Although laser ablation is not commonly used for liver cancer treatment, there are several benefits that make it an appealing alternative. Nevertheless, investigations on the efficacy of laser ablation for liver cancer has been limited to few clinical trials. Therefore, not much is known regarding the efficacy of the technique especially when operating under different protocols and device parameters. In this study, we performed a numerical study to investigate the effects of diffuser length, power density and the pullback technique on the coagulation zone formation during laser ablation of a spherical liver cancer. The objective is to demarcate the influence of diffuser length from power density, and to compare their performance to that when pullback is implemented. Four diffuser lengths (10, 15, 20 and 25 mm), and three pullback distances (5, 10 and 15 mm), were considered. Results showed that laser power density is a factor that limits the coagulation zone size when the diffuser length increases. A longer diffuser must be accompanied by an increase in laser power to achieve the desired treatment outcome. The pullback technique increases the effective diffuser length, but the coagulation volume obtained was smaller than that of a longer diffuser at the same power density. This suggests that increasing both the diffuser length and laser power is better at increasing the coagulation zone than the pullback technique. To obtain coagulation zone that is sufficiently large to cover the entire tumour, careful selection of the diffuser length, power density, and pullback distance is critical.
{"title":"A Computational Study Evaluating the Effects of Diffuser Length and Pullback Distance on the Ablation Zone During Laser Ablation Treatment of Liver Cancer","authors":"Zhi Q. Tan, E. Ooi, E. Ooi","doi":"10.1115/1.4062246","DOIUrl":"https://doi.org/10.1115/1.4062246","url":null,"abstract":"\u0000 Although laser ablation is not commonly used for liver cancer treatment, there are several benefits that make it an appealing alternative. Nevertheless, investigations on the efficacy of laser ablation for liver cancer has been limited to few clinical trials. Therefore, not much is known regarding the efficacy of the technique especially when operating under different protocols and device parameters. In this study, we performed a numerical study to investigate the effects of diffuser length, power density and the pullback technique on the coagulation zone formation during laser ablation of a spherical liver cancer. The objective is to demarcate the influence of diffuser length from power density, and to compare their performance to that when pullback is implemented. Four diffuser lengths (10, 15, 20 and 25 mm), and three pullback distances (5, 10 and 15 mm), were considered. Results showed that laser power density is a factor that limits the coagulation zone size when the diffuser length increases. A longer diffuser must be accompanied by an increase in laser power to achieve the desired treatment outcome. The pullback technique increases the effective diffuser length, but the coagulation volume obtained was smaller than that of a longer diffuser at the same power density. This suggests that increasing both the diffuser length and laser power is better at increasing the coagulation zone than the pullback technique. To obtain coagulation zone that is sufficiently large to cover the entire tumour, careful selection of the diffuser length, power density, and pullback distance is critical.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81124426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Biswas, Rururaj Pradhan, N. Mondal, Sejuti Ballav, Masud Rana
This study is being carried out to evaluate and compare the stress along the root surfaces of anterior maxillary dentition during retraction in labial and lingual mechanics with varying level of bone support. Eight 3D Finite Element models (FEM) were created with normal periodontium and different levels of alveolar bone loss; four with labial brackets and four with lingual brackets. Sliding mechanics were simulated as en-masse retraction of the anterior dentition. The equivalent stresses along the roots of six anterior maxillary teeth were measured in all the models. Equivalent stresses generated at the root surfaces of central incisors are always higher in labial technique and of canines are always higher in lingual technique, suggesting the increased vulnerability towards root resorption in both cases. Stresses at the root apices of all the teeth are increasing progressively when the bone loss is progressively more than 2mm in labial technique. In labial technique, the stresses at the root apices of all the teeth are increasing progressively when the bone loss is progressively more than 2mm. In Lingual technique, equivalent stresses generated at the root surfaces of canines are more than central and lateral incisors irrespective of the alveolar bone loss, suggesting increased susceptibility to root resorption.
{"title":"Finite Element Analysis of Maxillary Anterior Dentition During Retraction with Varying Level of Bone Support","authors":"J. Biswas, Rururaj Pradhan, N. Mondal, Sejuti Ballav, Masud Rana","doi":"10.1115/1.4062158","DOIUrl":"https://doi.org/10.1115/1.4062158","url":null,"abstract":"\u0000 This study is being carried out to evaluate and compare the stress along the root surfaces of anterior maxillary dentition during retraction in labial and lingual mechanics with varying level of bone support. Eight 3D Finite Element models (FEM) were created with normal periodontium and different levels of alveolar bone loss; four with labial brackets and four with lingual brackets. Sliding mechanics were simulated as en-masse retraction of the anterior dentition. The equivalent stresses along the roots of six anterior maxillary teeth were measured in all the models. Equivalent stresses generated at the root surfaces of central incisors are always higher in labial technique and of canines are always higher in lingual technique, suggesting the increased vulnerability towards root resorption in both cases. Stresses at the root apices of all the teeth are increasing progressively when the bone loss is progressively more than 2mm in labial technique. In labial technique, the stresses at the root apices of all the teeth are increasing progressively when the bone loss is progressively more than 2mm. In Lingual technique, equivalent stresses generated at the root surfaces of canines are more than central and lateral incisors irrespective of the alveolar bone loss, suggesting increased susceptibility to root resorption.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85553024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract We present the conceptual design and limited functionality prototype and characterization of a system for application in transurethral palpation of any targeted area of the bladder interior wall tissue consisting of a robotic manipulator and a microforce sensor attached at its tip all less than 3.5 mm in diameter. A hyper-redundant ten-joint six degrees-of-freedom (6DOF) manipulator (5DOF rigid and five-joint continuum segments) is presented along with the forward and inverse kinematics analyses based on a Jacobian formulation to prevent configuration singularities. Simulated motion studies demonstrate the ability of the proposed manipulator to attain a desired pose (normal to the tissue) with any area in the bladder including the difficult to reach trigone area. A strain gauge-based microforce sensor is designed using finite element analysis (safety factor > 3), prototyped using additive manufacturing, and characterized. The characterized sensor was used to acquire in vivo measurements to evaluate human palm tissue viscoelastic properties. A single module of the continuum segment is designed and prototyped using additive manufacturing, and used to characterize its tension-bend angle behavior. Finite element analysis is used to improve structurally weak regions of the vertebra. A three-joint four-vertebrae prototype was successfully actuated to reach a bend state using tendons. The developed robot and sensor prototypes demonstrate capabilities of the proposed concept which could be a possible solution to quantitatively evaluate localized biomechanical properties of the bladder tissue to improve treatment and provide better patient care.
{"title":"A Microrobot With an Attached Microforce Sensor for Transurethral Access to the Bladder Interior Wall","authors":"Samson Adejokun, Shashank Kumat, Panos Shiakolas","doi":"10.1115/1.4056884","DOIUrl":"https://doi.org/10.1115/1.4056884","url":null,"abstract":"Abstract We present the conceptual design and limited functionality prototype and characterization of a system for application in transurethral palpation of any targeted area of the bladder interior wall tissue consisting of a robotic manipulator and a microforce sensor attached at its tip all less than 3.5 mm in diameter. A hyper-redundant ten-joint six degrees-of-freedom (6DOF) manipulator (5DOF rigid and five-joint continuum segments) is presented along with the forward and inverse kinematics analyses based on a Jacobian formulation to prevent configuration singularities. Simulated motion studies demonstrate the ability of the proposed manipulator to attain a desired pose (normal to the tissue) with any area in the bladder including the difficult to reach trigone area. A strain gauge-based microforce sensor is designed using finite element analysis (safety factor > 3), prototyped using additive manufacturing, and characterized. The characterized sensor was used to acquire in vivo measurements to evaluate human palm tissue viscoelastic properties. A single module of the continuum segment is designed and prototyped using additive manufacturing, and used to characterize its tension-bend angle behavior. Finite element analysis is used to improve structurally weak regions of the vertebra. A three-joint four-vertebrae prototype was successfully actuated to reach a bend state using tendons. The developed robot and sensor prototypes demonstrate capabilities of the proposed concept which could be a possible solution to quantitatively evaluate localized biomechanical properties of the bladder tissue to improve treatment and provide better patient care.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"439 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135034488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Analysis of flow diverting intracranial aneurysm repair devices has traditionally focused on reducing intrasaccular blood flow velocity and aneurysm wall shear stress (WSS) as the primary metrics for improved perceived device performance. However, the interpretation of this data has been debated, particularly with regards to the specific biological benefits of high or low aneurysm WSS. Therefore, this research proposes an additional parameter of WSS at the stent struts that could provide valuable insight regarding the device's potential to promote occlusion at the aneurysm neck by indicating locations of increased platelet activation and microparticle shedding. Fluid flow effects were evaluated for two flow diverters (PipelineTM and FREDTM) and three stents (EnterpriseTM, AtlasTM, and LVISTM) using computational fluid dynamics (CFD) models developed from two patient-derived CTA datasets with aneurysms in the middle cerebral artery (MCA) and basilar artery (BA), respectively. The device WSS data provides an additional metric for evaluating the ability of the device to constrain the blood flow within the main vessel, as well as indicating potential locations of the initiation of aneurysm occlusion. It is hypothesized that high device WSS close to the aneurysm neck creates a higher likelihood of thrombus formation and aneurysm occlusion due to platelet activation and microparticle shedding, while high device WSS proximal or distal on the device would indicate higher likelihood of undesirable daughter vessel occlusion. Conversely, low-to-moderate device WSS throughout the device length could be interpreted as a reduced likelihood of complete occlusion of the aneurysm over time, resulting in lesser device performance.
{"title":"Quantifying Stent Wall Shear Stress for Assessing Stent and Flow Diverter Performance for Treating Intracranial Aneurysms","authors":"T. Suess, S. Gent","doi":"10.1115/1.4062107","DOIUrl":"https://doi.org/10.1115/1.4062107","url":null,"abstract":"\u0000 Analysis of flow diverting intracranial aneurysm repair devices has traditionally focused on reducing intrasaccular blood flow velocity and aneurysm wall shear stress (WSS) as the primary metrics for improved perceived device performance. However, the interpretation of this data has been debated, particularly with regards to the specific biological benefits of high or low aneurysm WSS. Therefore, this research proposes an additional parameter of WSS at the stent struts that could provide valuable insight regarding the device's potential to promote occlusion at the aneurysm neck by indicating locations of increased platelet activation and microparticle shedding. Fluid flow effects were evaluated for two flow diverters (PipelineTM and FREDTM) and three stents (EnterpriseTM, AtlasTM, and LVISTM) using computational fluid dynamics (CFD) models developed from two patient-derived CTA datasets with aneurysms in the middle cerebral artery (MCA) and basilar artery (BA), respectively. The device WSS data provides an additional metric for evaluating the ability of the device to constrain the blood flow within the main vessel, as well as indicating potential locations of the initiation of aneurysm occlusion. It is hypothesized that high device WSS close to the aneurysm neck creates a higher likelihood of thrombus formation and aneurysm occlusion due to platelet activation and microparticle shedding, while high device WSS proximal or distal on the device would indicate higher likelihood of undesirable daughter vessel occlusion. Conversely, low-to-moderate device WSS throughout the device length could be interpreted as a reduced likelihood of complete occlusion of the aneurysm over time, resulting in lesser device performance.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79298419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A tube-load model is used to reconstruct aortic pressure waveform from peripheral pressure waveform. Yet, the reconstructed aortic pressure waveform is greatly affected by load impedance used. In this work, a vibrating-string model for closed-loop wave transmission and reflection between the aorta and periphery is developed to examine the roles of all the parameters involved in aortic pressure waveform. The arterial pulsatile wave theory gives rise to the standard 1D wave equation for a vibrating string. A vibrating-string model based on radial displacement of the arterial wall is developed to relate aortic pressure waveform to peripheral pressure waveform, relate load impedance to input impedance, and derive theoretical expressions for associated clinical indices. The vibrating-string model is extended to incorporate blood velocity, and is further connected to the left ventricle (LV) to study the role of the LV in aortic pressure waveform. The difference between the vibrating-string model and the tube-load model is also examined. Load impedance is identified as an indispensable independent parameter for reconstruction of aortic pressure waveform with accuracy, and its physiologically realistic harmonic-dependence can only be obtained from the measured input impedance. The derived expressions for clinical indices interpret some clinical findings and underscore the role of harmonics in clinical indices. Some misconceptions in the tube-load model are revealed, including load impedance and characteristic impedance. This work clarifies the role of harmonics-dependence of load impedance and harmonics of aortic pressure waveform in determining clinical indices.
{"title":"A Vibrating-string Model for Closed-loop Wave Transmission and Reflection Between the Aorta and Periphery","authors":"Z. Hao","doi":"10.1115/1.4062078","DOIUrl":"https://doi.org/10.1115/1.4062078","url":null,"abstract":"\u0000 A tube-load model is used to reconstruct aortic pressure waveform from peripheral pressure waveform. Yet, the reconstructed aortic pressure waveform is greatly affected by load impedance used. In this work, a vibrating-string model for closed-loop wave transmission and reflection between the aorta and periphery is developed to examine the roles of all the parameters involved in aortic pressure waveform. The arterial pulsatile wave theory gives rise to the standard 1D wave equation for a vibrating string. A vibrating-string model based on radial displacement of the arterial wall is developed to relate aortic pressure waveform to peripheral pressure waveform, relate load impedance to input impedance, and derive theoretical expressions for associated clinical indices. The vibrating-string model is extended to incorporate blood velocity, and is further connected to the left ventricle (LV) to study the role of the LV in aortic pressure waveform. The difference between the vibrating-string model and the tube-load model is also examined. Load impedance is identified as an indispensable independent parameter for reconstruction of aortic pressure waveform with accuracy, and its physiologically realistic harmonic-dependence can only be obtained from the measured input impedance. The derived expressions for clinical indices interpret some clinical findings and underscore the role of harmonics in clinical indices. Some misconceptions in the tube-load model are revealed, including load impedance and characteristic impedance. This work clarifies the role of harmonics-dependence of load impedance and harmonics of aortic pressure waveform in determining clinical indices.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72399628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of the force field parallel to the surface of the scaffold plate on cell activity (deformation, migration) has been studied in vitro. Cell orientation was aligned by microtopography patterns (striped ridgelines; height 0.7 μm, width 3 μm, spacing 3 μm) on the scaffold plane. Three compartments were designed with different angles (0 degrees, 45 degrees, and 90 degrees) between the longitudinal direction of the ridge and the direction of the force field. Osteoblasts (MC3T3-E1; osteoblast precursor cell line derived from mouse calvaria) were used in the experiment. After applying a force field for 5 hours, the position and contour of each cell were tracked on time-lapse microscopy images for 48 hours. Experimental results show that force fields not parallel to the major axis of the cell activate subsequent actions (deformation, migration) of the cell. The effect is maintained for 48 hours even if the cells move to different areas of the topography pattern.
{"title":"Effect of Force Field On Deformation and Migration of Single Cell with Orientation Controlled by Micro-striped Topography Patterns","authors":"S. Hashimoto, Kazuya Kishimoto","doi":"10.1115/1.4057030","DOIUrl":"https://doi.org/10.1115/1.4057030","url":null,"abstract":"\u0000 The effect of the force field parallel to the surface of the scaffold plate on cell activity (deformation, migration) has been studied in vitro. Cell orientation was aligned by microtopography patterns (striped ridgelines; height 0.7 μm, width 3 μm, spacing 3 μm) on the scaffold plane. Three compartments were designed with different angles (0 degrees, 45 degrees, and 90 degrees) between the longitudinal direction of the ridge and the direction of the force field. Osteoblasts (MC3T3-E1; osteoblast precursor cell line derived from mouse calvaria) were used in the experiment. After applying a force field for 5 hours, the position and contour of each cell were tracked on time-lapse microscopy images for 48 hours. Experimental results show that force fields not parallel to the major axis of the cell activate subsequent actions (deformation, migration) of the cell. The effect is maintained for 48 hours even if the cells move to different areas of the topography pattern.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84711717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhongxia Yuan, P. L. Chong, Sandipan Roy, A. Merdji, Abdelhak Ouldyerou, F. Faraji, L. K. Moey, Mohammad Hossein Yazdi, O. Mukdadi
Dental implants have received a lot of attention and have been used to treat symptoms like missing teeth and bad teeth. Due to the wide range of occupations and ages of patients, the functions and aims of implants are different. There are many kinds of dental implant shapes. However, with the popularity of dental implants, some problems caused by the dental implant shape have appeared in people's eyes. In fact, some implants were used incorrectly. This makes the stress distribution around the implant unreasonable; it not only affects the surrounding bone resorption but also causes mechanical fracture of the implant. This work aims to evaluate the mechanical features of five different kinds of dental implant systems. By applying engineering systems of investigations like FEM, five types of dental implants and surrounding bone tissue were modeled and simulated under vertical loads of 90N. Distributions of stresses and deformations in the bone were obtained and ranked into statistical scores, which were used to judge the optimum geometry of implants. Analytical results showed that the cylindrical implant, is the most optimum shape among other types of implants.
{"title":"Investigation of Mechanical Behaviors of Dental Implants with Different Geometries","authors":"Zhongxia Yuan, P. L. Chong, Sandipan Roy, A. Merdji, Abdelhak Ouldyerou, F. Faraji, L. K. Moey, Mohammad Hossein Yazdi, O. Mukdadi","doi":"10.1115/1.4056952","DOIUrl":"https://doi.org/10.1115/1.4056952","url":null,"abstract":"\u0000 Dental implants have received a lot of attention and have been used to treat symptoms like missing teeth and bad teeth. Due to the wide range of occupations and ages of patients, the functions and aims of implants are different. There are many kinds of dental implant shapes. However, with the popularity of dental implants, some problems caused by the dental implant shape have appeared in people's eyes. In fact, some implants were used incorrectly. This makes the stress distribution around the implant unreasonable; it not only affects the surrounding bone resorption but also causes mechanical fracture of the implant. This work aims to evaluate the mechanical features of five different kinds of dental implant systems. By applying engineering systems of investigations like FEM, five types of dental implants and surrounding bone tissue were modeled and simulated under vertical loads of 90N. Distributions of stresses and deformations in the bone were obtained and ranked into statistical scores, which were used to judge the optimum geometry of implants. Analytical results showed that the cylindrical implant, is the most optimum shape among other types of implants.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83613695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this is to evaluate the biomechanical performance of double-level semi-rigid pedicle screw fixation and artificial intervertebral disc replacement in lumbar spine. Ti6Al4V and CFR-PEEK material are used for pedicle screw fixation and artificial disc replacement. In the present study, pedicle screw fixation and artificial intervertebral disc replacement are carried out between L3-L4-L5 regions under the application of moment 6,8,10 Nm and range of motion is compared during flexion, extension, and right-left lateral bending. Two level pedicle screw fusion and total disc replacement are developed in the L3-L4-L5 of the lumber spine vertebrae. Carbon fiber reinforced (CFR-PEEK) and Ultra High Molecular Weight Polyethylene (UHMWPE) are considered for the spinal fusion and the core part of the artificial disc respectively. Afterwards, applying the finite element analysis, it is detected that CFR-PEEK rod is able to increase range of motion at the implanted level in comparison to Ti6Al4V rod for both flexion-extension and lateral bending. In case of artificial intervertebral disc replacement hypermobility was observed. Hence, it is significant that rod material with CFR-PEEK is a better alternative for the treatment of degenerative diseases.
{"title":"A Finite Element Based Comparative Study of Lumbosacral Pedicle Screw Fixation and Artificial Disc Replacement","authors":"J. Biswas, Anik Banerjee, N. Mondal, Masud Rana","doi":"10.1115/1.4056953","DOIUrl":"https://doi.org/10.1115/1.4056953","url":null,"abstract":"\u0000 The aim of this is to evaluate the biomechanical performance of double-level semi-rigid pedicle screw fixation and artificial intervertebral disc replacement in lumbar spine. Ti6Al4V and CFR-PEEK material are used for pedicle screw fixation and artificial disc replacement. In the present study, pedicle screw fixation and artificial intervertebral disc replacement are carried out between L3-L4-L5 regions under the application of moment 6,8,10 Nm and range of motion is compared during flexion, extension, and right-left lateral bending. Two level pedicle screw fusion and total disc replacement are developed in the L3-L4-L5 of the lumber spine vertebrae. Carbon fiber reinforced (CFR-PEEK) and Ultra High Molecular Weight Polyethylene (UHMWPE) are considered for the spinal fusion and the core part of the artificial disc respectively. Afterwards, applying the finite element analysis, it is detected that CFR-PEEK rod is able to increase range of motion at the implanted level in comparison to Ti6Al4V rod for both flexion-extension and lateral bending. In case of artificial intervertebral disc replacement hypermobility was observed. Hence, it is significant that rod material with CFR-PEEK is a better alternative for the treatment of degenerative diseases.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75958482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dental implants are surgically implanted into the patient's jaw to replace a missing tooth. The implant should have adequate time to integrate with bone before being subjected to masticatory force to avoid early failure. Resonance Frequency Analysis (RFA) is one of the approaches for determining an implant system's primary stability in terms of micromotion. This research aims to create a two-degree of freedom (dof) mathematical model for dental prostheses based on the vibroacoustic RFA approach. In vibroacoustic system, a loudspeaker or buzzer is used as an input and the displacement of implant is measured using RFA. A sinusoidal force is used which produces a combination of translational and rotational motion of the implant system. While adjusting the input frequency from 4000 to 12000 Hz, is used with the help of MATLAB which later computes the implant system's subsequent micro-motion and resonance frequency. MATLAB is used to visualise the resonance frequency, which is 6658.38 Hz in case of rotational motion and 8138 Hz in translational motion. The micromotion was 1.2692 X 10-11 meters in case of translational motion and 6.91088 X 10-9 radians in case of rotational motion. When there is less micromotion, a higher resonance frequency suggests more excellent osseointegration. For the evaluation of implant stability, a mathematical model is a primary approach which can be implemented to design a stability device using vibroacoustic RFA.
植牙是通过外科手术将牙植入病人的下颌以代替缺牙。种植体在接受咀嚼力之前应有足够的时间与骨融合，以避免早期失效。共振频率分析(RFA)是确定植入体系统微动稳定性的方法之一。本研究旨在建立基于振动声学RFA方法的口腔修复体的二自由度数学模型。在振动声学系统中，使用扬声器或蜂鸣器作为输入，并使用RFA测量植入物的位移。使用正弦力产生植入体系统的平移和旋转运动的组合。在将输入频率从4000 Hz调整到12000 Hz的同时，借助MATLAB计算植入体系统的后续微运动和共振频率。利用MATLAB可视化了共振频率，旋转运动时为6658.38 Hz，平移运动时为8138 Hz。平移微运动为1.2692 X 10-11米，旋转微运动为6.91088 X 10-9弧度。微动越少，共振频率越高，骨整合越好。为了评估植入体的稳定性，数学模型是采用振动声RFA设计稳定装置的主要方法。
{"title":"Evaluation of Resonance Frequency and Micro motion to achieve Implant Stability using Vibroacoustic RFA: A Mathematical Model","authors":"Vineet Khened, Kanad Dhok, M. Pradhan, P. Dhatrak","doi":"10.1115/1.4056951","DOIUrl":"https://doi.org/10.1115/1.4056951","url":null,"abstract":"\u0000 Dental implants are surgically implanted into the patient's jaw to replace a missing tooth. The implant should have adequate time to integrate with bone before being subjected to masticatory force to avoid early failure. Resonance Frequency Analysis (RFA) is one of the approaches for determining an implant system's primary stability in terms of micromotion. This research aims to create a two-degree of freedom (dof) mathematical model for dental prostheses based on the vibroacoustic RFA approach. In vibroacoustic system, a loudspeaker or buzzer is used as an input and the displacement of implant is measured using RFA. A sinusoidal force is used which produces a combination of translational and rotational motion of the implant system. While adjusting the input frequency from 4000 to 12000 Hz, is used with the help of MATLAB which later computes the implant system's subsequent micro-motion and resonance frequency. MATLAB is used to visualise the resonance frequency, which is 6658.38 Hz in case of rotational motion and 8138 Hz in translational motion. The micromotion was 1.2692 X 10-11 meters in case of translational motion and 6.91088 X 10-9 radians in case of rotational motion. When there is less micromotion, a higher resonance frequency suggests more excellent osseointegration. For the evaluation of implant stability, a mathematical model is a primary approach which can be implemented to design a stability device using vibroacoustic RFA.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79384971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlo Carotenuto, L. Scurani, L. Fontanili, L. Montorsi, M. Milani
The lung is the human organ mainly affected by severe coronavirus disease (COVID-19) caused by the novel coronavirus SARS-CoV-2. In this pathology, the dynamic lung function and the respiratory mechanics are compromised, leading to the development of the ARDS (acute respiratory distress syndrome). The resulting damage is the progressive reduction of gas exchange and death in the most critical patients. For these reasons, it is important to study and analyze how this virus adversely affects lung dynamics. The main objective of the present paper is to propose a modeling methods of SARS-CoV-2 virus particles spread in the 23rd generation of lung tree and the mechanical estimation of how a severe stage of Covid-19 characterized by pulmonary fibrosis affects the alveolar sac expansion and hence the breathing capability of the sick person. In this context, the dynamic analysis of the influence of SARS-CoV-2 spread on human lung under real conditions has been shown by means of a numerical approach. Therefore, a multiphase three-dimensional computational fluid dynamics (CFD) study is performed to estimate the Covid-19 virus particles dispersion throughout a simplify model of the 23rd generation of bronchial tree, at the alveolar region. Then, a fully coupled fluid-structure interaction (FSI) with the mesh morphing technique and solid displacement characteristics are used to obtain and evaluate a realistic wall displacement during the expansion of the alveolar sac. A comparison is made between a healthy and a diseased lung. These phases are studied under cyclic steady-state conditions The novelties of this analysis are: firstly, the innovative CFD method proposed in order to model the particles spread inside the alveolar region, and secondly the evaluation of how the presence of Sars-Cov-2 can affect the mechanical properties of the alveolar sac and damage the lung function of a sick person at an advanced stage of infection, such as a person affected by pulmonary fibrosis.
{"title":"Computational Fluid Dynamics Study of Particle Deposition On Human Lung Dynamic: A Comparison Between the Healthy and Fibrotic Lung","authors":"Carlo Carotenuto, L. Scurani, L. Fontanili, L. Montorsi, M. Milani","doi":"10.1115/1.4056840","DOIUrl":"https://doi.org/10.1115/1.4056840","url":null,"abstract":"\u0000 The lung is the human organ mainly affected by severe coronavirus disease (COVID-19) caused by the novel coronavirus SARS-CoV-2. In this pathology, the dynamic lung function and the respiratory mechanics are compromised, leading to the development of the ARDS (acute respiratory distress syndrome). The resulting damage is the progressive reduction of gas exchange and death in the most critical patients. For these reasons, it is important to study and analyze how this virus adversely affects lung dynamics. The main objective of the present paper is to propose a modeling methods of SARS-CoV-2 virus particles spread in the 23rd generation of lung tree and the mechanical estimation of how a severe stage of Covid-19 characterized by pulmonary fibrosis affects the alveolar sac expansion and hence the breathing capability of the sick person. In this context, the dynamic analysis of the influence of SARS-CoV-2 spread on human lung under real conditions has been shown by means of a numerical approach. Therefore, a multiphase three-dimensional computational fluid dynamics (CFD) study is performed to estimate the Covid-19 virus particles dispersion throughout a simplify model of the 23rd generation of bronchial tree, at the alveolar region. Then, a fully coupled fluid-structure interaction (FSI) with the mesh morphing technique and solid displacement characteristics are used to obtain and evaluate a realistic wall displacement during the expansion of the alveolar sac. A comparison is made between a healthy and a diseased lung. These phases are studied under cyclic steady-state conditions The novelties of this analysis are: firstly, the innovative CFD method proposed in order to model the particles spread inside the alveolar region, and secondly the evaluation of how the presence of Sars-Cov-2 can affect the mechanical properties of the alveolar sac and damage the lung function of a sick person at an advanced stage of infection, such as a person affected by pulmonary fibrosis.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87546451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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