Doppler Vibrometer system (Polytec GmbH, Waldbronn, Germany) was used to determine the effect of the Teflon piston Stapes Prosthesis implantation on transmission of the acoustic signal through the middle ear. It was shown that the cochlear stimulation after Stapes piston Prosthesis implantation, in comparison with a physiological specimen was reduced several times.
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Differences in the perilymph fluid stimulation before and after experimental stapedotomy.
Acta of Bioengineering and Biomechanics, 2020Co-Authors: Monika Kwacz, Maciej Mrowka, Jarosław WysockiAbstract:A stapedotomy surgery using a piston Stapes Prosthesis significantly modifies the perilymph fluid stimulation level and always leads to alteration of conditions in sound transmission through the cochlea. This paper shows the results of non-contact measurements of the Stapes head velocity, a Teflon piston Stapes Prosthesis velocity and round window velocity conducted in freshly harvested human cadaver temporal bone specimens. The vibration patterns were measured within the frequency range of 0.4–10 kHz at the sound pressure level of 90 dB administered to the external auditory canal in the same specimen before and after experimental stapedotomy. It was shown that the vibrations of the Stapes Teflon piston Prosthesis and the physiological Stapes are similar and approximately five-fold lower amplitude of the round window membrane vibrations compared to a physiologic situation is caused by piston shape of the Stapes Prosthesis. The results in this report are the part of a larger study designed to develop a new type of chamber Stapes or whole middle ear Prosthesis.
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Round Window Membrane Vibration Measured by Laser Doppler Vibrometer
2020Co-Authors: Monika Kwacz, Maciej Mrowka, Jarosław WysockiAbstract:The paper describes the results of non-contact measurements of the human ear round window (RW) membrane vibration parameters using the scanning Laser Doppler Vibrometer (LDV) in freshly harvested human cadaver temporal bone specimens - a procedure conducted for the first time in Poland. A PSV 400 Scanning Laser Vibrometer system (Polytec, Waldbronn, Germany) was used in the research. The paper presents amplitude-frequency and phase-frequency characteristics of the RW membrane vibrations in an anatomically correct specimen (in its physiological conditions) and in the same specimen after teflon piston Stapes Prosthesis implantation. The characteristics were measured in a 400Hz - 10000Hz frequency range with a 90 dB sound pressure level applied to the external auditory canal. It was indicated that measurements of the round window membrane vibrations may be a tool for evaluating hearing results of surgical ossicular chain reconstruction, especially in case of otosclerosis surgery.
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new chamber Stapes Prosthesis a preliminary assessment of the functioning of the prototype
PLOS ONE, 2017Co-Authors: Monika Kwacz, Magdalena Solyga, Maciej Mrowka, Konrad KamienieckiAbstract:Piston-stapedotomy is the most common method for hearing restoration in patients with otosclerosis. In this study, we have experimentally examined a prototype of a new chamber Stapes Prosthesis. The prototype was implanted in a human cadaver temporal bone. The round window vibrations before and after implantation were measured for the acoustic signal (90 dB SPL, 0.8–8 kHz) in the external auditory canal. In comparison with a 0.4-mm piston Prosthesis, the chamber Prosthesis induced significantly higher vibration of the round window, especially for frequencies above 1.5 kHz. Based on the results, it can be surmised that stapedotomy with a chamber Stapes Prosthesis could provide better hearing results in comparison with the piston-stapedotomy.
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A three-dimensional finite element model of round window membrane vibration before and after stapedotomy surgery
Biomechanics and Modeling in Mechanobiology, 2013Co-Authors: Monika Kwacz, Paweł Borkowski, Piotr Marek, Maciej MrowkaAbstract:Piston Stapes prostheses are implanted in patients with refractory conductive or mixed hearing loss due to Stapes otosclerosis to stimulate the perilymph with varying degrees of success. The overclosure effect described by the majority of researchers affects mainly low and medium frequencies, and a large number of patients report a lack of satisfactory results for frequencies above 2 kHz. The mechanics of perilymph stimulation with the piston have not been studied in a systematic manner. The objective of this study was to assess the influence of stapedotomy surgery on round window membrane vibration and to estimate the postoperative outcomes using the finite element (FE) method. The study hypothesis is that the three-dimensional FE model developed of the human inner ear, which simulates the round window (RW) membrane vibration, can be used to assess the influence of stapedotomy on auditory outcomes achieved after the surgical procedure. An additional objective of the study was to enable the simulation of RW membrane vibration after stapedotomy using a new type of Stapes Prosthesis currently under investigation at Warsaw University of Technology. A three-dimensional finite element (FE) model of the human inner ear was developed and validated using experimental data. The model was then used to simulate the round window membrane vibration before and after stapedotomy surgery. Functional alterations of the RW membrane vibration were derived from the model and compared with the results of experimental measurements from temporal bones of a human cadaver. Piston Stapes Prosthesis implantation causes an approximately fivefold (14 dB) lower amplitude of the RW membrane vibrations compared with normal anatomical conditions. A satisfactory agreement between the FE model and the experimental data was found. The new Prosthesis caused an increase of 20–30 dB in the RW displacement amplitude compared with the 0.4-mm piston Prosthesis. In all frequencies, the FE model predicted a RW displacement curve that was above the experimental curves for the normal ear. The stapedotomy can be well simulated by the FE model to predict the auditory outcomes achieved following this otosurgery procedure. The 3D FE model developed in this study may be used to optimize the geometry of a new type of Stapes Prosthesis in order to achieve a similar sound transmission through the inner ear as for a normal middle ear. This should provide better auditory outcomes for patients with stapedial otosclerosis.