Breast cancer detection and differentiation of breast tissues are critical for accurate diagnosis and treatment planning. This study addresses the challenge of distinguishing between invasive ductal carcinoma (IDC), normal glandular breast tissues (nGBT), and adipose tissue using electrical impedance spectroscopy combined with Gaussian relaxation-time distribution (EIS-GRTD). The primary objective is to investigate the relaxation-time characteristics of these tissues and their potential to differentiate between normal and abnormal breast tissues. We applied a single-point EIS-GRTD measurement to ten mastectomy specimens across a frequency range f = 4 Hz to 5 MHz. The method calculates the differential ratio of the relaxation-time distribution function ∆γ between IDC and nGBT, which is denoted by 〖∆γ〗^(IDC-nGBT), and ∆γ between IDC and adipose tissues, which is denoted by 〖∆γ〗^(IDC-adipose). As a result, the differential ratio of ∆γ between IDC and nGBT 〖∆γ〗^(IDC-nGBT) is 0.36, and between IDC and adipose 〖∆γ〗^(IDC-adipose) is 0.27, which included in the α-dispersion at τ^peak1= 0.033 ± 0.001 s. In all specimens, the relaxation-time distribution function γ of IDC γ^IDC is higher, and there is no intersection with γ of nGBT γ^nGBT and adipose γ^adipose. The difference in γ suggests potential variations in relaxation properties at the molecular or structural level within each breast tissue that contribute to the overall relaxation response. The average mean percentage error δ for IDC, nGBT, and adipose tissues are 5.90%, 6.33%, and 8.07%, respectively, demonstrating the model's accuracy and reliability. This study provides novel insights into the use of relaxation-time characteristic for differentiating breast tissue types, offering potential advancements in diagnosis methods. Future research will focus on correlating EIS-GRTD finding with pathological results from the same test sites to further validate the method's efficacy.
{"title":"Detection of Invasive Ductal Carcinoma by Electrical Impedance Spectroscopy Implementing Gaussian Relaxation-Time Distribution (EIS-GRTD).","authors":"Galih Setyawan,Kiagus Aufa Ibrahim,Ryoma Ogawa,Prima Asmara Sejati,Hiroshi Fujimoto,Hiroto Yamamoto,Masahiro Takei","doi":"10.1088/2057-1976/ad795f","DOIUrl":"https://doi.org/10.1088/2057-1976/ad795f","url":null,"abstract":"Breast cancer detection and differentiation of breast tissues are critical for accurate diagnosis and treatment planning. This study addresses the challenge of distinguishing between invasive ductal carcinoma (IDC), normal glandular breast tissues (nGBT), and adipose tissue using electrical impedance spectroscopy combined with Gaussian relaxation-time distribution (EIS-GRTD). The primary objective is to investigate the relaxation-time characteristics of these tissues and their potential to differentiate between normal and abnormal breast tissues. We applied a single-point EIS-GRTD measurement to ten mastectomy specimens across a frequency range f = 4 Hz to 5 MHz. The method calculates the differential ratio of the relaxation-time distribution function ∆γ between IDC and nGBT, which is denoted by 〖∆γ〗^(IDC-nGBT), and ∆γ between IDC and adipose tissues, which is denoted by 〖∆γ〗^(IDC-adipose). As a result, the differential ratio of ∆γ between IDC and nGBT 〖∆γ〗^(IDC-nGBT) is 0.36, and between IDC and adipose 〖∆γ〗^(IDC-adipose) is 0.27, which included in the α-dispersion at τ^peak1= 0.033 ± 0.001 s. In all specimens, the relaxation-time distribution function γ of IDC γ^IDC is higher, and there is no intersection with γ of nGBT γ^nGBT and adipose γ^adipose. The difference in γ suggests potential variations in relaxation properties at the molecular or structural level within each breast tissue that contribute to the overall relaxation response. The average mean percentage error δ for IDC, nGBT, and adipose tissues are 5.90%, 6.33%, and 8.07%, respectively, demonstrating the model's accuracy and reliability. This study provides novel insights into the use of relaxation-time characteristic for differentiating breast tissue types, offering potential advancements in diagnosis methods. Future research will focus on correlating EIS-GRTD finding with pathological results from the same test sites to further validate the method's efficacy.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194414","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}
Pub Date : 2024-09-11DOI: 10.1088/2057-1976/ad795c
Xu Bocheng,Rodrigo França
This paper reviews 3D bioprinting technologies and Bio-inks materials in brain neuroscience applications. The integration of 3D bioprinting technology in neuroscience research offers a unique platform to create complex brain and tissue architectures that mimic the mechanical, architectural, and biochemical properties of native tissues, providing a robust tool for modeling, repair, and drug screening applications. The review provides discussions and conclusions to highlight the current research, research gaps and recommendations for the future research on 3D bioprinting in neuroscience. The investigation shows that 3D bioprinting has a great potential to fabricate brain-like tissue constructs, holds great promise for regenerative medicine and drug testing models, offering new avenues for studying brain diseases and potential treatments. It is also found that the future of bioinks requires continuous improvement and innovation to meet the needs of applications in the field of neuroscience, aiming to improve the functionality and performance of bioink materials for neural tissue engineering.
.
{"title":"Innovative 3D bioprinting approaches for advancing brain science and medicine: a literature review.","authors":"Xu Bocheng,Rodrigo França","doi":"10.1088/2057-1976/ad795c","DOIUrl":"https://doi.org/10.1088/2057-1976/ad795c","url":null,"abstract":"This paper reviews 3D bioprinting technologies and Bio-inks materials in brain neuroscience applications. The integration of 3D bioprinting technology in neuroscience research offers a unique platform to create complex brain and tissue architectures that mimic the mechanical, architectural, and biochemical properties of native tissues, providing a robust tool for modeling, repair, and drug screening applications. The review provides discussions and conclusions to highlight the current research, research gaps and recommendations for the future research on 3D bioprinting in neuroscience. The investigation shows that 3D bioprinting has a great potential to fabricate brain-like tissue constructs, holds great promise for regenerative medicine and drug testing models, offering new avenues for studying brain diseases and potential treatments. It is also found that the future of bioinks requires continuous improvement and innovation to meet the needs of applications in the field of neuroscience, aiming to improve the functionality and performance of bioink materials for neural tissue engineering.
.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194242","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}
OBJECTIVEAdvancements in data science and assistive technologies have made invasive brain-computer interfaces (iBCIs) increasingly viable for enhancing the quality of life in physically disabled individuals. Intracortical micro-electrode implants are a common choice for such a communication system due to their fine temporal and spatial resolution. The small size of these implants makes the implantation plan critical for the successful exfiltration of information, particularly when targeting representations of task goals that lack robust anatomical correlates.APPROACHWorking memory processes including encoding, retrieval, and maintenance are observed in many areas of the brain. Using human electrocorticography recordings during a working memory experiment, we provide proof that it is possible to localize cognitive activity associated with the task and to identify key locations involved with executive memory functions.
Results. From the analysis, we could propose an optimal iBCI implant location with the desired features. The general approach is not limited to working memory but could also be used to map other goal-encoding factors such as movement intentions, decision-making, and visual-spatial attention.SIGNIFICANCEDeciphering the intended action of a BCI user is a complex challenge that involves the extraction and integration of cognitive factors such as movement planning, working memory, visual spatial attention, and the decision state. Examining local field potentials from ECoG electrodes while participants engaged in tailored cognitive tasks can pinpoint location with valuable information related to anticipated actions. This manuscript demonstrates the feasibility of identifying electrodes involved in cognitive activity related to working memory during user engagement in the NBack task. Devoting time in meticulous preparation to identify the optimal brain regions for BCI implant locations will increase the likelihood of rich signal outcomes, thereby improving the overall BCI user experience.
.
{"title":"Mapping cognitive activity from electrocorticography field potentials in humans performing NBack task.","authors":"Renee Johnston,Chadwick Boulay,Kai Miller,Adam Sachs","doi":"10.1088/2057-1976/ad795e","DOIUrl":"https://doi.org/10.1088/2057-1976/ad795e","url":null,"abstract":"OBJECTIVEAdvancements in data science and assistive technologies have made invasive brain-computer interfaces (iBCIs) increasingly viable for enhancing the quality of life in physically disabled individuals. Intracortical micro-electrode implants are a common choice for such a communication system due to their fine temporal and spatial resolution. The small size of these implants makes the implantation plan critical for the successful exfiltration of information, particularly when targeting representations of task goals that lack robust anatomical correlates.APPROACHWorking memory processes including encoding, retrieval, and maintenance are observed in many areas of the brain. Using human electrocorticography recordings during a working memory experiment, we provide proof that it is possible to localize cognitive activity associated with the task and to identify key locations involved with executive memory functions.
Results. From the analysis, we could propose an optimal iBCI implant location with the desired features. The general approach is not limited to working memory but could also be used to map other goal-encoding factors such as movement intentions, decision-making, and visual-spatial attention.SIGNIFICANCEDeciphering the intended action of a BCI user is a complex challenge that involves the extraction and integration of cognitive factors such as movement planning, working memory, visual spatial attention, and the decision state. Examining local field potentials from ECoG electrodes while participants engaged in tailored cognitive tasks can pinpoint location with valuable information related to anticipated actions. This manuscript demonstrates the feasibility of identifying electrodes involved in cognitive activity related to working memory during user engagement in the NBack task. Devoting time in meticulous preparation to identify the optimal brain regions for BCI implant locations will increase the likelihood of rich signal outcomes, thereby improving the overall BCI user experience.
.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194415","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}
Pub Date : 2024-09-11DOI: 10.1088/2057-1976/ad795b
Raffael Willmann,Michael Almeida,Erick Stoppa,Luís Barbisan,Jose R A Miranda,Guilherme Soares
In recent years, magnetic nanoparticles (MNPs) have exhibited theranostic characteristics which confer a wide range of applications in the biomedical field. Consequently, through Alternating Current Biosusceptometry (ACB), magnetic nanoparticles can be used as tracers, allowing the study of healthy and cirrhotic livers and providing the ability to differentiate them through the reconstruction of quantitative images. The ACB system consists of a developing biomagnetic technique that has the ability to magnetize and measure the magnetic susceptibility of a material such as MNPs, thereby offering quantitative information about biological systems with magnetic tracers.
.
{"title":"Evaluation and imaging of biodistribution of magnetic nanoparticles in a model of hepatic cirrhosis via Alternating Current Biosusceptometry.","authors":"Raffael Willmann,Michael Almeida,Erick Stoppa,Luís Barbisan,Jose R A Miranda,Guilherme Soares","doi":"10.1088/2057-1976/ad795b","DOIUrl":"https://doi.org/10.1088/2057-1976/ad795b","url":null,"abstract":"In recent years, magnetic nanoparticles (MNPs) have exhibited theranostic characteristics which confer a wide range of applications in the biomedical field. Consequently, through Alternating Current Biosusceptometry (ACB), magnetic nanoparticles can be used as tracers, allowing the study of healthy and cirrhotic livers and providing the ability to differentiate them through the reconstruction of quantitative images. The ACB system consists of a developing biomagnetic technique that has the ability to magnetize and measure the magnetic susceptibility of a material such as MNPs, thereby offering quantitative information about biological systems with magnetic tracers.
.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224932","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}
Pub Date : 2024-09-11DOI: 10.1088/2057-1976/ad795d
Felicia Aswathy W,Jiya Jose,E I Anila
This study describes the in-vitro cytotoxic effects of PEG-400 (Polyethylene glycol-400)-capped platinum nanoparticles (PEGylated Pt NPs) on both normal and cancer cell lines. Structural characterization was carried out using X-ray diffraction and Raman spectroscopy with an average crystallite size 5.7 nm, and morphological assessment using Scanning electron microscopy (SEM) revealed the presence of spherical platinum nanoparticles. The results of energy-dispersive X-ray spectroscopy (EDX) showed a higher percentage fraction of platinum content by weight, along with carbon and oxygen, which are expected from the capping agent, confirming the purity of the platinum sample. The dynamic light scattering experiment revealed an average hydrodynamic diameter of 353.6 nm for the PEGylated Pt NPs. The cytotoxicity profile of PEGylated Pt NPs was assessed on a normal cell line (L929) and a breast cancer cell line (MCF-7) using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results revealed an IC50 of 79.18 µg/ml on the cancer cell line and non-toxic behaviour on the normal cell line. In the dual staining apoptosis assay, it was observed that the mortality of cells cultured in conjunction with platinum nanoparticles intensified and the proliferative activity of MCF-7 cells gradually diminished over time in correlation with the increasing concentration of the PEGylated Pt NPs sample. The in vitro DCFH-DA assay for oxidative stress assessment in nanoparticle-treated cells unveiled the mechanistic background of the anticancer activity of PEGylated platinum nanoparticles as ROS-assisted mitochondrial dysfunction.
{"title":"Assessing Anticancer Properties of PEGylated Platinum Nanoparticles on Human Breast Cancer Cell lines using in-vitro Assays.","authors":"Felicia Aswathy W,Jiya Jose,E I Anila","doi":"10.1088/2057-1976/ad795d","DOIUrl":"https://doi.org/10.1088/2057-1976/ad795d","url":null,"abstract":"This study describes the in-vitro cytotoxic effects of PEG-400 (Polyethylene glycol-400)-capped platinum nanoparticles (PEGylated Pt NPs) on both normal and cancer cell lines. Structural characterization was carried out using X-ray diffraction and Raman spectroscopy with an average crystallite size 5.7 nm, and morphological assessment using Scanning electron microscopy (SEM) revealed the presence of spherical platinum nanoparticles. The results of energy-dispersive X-ray spectroscopy (EDX) showed a higher percentage fraction of platinum content by weight, along with carbon and oxygen, which are expected from the capping agent, confirming the purity of the platinum sample. The dynamic light scattering experiment revealed an average hydrodynamic diameter of 353.6 nm for the PEGylated Pt NPs. The cytotoxicity profile of PEGylated Pt NPs was assessed on a normal cell line (L929) and a breast cancer cell line (MCF-7) using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results revealed an IC50 of 79.18 µg/ml on the cancer cell line and non-toxic behaviour on the normal cell line. In the dual staining apoptosis assay, it was observed that the mortality of cells cultured in conjunction with platinum nanoparticles intensified and the proliferative activity of MCF-7 cells gradually diminished over time in correlation with the increasing concentration of the PEGylated Pt NPs sample. The in vitro DCFH-DA assay for oxidative stress assessment in nanoparticle-treated cells unveiled the mechanistic background of the anticancer activity of PEGylated platinum nanoparticles as ROS-assisted mitochondrial dysfunction.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194243","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}
Pub Date : 2024-09-11DOI: 10.1088/2057-1976/ad7960
Amir Rouhollahi,Milad Rismanian,Amin Ebrahimi,Olusegun J Ilegbusi,Farhad R Nezami
Freeze casting, a manufacturing technique widely applied in biomedical fields for fabricating biomaterial scaffolds, poses challenges for predicting directional solidification due to its highly nonlinear behavior and complex interplay of process parameters. Conventional numerical methods, such as computational fluid dynamics (CFD), require adequate and accurate boundary condition knowledge, limiting their utility in real-world transient solidification applications due to technical limitations. In this study, we address this challenge by developing a physics-informed neural networks (PINNs) model to predict directional solidification in freeze-casting processes. The PINNs model integrates physical constraints with neural network predictions, requiring significantly fewer predetermined boundary conditions compared to CFD. Through a comparison with CFD simulations, the PINNs model demonstrates comparable accuracy in predicting temperature distribution and solidification patterns. This promising model achieves such a performance with only 5000 data points in space and time, equivalent to 250,000 timesteps, showcasing its ability to predict solidification dynamics with high accuracy. The study's major contributions lie in providing insights into solidification patterns during freeze-casting scaffold fabrication, facilitating the design of biomaterial scaffolds with finely tuned microstructures essential for various tissue engineering applications. Furthermore, the reduced computational demands of the PINNs model offer potential cost and time savings in scaffold fabrication, promising advancements in biomedical engineering research and development.
{"title":"Prediction of directional solidification in freeze casting of biomaterial scaffolds using physics-informed neural networks.","authors":"Amir Rouhollahi,Milad Rismanian,Amin Ebrahimi,Olusegun J Ilegbusi,Farhad R Nezami","doi":"10.1088/2057-1976/ad7960","DOIUrl":"https://doi.org/10.1088/2057-1976/ad7960","url":null,"abstract":"Freeze casting, a manufacturing technique widely applied in biomedical fields for fabricating biomaterial scaffolds, poses challenges for predicting directional solidification due to its highly nonlinear behavior and complex interplay of process parameters. Conventional numerical methods, such as computational fluid dynamics (CFD), require adequate and accurate boundary condition knowledge, limiting their utility in real-world transient solidification applications due to technical limitations. In this study, we address this challenge by developing a physics-informed neural networks (PINNs) model to predict directional solidification in freeze-casting processes. The PINNs model integrates physical constraints with neural network predictions, requiring significantly fewer predetermined boundary conditions compared to CFD. Through a comparison with CFD simulations, the PINNs model demonstrates comparable accuracy in predicting temperature distribution and solidification patterns. This promising model achieves such a performance with only 5000 data points in space and time, equivalent to 250,000 timesteps, showcasing its ability to predict solidification dynamics with high accuracy. The study's major contributions lie in providing insights into solidification patterns during freeze-casting scaffold fabrication, facilitating the design of biomaterial scaffolds with finely tuned microstructures essential for various tissue engineering applications. Furthermore, the reduced computational demands of the PINNs model offer potential cost and time savings in scaffold fabrication, promising advancements in biomedical engineering research and development.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194245","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}
Pub Date : 2024-09-11DOI: 10.1088/2057-1976/ad7607
Qianhong Lu, Feng Luo, Juntian Shi and Kunyuan Xu
Objective. Cone beam CT (CBCT) typically has severe image artifacts and inaccurate HU values, which limits its application in radiation medicines. Scholars have proposed the use of cycle consistent generative adversarial network (Cycle-GAN) to address these issues. However, the generation quality of Cycle-GAN needs to be improved. This issue is exacerbated by the inherent size discrepancies between pelvic CT scans from different patients, as well as varying slice positions within the same patient, which introduce a scaling problem during training. Approach. We introduced the Enhanced Edge and Mask (EEM) approach in our structural constraint Cycle-EEM-GAN. This approach is designed to not only solve the scaling problem but also significantly improve the generation quality of the synthetic CT images. Then data from sixty pelvic patients were used to investigate the generation of synthetic CT (sCT) from CBCT. Main results. The mean absolute error (MAE), the root mean square error (RMSE), the peak signal to noise ratio (PSNR), the structural similarity index (SSIM), and spatial nonuniformity (SNU) are used to assess the quality of the sCT generated from CBCT. Compared with CBCT images, the MAE improved from 53.09 to 37.74, RMSE from 185.22 to 146.63, SNU from 0.38 to 0.35, PSNR from 24.68 to 32.33, SSIM from 0.624 to 0.981. Also, the Cycle-EEM-GAN outperformed Cycle-GAN in terms of visual evaluation and loss. Significance. Cycle-EEM-GAN has improved the quality of CBCT images, making the structural details clear while prevents image scaling during the generation process, so that further promotes the application of CBCT in radiotherapy.
{"title":"Synthetic CT generation from CBCT based on structural constraint cycle-EEM-GAN","authors":"Qianhong Lu, Feng Luo, Juntian Shi and Kunyuan Xu","doi":"10.1088/2057-1976/ad7607","DOIUrl":"https://doi.org/10.1088/2057-1976/ad7607","url":null,"abstract":"Objective. Cone beam CT (CBCT) typically has severe image artifacts and inaccurate HU values, which limits its application in radiation medicines. Scholars have proposed the use of cycle consistent generative adversarial network (Cycle-GAN) to address these issues. However, the generation quality of Cycle-GAN needs to be improved. This issue is exacerbated by the inherent size discrepancies between pelvic CT scans from different patients, as well as varying slice positions within the same patient, which introduce a scaling problem during training. Approach. We introduced the Enhanced Edge and Mask (EEM) approach in our structural constraint Cycle-EEM-GAN. This approach is designed to not only solve the scaling problem but also significantly improve the generation quality of the synthetic CT images. Then data from sixty pelvic patients were used to investigate the generation of synthetic CT (sCT) from CBCT. Main results. The mean absolute error (MAE), the root mean square error (RMSE), the peak signal to noise ratio (PSNR), the structural similarity index (SSIM), and spatial nonuniformity (SNU) are used to assess the quality of the sCT generated from CBCT. Compared with CBCT images, the MAE improved from 53.09 to 37.74, RMSE from 185.22 to 146.63, SNU from 0.38 to 0.35, PSNR from 24.68 to 32.33, SSIM from 0.624 to 0.981. Also, the Cycle-EEM-GAN outperformed Cycle-GAN in terms of visual evaluation and loss. Significance. Cycle-EEM-GAN has improved the quality of CBCT images, making the structural details clear while prevents image scaling during the generation process, so that further promotes the application of CBCT in radiotherapy.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194412","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}
Pub Date : 2024-09-10DOI: 10.1088/2057-1976/ad78e3
Robson Rodrigues da Silva,Gabriel Marcos de Sousa Motta,Matheus Leonardo Alves de Camargo,Daniel Gustavo Goroso,José Luis Puglisi
This study addresses the Force - Frequency relationship, a fundamental characteristic of cardiac muscle influenced by β1-adrenergic stimulation. This relationship reveals that heart rate (HR) changes at the sinoatrial node lead to alterations in ventricular cell contractility, increasing the force and decreasing relaxation time for higher beat rates. Traditional models lacking this relationship offer an incomplete physiological depiction, impacting the interpretation of in silico experiment results. To improve this, we propose a new mathematical model for ventricular myocytes, named "Feed Forward Modeling" (FFM).
Methods:
FFM adjusts model parameters like channel conductance and Ca2+pump affinity according to stimulation frequency, in contrast to fixed parameter values. An empirical sigmoid curve guided the adaptation of each parameter, integrated into a rabbit ventricular cell electromechanical model. Model validation was achieved by comparing simulated data with experimental current-voltage (I-V) curves for L-type Calcium and slow Potassium currents.
Results:
FFM-enhanced simulations align more closely with physiological behaviors, accurately reflecting inotropic and lusitropic responses. For instance, action potential duration at 90% repolarization (APD90) decreased from 206 ms at 1 Hz to 173 ms at 4 Hz using FFM, contrary to the conventional model, where APD90 increased, limiting high-frequency heartbeats. Peak force also showed an increase with FFM, from 8.5 mN/mm2at 1 Hz to 11.9 mN/mm2at 4 Hz, while it barely changed without FFM. Relaxation time at 50% of maximum force (t50) similarly improved, dropping from 114 ms at 1 Hz to 75.9 ms at 4 Hz with FFM, a change not observed without the model.
Conclusion:
The FFM approach offers computational efficiency, bypassing the need to model all beta-adrenergic pathways, thus facilitating large-scale simulations. The study recommends that frequency change experiments include fractional dosing of isoproterenol to better replicate heart conditions in vivo.
.
{"title":"Feed Forward modeling: An efficient approach for mathematical modeling of the force frequency relationship in the rabbit isolated ventricular myocyte.","authors":"Robson Rodrigues da Silva,Gabriel Marcos de Sousa Motta,Matheus Leonardo Alves de Camargo,Daniel Gustavo Goroso,José Luis Puglisi","doi":"10.1088/2057-1976/ad78e3","DOIUrl":"https://doi.org/10.1088/2057-1976/ad78e3","url":null,"abstract":"
This study addresses the Force - Frequency relationship, a fundamental characteristic of cardiac muscle influenced by β1-adrenergic stimulation. This relationship reveals that heart rate (HR) changes at the sinoatrial node lead to alterations in ventricular cell contractility, increasing the force and decreasing relaxation time for higher beat rates. Traditional models lacking this relationship offer an incomplete physiological depiction, impacting the interpretation of in silico experiment results. To improve this, we propose a new mathematical model for ventricular myocytes, named \"Feed Forward Modeling\" (FFM).
Methods:
FFM adjusts model parameters like channel conductance and Ca2+pump affinity according to stimulation frequency, in contrast to fixed parameter values. An empirical sigmoid curve guided the adaptation of each parameter, integrated into a rabbit ventricular cell electromechanical model. Model validation was achieved by comparing simulated data with experimental current-voltage (I-V) curves for L-type Calcium and slow Potassium currents.
Results:
FFM-enhanced simulations align more closely with physiological behaviors, accurately reflecting inotropic and lusitropic responses. For instance, action potential duration at 90% repolarization (APD90) decreased from 206 ms at 1 Hz to 173 ms at 4 Hz using FFM, contrary to the conventional model, where APD90 increased, limiting high-frequency heartbeats. Peak force also showed an increase with FFM, from 8.5 mN/mm2at 1 Hz to 11.9 mN/mm2at 4 Hz, while it barely changed without FFM. Relaxation time at 50% of maximum force (t50) similarly improved, dropping from 114 ms at 1 Hz to 75.9 ms at 4 Hz with FFM, a change not observed without the model.
Conclusion:
The FFM approach offers computational efficiency, bypassing the need to model all beta-adrenergic pathways, thus facilitating large-scale simulations. The study recommends that frequency change experiments include fractional dosing of isoproterenol to better replicate heart conditions in vivo.
.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194247","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}
Pub Date : 2024-09-10DOI: 10.1088/2057-1976/ad7608
Vinyas, Subraya Krishna Bhat, Hiroshi Yamada and N Shyamasunder Bhat
Low back pain is a serious health concern prevalent in majority of the people around the world, especially in case of the elderly. The root cause for this is mostly observed to be the development of lesions/ tears complemented by degenerative effects in the intervertebral disc of L4-L5 and L5-S1 segments. This study aims to analyse the effects of disc degeneration and tears on the mechanical responses of the L5-S1 spinal unit, which has not been investigated. The annulus is represented by an anisotropic hyperelastic Gasser-Ogden-Holzapfel (GOH) model wherein the effect of degeneration is defined by varying the constants responsible for the behaviour of the material in different strain-ranges. A systematic approach is proposed for modelling the effects of disc degeneration in the annulus. Further, the commonly found anterior circumferential tear is modelled to understand its combined effects with degeneration of the annulus. The damaging effect of the tear was limited only to extension movement, causing critical stress variations in its vicinity. However, degeneration had a significant influence on both stress and range of motion of the spinal unit across all types of movements. This study highlights the complex relationship of the physiological movements with pathogenesis of tear and degeneration leading to discogenic pain thus enabling clinicians to develop conservative treatment strategies for specific age groups.
{"title":"In-silico study on cumulative effects of degeneration and anterior circumferential annular tear on the L5-S1 spinal unit","authors":"Vinyas, Subraya Krishna Bhat, Hiroshi Yamada and N Shyamasunder Bhat","doi":"10.1088/2057-1976/ad7608","DOIUrl":"https://doi.org/10.1088/2057-1976/ad7608","url":null,"abstract":"Low back pain is a serious health concern prevalent in majority of the people around the world, especially in case of the elderly. The root cause for this is mostly observed to be the development of lesions/ tears complemented by degenerative effects in the intervertebral disc of L4-L5 and L5-S1 segments. This study aims to analyse the effects of disc degeneration and tears on the mechanical responses of the L5-S1 spinal unit, which has not been investigated. The annulus is represented by an anisotropic hyperelastic Gasser-Ogden-Holzapfel (GOH) model wherein the effect of degeneration is defined by varying the constants responsible for the behaviour of the material in different strain-ranges. A systematic approach is proposed for modelling the effects of disc degeneration in the annulus. Further, the commonly found anterior circumferential tear is modelled to understand its combined effects with degeneration of the annulus. The damaging effect of the tear was limited only to extension movement, causing critical stress variations in its vicinity. However, degeneration had a significant influence on both stress and range of motion of the spinal unit across all types of movements. This study highlights the complex relationship of the physiological movements with pathogenesis of tear and degeneration leading to discogenic pain thus enabling clinicians to develop conservative treatment strategies for specific age groups.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194413","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}
Pub Date : 2024-09-10DOI: 10.1088/2057-1976/ad78e2
Filip Samal,Vojtech Cerny,Petr Kujal,Jakub Jezek,Jiri Skala-Rosenbaum,Josef Sepitka
This study aimed to characterize the mechanical properties of native human ligamentum flavum (LF) and correlate them with histopathological changes. Mechanical property gradients across the cranial, medial, and caudal regions of LF were mapped and compared with histological sections. We also compared lumbar spinal stenosis (LSS) samples with disc herniation (DH) samples as reference material to identify differences in mechanical properties and histopathological features. Our results revealed significant heterogeneity in LF mechanical properties, with local variations correlating with specific histopathological changes such as chondroid metaplasia and loss of elastic fibers. These findings underscore the importance of considering LF heterogeneity in mechanical characterization and provide insights into its behavior under pathological conditions.
{"title":"Distribution of mechanical properties of native human ligamentum flavum depending on histopathological changes.","authors":"Filip Samal,Vojtech Cerny,Petr Kujal,Jakub Jezek,Jiri Skala-Rosenbaum,Josef Sepitka","doi":"10.1088/2057-1976/ad78e2","DOIUrl":"https://doi.org/10.1088/2057-1976/ad78e2","url":null,"abstract":"This study aimed to characterize the mechanical properties of native human ligamentum flavum (LF) and correlate them with histopathological changes. Mechanical property gradients across the cranial, medial, and caudal regions of LF were mapped and compared with histological sections. We also compared lumbar spinal stenosis (LSS) samples with disc herniation (DH) samples as reference material to identify differences in mechanical properties and histopathological features. Our results revealed significant heterogeneity in LF mechanical properties, with local variations correlating with specific histopathological changes such as chondroid metaplasia and loss of elastic fibers. These findings underscore the importance of considering LF heterogeneity in mechanical characterization and provide insights into its behavior under pathological conditions.","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194244","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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