The gradient field, one of the core magnetic fields in magnetic resonance imaging (MRI) systems, is generated by gradient coils and plays a critical role in spatial encoding and the generation of echo signals. The uniformity or linearity of the gradient field directly impacts the quality and distortion level of MRI images. However, traditional point measurement methods lack accuracy in assessing the linearity of gradient fields, making it difficult to provide effective parameters for image distortion correction. This paper introduced a spherical measurement-based method that involved measuring the magnetic field distribution on a sphere, followed by detailed magnetic field calculations and linearity analysis. This study, applied to assess the nonlinearity of asymmetric head gradient coils, demonstrated more comprehensive and precise results compared to point measurement methods. This advancement not only strengthens the scientific basis for the design of gradient coils but also provides more reliable parameters and methods for the accurate correction of MRI image distortions.
Magnetic Resonance Imaging/instrumentation* ; Humans ; Image Processing, Computer-Assisted/methods* ; Nonlinear Dynamics ; Magnetic Fields ; Algorithms ; Phantoms, Imaging

The emergence of new-generation artificial intelligence technology has brought numerous innovations to the healthcare field, including telemedicine and intelligent care. However, the artificial intelligent medical device sector still faces significant challenges, such as data privacy protection and algorithm reliability. This study, based on invention patent analysis, revealed the technological innovation trends in the field of artificial intelligent medical devices from aspects such as patent application time trends, hot topics, regional distribution, and innovation players. The results showed that global invention patent applications had remained active, with technological innovations primarily focused on medical image processing, physiological signal processing, surgical robots, brain-computer interfaces, and intelligent physiological parameter monitoring technologies. The United States and China led the world in the number of invention patent applications. Major international medical device giants, such as Philips, Siemens, General Electric, and Medtronic, were at the forefront of global technological innovation, with significant advantages in patent application volumes and international market presence. Chinese universities and research institutes, such as Zhejiang University, Tianjin University, and the Shenzhen Institute of Advanced Technology, had demonstrated notable technological innovation, with a relatively high number of patent applications. However, their overseas market expansion remained limited. This study provides a comprehensive overview of the technological innovation trends in the artificial intelligent medical device field and offers valuable information support for industry development from an informatics perspective.
Artificial Intelligence ; Patents as Topic ; Humans ; Inventions ; China ; Brain-Computer Interfaces ; Telemedicine ; Equipment and Supplies ; Robotics ; Algorithms

The rapid development of artificial intelligence technology is driving profound changes in medical practice, particularly in the field of medical device application. Based on data from the U.S. clinical trials registry, this study analyzes the global registration landscape of clinical trials involving artificial intelligence-based medical devices, aiming to provide a reference for their clinical research and application. A total of 2 494 clinical trials related to artificial intelligence medical devices have been registered worldwide, with participation from 66 countries or regions. The United States leads with 908 trials, while for other countries or regions, including China, each has fewer than 300 trials. Germany, the United States, and Belgium serve as central hubs for international collaboration. Among the sponsors, 63.96% are universities or hospitals, 22.36% are enterprises, and the remainder includes individuals, government agencies and others. Of all trials, 79.99% are interventional studies, 94.67% place no restrictions on participant gender, and 69.69% exclude children. The targeted diseases are primarily neurological and mental disorders. This study systematically reveals the global distribution characteristics and research trends of artificial intelligence medical device clinical trials, offering valuable data support and practical insights for advancing international collaboration, resource allocation, and policy development in this field.
Artificial Intelligence ; Humans ; Clinical Trials as Topic/statistics & numerical data* ; Equipment and Supplies ; Registries ; United States

Objective To investigate the clinical effects and pregnancy outcomes of using luteal phase long protocol and GnRH antagonist protocol in patients with polycystic ovary syndrome(PCOS)who have failed their first GnRH antagonist protocol therapy.Methods The clinical data of 163 PCOS patients who underwent IVF/ICSI-ET were retrieved.After the failure of their first GnRH antagonist protocol treatment,they were divided into two groups in the second controlled ovarian hyperstimulation(COH)cycle:Luteal phase long protocol group(n=95)and Gn-RH antagonist protocol group(n=68).A retrospective analysis and comparison of basic clinical data,clinical and laboratory indicators,and pregnancy outcomes between two groups were conducted.Results ① There was no sta-tistically significant difference in basic clinical indicators between two group except LH.② Compared the first and second cycle treatments of patients in the luteal phase long protocol group,the initiation dose of gonadotropin(Gn),total number of Gn days,total Gn usage,estradiol(E2)on the day of hCG injection,number of retrieved eggs,oocyte maturation rate,2PN fertilization rate,2PN cleavage rate,blastocyst formation rate,high-quality blas-tocyst formation rate,and moderate to severe OHSS rate were significantly higher than those in the first GnRH an-tagonist cycle(P＜0.05).The GnRH antagonist protocol group also showed similar improvements.③ The com-parison of the second COH cycle between two groups showed that the total number of Gn days,total Gn usage,and total Gn cost in the luteal phase long protocol group were significantly higher(P＜0.05),while the E2 and LH on the day of hCG injection,and the maturation rate of eggs were significantly lower than those in the GnRH antagonist protocol group(P＜0.05).However,there was no statistically significant difference in the number of retrieved eggs,2PN fertilization,2PN cleavage,blastocyst formation rate,high-quality blastocyst formation rate,and OHSS rate between the two groups;④ The comparison of fresh transplantation cycles for the second COH cycle between the two groups showed that the luteal phase long protocol fresh transplantation rate,implantation rate,clinical preg-nancy rate,and live birth rate were slightly higher than those of the GnRH antagonist protocol group,but the differ-ence was not statistically significant.Comparing the outcomes of pregnancy following the initial frozen-thawed em-bryo transfer(FET)between two groups,the biochemical pregnancy rate and clinical pregnancy rate of the GnRH antagonist protocol group were higher than those of the luteal phase long protocol group(P＜0.05).However,no significant statistical variations were found in implantation rate,live birth rate,neonatal gestational age,and birth weight.Conclusion For PCOS patients who fail the first GnRH antagonist protocol,an appropriate increase in the initiating dose and usage of Gn can achieve satisfactory pregnancy outcomes with both protocols.Compared with change to a luteal phase long protocol,reusing the GnRH antagonist protocol still maintains its long-standing advan-tages,such as shorter total Gn days,lower costs,and better patient compliance.

Objective To investigate the application value of single nucleotide polymorphism(SNP)linkage analysis based on next-generation sequencing(NGS)technology in preimplantation genetic testing(PGT)of families with autosomal recessive polycystic kidney disease(ARPKD).Methods A family with ARPKD was selected,where the female member had a pregnancy ultrasound revealing polycystic kidney in the fetus.Genetic testing showed compound heterozygous mutations of the polycystic kidney/polycystic liver disease 1 gene(PKHD1),c.10444C>T(paternal)and c.4303del(maternal),with the c.4303del mutation being reported for the first time.Targeting the coding region of the PKHD1 gene,335 high-density tightly linked SNP sites were selected in the upstream and downstream 2M regions using multiplex polymerase chain reaction(PCR)and NGS.The couple′s SNP risk haplotypes carrying gene mutations were constructed.After in vitro fertilization,blastocyst culture was performed.Trophoblastic cells obtained from the biopsy were subjected to whole-genome amplification,and NGS was used for linkage analysis and low-depth chromosomal aneuploidy screening of the embryos.Sanger sequencing was used to verify the results of embryo linkage analysis.Results Among the 6 biopsied embryos,4 were mutation-free and euploid,1 exhibited heterozygous for the mutation and mosaic while another unstable sequencing data,making it impossible to judge.One of the mutation-free and developmentally healthy euploid embryos was implanted into the maternal uterus,resulting in the full-term delivery of a healthy baby.Conclusion Application of NGS-based SNP linkage analysis in PGT can effectively blocking the vertical transmission of ARPKD within families,while avoiding abortion issues caused by aneuploid embryos.This study is also the first PGT report target-ing the PKHD1 gene c.4303del mutation.

The gastrointestinal tract is an extremely complex ecosystem,and a healthy and intact intestinal mucosal barrier is the basic defense against the translocation of harmful substances.The impaired function of the intestinal barrier in acute-on-chronic liver failure(ACLF)is further aggravated by the dysregulation of intestinal microecology,which leads to bacterial translocation and endotoxemia.Maintaining the normal function of the intestinal mucosal barrier is important for the treatment of ACLF.This paper reviews the function of the normal intestinal mucosal barrier,the relationship between the damaged intestinal barrier and ACLF,and the impact of the damaged intestinal barrier on ACLF progression.

Objective : To analyze the data related to the clinical outcome of preimplantation genetic testing (PGT) for double frozen , double biopsied blastocysts and double frozen , once biopsied blastocysts , in order to expand the existing data and provide some guidance for the clinical value and safety of PGT for frozen⁃thawed embryos . Methods : Retrospective analysis was made on the 38 PGT cycles of frozen⁃thawed blastocysts . According to the frequency of biopsy , cases in the study were divided into two groups : double frozen , double biopsy ( DFDB) group and double frozen , single biopsy ( DFSB) group . The freezing method was vitrification . Results : There were 24 patients in DFDB group , 34 blastocysts were not diagnosed in the last PGT cycle , 32 blastocysts survived after thawing , and the survival rate of thawed blastocysts was 94. 12% . After the second biopsy of these 32 blastocysts , genetic testing was performed , and all of them were definitely diagnosed , including 15 normal blastocysts (46. 88% ) and 17 abnormal blastocysts (53 . 13% ) . There were 14 patients in DFSB . The remaining 50 blastocysts in the last ICSI cycle were thawed and all blastocysts survived after thawing . Biopsy of these 50 blastocysts and genetic analysis showed that 47 blastocysts were diagnosed , including 9 normal blastocysts (18 . 00% ) , 28 abnormal blastocysts (56. 00% ) , 10 mosaic blastocysts (20. 00% ) , and 3 undiagnosed blastocysts (6. 00% ) . In DFDB group and DFSB group , 8 patients and 5 patients transferred the normal blastocystswhich all survivedafter thawing . There were 5 clinical pregnancies and 3 clinical pregnancies , respectively . One healthy live birth was obtained respectively in each group . Conclusion Acceptable pregnancy rate can be obtained whatever DFSB or DFDB blastocyst , which is of clinical value . However , due to the small sample size , we need to expand the sample size to further explore its safety .

Objective : To develop a prediction model for live birth based on the basic characters of patients after transcervical resection of adhesions (TCRA) undergoing frozen⁃thawed embryo transfer (F⁃ET) . Methods : A total of 491 cycles who went F ⁃ET after TCRA were included. The cycles were randomly divided into training (n = 347) and validation (n = 144) cohorts at 7 ∶ 3 ratio. Relevant factors of live birth were selected via logistic regression analysis based on the data from patients in the training cohort. Multivariate logistic regression analysis was used to establish a nomogram , and then this predict model was calibrated and verified. Results : Age , body mass index (BMI) , miscarriages and endometrial thickness were significantly related to the live birth. The statistical nomogram was built with the area under the ROC cu2rve for the training cohort was 0. 713 (95% CI: 0. 519 - 0. 815) , Hosmer⁃Lemeshow goodness of fit test were χ = 7. 062 , P = 0. 530 , and the slope of calibration curve was close to 1. AUC of validation cohort was 0. 609 (95% CI: 0. 660 - 0. 561) , presenting a well⁃pleasing goodness⁃of⁃fit and stability in this model. Conclusion Age , BMI , miscarriages and endometrial thickness can better predict the probability of live birth undergoing F ⁃ET after TCRA.

Objective To explore the technology frontiers for neuroblastoma treatment from the perspective of patent citation network. Methods Through patent analysis for neuroblastoma treatment, highly cited patents and highly cited papers in the citation network were taken as the research objects. The title and abstract of the citing patents were analyzed by text clustering to identify the technology frontiers. Through social network analysis, the core patents were identified from the indices of degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality. Results A total of 6240 patent applications for neuroblastoma treatment were found, including 71304 patent citations and 88698 journal-article citations. Four technology frontiers were identified based on patent citation network, namely, drug target, drug design, tumor-indication expansion, and gene-expression regulation. Three technology frontiers were identified based on journal-article citation network. They were drug target, drug design, and tumor-indication expansion. Conclusion The development of technology for neuroblastoma treatment continues to be active. Drug target and drug design are the most important technology frontiers. This study could provide certain reference for neuroblastoma treatment from the perspective of information science.

Objective:By building a COVID-19 related scientific research progress monitoring system, to mitigate the information needs of different stakeholders such as government decision-makers, enterprises and scientific research institutions, provide reference for global scientific research progress monitoring for possible public health emergencies in the future.Methods:Literature review and expert consultation were adopted to systematically sort out the data sources of journal papers, preprints and other scientific papers, formed their respective monitoring catalogs and determined the tracking path.Results:COVID-19-related papers mainly include journal papers and preprints. The data source monitoring range of journal papers includes the official websites of top journals in biomedical and natural sciences, the database Web of Science and Science Direct, and the monitoring scope of the preprint platform includes medRxiv, bioRxiv, and SSRN, etc. In addition, the virological websites virological and nextstrain should also be monitored.Conclusions:COVID-19-related scientific research progress monitoring system can be used for daily monitoring to provide support for decision-making and deployment of prevention and control work.