Superhydrophobic Microspheres Research Articles

Fabrication of cellulose based superhydrophobic microspheres for the production of magnetically actuatable smart liquid marbles

Cellulose microspheres were fabricated on the basis of sol-gel transition using NaOH/urea/H 2 O as the solvent system. These microspheres had an average diameter of about 30 μm. Upon modification with Fe 3 O 4 and poly (DOPAm- co -PFOEA), superhydrophobic magnetic cellulose microspheres were generated, which were analyzed by FTIR, TG, XRD, XPS and water contact angle tests. Magnetic cellulose microspheres contained approximately 15 wt% of Fe 3 O 4 . Poly(DOPAm- co -PFOEA)/Fe 3 O 4 /cellulose microspheres and had a low surface energy and a high water-repellency. These superhydrophobic microspheres were also converted into liquid marbles via an easily scalable process.

Low-Frequency Sound Pressure and Transtympanic Endoscopy of the Middle Ear in Assessment of “Spontaneous” Perilymphatic Fistula

This study was designed to verify an eventual perilymphatic fistula (PLF) in 264 patients with sensorineural hearing loss (SNHL) and/or vertigo. The patients were exposed to a low-frequency sound stimulation (LFS) on posturography to objectively test Tullio's phenomenon and Hennebert's sign. Endoscopes with 5 degree and 25 degree of visual angle and an outer diameter of 1.7 mm were used. The round window niche, with its foldings, oval window with stapes superstructure, a part of the facial recess and the area in the fissula ante fenestram were examined and video recorded. In one patient, we endoscopically verified a fistula in the round window membrane (resulting from a diving accident) that was covered with a fibrinous layer. In 4 cases, there was abnormal mucosal shining in the round window but without PLF. In 7 cases, the tympanic cavity could not be visualized because of the adhesive middle ear process, the abnormal anatomy, or the prominent exostoses of the ear canal prohibited vision. In 34 patients, LFS provoked unsteadiness on posturography without PLF. In 6 cases, a postoperative middle ear infection was recorded. No permanent tympanic membrane perforation occurred. It is unlikely that disease entity of “spontaneous PLF” exists. Tympanoscopy should be regarded as the first choice when a PLF is suspected.

Endoscopic Transtympanic Tympanoplasty in the Treatment of Conductive Hearing Loss: Early Results

We describe our initial experience with endoscopic transtympanic tympanoplasty and evaluate whether this approach is adequate and minimally invasive in the treatment of conductive hearing loss. Prospective trial. University hospital. Nine patients underwent endoscopic transtympanic tympanoplasty, with an average follow-up period of 17 months. Presurgical diagnosis was made by transtympanic endoscopy through a perforation made by OtoScan laser-assisted myringotomy in the outpatient clinic. With clean endoscopic visualization, ossiculoplasty was performed by inserting a trimmed tragal cartilage through the myringotomy perforation made by laser-assisted myringotomy. Two types of ossiculoplasty were performed: columella reconstruction and interposition. The tympanic membrane was covered with a chitin membrane or sealed with a small piece of perichondrium from the tragal cartilage. Perioperative and postoperative complications and preoperative and postoperative hearing. Endoscopic transtympanic tympanoplasty with columella and endoscopic transtympanic tympanoplasty with interposition were performed in seven and two patients, respectively. Insertion of the cartilage was performed without conversion to a conventional otomicroscopic technique. The average hearing level before the operation was 59 dB. After the endoscopic transtympanic tympanoplasty, the average improved to the level of 27 dB, with an average air-bone gap of 11 dB. The myringotomy perforation was closed within 2 to 3 weeks. As opposed to conventional methods, this procedure does not require surgical exposure such as otosclerosis drilling and skin incision, and avoids the substantial risk of unnecessary injury to the chorda tympani. Endoscopic transtympanic tympanoplasty for a disrupted ossicular chain is an adequate and minimally invasive procedure and should prove to be a useful surgical procedure in future endoscopic tympanoplasty.

Office-based endoscopic procedure for diagnosis in conductive hearing loss cases using OtoScan Laser-Assisted Myringotomy.

In conductive hearing loss (HL), even though preoperative examinations including audiometry, tympanometry, and computed tomography (CT) scan are applied, exploratory tympanotomy is necessary to make an exact diagnosis of ossicular interruption and stapes fixation. Precise preoperative diagnosis would be useful for patient counseling, surgical indications, and planning. The advantages of office-based OtoScan laser-assisted myringotomy (LAM), which makes a circular and non-hemorrhagic perforation, prompted us to investigate other uses of LAM in addition to ventilation and drainage of the tympanic cavity. To make presurgical diagnosis in conductive HL, endoscopes with an outer diameter of 1.7 or 1.9 mm were used to inspect the middle ear pathology through perforations with a diameter of 2 mm made by LAM. In the outpatient clinic, a circular perforation with a diameter of 2 mm was made in the tympanic membrane with LAM. An endoscopic view of the ossicular chain through a 70degrees angled tip endoscope held immediately to the outer side of the perforation was obtained to diagnose conduction disturbance loci in conductive HL cases. Ossicular chain abnormalities were easily and safely detected by clean endoscopic views obtained through a nonhemorrhagic circular perforation. When necessary, insertion of the tip of the endoscope into the tympanic cavity provided additional views of epitympanum. We suggest that transtympanic endoscopy through the perforation made by LAM is an effective and safe office-based procedure for diagnosis in conductive HL cases and could be an alternative procedure to replace exploratory tympanotomy.

内視鏡による耳小骨離断の診断と治療

In conductive hearing loss with an intact ear drum, even though preoperative examinations including audiometry, tympanometry and CT scan are applied, exploratory tympanotomy is necessary to make an exact diagnosis of ossicular interruption and stapes fixation. In the exploratory tympanotomy, if an ossicular problem is detected during the procedure, it is usually followed by ossicular reconstruction surgery.Our current strategy for treatment of conductive hearing loss without tympanic membrane perforation is presented.The presurgical diagnosis is made in the outpatient clinic by transtympanic endoscopy through the circular and non-hemorrhagic perforation made by laser-assisted myringotomy (LAM). An endoscopic view of the ossicular chain through 30- or 70-degree angled tip endoscopes held immediately to the outer side of the perforation was obtained to diagnose conduction disturbance locus in conductive hearing loss cases. Precise preoperative diagnosis is useful for patient counseling, surgical indications and planning.When an ossicular interruption is diagnosed, endoscopic transtympanic tympanoplasty (ETT), a newly developed minimally invasive procedure, is planned. In the endoscopic visualization through the dry, circular myringotomy perforation using a 1.9mm diameter rigid angled endoscope, ossiculoplasty was performed by inserting a trimmed tragal cartilage through the myringotomy perforation. As opposed to conventional methods, this procedure does not require surgical exposure such as otosclerosis drilling and skin incision, and avoids the substantial risk of unnecessary injury to the chorda tympani. ETT for a disrupted ossicular chain is an adequate and minimally invasive procedure and should prove a useful surgical procedure in future endoscopic tympanoplasty.

Can low frequency sound stimulation during posturography help diagnosing possible perilymphatic fistula in patients with sensorineural hearing loss and/or vertigo?

Perilymphatic fistula (PLF) is often difficult to diagnose because of the similar symptomatology, such as vertigo, tinnitus and hearing loss, which is found in several inner ear diseases. We attempted to correlate a positive result of low frequency sound (LFS) stimulation tests in posturography with the presence or absence of a PLF confirmed by transtympanic endoscopy in 209 patients with various inner ear diseases (Meniere's disease ( n=128), vestibulopathy ( n=41), cochleopathy ( n=28) and sudden deafness ( n=12). LFS provoked unsteadiness in posturography without PLF in 24 patients with Meniere's disease, in 5 patients with vestibulopathy, in 3 patients with cochleopathy and in 2 patients with sudden deafness. In one patient, tympanoscopy revealed fistula in the round window membrane that was covered with a fibrinous layer. In four cases there was abnormal light reflex in the round window but without PLF. In eight cases, Hennebert's sign was present with nystagmus, without PLF. We conclude that pathological responses to the LFS test in posturography can also be encountered in other inner ear diseases without PLF.

Role of Transtympanic Endoscopy of the Middle Ear in the Diagnosis of Perilymphatic Fistula in Patients with Sensorineural Hearing Loss or Vertigo

Background: The diagnosis of perilymphatic fistula (PLF) is often difficult, and therefore the condition can be overlooked. Tympanoscopy presents an alternative procedure for visualising the middle ear anatomy, and it may help to diagnose PLF. Aim: The aim of this study was to evaluate the use of middle ear endoscopy in establishing the diagnosis of PLF and in defining its incidence in patients with sensorineural hearing loss and/or vertigo and tinnitus. Subjects and Methods: Two hundred and sixty-five patients (22–80 years of age, mean 48 years) were prospectively and consecutively referred for middle ear examination with tympanoscopy. Tympanoscopy was performed using endoscopes with visual angles of 5 and 25° and an outer diameter of 1.7 mm. The round window niche (with its secondary membrane), the oval window with a stapes superstructure, a part of the facial recess and the area in the fissula ante fenestram were examined and video-recorded. Results: For 1 patient, tympanoscopy revealed fistula in the round window membrane that was covered with a fibrinous layer. In 4 cases abnormal mucosal shining appeared in the round window, but no PLF was present. In 7 cases the tympanic cavity could not be visualised because of the adhesive tympanic membrane, abnormal anatomy or the prominent exostoses of the external ear canal. In 6 cases a postendoscopic middle ear infection was found. No permanent tympanic membrane perforation occurred in any of the patients in this study. Conclusions: Tympanoscopy is a rapid examination tool with which to verify certain areas of the middle ear anatomy, but it is of limited value for ruling out the presence of PLF.

Transtympanic endoscopy for drug delivery to the inner ear using a new microendoscope.

Anatomic variations of the round window (RW) niche found in approximately 33% of human temporal bones may account for some ofthe problems associated with local drug delivery to the inner car. A microendoscope with a total outer diameter of 1.2 mm was developed in particular for easy visualization and of drug delivery to the RW niche. It incorporated a thin fiber optic, a working/laser channel (0.3 mm) and an irrigation/suction channel (0.27 mm). When compared to a common 30 degree lens optic, with the microendoscope a greater area of the round window niche could be overseen. In addition, the endoscope could be advanced directly upon the surface of the RW membrane (RWM). The microendoscope may be used for evaluation of the anatomy of the RW niche prior to the placement of local drug delivery systems, for application of drugs directly onto the surface of the RWM or to verify the correct placement of inner ear drug delivery systems.

Virtual endoscopy of the tympanic cavity based on high-resolution multislice computed tomographic data.

This study was designed to assess the value of high-resolution multislice computed tomography (MSCT) data of the petrous bone for the virtual endoscopic visualization of the tympanic cavity. The recently introduced MSCT technology has improved spatial resolution in the z axis as well as scan speed in computed tomography. Three-dimensional rendering of high-resolution MSCT data of the petrous bone may be expected to provide endoluminal views of superior image quality, thus competing with transtympanic endoscopy (otoendoscopy). This study was conducted at a university teaching hospital. Cadaveric phantom studies in a MSCT scanner were performed to define a data acquisition protocol, combining adequate detail resolution with low tube current. Subsequently, the cadaveric phantom underwent otoendoscopy. The postprocessing parameters of the three-dimensional rendering protocol were chosen to produce views closely resembling the corresponding otoendoscopic images. High-resolution data from 18 patients with pathologic conditions of the middle ear, as suggested by clinical findings and assessment of cross-sectional data, were postprocessed using the volume rendering technique to generate standardized virtual endoscopic views. A total of 36 virtual endoscopic scans of the tympanic cavity were generated. With regard to intermediate and high-density structures, virtual endoscopic images, based on MSCT data, yielded endoluminal views closely resembling corresponding otoendoscopic views. Virtual endoscopy seems useful for imaging ossicular pathologic conditions such as dysplasia and chain disruption as well as for assessing patient status before and after otosurgery. MSCT data sets allow for generating virtual endoscopic views closely resembling otoendoscopic images. The technique is especially useful when ossicular pathologic changes are present as well as for preoperative and postoperative imaging of otologic procedures.

Virtual endoscopy of the middle ear.

Virtual endoscopy is a computer-generated simulation of fiberoptic endoscopy, and its application to the study of the middle ear has been recently proposed. The need to represent the middle ear anatomy by means of virtual endoscopy arose from the increased interest of otolarygologists in transtympanic endoscopy. In fact, this imaging method allows the visualization of middle ear anatomy with high detail, but it is evasive and is essentially used for surgical guidance. Virtual endoscopy provides similar perspectives of the tympanic cavity but does not require the tympanic perforation. In the study of the middle ear, specific attention is given to the retroperitoneum. This region contains elevations of the medial wall (pyramidal eminence and ridge, styloid eminence and ridge, subiculum, ponticulus) and depressions (sinus tympani, posterior sinus tympani, facial sinus, fossula of Grivot, oval window fossula), which can be effectively displayed by virtual endoscopy. Virtual endoscopy is foreseen as a useful tool in preoperative management of patients who are candidates for middle ear surgery, since it can predict with high detail the patient's specific anatomy by imaging perspectives familiar to otosurgeons.