Abhinaba Bhattacharjee, M. Terry Loghmani, Sohel Anwar
Abstract Surgical Haptics is an emergent field of research to integrate and advance the sense of robotic touch in laparoscopic tools in robot-assisted minimally invasive surgery. Haptic feedback from the tooltip and soft tissue surface interaction during robotic palpation can be leveraged to detect the texture and contour of subsurface geometry. However, precise force modulation of the robotic palpating probe is necessary to determine stiff inclusions of the anatomy and maneuver successive manipulation tasks during surgery. This paper focuses on investigating the layered deformations associated with different force profiles involved in manipulating the superficial anatomy of soft tissues during dynamic robotic palpation to determine the underlying anomaly. A realistic three-dimensional (3D) cross-sectional soft tissue phantom with anatomical layers and tumor, as an anomaly, is designed, modeled, and analyzed to examine the effects of oriented palpating forces (0–5 N) of a 7 DOF robot arm equipped with a contoured palpation probe. Finite element static structural analysis of oriented robotic palpation on the developed 3D soft tissue phantoms (with and without anomaly) reveals the soft tissue layer deformations and associated strains needed to identify presence of stiffer inclusions or anomaly during Robotic palpation. The finite element analysis study shows that the difference in deformations of soft tissue layers (e.g., underlying myofascial layers) under stiffer inclusions at different force levels can facilitate haptic feedback to acquire information about subsurface tumors. The deformation variations are further compared to assess better palpation orientations for subsurface anomaly detection.
{"title":"Modeling and Simulation of Robotic Palpation to Detect Subsurface Soft Tissue Anomaly for Presurgical Assessment","authors":"Abhinaba Bhattacharjee, M. Terry Loghmani, Sohel Anwar","doi":"10.1115/1.4063470","DOIUrl":"https://doi.org/10.1115/1.4063470","url":null,"abstract":"Abstract Surgical Haptics is an emergent field of research to integrate and advance the sense of robotic touch in laparoscopic tools in robot-assisted minimally invasive surgery. Haptic feedback from the tooltip and soft tissue surface interaction during robotic palpation can be leveraged to detect the texture and contour of subsurface geometry. However, precise force modulation of the robotic palpating probe is necessary to determine stiff inclusions of the anatomy and maneuver successive manipulation tasks during surgery. This paper focuses on investigating the layered deformations associated with different force profiles involved in manipulating the superficial anatomy of soft tissues during dynamic robotic palpation to determine the underlying anomaly. A realistic three-dimensional (3D) cross-sectional soft tissue phantom with anatomical layers and tumor, as an anomaly, is designed, modeled, and analyzed to examine the effects of oriented palpating forces (0–5 N) of a 7 DOF robot arm equipped with a contoured palpation probe. Finite element static structural analysis of oriented robotic palpation on the developed 3D soft tissue phantoms (with and without anomaly) reveals the soft tissue layer deformations and associated strains needed to identify presence of stiffer inclusions or anomaly during Robotic palpation. The finite element analysis study shows that the difference in deformations of soft tissue layers (e.g., underlying myofascial layers) under stiffer inclusions at different force levels can facilitate haptic feedback to acquire information about subsurface tumors. The deformation variations are further compared to assess better palpation orientations for subsurface anomaly detection.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135044298","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}
Narayan Yoganandan, Jamie L. Baisden, Aditya Vedantam, Anjishnu Banerjee
Abstract Advancements in automated vehicles may position the occupant in postures different from the current, standard posture. It may affect human tolerance responses. The objective of this study was to determine the lateral bending tolerance of the head-cervical spine with initial head rotation posture using loads at the occipital condyles and lower neck and describe injuries. Using a custom loading device, head-cervical spine complexes from human cadavers were prepared with load cells at the ends. Lateral bending loads were applied to the pre-rotated specimens at 1.5 m/s. At the occipital condyles, peak axial and antero-posterior and medial-lateral shear forces were: 316-954 N, 176-254 N, and 327-508 N, and coronal, sagittal, and axial moments were: 27 - 38 Nm, 21 - 38 Nm, and 9.7 - 19.8 Nm. At the lower neck, peak axial and shear forces were: 677 - 1004 N, 115 - 227 N, and 178 - 350 N, and coronal, sagittal, and axial moments were: 30 - 39 Nm, 7.6 - 21.3 Nm, and 5.7 - 13.4 Nm. Ipsilateral atlas lateral mass fractures occurred in four out of five specimens with varying joint diastasis and capsular ligament involvements. Acknowledging that the study used a small sample size, initial tolerances at the occipital condyles and lower neck were estimated using survival analysis. Injury patterns with posture variations are discussed.
{"title":"Complex Neck Loading and Injury Tolerance in Lateral Bending with Head Rotation From Human Cadaver Tests","authors":"Narayan Yoganandan, Jamie L. Baisden, Aditya Vedantam, Anjishnu Banerjee","doi":"10.1115/1.4063648","DOIUrl":"https://doi.org/10.1115/1.4063648","url":null,"abstract":"Abstract Advancements in automated vehicles may position the occupant in postures different from the current, standard posture. It may affect human tolerance responses. The objective of this study was to determine the lateral bending tolerance of the head-cervical spine with initial head rotation posture using loads at the occipital condyles and lower neck and describe injuries. Using a custom loading device, head-cervical spine complexes from human cadavers were prepared with load cells at the ends. Lateral bending loads were applied to the pre-rotated specimens at 1.5 m/s. At the occipital condyles, peak axial and antero-posterior and medial-lateral shear forces were: 316-954 N, 176-254 N, and 327-508 N, and coronal, sagittal, and axial moments were: 27 - 38 Nm, 21 - 38 Nm, and 9.7 - 19.8 Nm. At the lower neck, peak axial and shear forces were: 677 - 1004 N, 115 - 227 N, and 178 - 350 N, and coronal, sagittal, and axial moments were: 30 - 39 Nm, 7.6 - 21.3 Nm, and 5.7 - 13.4 Nm. Ipsilateral atlas lateral mass fractures occurred in four out of five specimens with varying joint diastasis and capsular ligament involvements. Acknowledging that the study used a small sample size, initial tolerances at the occipital condyles and lower neck were estimated using survival analysis. Injury patterns with posture variations are discussed.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135254964","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}
Ashish Tiwari, Pankaj Wahi, Shakti S Gupta, Niraj Sinha
Abstract Fracture may occur in human lower leg bones considering varying loads acting on them while performing various functions. Implants, commonly used in healing the fractures, must be properly aligned with the bones' anatomical axes for their proper functioning. While attempts to establish tibial anatomical axis have been made previously, combined central anatomical axis of human tibia and fibula remains unexplored. In this study, profiles of individual and combined central anatomical axes of tibia and fibula have been obtained using computed tomography (CT). These profiles are found to be approximately straight with the deviation from straight line for the centroidal axis of the combined system being approximately half of that for the tibia. It is further utilised in assessing the role of fibula in determining the critical stresses in the tibia with the help of static finite element analysis (FEA) of a tibia-fibula model. Even though fibula takes a smaller proportion of the total axial load, its absence increases the compressive stresses in the tibia due to increased bending moments at the critical cross-sections. Furthermore, FEA has been carried out to understand the clinical significance of the mismatch in the centroidal axis of an implant and its parent bone taking the example of the human tibia alone. FEA suggests that these central anatomical axes are in fact the load bearing axes of the bones and any misalignment of implant with the central anatomical axis may lead to patient discomfort and premature failure of the implant.
{"title":"Straightness of Central Anatomical Axes of Human Tibia-Fibula System: Role of Fibula and Its Importance in Biomechanics","authors":"Ashish Tiwari, Pankaj Wahi, Shakti S Gupta, Niraj Sinha","doi":"10.1115/1.4063649","DOIUrl":"https://doi.org/10.1115/1.4063649","url":null,"abstract":"Abstract Fracture may occur in human lower leg bones considering varying loads acting on them while performing various functions. Implants, commonly used in healing the fractures, must be properly aligned with the bones' anatomical axes for their proper functioning. While attempts to establish tibial anatomical axis have been made previously, combined central anatomical axis of human tibia and fibula remains unexplored. In this study, profiles of individual and combined central anatomical axes of tibia and fibula have been obtained using computed tomography (CT). These profiles are found to be approximately straight with the deviation from straight line for the centroidal axis of the combined system being approximately half of that for the tibia. It is further utilised in assessing the role of fibula in determining the critical stresses in the tibia with the help of static finite element analysis (FEA) of a tibia-fibula model. Even though fibula takes a smaller proportion of the total axial load, its absence increases the compressive stresses in the tibia due to increased bending moments at the critical cross-sections. Furthermore, FEA has been carried out to understand the clinical significance of the mismatch in the centroidal axis of an implant and its parent bone taking the example of the human tibia alone. FEA suggests that these central anatomical axes are in fact the load bearing axes of the bones and any misalignment of implant with the central anatomical axis may lead to patient discomfort and premature failure of the implant.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135351976","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 The elastography method has been widely used to estimate the stiffness of biomaterials based on the shear wave speed. The wave propagation excited by a single indent on the surface of the biomaterials is not always an ideal shear wave. The distance from the interested region to the indent, or different algorithms for elastography may affect the calculation of stiffness. This paper aims to analyze the shear wave propagation in soft biomaterials with a finite element model that was constructed based on the setup of our previous in-vitro experiments on gelatin. A shear wave propagation was induced by a single indent at 1kHz. The displacements along a path line, at three depths, were extracted for analyzing the shear wave propagation. The influence of the damping behavior and three different elastography algorithms were also investigated with our data. Results have shown that the finite element simulation agreed well with the previous in-vitro experiments. The stiffness increased by more than 10% as the depth increased from 1mm to 7mm, which is larger for materials with larger damping behavior (viscoelasticity). The precise estimation was related to the distance between the interested region and the indent for the material with a larger damping behavior. The feasibility of three algorithms: wavefront slope, cross-correlation algorithm, and finite differencing method (FDM), were investigated. The FDM can determine the shear wave speed based on local spatial and temporal data, while high-frequency data are required. This work provides valuable information for optimizing performance of elastography.
{"title":"A Finite Element Model for Analyzing the Shear Wave Propagation in Soft Biomaterials","authors":"Jianing Wang, Runze Li, Qifa Zhou, Linxia Gu, Pengfei Dong","doi":"10.1115/1.4063598","DOIUrl":"https://doi.org/10.1115/1.4063598","url":null,"abstract":"Abstract The elastography method has been widely used to estimate the stiffness of biomaterials based on the shear wave speed. The wave propagation excited by a single indent on the surface of the biomaterials is not always an ideal shear wave. The distance from the interested region to the indent, or different algorithms for elastography may affect the calculation of stiffness. This paper aims to analyze the shear wave propagation in soft biomaterials with a finite element model that was constructed based on the setup of our previous in-vitro experiments on gelatin. A shear wave propagation was induced by a single indent at 1kHz. The displacements along a path line, at three depths, were extracted for analyzing the shear wave propagation. The influence of the damping behavior and three different elastography algorithms were also investigated with our data. Results have shown that the finite element simulation agreed well with the previous in-vitro experiments. The stiffness increased by more than 10% as the depth increased from 1mm to 7mm, which is larger for materials with larger damping behavior (viscoelasticity). The precise estimation was related to the distance between the interested region and the indent for the material with a larger damping behavior. The feasibility of three algorithms: wavefront slope, cross-correlation algorithm, and finite differencing method (FDM), were investigated. The FDM can determine the shear wave speed based on local spatial and temporal data, while high-frequency data are required. This work provides valuable information for optimizing performance of elastography.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"448 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135482391","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 According to the obstructive sleep apnea Syndrome (OSAS), a wearable sleep monitoring system is designed based on machine learning using snoring sound signal. The system picks up snoring signal via bone conduction sensor, and calculates the apnea-hypopnea index (AHI). By analyzing the snoring signal in frequency domain, spectral entropy and other frequency-domain features are selected. Finally, the neural network classifier model is established. In the model, the input variables are eight frequency-domain features, and the output response is related to AHI value. Trained by machine learning, the result shows that the average accuracy in identifying the severity of the four kinds of OSAS categories is 59%. The system uses the measured data of snoring to analyze the symptoms of OSAS, so as to realize the preliminary forecast based on the snoring data. The system proposed in this paper has a good application development prospect in intelligent monitoring and medical instruments.
{"title":"Wearable Sleep Monitoring System Based On Machine Learning Using Snoring Sound Signal","authors":"Yi Xin, Rui Li, Xuefeng Song, Yuqi Wang, Hanshuo Zhang, Zhiying Chen","doi":"10.1115/1.4063395","DOIUrl":"https://doi.org/10.1115/1.4063395","url":null,"abstract":"Abstract According to the obstructive sleep apnea Syndrome (OSAS), a wearable sleep monitoring system is designed based on machine learning using snoring sound signal. The system picks up snoring signal via bone conduction sensor, and calculates the apnea-hypopnea index (AHI). By analyzing the snoring signal in frequency domain, spectral entropy and other frequency-domain features are selected. Finally, the neural network classifier model is established. In the model, the input variables are eight frequency-domain features, and the output response is related to AHI value. Trained by machine learning, the result shows that the average accuracy in identifying the severity of the four kinds of OSAS categories is 59%. The system uses the measured data of snoring to analyze the symptoms of OSAS, so as to realize the preliminary forecast based on the snoring data. The system proposed in this paper has a good application development prospect in intelligent monitoring and medical instruments.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135648234","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 Recent data from heavy weapons training and breaching exercise environments suggest that protection of the ear canal alone may not be sufficient to prevent detrimental effects of blast-induced impulse noise on the Warfighter. This work is to elucidate alternate pathways of impulse noise penetration into the inner ear, including through the soft tissues of the head and bone conduction, gain insight into the fundamental mechanism(s) of blast induced hearing loss and validate the computational model with experiment. We have exposed the instrumented head model to impulse noise events generated via a shock tube (sound pressure level > 140 dB) to identify the role of bone conduction in pressure build up in the inner ear. Concurrently, we have developed a finite element (FE) model of the head to simulate the biomechanical response of the ear to impulse noise. The loading condition applied to the model to characterize the biomechanical effects in the ear is derived from notional weapons firing incidents. We have also developed an inner ear model to analyze the dynamic behavior of the basilar membrane when subjected to skull vibration stimulated by an impulse noise event. Using the simulated motion of the basilar membrane, we attempted to establish the relationship between the impulse noise and possible auditory disruption outcomes to the inner ear.
{"title":"Simulation and Experimental Validation of Alternate Pathways of Impulse Noise Conduction Into the Inner Ear","authors":"X. Gary Tan, YungChia Chen, Thomas O'Shaughnessy","doi":"10.1115/1.4063472","DOIUrl":"https://doi.org/10.1115/1.4063472","url":null,"abstract":"Abstract Recent data from heavy weapons training and breaching exercise environments suggest that protection of the ear canal alone may not be sufficient to prevent detrimental effects of blast-induced impulse noise on the Warfighter. This work is to elucidate alternate pathways of impulse noise penetration into the inner ear, including through the soft tissues of the head and bone conduction, gain insight into the fundamental mechanism(s) of blast induced hearing loss and validate the computational model with experiment. We have exposed the instrumented head model to impulse noise events generated via a shock tube (sound pressure level > 140 dB) to identify the role of bone conduction in pressure build up in the inner ear. Concurrently, we have developed a finite element (FE) model of the head to simulate the biomechanical response of the ear to impulse noise. The loading condition applied to the model to characterize the biomechanical effects in the ear is derived from notional weapons firing incidents. We have also developed an inner ear model to analyze the dynamic behavior of the basilar membrane when subjected to skull vibration stimulated by an impulse noise event. Using the simulated motion of the basilar membrane, we attempted to establish the relationship between the impulse noise and possible auditory disruption outcomes to the inner ear.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135689327","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}
Cerebral aneurysms are potentially life-threatening cerebrovascular conditions where a weakened blood vessel in the brain bulges or protrudes over time. The most common way to treat aneurysms is surgical clipping, an approach where blood flow to the aneurysm is blocked by a permanently placed clip on the artery. However, not all aneurysms are identical; thus, there has been a need for patient-specific treatment options, where each aneurysm is treated based on its individual characteristics. Computational fluid dynamics (CFD) modeling can offer insights to predict how different treatment procedures will affect cerebral hemodynamics. In that regard, the goal of this pilot study was to investigate the flow characteristics and hemodynamic parameters in cerebral arteries before and after neurosurgical clipping. For this purpose, two patient-specific cerebral artery geometries with at least one aneurysm at the middle cerebral artery bifurcation were selected from an online dataset. A companion post-clipping model was created for each geometry by removing the aneurysm from the original geometry. Tetrahedral mesh elements were then generated and CFD simulations were conducted to compare the blood velocity profile, secondary flow, flow streamline, and wall shear stress in the computational models with and without aneurysm. Results showed that the clipping treatment led to changes in the velocity profiles, secondary flow structures, and wall shear stress in the middle cerebral artery. In conclusion, our results suggest that CFD modeling can assist in predicting hemodynamic parameters prior to treatment, thus facilitating more tailored planning for each patient's treatment.
{"title":"Variations of Middle Cerebral Artery Hemodynamics Due to Aneurysm Clipping Surgery","authors":"Haleigh Davidson, Brooke Scardino, Peshala Thibbotuwawa Gamage, Amirtahà Taebi","doi":"10.1115/1.4063204","DOIUrl":"https://doi.org/10.1115/1.4063204","url":null,"abstract":"\u0000 Cerebral aneurysms are potentially life-threatening cerebrovascular conditions where a weakened blood vessel in the brain bulges or protrudes over time. The most common way to treat aneurysms is surgical clipping, an approach where blood flow to the aneurysm is blocked by a permanently placed clip on the artery. However, not all aneurysms are identical; thus, there has been a need for patient-specific treatment options, where each aneurysm is treated based on its individual characteristics. Computational fluid dynamics (CFD) modeling can offer insights to predict how different treatment procedures will affect cerebral hemodynamics. In that regard, the goal of this pilot study was to investigate the flow characteristics and hemodynamic parameters in cerebral arteries before and after neurosurgical clipping. For this purpose, two patient-specific cerebral artery geometries with at least one aneurysm at the middle cerebral artery bifurcation were selected from an online dataset. A companion post-clipping model was created for each geometry by removing the aneurysm from the original geometry. Tetrahedral mesh elements were then generated and CFD simulations were conducted to compare the blood velocity profile, secondary flow, flow streamline, and wall shear stress in the computational models with and without aneurysm. Results showed that the clipping treatment led to changes in the velocity profiles, secondary flow structures, and wall shear stress in the middle cerebral artery. In conclusion, our results suggest that CFD modeling can assist in predicting hemodynamic parameters prior to treatment, thus facilitating more tailored planning for each patient's treatment.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86705130","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}
Aysha Mann, Peshala Thibbotuwawa Gamage, B. Kakavand, Amirtahà Taebi
Cardiac time intervals (CTIs) are important parameters for evaluating cardiac function and can be measured noninvasively through electrocardiography (ECG) and seismocardiography (SCG). SCG signals exhibit distinct spectrotemporal characteristics when acquired from various locations on the chest. Thus, this study aimed to explore how SCG measurement location affects the estimation of SCG-based CTIs. ECG and SCG signals were acquired from 14 healthy adults, with three accelerometers placed on the top, middle, and bottom of the sternum. A custom-built algorithm was developed to estimate heart rates (HRs) from ECG (HRECG) and SCG (HRSCG) signals. Moreover, SCG fiducial points and CTIs, including aortic valve opening and closure, R-R interval, preejection period, left ventricular ejection time, and electromechanical systole, were estimated from the SCG signals at different sternal locations. The average and correlation coefficient (R2) of the CTIs and HRs derived from all three locations were compared, along with the analysis of mean differences for the CTIs and their corresponding sensor locations. The results indicated strong correlations between HRECG and HRSCG, with average R2 values of 0.9930, 0.9968, and 0.9790 for the top, middle, and bottom sternal locations, respectively. Additionally, the study demonstrated that SCG-based CTIs varied depending on the SCG measurement locations. In conclusion, these findings underscore the importance of establishing consistent protocols for reporting CTIs based on SCG. Furthermore, they call for further investigation to compare estimated CTIs with gold-standard methods like echocardiography to identify the best SCG measurement location for accurate CTI estimations.
{"title":"Exploring the Impact of Sensor Location On Seismocardiography-Derived Cardiac Time Intervals","authors":"Aysha Mann, Peshala Thibbotuwawa Gamage, B. Kakavand, Amirtahà Taebi","doi":"10.1115/1.4063203","DOIUrl":"https://doi.org/10.1115/1.4063203","url":null,"abstract":"\u0000 Cardiac time intervals (CTIs) are important parameters for evaluating cardiac function and can be measured noninvasively through electrocardiography (ECG) and seismocardiography (SCG). SCG signals exhibit distinct spectrotemporal characteristics when acquired from various locations on the chest. Thus, this study aimed to explore how SCG measurement location affects the estimation of SCG-based CTIs. ECG and SCG signals were acquired from 14 healthy adults, with three accelerometers placed on the top, middle, and bottom of the sternum. A custom-built algorithm was developed to estimate heart rates (HRs) from ECG (HRECG) and SCG (HRSCG) signals. Moreover, SCG fiducial points and CTIs, including aortic valve opening and closure, R-R interval, preejection period, left ventricular ejection time, and electromechanical systole, were estimated from the SCG signals at different sternal locations. The average and correlation coefficient (R2) of the CTIs and HRs derived from all three locations were compared, along with the analysis of mean differences for the CTIs and their corresponding sensor locations. The results indicated strong correlations between HRECG and HRSCG, with average R2 values of 0.9930, 0.9968, and 0.9790 for the top, middle, and bottom sternal locations, respectively. Additionally, the study demonstrated that SCG-based CTIs varied depending on the SCG measurement locations. In conclusion, these findings underscore the importance of establishing consistent protocols for reporting CTIs based on SCG. Furthermore, they call for further investigation to compare estimated CTIs with gold-standard methods like echocardiography to identify the best SCG measurement location for accurate CTI estimations.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78502667","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}
Active needles obtain more significant tip deflection and improved accuracy over passive needles for percutaneous procedures. However, their ability to navigate through tissues to reach targets depends upon the actuation mechanism, the tip shape, and the surface geometry of the shaft. In this study, we investigate the benefits of changing the surface geometry of the active needle shaft in a) needle tip deflection and b) trajectory tracking during tissue insertion. The modifications in passive needle surface geometry have been proven to reduce friction force, tissue displacement, and tissue damage. This study incorporates the effect of modifying the regular smooth cannula with a mosquito proboscis-inspired design in the active needles. The changes in insertion force, tip deflection, and trajectory tracking control during insertion into a prostate-mimicking phantom are measured. Results show that insertion force is reduced by up to 10.67% in passive bevel-tip needles. In active needles, tip deflection increased by 12.91% at 150mm when the cannula is modified. The bioinspired cannula improved trajectory tracking error in the active needle by 39.00% while utilizing up to 17.65% lower control duty cycle. Improving tip deflection and tracking control would lead to better patient outcomes and reduced risk of complications during percutaneous procedures.
{"title":"Steering Control Improvement of Active Surgical Needle using Mosquito Proboscis-Inspired Cannula","authors":"Sharada Acharya, Doyoung Kim, P. Hutapea","doi":"10.1115/1.4063200","DOIUrl":"https://doi.org/10.1115/1.4063200","url":null,"abstract":"\u0000 Active needles obtain more significant tip deflection and improved accuracy over passive needles for percutaneous procedures. However, their ability to navigate through tissues to reach targets depends upon the actuation mechanism, the tip shape, and the surface geometry of the shaft. In this study, we investigate the benefits of changing the surface geometry of the active needle shaft in a) needle tip deflection and b) trajectory tracking during tissue insertion. The modifications in passive needle surface geometry have been proven to reduce friction force, tissue displacement, and tissue damage. This study incorporates the effect of modifying the regular smooth cannula with a mosquito proboscis-inspired design in the active needles. The changes in insertion force, tip deflection, and trajectory tracking control during insertion into a prostate-mimicking phantom are measured. Results show that insertion force is reduced by up to 10.67% in passive bevel-tip needles. In active needles, tip deflection increased by 12.91% at 150mm when the cannula is modified. The bioinspired cannula improved trajectory tracking error in the active needle by 39.00% while utilizing up to 17.65% lower control duty cycle. Improving tip deflection and tracking control would lead to better patient outcomes and reduced risk of complications during percutaneous procedures.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77371372","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 aorta is the largest artery in an animal body and is an important organ in the pulsatile flow regulation from the left ventricle. The mechanical and structural characteristics of the aortic media, which are primarily composed of smooth muscle cell layers (SMLs) and elastic laminae (ELs), have profound effects on the physiology and pathophysiology of the aorta. However, many aspects of the aortic tissue remain unknown due to the inherent layered wall structure and the regionally varying residual stresses. This study aimed to computationally represent EL buckling in the aortic medial ring at the unloaded state and reproduce the transmural variation in residual stresses and EL waviness across the vascular wall. A multiobjective optimization technique was applied to a series of simulations with the "unit" structure to obtain an idealized stress distribution throughout the aortic wall thickness. Hence, an appropriate boundary condition given to an initial reference configuration of the aortic ring was successfully identified. As a result, the average "idealized" residual stresses of SML and EL were on the order of 20 and -80 kPa, respectively, while EL waviness was ~1.01 in the unloaded state. Further, it was verified that the ring model with a radial cut will open spontaneously when the inner and outer layers of the medial wall are subjected to relative compressive and tensile residual stresses, respectively, in the unloaded state.
{"title":"Computational Modeling of an Aortic Medial Ring: Effect of Residual Stresses On a Mechanical Behavior of the Aortic Ring","authors":"A. Tamura, K. Matsumoto, Junichi Hongu","doi":"10.1115/1.4063140","DOIUrl":"https://doi.org/10.1115/1.4063140","url":null,"abstract":"\u0000 The aorta is the largest artery in an animal body and is an important organ in the pulsatile flow regulation from the left ventricle. The mechanical and structural characteristics of the aortic media, which are primarily composed of smooth muscle cell layers (SMLs) and elastic laminae (ELs), have profound effects on the physiology and pathophysiology of the aorta. However, many aspects of the aortic tissue remain unknown due to the inherent layered wall structure and the regionally varying residual stresses. This study aimed to computationally represent EL buckling in the aortic medial ring at the unloaded state and reproduce the transmural variation in residual stresses and EL waviness across the vascular wall. A multiobjective optimization technique was applied to a series of simulations with the \"unit\" structure to obtain an idealized stress distribution throughout the aortic wall thickness. Hence, an appropriate boundary condition given to an initial reference configuration of the aortic ring was successfully identified. As a result, the average \"idealized\" residual stresses of SML and EL were on the order of 20 and -80 kPa, respectively, while EL waviness was ~1.01 in the unloaded state. Further, it was verified that the ring model with a radial cut will open spontaneously when the inner and outer layers of the medial wall are subjected to relative compressive and tensile residual stresses, respectively, in the unloaded state.","PeriodicalId":73734,"journal":{"name":"Journal of engineering and science in medical diagnostics and therapy","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91329616","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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