Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
Add more filters










Publication year range
1.
Dysphagia ; 36(1): 73-82, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32279120

ABSTRACT

Videofluoroscopic swallowing study (VFSS) is generally used to diagnose dysphagia and oropharyngeal aspiration during swallowing movement. Patients and bolus-feeding operators (such as occupational therapist and speech language pathologist) may undergo multiple VFSS procedure, placing them at risk for more radiation exposure due to increased scan time. The present study investigated the dose-area product, effective dose of various protocols, and summarized dose reports from various studies of VFSS. The PubMed database searched for relevant publications reporting radiation dose in the VFSS procedure. 13 articles were selected to be reviewed. This systematic review involved 13 peer-reviewed articles that reported the specific dose of the VFSS procedure. The articles were categorized into three types: operator radiation dose, adult patient radiation dose, and pediatric radiation dose. The operator dose reports showed that the operators' scattering exposure, equivalent dose (across the whole body, eyes, and hands), and annual effective dose were significantly lower than the annual dose limit of 20 mSv. Both adult and pediatric patient dose reports showed that the effective dose, which was estimated from recorded dose-area product, was significantly lower than the annual background exposure of 2.4 mSv in various protocols. The present literature review suggested that the radiation dose of VFSS by modified barium swallowing is acceptable in both operators and patients. However, various radiation protection strategies should be conducted during the procedure to reduce the risk of stochastic effect.

3.
Healthcare (Basel) ; 8(3)2020 Sep 11.
Article in English | MEDLINE | ID: mdl-32932997

ABSTRACT

The purpose of this study was to investigate the effects of virtual reality-based cognitive-motor rehabilitation (VRCMR) on the rehabilitation motivation and cognitive function in older adults. This study enrolled 40 older adults with mild cognitive impairment (MCI), living in the community. The subjects were randomly assigned to a VRCMR group (n = 20) or a conventional cognitive rehabilitation (CCR) group (n = 20). The VRCMR group underwent VRCMR using MOTOcog, a computer recognition program, whereas the CCR group underwent conventional cognitive rehabilitation, which included puzzles, wood blocks, card play, stick construction activity, and maze activity. Both interventions were performed 30 min per day, 5 days/week, for 6 weeks. This study performed a cognitive assessment using the Montreal Cognitive Assessment (MoCA) scale, Trail Making Test A and B (TMT-A/B), and Digit Span Test forward and backward (DST-forward/backward). In addition, a 0-to-10 numeric rating self-report scale was used to assess interest and motivation during the rehabilitation training. After the intervention, the VRCMR group showed a significantly greater improvement in the MoCA (p = 0.045), TMT-A (p = 0.039), TMT-B (p = 0.040), and DST-forward (p = 0.011) scores compared to the CCR group, but not in the DST-backward score (p = 0.424). In addition, subjects in the experimental group had significantly higher interest (p = 0.03) and motivation (p = 0.03) than those in the control group. Cohen's d effect size was 0.4, 0.3, 0.35, 0.4, and 0.5 for the MoCA, TMT-A, TMT-B, DST-forward, and DST-backward tests, respectively. This study demonstrates that VRCMR enhances motivation for rehabilitation and cognitive function in older adults with MCI better than CCR.

4.
Brain Sci ; 10(8)2020 Jul 27.
Article in English | MEDLINE | ID: mdl-32726991

ABSTRACT

In daily living, people are challenged to focus on their goal while eliminating interferences. Specifically, this study investigated the pre-frontal cortex (PFC) activity while attention control was tested using the self-made color-word interference test (CWIT) with a functional near-infrared spectroscopy device (fNIRS). Among 11 healthy Korean university students, overall the highest scores were obtained in the congruent Korean condition 1 (CKC-1) and had the least vascular response (VR) as opposed to the incongruent Korean condition 2 (IKC-2). The individual's automatic reading response caused less brain activation while IKC-2 involves color suppression. Across the three trials per each condition, no significant differences (SD) in scores and in VR since there was no intervention did. Meanwhile, SD was observed between CKC-1 and English Congruent Condition 3 (ECC-3) across trials. However, SD was only observed on the third trial of VR. In the connectivity analysis, right and left PFC are activated on ECC-3. In CKC-1 and IKC-2, encompassing dorsomedial and dorsolateral although CKC-1 has less connection and connectivity due to less brain activation as compared. Therefore, aside from VR, brain connectivity could be identified non-invasively using fNIRS without ionizing radiation and at low-cost.

5.
Sensors (Basel) ; 20(11)2020 May 28.
Article in English | MEDLINE | ID: mdl-32481740

ABSTRACT

Computed tomography (CT) is a widely used medical imaging modality for diagnosing various diseases. Among CT techniques, 4-dimensional CT perfusion (4D-CTP) of the brain is established in most centers for diagnosing strokes and is considered the gold standard for hyperacute stroke diagnosis. However, because the detrimental effects of high radiation doses from 4D-CTP may cause serious health risks in stroke survivors, our research team aimed to introduce a novel image-processing technique. Our singular value decomposition (SVD)-based image-processing technique can improve image quality, first, by separating several image components using SVD and, second, by reconstructing signal component images to remove noise, thereby improving image quality. For the demonstration in this study, 20 4D-CTP dynamic images of suspected acute stroke patients were collected. Both the images that were and were not processed via the proposed method were compared. Each acquired image was objectively evaluated using contrast-to-noise and signal-to-noise ratios. The scores of the parameters assessed for the qualitative evaluation of image quality improved to an excellent rating (p < 0.05). Therefore, our SVD-based image-denoising technique improved the diagnostic value of images by improving their quality. The denoising technique and statistical evaluation can be utilized in various clinical applications to provide advanced medical services.


Subject(s)
Brain/diagnostic imaging , Image Processing, Computer-Assisted , Stroke , Tomography, X-Ray Computed , Algorithms , Brain/pathology , Humans , Signal-To-Noise Ratio , Stroke/diagnostic imaging
6.
J Oral Rehabil ; 47(9): 1103-1109, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32589302

ABSTRACT

Chewing exercises have been applied in clinical settings to improve the occlusal force and function of the masseter muscle in elderly individuals. However, the clinical relevance and effects of chewing exercises are unclear. This study aimed to investigate the effects of bilateral chewing exercises on the occlusal force and masseter muscle thickness in community-dwelling Koreans aged 65 years. Forty community-dwelling healthy elderly individuals were enrolled in this study. They were assigned to the experimental or the control group. The experimental group performed chewing exercises using medical equipment developed to facilitate such exercises. The chewing exercises were divided into isometric and isotonic types and were performed for 20 min/d, 5 days/wk, for 6 weeks. The control group did not perform any chewing exercises. The outcome measures were occlusal force and masseter muscle thickness, which were evaluated using an occlusometer and ultrasound device, respectively. A paired t test and an independent t test were used to evaluate the training effects. Within-group comparisons showed that occlusal force and masseter muscle thickness improved significantly in the experimental group (P < .001 for both), while the control group showed no significant improvements (P = .098 and .130). Between-group comparisons showed that the experimental group had a greater increase in occlusal force and masseter muscle thickness (P < .05 for both) compared to the control group. These results suggest that chewing exercises are effective in improving occlusal force and masseter muscle thickness in healthy elderly individuals.


Subject(s)
Bite Force , Exercise Therapy , Masseter Muscle , Mastication , Aged , Electromyography , Humans , Independent Living , Republic of Korea
7.
Technol Health Care ; 28(S1): 311-319, 2020.
Article in English | MEDLINE | ID: mdl-32364163

ABSTRACT

BACKGROUND: Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that can help modulate cortical excitability by transmitting direct current (DC) between a pair of scalp electrodes. To date, most studies on tDCS have been relatively short-lived, and the DC stimulations only lasted a few minutes. Conventional tDCS devices usually have some problems such as needing a lot of patches and lead lines. OBJECTIVE: Since conventional tDCS devices are unsuitable for use in long-term stimulations, we developed a new tDCS which can easily be used by unskilled persons. METHODS: We developed a new tDCS device that does not have lead lines for tDCS electrodes and has a simple structure. RESULT: This device can achieve stimulation with polarity interchangeable DC without physically swapping the anode and cathode. The performance of the proposed device was verified through an experiment. CONCLUSION: The developed tDCS device can contribute to long-term research as it uses neuroelectric stimulation.


Subject(s)
Electrodes , Transcranial Direct Current Stimulation/instrumentation , Transcranial Direct Current Stimulation/methods , Humans
8.
Article in English | MEDLINE | ID: mdl-32466588

ABSTRACT

AIM: This study investigated the effect of neuromuscular electrical stimulation (NMES) on masseter muscle thickness and maximal bite force among healthy community-dwelling elderly persons older than 65 years. MATERIALS AND METHODS: A total of 40 participants were randomly assigned to the experimental and placebo groups. In the experimental group, NMES was applied to both masseter muscles, and electrical signals were gradually increased until the participants felt a grabbing sensation (range 6.0-7.5 mA) in the masseter muscle. The placebo group, in contrast, underwent NMES in the same manner and procedure as the experimental group with less electrical intensity (0.5 mA). All interventions were administered five times a week for six weeks, 20 min per day. The outcomes were masseter muscle thickness assessed using ultrasound and maximal bite force using a bite force meter. The level of significance was set as p < 0.05. RESULTS: The experimental group showed a significant increase in both masseter muscle thickness and maximal bite force as compared with the placebo group (p = 0.002 and 0.019, respectively). Moreover, the degree of change in the masseter muscle thickness and maximal bite force significantly increased in the experimental and placebo groups (p < 0.001, both). CONCLUSIONS: This study demonstrated that NMES could be an effective modality for increasing masseter muscle thickness and maximal bite force in healthy older adults.


Subject(s)
Bite Force , Independent Living , Masseter Muscle , Aged , Double-Blind Method , Electric Stimulation , Electromyography , Female , Humans , Male , Masseter Muscle/physiology
9.
J Oral Rehabil ; 47(5): 606-612, 2020 May.
Article in English | MEDLINE | ID: mdl-32053221

ABSTRACT

BACKGROUND: Game-based training has been shown to improve behavioural motor learning in various medical fields including rehabilitation. OBJECTIVES: This study aimed to investigate the effects of a tablet PC (personal computer) game-based tongue training on tongue strength, thickness and compliance in healthy adults. METHODS: This study recruited 30 healthy volunteers. Subjects were randomly assigned to two groups (n = 15/group). Group 1 performed game-based tongue training, and group 2 performed tongue resistance training using the Iowa Oral Performance Instrument. Both groups performed the same tongue exercises as follows: frequency (isotonic = 30 times × 3, isometric = 20 seconds × 3), intensity (70% of 1-repeated maximum contraction) and intervention period (5 days for 6 weeks). The primary outcomes were tongue muscle strength and thickness. Secondary outcomes were assessed using a 0-to-10 numerical rating self-report scale that included motivation, interest/fun, physical effort and muscle fatigue/pain. RESULTS: Both groups showed significant improvement in tongue strength and thickness, but there were no significant differences between the groups after the intervention. The self-report scale numerical rating revealed that group 1 had significantly higher motivation and interest/fun after the exercise than group 2. Group 1 had expended a significantly lower physical effort than group 2. No significant differences were noted between the 2 groups for muscle fatigue/pain. CONCLUSION: This study showed that both exercises had similar effects on tongue strength and thickness increase in healthy adults, but game-based tongue training was more fun and physically less demanding.


Subject(s)
Resistance Training , Tongue , Adult , Exercise Therapy , Humans , Microcomputers , Muscle Strength
10.
Dysphagia ; 35(4): 636-642, 2020 08.
Article in English | MEDLINE | ID: mdl-31620860

ABSTRACT

The suprahyoid muscles play a major role in safe swallowing in the pharyngeal phase. Therefore, it is clinically important to design a therapeutic approach for strengthening the suprahyoid muscles for safe and normal swallowing. This study aimed to investigate the activation of suprahyoid muscles by resistance training using kinesiology taping (KT). We enrolled 23 healthy adults. All participants performed saliva swallowing five times at 5 s intervals in three conditions (without KT, 50% stretch with KT, and 80% stretch with KT). KT in the I and reverse V shapes was pulled vertically from the hyolaryngeal complex to the sternum and medially from the superior surface of the clavicle, respectively. Another KT horizontally covered the hyolaryngeal complex to enhance the movement restriction of the hyolaryngeal complex during swallowing. Activation of the suprahyoid muscles during swallowing in the two conditions was measured using surface electromyography. In addition, a 0-10 numerical rating self-report scale was used to evaluate the required effort and the resistance felt during swallowing. Both KT 50% and 80% were significantly higher in surface electromyography (sEMG) mean value, peak value, required effort, and resistance felt during swallowing compared to normal swallowing (p < 0.05). In addition, KT 80% was significantly higher in sEMG value, peak value, required effort, and resistance felt during swallowing than KT 50% (p < 0.05). This study demonstrated that KT applied to the area under the hyolaryngeal complex improves activation of the suprahyoid muscle during swallowing. Therefore, KT applied as resistance during swallowing is considered to have therapeutic potential in dysphagia rehabilitation.

11.
Medicine (Baltimore) ; 98(45): e17880, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31702659

ABSTRACT

BACKGROUND: Osteoarthritis (OA) is a degenerative disease that not only causes knee pain in older adults, but also has an adverse effect on walking. Therefore, intervention for older patients with OA is important. To investigate the immediate effects of kinesiology taping (KT) on the pain and gait function of the older adults with knee OA. METHODS: This study enrolled 10 older adults individuals living in the community who were diagnosed with knee OA. All participants were assessed for knee pain, walking ability, and balance before and after application of knee KT. Knee pain was assessed in resting and walking conditions using the visual analog scale. Walking and balance were assessed using a 10-m walking test and a timed up and go test. RESULTS: In the present study, KT significantly improved gait and balance with reduction in knee pain during walking than non-KT (P < .05). CONCLUSIONS: This study demonstrated that knee KT has a positive effect on pain reduction and walking and balance ability of the older adults with OA. Therefore, this study suggests that KT can be used as an intervention to relieve knee pain and aid walking and balance ability in the older adult.


Subject(s)
Athletic Tape , Gait/physiology , Osteoarthritis, Knee/therapy , Pain Management/methods , Aged , Controlled Before-After Studies , Exercise Test/methods , Humans , Middle Aged , Postural Balance/physiology , Treatment Outcome , Visual Analog Scale
12.
Medicine (Baltimore) ; 98(44): e17702, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31689798

ABSTRACT

BACKGROUND: Electromyographic biofeedback (EMG-BF) is known to be an effective therapy for stroke rehabilitation. However, because few studies have investigated the therapy in patients with dysphagia, its effectiveness is not yet clear. This study aimed to investigate the effect of neuromuscular electrical stimulation (NMES) using EMG-BF on swallowing function in stroke patients with oropharyngeal dysphagia. METHODS: In this study, 10 patients with dysphagia were recruited. The 1-group, pre-post study design was adopted. All subjects received NMES combined with EMG-BF in the suprahyoid area. Electrical stimulation was provided as a reward when the electrical signal generated by effortful swallowing reached a preset threshold. The intervention was provided for 30 minutes a day, 5 times a week for 4 weeks. The videofluoroscopic dysphagia scale (VDS) and penetration-aspiration scale (PAS) based on the videofluoroscopic swallowing study were used to evaluate the swallowing function. RESULTS: Pre-intervention showed no significant differences in all items of VDS (P > .05). However, there was a statistically significant change in VDS from 13.36 ±â€Š5.94 to 9.36 ±â€Š5.14 (P = .015) in the oral phase, and from 38.36 ±â€Š7.42 to 20.71 ±â€Š14.61 (P = .016) in the pharyngeal phase. The PAS scores showed significant change from 5.14 ±â€Š2.27 to 3.00 ±â€Š1.00 (P = .031). CONCLUSION: This study demonstrated that the use of NMES combined with EMG-BF had the potential to improve oropharyngeal swallowing in stroke patients with dysphagia.


Subject(s)
Biofeedback, Psychology/methods , Deglutition Disorders/rehabilitation , Deglutition/physiology , Electric Stimulation Therapy/methods , Stroke Rehabilitation/methods , Aged , Aged, 80 and over , Electromyography , Female , Humans , Male , Middle Aged , Pilot Projects
13.
J Rehabil Med ; 51(10): 749-754, 2019 Oct 29.
Article in English | MEDLINE | ID: mdl-31515567

ABSTRACT

OBJECTIVE: To compare the effects of game-based chin-tuck against resistance exercise and head-lift exercise on swallowing function and compliance of patients with dysphagia after stroke. PATIENTS AND METHODS: A total of 37 patients with stroke were randomly assigned to 2 groups. The experimental group performed game-based chin tuck against resistance exercise, whereas the control group performed traditional head-lift exercise. The videofluoroscopic dysphagia scale (VDS) and penetration-aspiration scale (PAS) were used to evaluate swallowing function. In addition, the functional oral intake scale (FOIS) was used for dietary assessment. Finally, the numerical rating self-report scale was used to assess compliance (motivation, interest/enjoyment, physical effort needed, muscle fatigue) with the 2 exercises. RESULTS: After intervention, there was no significant difference in VDS, PAS, and FOIS between the 2 groups. Comparing the compliance with the 2 exercises, the scores for motivation and interest/enjoyment items were significantly higher, and the scores for physical effort needed and muscle fatigue were significantly lower, in the experimental group than in the control group. CONCLUSION: Game-based chin-tuck against resistance exercise not only has a similar effect to head-lift exercise on swallowing function of patients with dysphagia, but is also a less strict and more enjoyable and interesting method.


Subject(s)
Chin/physiology , Deglutition Disorders , Exercise Therapy/methods , Resistance Training/methods , Stroke Rehabilitation/methods , Deglutition Disorders/etiology , Deglutition Disorders/therapy , Humans , Muscle Fatigue/physiology , Stroke/complications
14.
NeuroRehabilitation ; 45(2): 221-227, 2019.
Article in English | MEDLINE | ID: mdl-31498145

ABSTRACT

BACKGROUND: Game-based exercise is effective for improving strength and motor function in stroke patients undergoing rehabilitation, and it creates fun and motivation for exercise. OBJECTIVE: We investigated the effect of game-based exercise on hand strength, motor function, and compliance in stroke patients. METHODS: Fifty stroke patients were randomly divided into experimental and control groups. The experimental group performed a game-based hand resistance exercise. This exercise was divided into isotonic and isometric types and was performed 30 min/day, 5 days/week, for 6 weeks with 70% of the 1-repetition maximum. In contrast, the control group was given a traditional manual exercise by the occupational therapist, and the type of exercise and time involved were the same as those in the experimental group. The primary outcome measure was hand strength test measured using a dynamometer. Secondary outcome measures were manual function tests (MFT) and hand function tests using box and block test (BBT). Subject-based reports of motivation, fun, pain/fatigue evaluated on 0 to 10 numeric rating scales were compared between groups. RESULTS: After training, hand strength, MFT and BBT was improved in the experimental group compared to the control group (P < 0.001, both). Subject-based reports of motivation and fun was significantly greater in the experimental group than the control group (P < 0.001, both), except to pain/fatigue (P = 0.728). CONCLUSIONS: In conclusion, we demonstrated that game-based exercise is more effective than manual exercise in improving muscle strength, motor function, and compliance in stroke patients.


Subject(s)
Fatigue/etiology , Hand Strength , Motor Skills , Pain/etiology , Resistance Training/methods , Stroke Rehabilitation/methods , Female , Humans , Male , Middle Aged , Muscle Strength , Resistance Training/adverse effects , Stroke Rehabilitation/adverse effects
15.
Sensors (Basel) ; 18(9)2018 Sep 05.
Article in English | MEDLINE | ID: mdl-30189651

ABSTRACT

In this paper, a new motion artifact correction method is proposed based on multi-channel functional near-infrared spectroscopy (fNIRS) signals. Recently, wavelet transform and hemodynamic response function-based algorithms were proposed as methods of denoising and detrending fNIRS signals. However, these techniques cannot achieve impressive performance in the experimental environment with lots of movement such as gait and rehabilitation tasks because hemodynamic responses have features similar to those of motion artifacts. Moreover, it is difficult to correct motion artifacts in multi-measured fNIRS systems, which have multiple channels and different noise features in each channel. Thus, a new motion artifact correction method for multi-measured fNIRS is proposed in this study, which includes a decision algorithm to determine the most contaminated fNIRS channel based on entropy and a reconstruction algorithm to correct motion artifacts by using a wavelet-decomposed back-propagation neural network. The experimental data was achieved from six subjects and the results were analyzed in comparing conventional algorithms such as HRF smoothing, wavelet denoising, and wavelet MDL. The performance of the proposed method was proven experimentally using the graphical results of the corrected fNIRS signal, CNR that is a performance evaluation index, and the brain activation map.

16.
Technol Health Care ; 25(S1): 29-34, 2017 Jul 20.
Article in English | MEDLINE | ID: mdl-28582889

ABSTRACT

BACKGROUND: Fully implantable hearing devices (FIHDs) can be affected by generated biomechanical noise such as mastication noise. OBJECTIVE: To reduce the mastication noise using a piezo-electric sensor, the mastication noise is measured with the piezo-electric sensor, and noise reduction is practiced by the energy difference. METHODS: For the experiment on mastication noise, a skull model was designed using artificial skull model and a piezo-electric sensor that can measure the vibration signals better than other sensors. A 1 kHz pure-tone sound through a standard speaker was applied to the model while the lower jawbone of the model was moved in a masticatory fashion. RESULTS: The correlation coefficients and signal-to-noise ratio (SNR) before and after application of the proposed method were compared. It was found that the signal-to-noise ratio and correlation coefficients increased by 4.48 dB and 0.45, respectively. CONCLUSION: The mastication noise is measured by piezo-electric sensor as the mastication noise that occurred during vibration. In addition, the noise was reduced by using the proposed method in conjunction with MATLAB. In order to confirm the performance of the proposed method, the correlation coefficients and signal-to-noise ratio before and after signal processing were calculated. In the future, an implantable microphone for real-time processing will be developed.


Subject(s)
Cochlear Implants , Mastication , Noise/prevention & control , Algorithms , Humans , Models, Anatomic , Prosthesis Design , Signal Processing, Computer-Assisted , Signal-To-Noise Ratio
17.
Bioengineered ; 7(5): 352-356, 2016 Sep 02.
Article in English | MEDLINE | ID: mdl-27436063

ABSTRACT

In this paper, we propose a new speech enhancement algorithm based on wavelet packet decomposition and mask filtering. In the traditional mask filtering such as ideal binary mask (IBM), the basic idea is to classify speech components as target signal and non-speech components as background noises. However, speech and non-speech components cannot be well separated in target signal and background noise. Therefore, the IBM has residual noise and signal loss. To overcome this problem, the proposed algorithm used semi-soft mask filter to exponentially increase. The semi-soft mask minimizes signal loss and the exponential filter removes residual noise. We performed experiments using various types of speech and noise signals, and experimental results show that the proposed algorithm achieves better performances than the traditional other speech enhancement algorithms.


Subject(s)
Algorithms , Speech Acoustics , Wavelet Analysis , Female , Humans , Male , Models, Theoretical , Noise , Signal Processing, Computer-Assisted , Signal-To-Noise Ratio
18.
Biomed Mater Eng ; 24(6): 3295-301, 2014.
Article in English | MEDLINE | ID: mdl-25227039

ABSTRACT

This paper presents a voice activity detection (VAD) approach using a perceptual wavelet entropy neighbor slope (PWENS) in a low signal-to-noise (SNR) environment and with a variety of noise types. The basis for our study is to use acoustic features that have large entropy variance for each wavelet critical band. The speech signal is decomposed by the proposed perceptual wavelet packet decomposition (PWPD), and the VAD function is extracted by PWENS. Finally, VAD is decided by the proposed VAD decision rule using two memory buffers. In order to evaluate the performance of the VAD decision, many speech samples and a variety of SNR conditions were used in the experiment. The performance of the VAD decision is confirmed using objective indexes such as a graph of the VAD decision and the relative error rate.


Subject(s)
Algorithms , Pattern Recognition, Automated/methods , Signal Processing, Computer-Assisted , Sound Spectrography/methods , Speech Production Measurement/methods , Wavelet Analysis , Humans , Reproducibility of Results , Sensitivity and Specificity , Signal-To-Noise Ratio
19.
Biomed Mater Eng ; 24(6): 3303-9, 2014.
Article in English | MEDLINE | ID: mdl-25227040

ABSTRACT

In this paper, a new method for individual tooth segmentation was proposed. The proposed method is composed of enhancement and extraction of boundary and seed of watershed algorithm using trisection areas by morphological characteristic of teeth. The watershed algorithm is one of the conventional methods for tooth segmentation; however, the method has some problems. First, molar region detection ratio is reduced because of oral structure features that is low intensities in molar region. Second, inaccurate segmentation occurs in incisor region owing to specular reflection. To solve the problems, the trisection method using morphological characteristic was proposed, where three tooth areas are made using ratio of entire tooth to each tooth. Moreover, the enhancement is to improve the intensity of molar using the proposed method. In addition, boundary and seed of watershed are extracted using trisection areas applied other parameters each area. Finally, individual tooth segmentation was performed using extracted boundary and seed. Furthermore, the proposed method was compared with conventional methods to confirm its efficiency. As a result, the proposed method was demonstrated to have higher detection ratio, better over segmentation, and overlap segmentation than conventional methods.


Subject(s)
Algorithms , Colorimetry/methods , Image Interpretation, Computer-Assisted/methods , Multimodal Imaging/methods , Pattern Recognition, Automated/methods , Photography, Dental/methods , Tooth/anatomy & histology , Humans , Image Enhancement/methods , Reproducibility of Results , Sensitivity and Specificity , Subtraction Technique
20.
Biomed Mater Eng ; 24(6): 3685-91, 2014.
Article in English | MEDLINE | ID: mdl-25227083

ABSTRACT

The microphone in a fully implantable hearing device (FIHD) is generally implanted under the skin covering the temporal bone. However, the implanted microphone can be affected by the skin, which causes both sound attenuation and distortion, particularly at high frequencies. As the degree of attenuation and distortion through the skin is severe, speech quality evaluation parameters are needed for the received signal when designing an implantable microphone. However, the performance of most implantable microphones is only assessed based on the sensitivity and frequency response. Thus, practical indicators based on human auditory characteristics are needed for an objective evaluation of the performance of implantable microphones. In this study, a subcutaneously implantable microphone was designed, and its frequency response investigated using an in vivo experiment. Plus, to evaluate the objective indicators, the speech quality of the signals measured by the implanted microphone was calculated using a MATLAB program, and the indicators compared before and after implantation.


Subject(s)
Hearing Aids , Ossicular Prosthesis , Speech Production Measurement/instrumentation , Transducers , Animals , Equipment Design , Equipment Failure Analysis , Guinea Pigs
SELECTION OF CITATIONS
SEARCH DETAIL
...