Korean Journal of Otorhinolaryngology-head and Neck Surgery, 2005
BACKGROUND AND OBJECTIVES: As indications for tracheotomy have evolved over the decades, the tren... more BACKGROUND AND OBJECTIVES: As indications for tracheotomy have evolved over the decades, the trends in the pediatric tracheotomy also have changed. The purpose of this study is to review the clinical courses and outcomes in the current pediatric tracheotomy. MATERIALS AND METHOD: A retrospective study was performed on 42 pediatric patients who underwent tracheotomies at Ajou University Hospital from June, 1994 to May, 2004. Charts were reviewed with respect to indications for tracheotomy, underlying diseases, success rate in decannulation and length of support time until decannulation, complication and mortality rate. RESULTS: There were 34 (81.0%) male patients and 8 (19.0%) female patients. Ventilatory support for neurological impairment (47.6%) was the leading indication for tracheotomy, followed by upper airway obstruction (19.0%), prolonged intubation due to respiratory failure (16.7%), cervical trauma (7.1%), craniofacial abnormalities (4.8%) and vocal cord palsy (4.8%). Convu...
Active middle ear implants (AMEIs) have been studied to overcome the limitations of conventional ... more Active middle ear implants (AMEIs) have been studied to overcome the limitations of conventional hearing aids such as howling, occlusion, and social discrimination. AMEIs usually drive the oval window (OW) by means of transmitting vibrational force through the ossicles and the vibrational force corresponding to sound is generated from a mechanical actuator. Recently, round window (RW) stimulation using an AMEI such as a floating mass transducer (FMT) to deliver sound to the cochlea has been introduced and hearing improvement in clinical use has been reported. Although previous studies demonstrated that the auditory response to RW stimulation was comparable to a sound-evoked auditory response, few studies have investigated the quantification of the physiologic performance of an AMEI through RW stimulation on the inner ear in vivo. There is no established relationship between the cochlear responses and mechanical stimulation to RW. The aim of this study is to assess the physiologic response in RW stimulation by an AMEI. The transferred energy through the RW to the inner ear could estimate the response corresponding to acoustic stimulation in order to quantify the AMEI output in the ossicular chain or OW stimulation. The parameters of the auditory brainstem responses (ABRs) were measured and compared based on stapes velocities similar enough to be regarded as the same for acoustic stimulation to the external auditory canal (EAC) and mechanical stimulation to the RW in an in vivo system. In conclusion, this study showed that the amplitudes and latencies of the ABRs of acoustic and RW stimulation showed significant differences at comparable stapes velocities in an in vivo system. These differences in the ABR amplitudes and latencies reflect different output functions of the cochlea in response to different stimulation pathways. Therefore, it is necessary to develop a new method for quantifying the output of the cochlea in the case of RW stimulation.
Korean Journal of Otorhinolaryngology-head and Neck Surgery, 2005
BACKGROUND AND OBJECTIVES: As indications for tracheotomy have evolved over the decades, the tren... more BACKGROUND AND OBJECTIVES: As indications for tracheotomy have evolved over the decades, the trends in the pediatric tracheotomy also have changed. The purpose of this study is to review the clinical courses and outcomes in the current pediatric tracheotomy. MATERIALS AND METHOD: A retrospective study was performed on 42 pediatric patients who underwent tracheotomies at Ajou University Hospital from June, 1994 to May, 2004. Charts were reviewed with respect to indications for tracheotomy, underlying diseases, success rate in decannulation and length of support time until decannulation, complication and mortality rate. RESULTS: There were 34 (81.0%) male patients and 8 (19.0%) female patients. Ventilatory support for neurological impairment (47.6%) was the leading indication for tracheotomy, followed by upper airway obstruction (19.0%), prolonged intubation due to respiratory failure (16.7%), cervical trauma (7.1%), craniofacial abnormalities (4.8%) and vocal cord palsy (4.8%). Convu...
Active middle ear implants (AMEIs) have been studied to overcome the limitations of conventional ... more Active middle ear implants (AMEIs) have been studied to overcome the limitations of conventional hearing aids such as howling, occlusion, and social discrimination. AMEIs usually drive the oval window (OW) by means of transmitting vibrational force through the ossicles and the vibrational force corresponding to sound is generated from a mechanical actuator. Recently, round window (RW) stimulation using an AMEI such as a floating mass transducer (FMT) to deliver sound to the cochlea has been introduced and hearing improvement in clinical use has been reported. Although previous studies demonstrated that the auditory response to RW stimulation was comparable to a sound-evoked auditory response, few studies have investigated the quantification of the physiologic performance of an AMEI through RW stimulation on the inner ear in vivo. There is no established relationship between the cochlear responses and mechanical stimulation to RW. The aim of this study is to assess the physiologic response in RW stimulation by an AMEI. The transferred energy through the RW to the inner ear could estimate the response corresponding to acoustic stimulation in order to quantify the AMEI output in the ossicular chain or OW stimulation. The parameters of the auditory brainstem responses (ABRs) were measured and compared based on stapes velocities similar enough to be regarded as the same for acoustic stimulation to the external auditory canal (EAC) and mechanical stimulation to the RW in an in vivo system. In conclusion, this study showed that the amplitudes and latencies of the ABRs of acoustic and RW stimulation showed significant differences at comparable stapes velocities in an in vivo system. These differences in the ABR amplitudes and latencies reflect different output functions of the cochlea in response to different stimulation pathways. Therefore, it is necessary to develop a new method for quantifying the output of the cochlea in the case of RW stimulation.
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