Technology and Health Care - Volume 26, issue 6

Authors: Zarei, Elham | Sadjedi, Hamed | Farhadi, Mohammad

Article Type: Research Article

Abstract: BACKGROUND: The performance of a cochlear implant (CI), especially in conveying pitch depends on its electrical stimulation strategy. OBJECTIVE: The present study proposes a variable-rate stimulation algorithm which improves speech emotion perception by using temporal fine-structure cues and electrophysiological parameters of the patient. METHODS: This method is based on the coding of the phase information at the peak time intervals of the band-passed signals. The stimulation pulse is generated at the time of peak occurrence, which is able to excite the number of fibers with a discharge probability above a threshold. Calculating …the discharge probability is based on the excitable fiber model and taking into account the biological characteristics of the patient, such as the fiber threshold and the distribution of remaining intact fibers. RESULTS: The results of the emotion detection test on selective reconstructed sentences from the Persian emotional speech database (Persian ESD) indicated that the listeners have been able to detect the emotion by an average of 83.82% using the proposed stimulation algorithm while it was 75% and 48.03% for the zero-crossing and the continuous interleaved sampling (CIS), respectively. Furthermore, the number of pulses compared to the zero-crossing and the CIS has decreased by 76.3% and 75.4%, respectively. CONCLUSIONS: In this paper, a stimulation method was proposed for cochlear implants by considering the patient’s biological parameters. It has been successful in transmitting speech emotion despite the reduction of stimulating pulses. This has some advantages such as reducing the interaction of current fields between electrodes during stimulation and reducing battery usage. Show more

Keywords: Cochlear implant, electrical stimulation, excitable nerve fiber, voice pitch frequency, emotion detection

DOI: 10.3233/THC-171154

Citation: Technology and Health Care, vol. 26, no. 6, pp. 879-888, 2018

Authors: Rahmati, Seyed Mohammadali | Rostami, Mostafa | Beigzadeh, Borhan

Article Type: Research Article

Abstract: The parametric optimization techniques have been widely employed to predict human gait trajectories; however, their applications to reveal the other aspects of gait are questionable. The aim of this study is to investigate whether or not the gait prediction model is able to justify the movement trajectories for the higher average velocities. A planar, seven-segment model with sixteen muscle groups was used to represent human neuro-musculoskeletal dynamics. At first, the joint angles, ground reaction forces (GRFs) and muscle activations were predicted and validated for normal average velocity (1.55 m/s) in the single support phase (SSP) by minimizing energy expenditure, which is …subject to the non-linear constraints of the gait. The unconstrained system dynamics of extended inverse dynamics (USDEID) approach was used to estimate muscle activations. Then by scaling time and applying the same procedure, the movement trajectories were predicted for higher average velocities (from 2.07 m/s to 4.07 m/s) and compared to the pattern of movement with fast walking speed. The comparison indicated a high level of compatibility between the experimental and predicted results, except for the vertical position of the center of gravity (COG). It was concluded that the gait prediction model can be effectively used to predict gait trajectories for higher average velocities. Show more

Keywords: Gait prediction, optimization, inverse dynamics, Newton-Euler dynamics, nonlinear dynamics

DOI: 10.3233/THC-171171

Citation: Technology and Health Care, vol. 26, no. 6, pp. 889-907, 2018

Authors: Sun, Lixin | Sun, Yingfei | Huang, Zhipei | Hou, Jiateng | Wu, Jiankang

Article Type: Research Article

Abstract: BACKGROUND: Hill-type musculotendon models are most commonly used in biomechanical simulations for their computational efficacy and efficiency. But these models are generally built for maximally-activated muscles and linearly scale muscle properties when applied to submaximal conditions. However, the precondition of this scaling, which is muscle activation and properties are independent each other, has been proven unreal in many studies. Actually, the maximal activation condition is not ubiquitous for muscles in vivo , so it is necessary to adapt the linear scaling approach to improve the model practicability. OBJECTIVE: This paper aimed at proposing two improved Hill-type …musculotendon models that are better suited for submaximal conditions. METHOD: These two models were built by including the activation-force-length coupling and their biological accuracy and computation speed were evaluated by a series of benchmark simulations. RESULTS: Compared to experimental measurements, the percent root mean square errors of forces calculated by the two AFLC models were less than 13.98% and 13.81% respectively. However, the average running time of the second AFLC model was nearly 17 times that of the first one with only a little improvement in accuracy. CONCLUSION: The two AFLC models were validated more accurate than the common Hill-type model in submaximally activated conditions and the first one was recommended in the construction of upper-layer musculoskeletal models. Show more

Keywords: Hill-type model, musculotendon model, activation force-length coupling, submaximal activation

DOI: 10.3233/THC-181267

Citation: Technology and Health Care, vol. 26, no. 6, pp. 909-920, 2018

Authors: Faskhodi, Mahtab Mohammadpoor | Einalou, Zahra | Dadgostar, Mehrdad

Article Type: Research Article

Abstract: BACKGROUND: The study of the brain network based on the basis of the resting-state functional Magnetic Resonance Imaging (fMRI) provided some promising results to investigate changes in connectivity among different brain regions because of Alzheimer’s disease (AD). OBJECTIVE: In addition, the graph theory has been utilized as an efficient tool in diagnosing Alzheimer and in finding the developed differences in the brain as the result of this disease. METHODS: This study considers 16 areas of the brain, which play a major role in the development of AD. Accordingly, the time series and the correlation …matrix were yielded for each of these areas. Then, by using threshold we obtained functional connectivity from correlation matrices along with the brain graph parameter for Normal Controls and AD groups were obtained in order to compare the existing differences. RESULTS: The differences of characteristics among healthy individuals and patients suffering from Alzheimer has been investigated in this study through the formation of brain graphs for 16 areas and the utilization of data on Normal Controls (13 persons) and patients suffering from Alzheimer (13 patients). CONCLUSIONS: Some of the properties of the graph are the characteristic path length, the clustering coefficient, the local and global efficiency yield of ability to separate the two groups which may be used to diagnose Alzheimer. Show more

Keywords: Functional Magnetic Resonance Imaging, graph, small world, connectivity, Alzheimer’s disease

DOI: 10.3233/THC-181312

Citation: Technology and Health Care, vol. 26, no. 6, pp. 921-931, 2018

Authors: Zhang, Melvyn W.B. | Ying, Jiang Bo | Song, Guo | Ho, Roger C.M.

Article Type: Research Article

Abstract: BACKGROUND: Cognitive biases are mostly automatic processes that result in individuals giving increased attention to threatening stimuli, with the difficulties in disengaging from these stimuli. Recent reviews have reported the presence for attention bias in several psychiatric conditions and provided evidence that such biases could be subjected to modification. Web-based and mobile based bias modification have mixed efficacy and gamification techniques proposed as a solution. There remains a gap in knowledge pertaining to the gamified applications for bias modification that are commercially available. OBJECTIVE: An analysis of their gamification approach will help in identification of common gaming …elements adopted for use. METHODS: To identify commercial applications, a manual cross-sectional search was conducted between 1 and 11 November 2017 on the Google Play store. The following search terminologies were used: “Attention bias” and “Cognitive bias”. The classification of the gamification technique for both the published applications and commercial applications were based on the six approaches described by Wouter et al. [17 ] and the 17 gamification techniques described by Hoffman et al. [18 ]. RESULTS: A total of nine applications were included in the current review. Five out of the nine applications involved the addition of gaming elements to an evidence-based task, and three involved the usage of intrinsic integration while leaving the evidence-based task intact. Other common gamification strategies used are that of the inclusion of digital rewards (n = 8) and the provision of feedback (n = 7). The average number of gamification techniques across all the nine applications is 3.2. CONCLUSIONS: Even though most commercial applications appear to have their basis on a validated gamification approach for the delivery of attention bias modification, there remains a need for further research in evaluating these applications clinically. Show more

Keywords: Attention bias, cognitive bias, gamification, smartphone, M-health

DOI: 10.3233/THC-181313

Citation: Technology and Health Care, vol. 26, no. 6, pp. 933-944, 2018

Authors: Alabdulkader, Malek Ahmed | Habib, Syed Rashid

Article Type: Research Article

Abstract: BACKGROUND: A well-made and properly cemented provisional restoration is essential for the health of abutment teeth and periodontium. Few focused studies are available on the effect of cementation techniques on the fit as well as on the retention of the provisional crowns. OBJECTIVE: To investigate the effect of six cement application techniques on the adaptation and retention of provisional crowns. METHODS: Seventy-two provisional crowns (Bisacryl resin) were fabricated over identical self-cured resin dies and were divided into six groups (N = 72; 6 × n = …12) of cement application techniques (Temp Bond NE, Kerr Corporation). Group-A (Bulk Fill); Group-B (Cement on inner walls); Group-C (Cement on axial walls); Group-D (Cement on crown margin); Group-E (Cement on tooth margin); Group-F (Cement with vent-holes). Adaptation was assessed before and after cementation with digital caliper (0.001 mm). Universal testing machine was used for retention measurement in Mega Pascal’s (MPa). Data was analyzed by SPSS using Paired T-Test and Tukey’s test (p < 0.05). RESULTS: The highest and lowest difference between the two measurements was observed for the Group A (0.095 mm) and Group C (0.030 mm) respectively. Paired T-Test revealed significance (p < 0.05) between before and after cementation. Group-F (0.6094 MPa) and Group-E (0.1858 MPa) showed the highest and lowest retention respectively. Group-E (Cement on tooth margin) with lowest retention significantly differed (Tukey’s Test; p < 0.05) from other groups. CONCLUSIONS: Bulk filling of the provisional crown with luting cement significantly increases the adaptation discrepancies. Discrepancies are more when luting cement is applied on the occlusal surface of the crowns. However, it didn’t influence the retention of the crowns. Cement application on axial walls and cervical third of intaglio surface of crowns was the method of choice with regards to adaptation and retention combined. Addition of vent-holes improved the adaptation with best possible retention. Show more

Keywords: Cementation, provisional crowns, adaptation, retention, cementation techniques, temporary crowns

DOI: 10.3233/THC-181351

Citation: Technology and Health Care, vol. 26, no. 6, pp. 945-955, 2018

Authors: Lee, Kyoung Bo | Kim, Bo Ra | Lee, Kang Seong

Article Type: Research Article

Abstract: BACKGROUND: The feet make the initial contact with the ground when walking and critically control both posture and gait. Claw toe, a structural change in the foot that may develop after stroke, triggers functional changes affecting both the lower limbs and balance. OBJECTIVE: We analyzed the effects of a toe spreader on foot pressure and gait in chronic stroke patients. METHODS: We enrolled 25 stroke patients. We used Gaitview AFA-50 and GAITRite instruments to measure plantar pressure distribution and gait with and without a toe spreader. RESULTS: The average and rear …foot pressures increased somewhat when a toe spreader was used. However, the differences were not significant in post hoc tests. In terms of gait, all variables significantly improved when the toe spreader was used. CONCLUSIONS: A toe spreader may improve overall gait and spatiotemporal gait parameters in chronic stroke patients. Show more

Keywords: Toe spreader, chronic stroke, plantar foot pressure, spatiotemporal gait parameters

DOI: 10.3233/THC-181316

Citation: Technology and Health Care, vol. 26, no. 6, pp. 957-962, 2018

Authors: Karimi, Alireza | Razaghi, Reza

Article Type: Research Article

Abstract: The mechanical functions of the lungs are concerned with ventilating the alveoli and aiding venous return to the heart. The mechanical properties of the lung allow this to be fulfilled with a very small expenditure of energy. Smoking via chronic obstructive pulmonary disease (COPD) can affect this mechanical function through the alteration of the mechanical properties of the lung tissue. So far, no study has been conducted to experimentally compare the in vitro mechanical properties of the human lung tissue among the healthy nonsmokers and unhealthy smokers. Therefore, there is a paucity of knowledge on how the macro-mechanical properties …of the lung tissue as a consequence of at least 7 years of smoking can alter. This study was, hence, aimed at performing a comparative study to compare the linear elastic and nonlinear hyperelastic mechanical properties of the healthy nonsmokers and unhealthy smokers’ lung using uniaxial tensile testing under two different loading directions, i.e., the axial and transversal. To do that, the COppm (Carbon Monoxide part per million) and %COHb (blood Carboxyhemoglobin) of 18 cadaveric individuals, including 9 nonsmokers and 9 smokers were measured. The COppm and %COHb were found to be 26 ± 1.58 (Mean ± SD) and 4 ± 1.16 for the smokers and 4.79 ± 0.25 and 1.27 ± 0.16 for the nonsmokers, respectively. The lung tissues were excised from the cadavers and mounted on the uniaxial tensile test machine under the loading rate of 5 mm/min. The stress-strain data of the tissues revealed the axial elastic modulus of 58 ± 4.21 and 142 ± 8.84 kPa for the nonsmokers and smokers’ lungs, respectively. Similarly, the transversal elastic modulus of 53 ± 7.16 and 127 ± 11.15 kPa were found for the nonsmokers and smokers’ lungs, respectively. The results revealed a significant difference between the axial and transversal mechanical properties of the nonsmokers and smokers’ lung tissues (p < 0.05, post hoc Scheffe method). The hyperelastic material coefficients of the lung tissues were also calculated and reported. These findings have implications not only for understanding the role of smoking on the mechanical properties of the lung tissue but also to give rise to novel therapeutic strategies for the management of the disease and prevention of smoking addiction. Show more

Keywords: Lung, smoking, axial and transversal loadings, mechanical properties, elastic modulus, toughness, hyperelastic

DOI: 10.3233/THC-181340

Citation: Technology and Health Care, vol. 26, no. 6, pp. 963-972, 2018

Authors: Claassen, Leif | Wirries, Nils | Ettinger, Sarah | Pastor, Marc-Frederic | Windhagen, Henning | Flörkemeier, Thilo

Article Type: Research Article

Abstract: BACKGROUND: There is currently a lack of consensus regarding the most effective diagnostic algorithm for cases of supposed low-grade infection after total hip arthoplasty (THA). OBJECTIVE: The aim of this study was to assess reliability in the use of biopsies, obtained by hip arthroscopy, to detect a periprosthetic hip joint infection (PJI). METHODS: From 2012 to 2016, diagnostic arthroscopy of the hip joint was performed in 20 patients with a supposed PJI following THA. In 10 of these patients, the THA was revised for various reasons after diagnostic arthroscopy. The microbiological and histological findings of …the biopsies obtained by arthroscopy were compared to findings from intraoperative samples of the revision arthroplasty. RESULTS: For arthroscopic biopsies, we detected a sensitivity of 1.00 (95% confidence interval [CI] 0.40–1.00), a specificity of 0.83 (95% CI 0.36–1.00), a positive predictive value of 0.80 (95% CI 0.28–1.00), and a negative predictive value of 1.00 (95% CI 0.48–1.00). The accuracy was 0.90. CONCLUSIONS: The analysis of arthroscopic biopsies represents a helpful tool to verify or rule out a PJI in selected patients. Nevertheless, minimally invasive diagnostic tools (e.g., laboratory analysis and aspiration) should be utilized beforehand. Show more

Keywords: Arthroscopy, synovial biopsy, periprosthetic joint infection, low-grade infection, revision arthroplasty, hip joint

DOI: 10.3233/THC-181265

Citation: Technology and Health Care, vol. 26, no. 6, pp. 973-982, 2018