Design of Floating Mass Type Piezoelectric Actuator for Implantable Middle Ear Hearing Devices

To overcome some of the problems inherent in conventional heating aids such as low gain at high fi＇equencies due to acoustic feedback, discomfort in occlusion of the extemal ear canal and so on, implantable middle ear hearing devices （IMEHDs） have been developed over the past two decades. For such kinds of IMEHDs, this paper presents the design of a floating mass piezoelectric actuator using a PMN-30%PT stack as a new type of vibrator. The proposed piezoelectric actuator consists of only three components of a piezoelectric stack, a metal case and a clamp. For the purpose of aiding the design of this actuator, a coupling biomechanics model of human middle ear and the piezoelectric actuator was constructed. This model was built based on a complete set of computerized tomography section images of a healthy volunteer＇s left ear by reverse engineering technology. The validity of this model was confirmed by comparing the motion of the tympanic membrane and stapes footplate obtained by this model with published experimental measurements on human temporal bones. It is shown that the designed actuator can be implanted on the incus long process by a simple surgical operation, and the stapes footplate displacement by its excitation at 10.5 V root-mean-square（RMS） voltage was equivalent to that from acoustic stimulation at 100 dB sound pressure level（SPL）, which is adequate stimulation to the ossicular chain. The corresponding power consumption is 0.04 mW per volt of excitation at 1 kHz, which is low enough for the transducer to be used in an implantable middle ear device.

Bacteriolgy before and after total middle ear reconstruction

Objectives To investigate pre-and post-total middle ear reconstruction bacteriological changes in order to facilitate prevention and treatment of surgical infections. Methods Specimens from 128 ears in 124 patients with problematic mastoid cavities who underwent revision total middle ear reconstruction were studied. Results Bacteriological tests were positive in 87(68.0%) pre-operative specimens, despite local treatment, and in 74 (57.8%) specimens collected 10 days after operation. Common organism strains in pre-and post-operative specimens were slightly different and included: coagulase-staphylococcus, GRAM+ rods, staphylococcus aureus, pseudomonas aeruginosa and fungi. At the time of patient discharge(15-20 days post-operative), only 3 ears (2.3%) were tested positive which responded well to and became dry after local treatment. At one year, 4 ears (3.1%) showed recurrent otorrhea which again responded to local treatment. Conclusion For infection of problematic mastoid cavities after an open cavity procedure, revision total middle ear reconstruction is effective in controlling infection and promoting a dry ear. Infection prevention and treatment is important considering the relatively high rates of peri-operative local infections.

Pediatric Middle Ear Congenital Cholesteatoma: A Case Report

Congenital cholesteatoma（CC）is a rarely seen benign tumor of the temporal bone. There are five general sites of extradural occurrence: the middle ear, external auditory meatus, mastoid, squamous portion and the petrous apex of the temporal bone. CC grows slowly and presents no symptoms at the early stage. Delayed and mis-diagnosis are common with this condition. Case report A 10-year-old boy presented with a 3-month history of hearing loss on right side. There was no history of otorrhea, facial palsy, previous otological procedures or trauma. Otoscopy revealed a bulging posterosuperior quadrant in the otherwise intact right tympanic membrane （Fig.1）. Pure tone audiometry showed an average threshold of 51 dB for 500, 1000, 2000 and 4000Hz, with a 40 dB air-bone gap, suggesting a moderate conductive hearing loss（Fig.4）. CT scan of the temporal bone showed an isolated soft tissue density lesion in the middle ear（Fig.2）.

Capillary Hemangioma of the Middle Ear and External Auditory Canal:a Case Report

We report a case of capillary hemangiomsa that involved the entire middle ear space,external auditory canal(EAC) and tympanic antrum.Symptoms in the case included ear fullness,hearing loss,otalgia and otorrhea.The case was misdiagnosed as recurrent chronic otitis media with granulation preoperatively.A diagnosis of capillary hemangioma was established by postoperative histological examination.The management of capillary hemangioma of the middle ear and external auditory canal is discussed,with a review of the literature.Because of its variable and sometimes misleading clinical presentation,hemangioma can initially be misdiagnosed as other lesions.Therefore,a high index of suspicion is necessary for early and accurate diagnosis.

Endoscopic ear surgery in middle ear cholesteatoma

Objective:Endoscope has been used as diagnostic tool for recidivism and as an adjunct to microscopic technique in the management of cholesteatoma.At present transcanal endoscopic ear surgery(TEES)is being used as a minimally invasive alternative for microscopic approach.We aim to evaluate the feasibility,structural,functional and quality of life outcomes of endoscopic technique in middle ear cholesteatoma.Method:This prospective study was conducted at a tertiary care hospital from January 2017 to January 2018 including 32 adult patients who were treated by TEES for middle ear cholesteatoma.Feasibility of endoscopic technique was assessed by the conversion rates,visualization of middle ear structures and complications.Structural outcomes were evaluated in terms of graft uptake at the third month follow-up and presence of residual or recurrent disease.Functional outcomes were evaluated in terms of postoperative air-bone gap closure at third month follow-up.Patient outcomes in terms of post-operative pain,cosmetic score,day of return to daily activities and patient comfort scores were evaluated.The quality of life outcomes were evaluated using chronic ear survey(CES)and short form questionnaire12 version 2(SF-12V2)which are disease specific and general quality of life assessment tools respectively.Result:Out of 32 patients,endoscopic intact canal wall mastoidectomy was done for 28 and endoscopic canal wall down mastoidectomy in 4 patients.One(3.1%)patient had to be converted to microscopic technique.Median follow-up period was 32.8 months(9e46 months).There were no post-operative complications in any of our patients.The mean middle ear structural visibility index score was 8.4±1.4 with the use of zero-degree endoscope.Graft uptake rate at third month follow-up was 100%.Two(6.3%)patients had recurrent disease at 6 months follow-up and were treated by revision endoscopic surgery.The air conduction(51.3±20.2 dB vs.34.5±20.4 dB,p<0.001),and air-bone gap(33.5±11.1 dB vs.16.9±11.8 dB,p<0.001)has been significantly improved.The mean pain score at 0 hours,6 hours and 24 hours after surgery were 2.5/10,1.6/10 and 0.75/10 respectively.At the discharge,the mean patient comfort score was 9.3±0.6 out of 10.Mean cosmetic score was 9.3±0.5 at the third month follow-up.There was significant post-operative improvement in the sub-scale and total scores of CES and SF-12V2.Conclusion:Endoscopic approach to middle ear cholesteatoma is feasible and confers excellent structural,functional as well as patient related quality of life outcomes.

Fresh Clues about the Origin of Mammalian Middle Ear Revealed

CAS paleontologists have identified a rod-like bone from two early Cretaceous mammals as ossified Meckel's cartilage (OMC). This clears some doubts on the controversial topic of the origin of definitive mannalian middle ear (DMME).……

Intra-operative hearing monitoring methods in middle ear surgeries

Hearing loss is a condition affecting millions of people worldwide. Conductive hearing loss(CHL) is mainly caused by middle ear diseases.The low frequency area is the pivotal part of speech frequencies and most frequently impaired in patients with CHL. Among various treatments of CHL, middle ear surgery is efficient to improve hearing. However, variable success rates and possible needs for prolonged revision surgery still frustrate both surgeons and patients. Nowadays, increasing numbers of researchers explore various methods to monitor the efficacy of ossicular reconstruction intraoperatively, including electrocochleography(ECoch G), auditory brainstem response(ABR), auditory steady state response(ASSR), distortion product otoacoustic emissions(DPOAE), subjective whisper test, and optical coherence tomography(OCT). Here,we illustrate several methods used clinically by reviewing the literature.

Potential otogenic complications caused by cholesteatoma of the contralateral ear in patients with otogenic abscess secondary to middle ear cholesteatoma of one ear:A case report

BACKGROUND Otogenic brain abscess caused by middle ear cholesteatoma is a potentially serious and life-threatening complication in the ear,nose,and throat clinic.The mortality rate associated with otogenic brain abscesses is 8%–26.3%.Recently,in China,the incidence of brain abscess secondary to middle ear cholesteatoma has started to increase due to antibiotic resistance.CASE SUMMARY A 55-year-old male presented hearing loss in the right ear and headache for 1 mo in 2018.Computed tomography(CT) showed an area of low density in the right middle ear and mastoid and auditory ossicle defects and a small amount of soft tissue density in the left middle ear.The parietal wall of the right tympanic cavity and the posterior wall of the mastoid sinus were thin and less continuous.Cranial magnetic resonance imaging revealed an area of low intensity encapsulated by an area of high intensity in the right temporal lobe.We diagnosed him with a brain abscess secondary to middle ear cholesteatoma.He received surgery to drain the abscess followed by a modified radical mastoidectomy.The patient visited our department 3 years later because of intermittent otorrhea in the left ear.CT revealed that the area of the soft tissue density in the left middle ear and mastoid was significantly increased.The posterior wall of the mastoid sinus was destroyed,leaving the left middle ear connecting with the brain.The patient underwent a modified radical mastoidectomy in the left ear CONCLUSION Regular follow-up and timely treatment of contralateral ear disease are vital for the prevention of otogenic complications in patients with otogenic abscesses secondary to middle ear cholesteatoma in the unilateral ear.

First branchial cleft cyst accompanied by external auditory canal atresia and middle ear malformation:A case report

BACKGROUND We report a rare case of first branchial cleft anomaly(FBCA)accompanied by bony atresia of the external auditory canal,middle ear malformation,and location malformation of the facial nerve according to the intraoperative findings.CASE SUMMARY A 19-year-old male patient presented to our department with a mass behind the right earlobe and recurrent postauricular swelling and pain since childhood,he also had severe hearing loss in the right ear since birth.The patient underwent surgery including mass removal,mastoidectomy,and simultaneous meatoplasty and ossiculoplasty under microscopy.No facial palsy or recurrence was noted during postoperative follow-up.CONCLUSION FBCAs are rare,and to our knowledge,this is the first report of FBCA accompanied by external auditory canal bony atresia,middle ear malformation,and location malformation of the facial nerve.An effective postauricular approach under microscopy facilitated complete lesion removal and simultaneous otologic reconstruction.

A Novel Surgery Classification for Endoscopic Approaches to Middle Ear Cholesteatoma

This study aimed to develop a novel surgery classification for an endoscopic approach to middle ear cholesteatoma.We retrospectively analyzed the surgical approaches and outcomes of patients with middle ear cholesteatoma.Middle ear cholesteatoma surgeries were divided into four types and two special types as follows:type I,attic retraction pocket,which only requires tympanostomy tube placement or retraction pocket resection and cartilage reconstruction;typeⅡ,cholesteatoma which is limited to the attic or in which endoscopy can confirm complete removal of mastoid cholesteatoma lesions,including type Ⅱa,requiring only use of a curette,and type Ⅱ b,requiring use of an electric drill or chisel;type Ⅲ,cholesteatoma not limited to the attic,in which endoscopy cannot confirm complete removal of mastoid cholesteatoma lesions,requiring the combined use of endoscope and microscope to perform endoscopic tympanoplasty and"Canal Wall Up"mastoidectomy;type Ⅳ,extensive involvement of mastoid cavity cholesteatoma lesions and/or cases with a potential risk of complications,removal of which can only be performed under a microscope for"Canal Wall Down"mastoidectomy.In addition,there were two special types:"difficult external auditory canal"and congenital cholesteatoma in children.In our system,type I and type U middle ear cholesteatoma surgery was completely performed under an endoscope alone.However,estimating the extent of the lesions,determining the choice of mastoid opening and reestablishing ventilation are the key points for an endoscopic approach to middle ear cholesteatoma.The classification of endoscopic middle ear cholesteatoma surgery may benefit the selection of surgical indications.

Disagreement in middle ear volume estimation between tympanometry and three-dimensional volume reconstruction in the context of tympanic membrane perforation

Introduction: Middle ear volume(MEV) is a clinically relevant parameter across middle ear diseases. MEV values between these techniques have never before been tested for agreement in ears with perforated tympanic membranes(TMs).Methods: Middle ears were identified from 36 patients ranging 18-89 years of age with TM perforations who underwent tympanometry and temporal bone computed tomography(CT) between 2005 and 2015. MEVs calculated by both tympanometry and three-dimensional volume reconstruction(3DVR) were analyzed for agreement using Bland Altman plots. The differences between tympanometric and 3DVR MEV values for each given middle ear were characterized across MEV quartiles(1= smallest; 4= largest) and across increasing states of middle ear disease using Kruskale Wallis and Wilcoxon testing with Bonferroni correction.Results: Bland Altman plots demonstrated significant disagreement between MEV measurement techniques. Differences between tympanometric(T) and 3DVR MEV values were significantly greater with increasing average(i.e.(Tt3DVR)/2)) MEV per linear regression(p < 0.0001). Significance was demonstrated between fourth and first average MEV quartiles(p= 0.0024), fourth and second quartiles(p= 0.0024), third and first quartiles(p= 0.0048), and third and second quartiles(p= 0.048). Absolute MEV difference was not significantly different across varying states of middle ear disease(p= 0.44).Conclusion: Statistically and clinically significant disagreement was demonstrated between tympanometric and 3DVR MEV values. Studies that vary in MEV estimation techniques may be expected to demonstrate significantly different results. These preliminary results suggest that clinicians should endeavor to seek further confirmation when interpreting high tympanometric MEV values.

Numerical Modeling of Human Middle Ear Biomechanics Using Finite Element Method

An accurate finite element (FE) model of the human middle ear can provide better understanding of the mechanics of middle ear, and can be used for aiding the design of the implantable middle ear hearing devices. In this paper, a three-dimensional (3D) FE model of the human middle ear was constructed, including the tympanic membrane, ossicular bones, and middle ear suspensory ligaments/muscles. This model was constructed based on a complete set of computerized tomography section images of a healthy volunteer's left ear by reverse engineering technology. The validity of this model was confirmed by comparing the motions of the tympanic membrane and stapes footplate obtained by this model with published experimental measurements on human temporal bones. The result shows that the model is reasonable in predicting the biomechanics of the human middle ear.

Inflammatory responses to Hydroxyapatite implants in middle ear in rats

Objective To study local inflammatory response after implantation of hydroxyapatite synthetic ossicular prosthesis. Methods Hydroxyapatite granules were implanted in the bulla in 32 rats. Sham surgical procedures were performed in 10 rats as the control. Animals were sacrificed at 1 to 300 days after surgery. Bulla sections, stained with HE and Mallory’s azan, were examined for numbers and percentages of various inflammatory cell types. Results Slightly more inflammatory reaction was seen in animals with the implant than in the controls, mostly during the early stage following the implantation procedure. Few inflammatory cells were observed at later times. There were satisfactory fibrosis in both implanted and control ears. Conclusion The results indicate that hydroxyapatite synthetic prosthesis is a biocompatible implantation material in the middle ear. Nonetheless, the presence of inflammatory reaction immediately following implantation implies that control of infection is important in the early times after the implantation procedure.

UTILITY OF VIBRANT SOUNDBRIDGE IN PATIENTS WITH CONGENITAL MIDDLE AND OUTER EAR DEFORMITIES

Objective To report use of the Vibrant Soundbridge (VSB) in patients with congenital deformation of the middle and outer ears and investigate its utility in this patient population.Method Four patients with congenital deformation of middle and outer ears underwent VSB implantation. All were male (aged 3-18 years,average 13.5 years) and operated on the left side.Malformation was bilateral in 3 patients and unilateral in 1 patient. Surgical techniques were modified to accommodate each patient’s unique conditions and needs.The implant site was approached via the facial recess in 3 patients and through a retro-facial nerve route in 1 patient. The VSB implant was connected to either the stapes (2 cases) or the round window (2 cases).Pure tone and speech audiometry results and daily communication capabilities before and after VSB activation were compared.Results The operations were successful in all patients, with no complications. The patient communication level improved significantly after VSB activation. Average air conduction pure tone threshold or conditioned reflex audiometry threshold improved by 35 dB in the 0.25-4 kHz range,from 69 dB HL before VSB activation to 34 dB HL after.The sentence recognition rate in quiet at 65 dB SPL went up to 86% from 0% without VSB for patients with bilateral deformation and remained at 100% for the patient with unilateral deformity. However, for the latter patient, the rate improved to 20% from 0% without VSB in noise (-8 dB SNR).Conclusion VSB is an excellent solution for improving hearing in patients with congenital deformation of middle and outer ears.Operation can be completed and good results can be achieved even in patients with unique conditions and needs.

Salivary Gland Choristoma of the Middle Ear and Review of the Literature

Conductive hearing loss due to middle ear masses is uncommon and usually diagnosed after biopsy. We present a case of a permanent facial palsy occurred following an uneventful biopsy during an exploratory tympanotomy in a salivary gland choristoma of the middle ear. Most salivary gland choristomas have been found in the head and neck. Its location in the ear is extremely rare, and thus we present the 38th case in English and non-English literature from the first publication by Taylor in 1961. Complete surgical removal of salivary gland choristomas of the middle ear is indicated when may not result in permanent damage to the facial nerve. Only biopsy and observation are recommended when the mass is intimately associated with the facial nerve or there are unsafe facial nerve abnormalities. Although the facial nerve is involved in 40% of cases, transient or even permanent facial palsies are exceptional. The reactivation of latent herpes virus in the facial canal may be involved in facial palsy’ etiology following minimal and uneventful middle ear surgery like a biopsy rather than nerve injury related to facial canal malformations.

Survival in Primary Carcinoma of the External and Middle Ear Is Strongly Dependent on Stage at Diagnosi

Conclusion: Early-stage detection of temporal bone carcinoma improves the survival rate. When detected at an advanced stage, predicted prognosis is poor even with a combination of surgery, radiotherapy and chemotherapy. Objectives: We evaluated treatment strategies and survival rates in cases of carcinomas of the external and middle ear. Method: Retrospective review of patients treated at Ehime University Hospital during the 32 years from 1977 to 2008. Subjects were 41 patients, consisting of 21 men and 20 women with a mean age of 63.2 years. Modified Pittsburgh staging system: stage I in 11 cases (27%), stage II in 4 (10%), stage III in 6 (15%) and stage IV in 20 (49%). Histopathology: squamous cell carcinoma (SCC) in 35 cases, adenoid cystic carcinoma (ACC) in 3, and adenocarcinoma (AC) in 3. Thirty-eight patients were treated by surgery. Radiation was added postoperatively in 23 patients. Three patients were treated by chemoradiotherapy. Results: The survival rate of carcinomas detected at an advanced stage was poor with a disease-specific 5-year survival rate of 100% in early-stage disease (stage I and II) versus 20.8% in stage III and 27.5% in stage IV disease, irrespective of histopathology of the tumor.

Finite Element Dynamics of Human Ear System Comprising Middle Ear and Cochlea in Inner Ear

A human middle ear consists of an eardrum and three ossicles which are linked by each other, and connect with the eardrum and an inner ear. The inner ear consists of a cochlea and a vestibular system. An abnormality of the human middle ear such as ossicular dislocation may cause conductive hearing loss. The conductive hearing loss is generally treated by surgery using artificial ossicles. The treatments of conductive hearing loss require a better understanding of characteristics and dynamic behaviors of the human middle ear when the sounds transmit from outer inner to inner ear. The purpose of this research is to simulate the dynamic behaviors of a human ear system comprising the middle ear and the cochlea in the inner ear using the finite element method (FEM). Firstly, the eigen-value analysis was performed to obtain the natural frequencies and vibration modes of the total ear system. Secondly, the frequency response analysis was carried out. Thirdly, the time history response analyses were performed using human voices as the external forces. In the time history response analyses, the sounds created as input sound pressures were used. Human voices, for example vowels “I”, “u” and “e” as input sound pressures were created by using the sound pressures downloaded from the opening samples of human voices as wav files in a website. Then it was clarified that the high frequency components of sounds are reduced by the middle ear system.

Observation with Light Microscopy on Pathological Changes of the Middle and Inner Ear Caused by Respiratory Syncytial Virus in Guinea Pigs.

Respiratory syncytial virus(RSV)was inocu-lated into the middle ear of guinea pigs.Sampleswere taken on the 2nd,4th,7th,10th,14th,21thand 30th days after inoculation for virus cultureand serologic test as well as observation with lig-ht microscopy.The positive rate of RSV culturefrom middle ear mucous membrane was 50%

Systematic review of animal models of middle ear surgery

Animal models of middle ear surgery help us to explore disease processes and intervention outcomes in a manner not possible in patients. This review begins with an overview of animal models of middle ear surgery which outlines the advantages and limitations of such models. Procedures of interest include myringoplasty/tympanoplasty, mastoidectomy, ossiculoplasty, stapedectomy, and active middle ear implants. The most important issue is how well the model reflects the human response to surgery. Primates are most similar to humans with respect to anatomy; however, such studies are uncommon now due to expense and ethical issues. Conversely, small animals are easily obtained and housed, but experimental findings may not accurately represent what happens in humans. We then present a systematic review of animal models of middle ear surgery. Particular attention is paid to any distinctive anatomical features of the middle ear, the method of accessing the middle ear and the chosen outcomes. These outcomes are classified as either physiological in live animals,(e.g., behavioural or electrophysiological responses), or anatomical in cadaveric animals,(e.g., light or electron microscopy). Evoked physiological measures are limited by the disruption of the evoking air-conducted sound across the manipulated middle ear. The eleven identified species suitable as animal models are mouse, rat, gerbil, chinchilla, guinea pig, rabbit, cat, dog, sheep, pig and primate. Advantages and disadvantages of each species as a middle ear surgical model are outlined, and a suggested framework to aid in choosing a particular model is presented.

Excessive 5-year weight gain predicts metabolic syndrome development in healthy middle-aged adults

AIM:To quantitatively examine the impacts of an easyto-measure parameter-weight gain-on metabolic syndrome development among middle-aged adults. METHODS:We conducted a five-year interval observational study.A total of 1384 middle-aged adults not meeting metabolic syndrome(MetS)criteria at the initial screening were included in our analysis.Baseline data such as MetS-components and lifestyle factors were collected in 2002.Body weight and MetS-components were measured in both 2002 and 2007.Participants were classified according to proximal quartiles of weight gain(WG)in percentages(%WG≤1%,1%< %WG≤5%,5%<%WG≤10%and%WG>10%, defined as:control,mild-WG,moderate-WG and severe-WG groups,respectively)at the end of the follow-up. Multivariate models were used to assess the association between MetS outcome and excessive WG in the total population,as well as in both genders. RESULTS:In total,175(12.6%)participants fulfilled MetS criteria within five years.In comparison to the control group,mild-WG adults had an insignificant risk for MetS development while adults having moderate-WG had a 3.0-fold increased risk for progression to MetS [95%confidence interval(CI),1.8-5.1],and this risk was increased 5.4-fold(95%CI,3.0-9.7)in subjects having severe-WG.For females having moderate-and severe-WG,the risk for developing MetS was 3.6(95% CI,1.03-12.4)and 5.5(95%CI,1.4-21.4),respectively. For males having moderate-and severe-WG,the odds ratio for MetS outcome was respectively 3.0(95%CI, 1.6-5.5)and 5.2(95%CI,2.6-10.2). CONCLUSION:For early-middle-aged healthy adults with a five-year weight gain over 5%,the severity of weight gain is related to the risk for developing metabolic syndrome.