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A J Maniglia

Publications and source records attributed to A J Maniglia.

At least 19 recordsLinked to original sources
PubMed2001

Engineering principles applied to implantable otologic devices.

The engineering principles of possible actuators and sensors for totally implantable mid-ear or cochlear hearing devices are summarized. The selection considerations are discussed. The frequency response, and the needed force and displacement at the ossicular chain sites were measured on fresh temporal bones to determine approximately the middle ear device requirements and design considerations. A design example of the actuator and sensor is outlined with laboratory and acute animal evaluation results.

Acoustics↗
PubMed2001

Bioelectronic options for a totally implantable hearing device for partial and total hearing loss.

A semi-implantable electromagnetic hearing device (SIMEHD) for sensorineural hearing loss has been developed and tested in animals and limited clinical trial. The authors' electromagnetic transducer, which is the driver of the SIMEHD, when used in reverse mode is applicable to the fabrication of a bioelectronic microphone. Instead of being a driver, it transforms the sound-activated eardrum-ossicular vibration into an electric signal through the NdFeBo magnet implanted on the head of the malleus, interacting in a contactless manner with the electromagnetic coil.

Acoustics↗
PubMed1999

Complications of rhytidectomy in an otolaryngology training program.

OBJECTIVES/HYPOTHESIS: Complications of rhytidectomy have been widely reported in the literature. This study examines the incidence of complications after rhytidectomy in the hands of chief residents under appropriate attending supervision in an otolaryngology-head and neck surgery training program. MATERIALS AND METHODS: The charts of 96 consecutive SMAS rhytidectomy patients were retrospectively reviewed. Patients were selected for surgery from a clinic designed exclusively for cosmetic facial surgery patients. This clinic was run by the otolaryngology chief resident and was supervised by an attending staff surgeon. Most patients elected local anesthesia and sedation administered by the surgical team. Submental liposuction was performed followed by SMAS plication rhytidectomy. RESULTS: Follow-up ranged from 1 to 60 months. Complications included expanding hematoma (1%), temporary facial nerve weakness (3%), pretragal/mastoid skin slough (4.2%), permanent ear numbness (1%), hypertrophic scar (3.1%), wound infection (1%), and dissatisfaction with result (4%). There were no cases of permanent facial nerve injury. CONCLUSION: These complication rates compare favorably with reported rates of larger studies over the past 30 years. These data support the conclusion that rhytidectomy can be performed safely by otolaryngology residents with little morbidity and good patient satisfaction.

Aged↗
PubMed1999

The middle ear bioelectronic microphone for a totally implantable cochlear hearing device for profound and total hearing loss.

BACKGROUND: A bioelectronic middle ear microphone (BMEM) has been developed in a laboratory bench model and successfully tested in fresh human temporal bones. A transducer actually has been bench-tested in our laboratory; it was implanted in chronic animal experiments (cats) as well as in humans for a period of 1 year as a driver of a semi-implantable electromagnetic middle ear hearing device (IDE, FDA approved). This BMEM is the result of the use of this same electromagnetic transducer used in a reverse mode. The applicability of the BMEM is for the development of a totally implantable cochlear implant using the eardrum as a diaphragm that transmits vibrations to a magnet cemented to the ossicles. This BMEM is to be powered by a lithium-ion implantable, rechargeable battery. MATERIALS AND METHODS: To test the efficacy of this BMEM, the experiment was divided into two parts: (1) bench model, and (2) fresh human temporal bones, using an air-core electromagnetic (EM) coil and a ferrite core EM coil for comparison. RESULTS: In the bench model, the average displacement at 3 kHz was 0.95 microns (peak) for 4 V p-p and 1.65 microns (peak) for 10 V p-p. At 5 kHz, the measurements were somewhat higher. In fresh human temporal bones, with sound source in the ear canal (60 dB HL and 90 dB HL), the result was better with the magnet implanted on the head of the malleus with the incus removed. The ferrite core EM coil with the magnet implanted on the malleus with the incus removed was compared with the air-core EM coil. At 60 dB HL, the ferrite core EM coil yielded more than four times the amplitude of the EM coil. At 90 dB HL, the ferrite core EM coil produced more than five times the amplitude compared with the air-core coil. CONCLUSION: This BMEM using an EM ferrite coil and a permanent magnet on the head of the malleus is more efficient when compared with an EM air-core coil. This BMEM may be applicable to the construction of a totally implantable cochlear implant. Further research is necessary to integrate this BMEM with the other components of the design concept of the totally implantable cochlear implant.

Animals↗
PubMed1997

A new adhesive bonding material for the cementation of implantable devices in otologic surgery.

BACKGROUND: Presently, there are no U.S. Food and Drug Administration (FDA)-approved adhesive bone cements for the surgical fixation of prosthetic materials in the middle ear. A promising new cement, 4-META/MMA-TBB opaque resin, has shown remarkable adhesive properties as a bone cement in vivo. The cement is composed of 4-methacryloyloxyethyl trimellitate anhydride (4-META) and methyl methacrylate (MMA) as monomers and tri-n-butyl borane (TBB) as an initiator. METHODS: An electromagnetic semiimplantable hearing device presently under development was implanted into the middle ear of six cats using 4-META/MMA-TBB resin to cement a titanium-encased magnet to the incus. The animals were subsequently killed (at a mean of 9.6 months) to assess the (temporal bones and specifically the magnet-incus complex in each animal. RESULTS: The titanium-encapsulated magnet was firmly adherent to all incuses without any failure of the cement-bone interface. Histopathologic examination of the implanted temporal bones demonstrated lack of middle ear inflammation. Transmission electron microscopy of the incuses demonstrated a unique "hybrid layer" in the bone-side subsurface of the bone-cement interface that elucidates the mechanism of interfacial adhesion. CONCLUSIONS: Our investigation highlights the special biomechanical properties as well as the biocompatibility of 4-META/ MMA-TBB resin that make it an attractive bone-bonding agent for use in otologic surgery, including its potential usefulness during ossicular reconstruction.

Animals↗
PubMed1997

Effect of magnetic resonance imaging on a new electromagnetic implantable middle ear hearing device.

OBJECTIVE: A 1.5-T magnetic resonance imager has been shown to be contraindicated for use in patients with pacemakers, cochlear implants, and neurostimulators. Our semi-implantable middle ear device uses a new adhesive bone cement. 4-META/MMA-TBB, for cementation of a 29-mg titanium-encased neodymium-iron-boron (NdFeB) magnet to the incus. METHODS: Five NdFeB magnets and four solid titanium cylinders were cemented onto the incus of five preserved human temporal bones and two cadaver heads. They were all inserted into a magnetic resonance imager and evaluated for possible disruption. RESULTS: Owing to the magnetic torque, the three magnets on the temporal bone were disrupted from the incus. The two cylinders on the temporal bones and the two cylinders and two magnets on the whole heads were not affected. The magnetic resonance imaging field did not affect the coercive force of the NdFeB magnets. CONCLUSION: The large torque produced by a magnetic resonance imager may disrupt the magnet-cement and cement-incus interfaces, causing dislodgement. We postulate that patients with implantable magnets on the incus should not undergo magnetic resonance imaging testing.

Cochlear Implants↗
PubMed1997

Mechanical, acoustic and electromagnetic evaluation of the semi-implantable middle ear hearing device (SIMEHD).

The properties of the partially implantable middle ear hearing device (SIMEHD) were extensively studied. The internal unit was subjected to 5,000 cycles of bending at a force of 75 g (gravity) without failure. An accurate measurement of the force output of the SIMEHD was obtained (14-25 dynes/mA). This force is too small to cause any damage to the ossicular chain. The force resulting from electromagnetic interference over a wide frequency range (500 khz -1 Giga (10(9)) Hz) was measured and noted to be within the margin of safety. The frequency response plots (500-8,000 Hz) were also obtained and revealed an excellent ability to amplify middle and high-frequency sounds.

Acoustics↗
PubMed1997

Semi-implantable middle ear electromagnetic hearing device for sensorineural hearing loss.

A semi-implantable middle ear electromagnetic hearing device (SIMEHD) is proposed for limited clinical trial in adult patients to evaluate the implantable hearing device for moderate to severe sensorineural hearing loss. Food and Drug Administration (FDA) investigational device exemption (IDE) approval has been granted (May 1996) for clinical trials. The implant unit has been evaluated acutely and chronically in animals (cats) with excellent results. Five cats undergoing chronic implantation were allowed to survive an average of 9.6 months, showing that the SIMEHD is biocompatible, functional and without untoward complications. All implant units recovered from the cats were functional, except for wire breakage of the internal antenna. A new antenna was redesigned for human implantation. The SIMEHD system consists of an external and internal unit. The external unit consists of a microphone, audio amplifier, modulator, radio frequency (RF) amplifier, antenna and battery. The internal unit is composed of a receiving antenna, hybrid electronic circuit, air core driving coil, and a target magnet cemented to the incus. All materials in contact with the body are biocompatible and expected to survive indefinitely. The implant unit is miniaturized and manufactured with existing fabrication technology by our industrial collaborator, Wilson Greatbatch, Ltd. The specific aims and major tasks of the proposed research are: a) to evaluate reliability, safety and efficacy of the SIMEHD system in a selected group of patients diagnosed with sensorineural hearing loss, due mainly to presbycusis or aging of the inner ear; and b) to obtain objective and subjective evaluation of audiologic and psychoacoustic performance as compared to the acoustic hearing aid. This paper describes the design, illustrates the actual device (newest prototype) and details the technique for surgical implantation in the attic and mastoid antrum in humans.

Adult↗
PubMed1997

External unit for a semi-implantable middle ear hearing device.

A miniaturized, low-power external unit has been developed for the clinical trials of a semi-implantable middle ear electromagnetic hearing device (SIMEHD) which uses radio-frequency telemetry to couple sound signals to the internal unit. The external unit is based on a commercial hearing aid which provides proven audio amplification and compression. Its receiver is replaced by an application-specific integrated circuit (ASIC) which: 1) adjusts the direct-current bias of the audio input according to its peak value; 2) converts the audio signal to a one-bit digital form using sigma-delta modulation; 3) modulates the sigma-delta output with a radio-frequency (RF) oscillator; and 4) drives the external RF coil and tuning capacitor using a field-effect transistor operated in class D. The external unit functions as expected and has been used to operate bench-top tests to the SIMEHD. Measured current consumption is 1.65-2.15 mA, which projects to a battery lifetime of about 15 days. Bandwidth is 6 kHz and harmonic distortion is about 2%.

Ear, Middle↗
PubMed1996

State of the art on the development of the implantable hearing device for partial hearing loss.

This article summarizes the state of the art of the implantable hearing devices for partial hearing loss. Devices such as temporal bone stimulators and piezoelectric and electromagnetic middle and inner ear transducers are discussed. Cochlear implants are excluded. (See "Update on Cochlear Implantation" in this issue.) Those readers interested in a more in-depth study of implantable hearing devices should consult the February 1995 issue of The Otolaryngologic Clinics of North America which is dedicated to this matter (Guest Editor: Anthony J. Maniglia, MD).

Bone Conduction↗
PubMed1995

Endolymphatic sac tumors: histopathologic confirmation, clinical characterization, and implication in von Hippel-Lindau disease.

The term "endolymphatic sac tumor" (ELST) was coined to identify the likely origin of aggressive papillary tumors of the temporal bone. To evaluate the validity of this designation, the temporal bone collection at the Massachusetts Eye and Ear Infirmary was accessed in an effort to determine the pathologic relationship between these tumors and the endolymphatic sac. The search resulted in the identification of a de-novo papillary epithelial lesion arising within the confines of the endolymphatic sac in a patient with von Hippel-Lindau (VHL) disease who harbored a large, destructive ELST in the opposite temporal bone. This finding provides the most substantial evidence to date regarding the origin of the ELST and the accuracy of its nomenclature. Seven additional clinical cases of ELST were identified and analyzed in order to define the natural history of these tumors. All patients had a history of sensorineural hearing loss diagnosed an average of 10.6 years prior to tumor discovery. The presence of a polypoid external auditory canal mass, facial paralysis, and evidence of a destructive mass arising on the posterior fossa surface of the temporal bone were common physical and radiographic findings. The management of these patients, as well as those who are probably prone to such tumors (i.e., VHL patients), is discussed.

Adenocarcinoma↗
PubMed1995

The history and development of the implantable hearing aid.

Implantable hearing aids have an interesting and colorful history. These devices have usually been investigational, but this has changed. Currently, several implantable devices are available for ongoing clinical trials in humans. They have promise in providing improved hearing in certain cases of conductive, mixed, and sensorineural hearing loss.

Bone Conduction↗
PubMed1995

Contactless semi-implantable electromagnetic middle ear device for the treatment of sensorineural hearing loss. Short-term and long-term animal experiments.

A contactless electromagnetic hearing device has been designed following basic science experiments, improvement of electronics, and precision micromechanics. Different prototypes have been developed and tested in the laboratory, fresh human temporal bones, and acute and chronic animal experimentation. A conductive hearing loss model was first developed in the cat using samarium cobalt as the target magnet. Later, a highly efficient electromagnetic air-core coil was selected to vibrate a neodymium iron boron magnet cemented to the body of the incus and tested in acute and chronic experiments using the cat as the model. In this group of animals, the ossicular chain was left intact. There was no failure of the target magnet, driving coil, or implanted electronics. The only problem encountered in this evaluation was a malfunction of the receiving antenna that had to be redesigned and retrofitted into the implanted units. This system would be suitable for the treatment of moderate to severe sensorineural hearing loss. Planning to begin human clinical trials is ongoing.

Animals↗
PubMed1995

Engineering principles of mechanical stimulation of the middle ear.

This article presents the transducer principles of possible middle ear hearing devices with their characteristics and selection considerations summarized. The frequency response and the needed force and displacement at the ossicular chain sites were measured to determine approximately the system requirements and design considerations. The power required to vibrate the ossicular chain is estimated to be of the order of 0.1 watt, which is three orders of magnitude smaller than the power consumption of devices being developed in various laboratories. Careful engineering design and evaluation is needed. A design example of the transducer used with a partially implantable, noncontact electromagnetic hearing device is presented in this article with laboratory evaluation results.

Biomedical Engineering↗
PubMed1995

Biomechanical assessment of a new adhesive bone cement for otologic surgery.

The adhesion of metallic prostheses to bone is a major problem in otologic surgery. Conventional bone cements lack significant adhesive strength, which predisposes the cemented prosthesis to loosening. The advent of surgically implantable hearing devices is one example where an adhesive cement to secure metal to bone would be useful. The biomechanical properties of a new cement, 4-META/MMA-TBB opaque resin, were evaluated in an animal model. The cement is composed of 4-methacryloyloxyethyl trimellitate anhydride (4-META) and methyl methacrylate (MMA) as monomers and tri-n-butyl borane (TBB) as an initiator. Titanium disks were cemented to the tibias of rabbits, which were sacrificed at 0 and 90 days. Tensile and shear bond strengths between bone and metal were tested at both times. The mean baseline tensile and shear bond strengths were 8.92 MPa and 11.96 MPa, respectively. Adhesive failure occurred at the bone-cement interface. The decrease in bond strength at 90 days was minimal. Thus, 4-META/MMA-TBB cement is a promising new metal-to-bone adhesive that may be useful for the surgical fixation of metallic prostheses in otologic surgery.

Adhesives↗
PubMed1995

Midfacial degloving for the management of nasal, sinus, and skull-base neoplasms.

The midfacial degloving approach to the midfacial orbital and anterior skull base structures is very versatile. It provides excellent access to a wide range of resections, such as medial maxillectomy, radical maxillectomy with and without orbital exenteration, anterior skull base cranifacial resection, and partial rhinectomy. This technique is useful for removal of benign and malignant lesions. The postoperative complications are rare. Because of absence of external skin incisions the cosmetic results are excellent.

Adult↗
PubMed1994

Parotidectomy: a ten year experience with fine needle aspiration and frozen section biopsy correlation.

During the years 1980 through 1990, 247 patients underwent parotidectomy at our institution for the removal of primary parotid lesions. Charts were reviewed in an effort to document the distribution of pathology in patients undergoing parotidectomy and the histopathology from each case was organized and tallied by virtue of the final specific diagnoses. An additional goal of this study was to evaluate the efficacy of pre-operative fine-needle aspiration biopsy (FNAB) and frozen section pathology in accurately predicting final histopathology. In our series, 86.7% of lesions were found to be benign and 13.3% were malignant in nature. When compared to final pathologic findings, FNAB yielded a diagnostic accuracy rate of 89.3% with a 2.1% false negative rate with regards to pre-operative detection of malignancy. Frozen section biopsy was found to have a diagnostic accuracy of 94.1% and also demonstrated a 2.1% false-negative rate. We believe these studies are indeed complementary to each other, as reflected in the 96.2% diagnostic accuracy achieved with a combination of FNAB and frozen section biopsy information. This report will review the patterns of misdiagnosis for each modality of diagnostic testing and present the parotid histopathology found over a 10-year period.

Adolescent↗