1.Prediction of Sleep Disorder From Actigraphy Data Using Deep Learning
Kyoungmin KIM ; Jeongho PARK ; Soonhyun YOOK ; Ho Sung KIM ; Eun Yeon JOO
Journal of Sleep Medicine 2024;21(2):73-79
Objectives:
The aim of this study was to classify polysomnography (PSG)-based sleep disorders using actigraphy data using a convolutional neural network (CNN).
Methods:
Actigraphy data, PSG data, and diagnoses were obtained from 214 patients from a single-center sleep clinic. Patients diagnosed with circadian sleep disorders, narcolepsy, or periodic limb movement disorders were excluded. From the actigraphy data, three types of data were selected from the first 5 days, namely, sleep-wake status, activity count, and light exposure per epoch. The data were processed into a two-dimensional array with four instances, namely, 24-hour full-day data and data for 6, 8, and 10 hours timepoints after sleep onset, and then analyzed. Using a CNN, we attempted to classify the processed data into PSG-based diagnoses.
Results:
Overfitting of the training data was observed. The CNN showed near-perfect accuracy on the test data, but failed to classify the validation data (area under the curve: 24-hour full-day data: 0.6031, 6 hours after sleep onset: 0.5148, 8 hours: 0.6122, and 10 hours: 0.5769).
Conclusions
The lack and inaccuracy of data were responsible for the results. A higher sampling rate and additional ancillary data, such as PSG or heart rate variability data, are necessary for accurate classification. Additionally, alternative approaches to machine learning, such as transformers, should be considered in future studies.
2.Prediction of Sleep Disorder From Actigraphy Data Using Deep Learning
Kyoungmin KIM ; Jeongho PARK ; Soonhyun YOOK ; Ho Sung KIM ; Eun Yeon JOO
Journal of Sleep Medicine 2024;21(2):73-79
Objectives:
The aim of this study was to classify polysomnography (PSG)-based sleep disorders using actigraphy data using a convolutional neural network (CNN).
Methods:
Actigraphy data, PSG data, and diagnoses were obtained from 214 patients from a single-center sleep clinic. Patients diagnosed with circadian sleep disorders, narcolepsy, or periodic limb movement disorders were excluded. From the actigraphy data, three types of data were selected from the first 5 days, namely, sleep-wake status, activity count, and light exposure per epoch. The data were processed into a two-dimensional array with four instances, namely, 24-hour full-day data and data for 6, 8, and 10 hours timepoints after sleep onset, and then analyzed. Using a CNN, we attempted to classify the processed data into PSG-based diagnoses.
Results:
Overfitting of the training data was observed. The CNN showed near-perfect accuracy on the test data, but failed to classify the validation data (area under the curve: 24-hour full-day data: 0.6031, 6 hours after sleep onset: 0.5148, 8 hours: 0.6122, and 10 hours: 0.5769).
Conclusions
The lack and inaccuracy of data were responsible for the results. A higher sampling rate and additional ancillary data, such as PSG or heart rate variability data, are necessary for accurate classification. Additionally, alternative approaches to machine learning, such as transformers, should be considered in future studies.
3.Prediction of Sleep Disorder From Actigraphy Data Using Deep Learning
Kyoungmin KIM ; Jeongho PARK ; Soonhyun YOOK ; Ho Sung KIM ; Eun Yeon JOO
Journal of Sleep Medicine 2024;21(2):73-79
Objectives:
The aim of this study was to classify polysomnography (PSG)-based sleep disorders using actigraphy data using a convolutional neural network (CNN).
Methods:
Actigraphy data, PSG data, and diagnoses were obtained from 214 patients from a single-center sleep clinic. Patients diagnosed with circadian sleep disorders, narcolepsy, or periodic limb movement disorders were excluded. From the actigraphy data, three types of data were selected from the first 5 days, namely, sleep-wake status, activity count, and light exposure per epoch. The data were processed into a two-dimensional array with four instances, namely, 24-hour full-day data and data for 6, 8, and 10 hours timepoints after sleep onset, and then analyzed. Using a CNN, we attempted to classify the processed data into PSG-based diagnoses.
Results:
Overfitting of the training data was observed. The CNN showed near-perfect accuracy on the test data, but failed to classify the validation data (area under the curve: 24-hour full-day data: 0.6031, 6 hours after sleep onset: 0.5148, 8 hours: 0.6122, and 10 hours: 0.5769).
Conclusions
The lack and inaccuracy of data were responsible for the results. A higher sampling rate and additional ancillary data, such as PSG or heart rate variability data, are necessary for accurate classification. Additionally, alternative approaches to machine learning, such as transformers, should be considered in future studies.
4.Surgical Treatment of Patients with Abdominal Aortic Aneurysm.
KyoungMin RYU ; Pil Won SEO ; Seong Sik PARK ; Jae Wook RYU ; Seok Kon KIM ; Wook Ki LEE
The Korean Journal of Thoracic and Cardiovascular Surgery 2009;42(3):331-336
BACKGROUND: Open surgical repair of abdominal aortic aneurysms was initiated by Dubost in 1952. Despite the rapid expansion of percutaneous endovascular repair, open surgical repair is still recognized for curative intent. We retrospectively analyzed surgical outcome, complications, and mortality-related factors for patients with abdominal aortic aneurysms over a 6 year period. MATERIAL AND METHOD: We analyzed 18 patients who underwent surgery for abdominal aortic aneurysms between March 2002 and March 2008. The indications for surgery were rupture, a maximal aortic diameter >60 mm, medically intractable hypertension, or pain. RESULT: The mean age was 66.6+/-9.3 years (range, 49~81 years). Twelve patients (66.7%) were males and 6 patients were females. Extension of the aneurysm superior to the renal artery existed in 6 patients (33.3%), and extension to the iliac artery existed in 13 patients (72.2%). Five patients (27.8%) had ruptured aortic aneurysms. The mean maximal diameter of the aorta was 72.2+/-12.9 mm (range, 58~109 mm). Surgery was performed by a midline laparotomy, and 6 patients underwent emergency surgery. The mean total ischemic time from aorta clamping to revascularization was 82+/-42 minutes (range, 35~180 minutes). The mortality rate was 16.7%; the mortality rate for patients with ruptured aneurysms was 60%, and the mortality rate for patients with unruptured aneurysms was 0%. The postoperative complications included one each of renal failure, femoral artery and vein occlusion, and wound infection. The patients who were discharged had a long-term survival of 34+/-26 months (range, 4~90 months). Rupture and emergency surgery had a statistically significant mortality-related factor (p<0.05). CONCLUSION: Emergency surgery for ruptured aortic aneurysms continues to have a high mortality, but unruptured cases are repaired with relative safety. Successfully operated patients had long-term survival. Even though endovascular aortic repair is the trend for abdominal aortic aneurysms, aggressive application should be determined with care. Experience and systemic support of each center is important in the treatment plan
Aneurysm
;
Aneurysm, Ruptured
;
Aorta
;
Aorta, Abdominal
;
Aortic Aneurysm, Abdominal
;
Aortic Rupture
;
Constriction
;
Emergencies
;
Female
;
Femoral Artery
;
Humans
;
Hypertension
;
Iliac Artery
;
Laparotomy
;
Male
;
Postoperative Complications
;
Renal Artery
;
Renal Insufficiency
;
Retrospective Studies
;
Rupture
;
Veins
;
Wound Infection
5.Real-world Experience of Improvement in the Survival of Lymphoma and Myeloma Patients with Autologous Stem Cell Transplantation over a 25-year Period
Hyungwoo CHO ; Shin KIM ; Kyoungmin LEE ; Jung Sun PARK ; Cheolwon SUH
Korean Journal of Medicine 2021;96(6):501-511
Background/Aims:
The first autologous peripheral blood stem cell transplantation (ASCT) in Korea was performed for a small-cell lung cancer patient at Asan Medical Center (AMC) in 1993. Recently, lymphoma and myeloma have been the main indications; there has been progress in the treatments for these lymphoid malignancies. We explored the real-world experience of ASCT for lymphoma and myeloma at AMC over a 25-year period.
Methods:
We used the AMC ASCT registry, which has collected ASCT data prospectively since January 1993. Data for Hodgkin lymphoma, non-Hodgkin lymphoma, and multiple myeloma patients were analyzed. Patients transplanted up to December 2018 were included to assess adequate survival data. The ASCT time period was divided arbitrarily into 1994-1999, 2000-2009, and 2010-2018. In cases of multiple myeloma, we analyzed the 1st ASCT data only.
Results:
Survival of these lymphoid malignancy patients after ASCT has progressively improved. The increase in survival may be related to advances in various medical skills supporting ASCT. However, overall survival has improved much more than progression-free survival. This suggests that better salvage therapies after ASCT failure have mainly affected the improvement in overall survival. The hematopoietic cell transplantation-specific comorbidity index could not be used as a survival indicator in this analysis.
Conclusions
This real-world experience study showed that the survival of lymphoid malignancy patients treated with ASCT has improved over the past 25 years.
6.Single-Center Real-World Experience of Multiple Myeloma in the 21st Century
Hyungwoo CHO ; Shin KIM ; Kyoungmin LEE ; Eun Hee KANG ; Jung Sun PARK ; Cheolwon SUH
Korean Journal of Medicine 2022;97(2):125-140
Background/Aims:
The incidence of multiple myeloma (MM) in Korea is rapidly increasing. The diagnostic criteria of MM have been updated and novel therapeutic agents are available. This study explored the features of MM patients registered at Asan Medical Center (AMC) and the outcomes over the past 15 years.
Methods:
Data were obtained from the AMC MM registry, which has been collecting the data of MM patients prospectively. The 774 MM patients included in our analysis were diagnosed from 2003, when thalidomide became available as a novel therapeutic agent, until April 2019. The 2-year survival rate of these patients was assessed. Patients were divided into two groups based on whether they were older or younger than 65 years, which is the cutoff age for the indication of autologous stem cell transplantation. Patients were also grouped according to the year of diagnosis: up to 2006, when bortezomib became available, and up to 2010, when the cost of lenalidomide was reimbursed.
Results:
Patients < 65 years of age had better prognostic features, including a better performance, less advanced disease stage, and fewer abnormalities in their fluorescent in-situ hybridization (FISH) analysis results. A comparison of our Korean patients with patients registered in the Myeloma Related Disorder Registry data of Australia and New Zealand, showed ethnic discrepancies. The median overall survival of all patients was 3.7 years, with a 5-year survival rate of 41.8% and a 10-year survival rate of 23.4%. Survival progressively improved in patients diagnosed later. Age, performance status, renal function, C-reactive protein level, lactate dehydrogenase level, and cytogenetic findings were identified as significant prognostic factors.
Conclusions
This real-world survey revealed the clinical features and survival rates of patients at a tertiary Korean Hospital who were diagnosed with MM at the beginning of 21st century.
7.Pyrazinamide-Induced Urticaria and Angioedema: a Case Report.
Yewon KANG ; Jieun KANG ; Kyoungmin LEE ; Dae Hyun JEONG ; Soomin NOH ; Bomi SEO ; Tae Bum KIM
Korean Journal of Medicine 2018;93(3):306-310
Pyrazinamide (PZA) is an anti-tuberculosis drug and an essential component of the standard four-drug regimen for tuberculosis. Here, we report a case of immediate angioedema secondary to PZA administration intended for pulmonary tuberculosis treatment. A previously healthy 48-year-old woman was diagnosed with pulmonary tuberculosis and tuberculous lymphadenitis. Thirty minutes after taking the first dose of isoniazid, rifampicin, pyrazinamide, and ethambutol, the patient developed facial edema, generalized rash, and dizziness. An oral provocation test was performed on the four drugs, and 1,000 mg pyrazinamide showed a positive result characterized by 50 minutes of urticaria, angioedema, and hypotension. As the prevalence of tuberculosis increases, prescriptions for anti-tuberculosis drugs may increase as well. Clinicians should be aware of the possibility of immediate hypersensitivity as well as delayed hypersensitivity to anti-tuberculosis drugs.
Angioedema*
;
Dizziness
;
Drug Hypersensitivity
;
Edema
;
Ethambutol
;
Exanthema
;
Female
;
Humans
;
Hypersensitivity, Delayed
;
Hypersensitivity, Immediate
;
Hypotension
;
Isoniazid
;
Middle Aged
;
Prescriptions
;
Prevalence
;
Pyrazinamide
;
Rifampin
;
Tuberculosis
;
Tuberculosis, Lymph Node
;
Tuberculosis, Pulmonary
;
Urticaria*
8.Establishing Regional Aβ Cutoffs andExploring Subgroup Prevalence Across Cognitive Stages Using BeauBrain Amylo®
Seongbeom PARK ; Kyoungmin KIM ; Soyeon YOON ; Seongmi KIM ; Jehyun AHN ; Kyoung Yoon LIM ; Hyemin JANG ; Duk L. NA ; Hee Jin KIM ; Seung Hwan MOON ; Jun Pyo KIM ; Sang Won SEO ; Jaeho KIM ; Kichang KWAK
Dementia and Neurocognitive Disorders 2025;24(2):135-146
Background:
and Purpose: Amyloid-beta (Aβ) plaques are key in Alzheimer’s disease (AD), with Aβ positron emission tomography imaging enabling non-invasive quantification.To address regional Aβ deposition, we developed regional Centiloid scales (rdcCL) and commercialized them through the computed tomography (CT)-based BeauBrain Amylo platform, eliminating the need for three-dimensional T1 magnetic resonance imaging (MRI).
Objective:
We aimed to establish robust regional Aβ cutoffs using the commercialized BeauBrain Amylo platform and to explore the prevalence of subgroups defined by global, regional, and striatal Aβ cutoffs across cognitive stages.
Methods:
We included 2,428 individuals recruited from the Korea-Registries to Overcome Dementia and Accelerate Dementia Research project. We calculated regional Aβ cutoffs using Gaussian Mixture Modeling. Participants were classified into subgroups based on global, regional, and striatal Aβ positivity across cognitive stages (cognitively unimpaired [CU], mild cognitive impairment, and dementia of the Alzheimer’s type).
Results:
MRI-based and CT-based global Aβ cutoffs were highly comparable and consistent with previously reported Centiloid values. Regional cutoffs revealed both similarities and differences between MRI- and CT-based methods, reflecting modality-specific segmentation processes. Subgroups such as global(−)regional(+) were more frequent in non-dementia stages, while global(+)striatal(−) was primarily observed in CU individuals.
Conclusions
Our study established robust regional Aβ cutoffs using a CT-based rdcCL method and demonstrated its clinical utility in classifying amyloid subgroups across cognitive stages. These findings highlight the importance of regional Aβ quantification in understanding amyloid pathology and its implications for biomarker-guided diagnosis and treatment in AD.
9.Establishing Regional Aβ Cutoffs andExploring Subgroup Prevalence Across Cognitive Stages Using BeauBrain Amylo®
Seongbeom PARK ; Kyoungmin KIM ; Soyeon YOON ; Seongmi KIM ; Jehyun AHN ; Kyoung Yoon LIM ; Hyemin JANG ; Duk L. NA ; Hee Jin KIM ; Seung Hwan MOON ; Jun Pyo KIM ; Sang Won SEO ; Jaeho KIM ; Kichang KWAK
Dementia and Neurocognitive Disorders 2025;24(2):135-146
Background:
and Purpose: Amyloid-beta (Aβ) plaques are key in Alzheimer’s disease (AD), with Aβ positron emission tomography imaging enabling non-invasive quantification.To address regional Aβ deposition, we developed regional Centiloid scales (rdcCL) and commercialized them through the computed tomography (CT)-based BeauBrain Amylo platform, eliminating the need for three-dimensional T1 magnetic resonance imaging (MRI).
Objective:
We aimed to establish robust regional Aβ cutoffs using the commercialized BeauBrain Amylo platform and to explore the prevalence of subgroups defined by global, regional, and striatal Aβ cutoffs across cognitive stages.
Methods:
We included 2,428 individuals recruited from the Korea-Registries to Overcome Dementia and Accelerate Dementia Research project. We calculated regional Aβ cutoffs using Gaussian Mixture Modeling. Participants were classified into subgroups based on global, regional, and striatal Aβ positivity across cognitive stages (cognitively unimpaired [CU], mild cognitive impairment, and dementia of the Alzheimer’s type).
Results:
MRI-based and CT-based global Aβ cutoffs were highly comparable and consistent with previously reported Centiloid values. Regional cutoffs revealed both similarities and differences between MRI- and CT-based methods, reflecting modality-specific segmentation processes. Subgroups such as global(−)regional(+) were more frequent in non-dementia stages, while global(+)striatal(−) was primarily observed in CU individuals.
Conclusions
Our study established robust regional Aβ cutoffs using a CT-based rdcCL method and demonstrated its clinical utility in classifying amyloid subgroups across cognitive stages. These findings highlight the importance of regional Aβ quantification in understanding amyloid pathology and its implications for biomarker-guided diagnosis and treatment in AD.
10.Establishing Regional Aβ Cutoffs andExploring Subgroup Prevalence Across Cognitive Stages Using BeauBrain Amylo®
Seongbeom PARK ; Kyoungmin KIM ; Soyeon YOON ; Seongmi KIM ; Jehyun AHN ; Kyoung Yoon LIM ; Hyemin JANG ; Duk L. NA ; Hee Jin KIM ; Seung Hwan MOON ; Jun Pyo KIM ; Sang Won SEO ; Jaeho KIM ; Kichang KWAK
Dementia and Neurocognitive Disorders 2025;24(2):135-146
Background:
and Purpose: Amyloid-beta (Aβ) plaques are key in Alzheimer’s disease (AD), with Aβ positron emission tomography imaging enabling non-invasive quantification.To address regional Aβ deposition, we developed regional Centiloid scales (rdcCL) and commercialized them through the computed tomography (CT)-based BeauBrain Amylo platform, eliminating the need for three-dimensional T1 magnetic resonance imaging (MRI).
Objective:
We aimed to establish robust regional Aβ cutoffs using the commercialized BeauBrain Amylo platform and to explore the prevalence of subgroups defined by global, regional, and striatal Aβ cutoffs across cognitive stages.
Methods:
We included 2,428 individuals recruited from the Korea-Registries to Overcome Dementia and Accelerate Dementia Research project. We calculated regional Aβ cutoffs using Gaussian Mixture Modeling. Participants were classified into subgroups based on global, regional, and striatal Aβ positivity across cognitive stages (cognitively unimpaired [CU], mild cognitive impairment, and dementia of the Alzheimer’s type).
Results:
MRI-based and CT-based global Aβ cutoffs were highly comparable and consistent with previously reported Centiloid values. Regional cutoffs revealed both similarities and differences between MRI- and CT-based methods, reflecting modality-specific segmentation processes. Subgroups such as global(−)regional(+) were more frequent in non-dementia stages, while global(+)striatal(−) was primarily observed in CU individuals.
Conclusions
Our study established robust regional Aβ cutoffs using a CT-based rdcCL method and demonstrated its clinical utility in classifying amyloid subgroups across cognitive stages. These findings highlight the importance of regional Aβ quantification in understanding amyloid pathology and its implications for biomarker-guided diagnosis and treatment in AD.