Publications by authors named "Seungjun Ryu"

This paper analyzes the regulatory frameworks for artificial intelligence/machine learning AI/ML-enabled medical devices in the European Union (EU), the United States (US), and the Republic of Korea, with a focus on applications in spine surgery. The aim is to provide guidance for developers and researchers navigating regulatory pathways. A review of current literature, regulatory documents, and legislative frameworks was conducted.

View Article and Find Full Text PDF

This study proposes modeling methodology based on a continuous model for conducting thermo-electric-structural analyses of V-NAND flash memory structure under the Joule heating effect. The modeling methodology is based on a homogeneous method for investigating the thermal mechanical characteristics of a V-NAND flash memory structure. Firstly, theoretical formulation of thermo-electric behavior with Joule heating effect is presented by energy balance equation, Watt's law.

View Article and Find Full Text PDF

Neuromodulation therapy using chemogenetic stimulation has shown potential in enhancing motor recovery and neuroregeneration following spinal cord injury (SCI). These therapeutic benefits are hypothesized to result from the promotion of neuroplasticity, particularly when administered during the acute phase of injury. In this study, we investigated the effects of chemogenetic stimulation using Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) in conjunction with clozapine, a ligand for receptor activation.

View Article and Find Full Text PDF

Background: Comparative studies of posterior lumbar interbody fusion with cortical bone trajectory and pedicle screw in older patients, particularly in those aged ≥ 80 years, are rare. This study aimed to retrospectively analyze the clinical and surgical outcomes following posterior lumbar interbody fusion with pedicle screw fixation compared to cortical bone trajectory in patients aged ≥ 80 years with degenerative lumbar spine disease.

Methods: We included 68 patients aged ≥ 80 years who underwent degenerative lumbar spinal surgery at our spine center between January 2011 and December 2020.

View Article and Find Full Text PDF
Article Synopsis
  • - The study investigates how preoperative musculoskeletal health affects postoperative leg pain in elderly patients with lumbar spinal stenosis (LSS), focusing on differences between men and women.
  • - Data from the STRATEGY-SS cohort revealed that for female patients, arm and calf circumferences were linked to the severity of leg pain a year after surgery, while no preoperative factors predicted pain for males.
  • - The findings stress the importance of tailored preoperative evaluations for both sexes and suggest that improving musculoskeletal health, particularly in women, could lead to better surgical outcomes.
View Article and Find Full Text PDF
Article Synopsis
  • Increasing evidence shows that frontal channel EEG signals can effectively measure pain using advanced analysis techniques like spectral analysis and phase-amplitude coupling.
  • A study analyzed EEG data from 36 chronic pain patients to find correlations between EEG features (like asymmetry in brain wave power) and clinical pain scores, revealing significant links with certain EEG characteristics.
  • The best machine learning model, Support Vector Regression with a polynomial kernel, successfully predicted pain intensity, highlighting the relevance of complex EEG features in understanding and objectively measuring pain for better clinical intervention.
View Article and Find Full Text PDF

This cadaveric study aimed to evaluate the safety and usability of a novel robotic system for posterior cervical pedicle screw fixation. Three human cadaveric specimens and C2-T3 were included. Freshly frozen human cadaver specimens were prepared and subjected to robot-assisted posterior cervical pedicle screw fixation using the robotic system.

View Article and Find Full Text PDF

Objective: Computed tomography (CT) imaging is a cornerstone in the assessment of patients with spinal trauma and in the planning of spinal interventions. However, CT studies are associated with logistical problems, acquisition costs, and radiation exposure. In this proof-of-concept study, the feasibility of generating synthetic spinal CT images using biplanar radiographs was explored.

View Article and Find Full Text PDF

Objective: Virtual and augmented reality have enjoyed increased attention in spine surgery. Preoperative planning, pedicle screw placement, and surgical training are among the most studied use cases. Identifying osseous structures is a key aspect of navigating a 3-dimensional virtual reconstruction.

View Article and Find Full Text PDF

Objective: The risks of nonunion and subsidence are high in patients with bone density loss undergoing spinal fusion surgery. The internal application of recombinant human bone morphogenic protein 2 (rhBMP-2) in an interbody cage improves spinal fusion; however, related complications have been reported. Denosumab, a human monoclonal antibody targeting the receptor activator of nuclear factor kappa B ligand (RANKL), hinders osteoblast differentiation and function.

View Article and Find Full Text PDF

Background: Work-Family Conflict means that the demands of work and family roles cannot be met simultaneously, so one cannot concentrate on one's work or family role. This conflict can negatively affect mental health and cause insomnia symptoms.

Methods: This study was conducted on 20,442 subjects.

View Article and Find Full Text PDF

This study investigates the long-term outcomes of clival chordoma patients treated with the endonasal transclival approach (ETCA) and early adjuvant radiation therapy. A retrospective review of 17 patients (2002-2013) showed a 10-year progression-free survival (PFS) rate of 67.4%, with the ETCA group showing fewer progressions and cranial neuropathies than those treated with combined approaches.

View Article and Find Full Text PDF

In an anterior cervical discectomy and fusion (ACDF), various types of graft materials including autograft, allograft, and synthetic graft have been used to achieve adequate spinal fusion. Allograft spacer is mainly used in cervical fusion, especially in the anterior approach. The synthetic bone graft material BGS-7(CaO-SiO2-P2O5-B2O3, bioactive Glass-Ceramics) can bind with surrounding bone tissue by forming a hydroxyapatite layer bone bridge, leading to faster graft osseointegration.

View Article and Find Full Text PDF

To determine the major risk factors for unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) and their interactions, using machine learning-based prediction algorithms and game theory. Patients who underwent surgery for ASD, with a minimum of two-year follow-up, were retrospectively reviewed. In total, 210 patients were included and randomly allocated into training (70% of the sample size) and test (the remaining 30%) sets to develop the machine learning algorithm.

View Article and Find Full Text PDF

Objective: This study aimed to investigate the efficacy of transverse process (TP) hook system at the upper instrumented vertebra (UIV) for preventing screw pullout in adult spinal deformity surgery using the pedicle Hounsfield unit (HU) stratification based on K-means clustering.

Methods: We retrospectively reviewed 74 patients who underwent deformity correction surgery between 2011 and 2020 and were followed up for >12 months. Pre- and post-operative data were used to determine the incidence of screw pullout, UIV TP hook implementation, vertebral body HU, pedicle HU, and patient outcomes.

View Article and Find Full Text PDF

Long-term disabilities induced by stroke impose a heavy burden on patients, families, caregivers, and public health systems. Extensive studies have demonstrated the therapeutic value of neuromodulation in enhancing post-stroke recovery. Among them, chemogenetic neuromodulation activated by clozapine-N-oxide (CNO) has been proposed as the potential tool of neuromodulation.

View Article and Find Full Text PDF
Article Synopsis
  • Seizures are common emergencies in neonatal intensive care and are typically identified through EEG reports, but existing detection algorithms are often inaccurate.
  • A new machine learning algorithm was developed using EEG recordings from 79 neonates, allowing for effective seizure detection with a significant improvement in accuracy (ROC score of 0.91) and efficiency (using only 5 seconds for decision-making).
  • The algorithm's performance indicates strong potential for clinical use in various environments, including NICUs and even at home, due to its reliance on a single-channel EEG.
View Article and Find Full Text PDF

Clozapine (CLZ) has been proposed as an agonist for Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), to replace Clozapine-N-oxide (CNO); however, there are no reliable guidelines for the use of CLZ for chemogenetic neuromodulation. We titrated the optimal dose of CLZ required to evoke changes in neural activity whilst avoiding off-target effects. We also performed [F]Fluoro-deoxy-glucose micro positron emission tomography (FDG-microPET) scans to determine the global effect of CLZ-induced hM3D(Gq) DREADD activation in the rat brain.

View Article and Find Full Text PDF

This paper proposed a classification framework that integrates hybrid multivoxel pattern analyses (MVPA) and extreme learning machine (ELM) for automated Mild Cognitive Impairment (MCI) diagnosis applied on concatenations of multi-biomarker resting-state fMRI. Given three-dimensional (3D) regional coherences and functional connectivity patterns measured during resting state, we performed 3D univariate t-tests to obtain initial univariate features which show the significant changes. To enhance discriminative patterns, we employed multivariate feature reductions using recursive feature elimination in combination with univariate t-test.

View Article and Find Full Text PDF

We performed this research to 1) evaluate a novel deep learning method for the diagnosis of Alzheimer's disease (AD) and 2) jointly predict the Mini Mental State Examination (MMSE) scores of South Korean patients with AD. Using resting-state functional Magnetic Resonance Imaging (rs-fMRI) scans of 331 participants, we obtained functional 3-dimensional (3-D) independent component spatial maps for use as features in classification and regression tasks. A 3-D convolutional neural network (CNN) architecture was developed for the classification task.

View Article and Find Full Text PDF

: To perform automatic assessment of dementia severity using a deep learning framework applied to resting-state functional magnetic resonance imaging (rs-fMRI) data. : We divided 133 Alzheimer's disease (AD) patients with clinical dementia rating (CDR) scores from 0.5 to 3 into two groups based on dementia severity; the groups with very mild/mild (CDR: 0.

View Article and Find Full Text PDF

Background: Early diagnosis of Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI) is essential for timely treatment. Machine learning and multivariate pattern analysis (MVPA) for the diagnosis of brain disorders are explicitly attracting attention in the neuroimaging community. In this paper, we propose a voxel-wise discriminative framework applied to multi-measure resting-state fMRI (rs-fMRI) that integrates hybrid MVPA and extreme learning machine (ELM) for the automated discrimination of AD and MCI from the cognitive normal (CN) state.

View Article and Find Full Text PDF