Texture Analysis of Supraspinatus Ultrasound Image for Computer Aided Diagnostic System / 대한의료정보학회지

OBJECTIVES: In this paper, we proposed an algorithm for recognizing a rotator cuff supraspinatus tendon tear using a texture analysis based on a histogram, gray level co-occurrence matrix (GLCM), and gray level run length matrix (GLRLM). METHODS: First, we applied a total of 57 features (5 first order descriptors, 40 GLCM features, and 12 GLRLM features) to each rotator cuff region of interest. Our results show that first order statistics (mean, skewness, entropy, energy, smoothness), GLCM (correlation, contrast, energy, entropy, difference entropy, homogeneity, maximum probability, sum average, sum entropy), and GLRLM features are helpful to distinguish a normal supraspinatus tendon and an abnormal supraspinatus tendon. The statistical significance of these features is verified using a t-test. The support vector machine classification showed accuracy using feature combinations. Support Vector Machine offers good performance with a small amount of training data. Sensitivity, specificity, and accuracy are used to evaluate performance of a classification test. RESULTS: From the results, first order statics features and GLCM and GLRLM features afford 95%, 85%, and 100% accuracy, respectively. First order statistics and GLCM and GLRLM features in combination provided 100% accuracy. Combinations that include GLRLM features had high accuracy. GLRLM features were confirmed as highly accurate features for classified normal and abnormal. CONCLUSIONS: This algorithm will be helpful to diagnose supraspinatus tendon tear on ultrasound images.

Working Memory Deficits in Ultra-High Risk for Psychosis and Schizophrenia / 대한정신분열병학회지

OBJECTIVES: The aim of this study was to investigate whether verbal and spatial working memory functions were impaired not only in patients with schizophrenia but also in people at ultra-high risk for first-episode psychosis. METHODS: Twenty-five patients (M 13, F 12) with schizophrenia (SPR), 21 people at ultra-high risk for psychosis (UHR)(M 10, F 11) and 19 normal controls (NC)(M 10, F 9) were recruited. The working memory was assessed by using the verbal and spatial n-back test. The working memory load increased incrementally from the 0-back to the 3-back condition. RESULTS: SPR performed significantly lower than NC and UHR in terms of hit rates of verbal and spatial n-back test. UHR subjects conducted significantly lower than NC and higher in trend-level than SPR in terms of hit rates of verbal and spatial n-back test. These differences were derived from the high working memory load (2-back and 3-back), not from the low working memory load (0-back and 1-back). There was no significant difference between the verbal and spatial n-back test across the three groups. CONCLUSION: These findings suggest that verbal and spatial working memory dysfunction may be general rather than differential in terms of stimuli modality, and this working memory deficit may be an important trait factor in schizophrenia.

Integrated Solution for Physical Activity Monitoring Based on Mobile Phone and PC / 대한의료정보학회지

OBJECTIVES: This study is part of the ongoing development of treatment methods for metabolic syndrome (MS) project, which involves monitoring daily physical activity. In this study, we have focused on detecting walking activity from subjects which includes many other physical activities such as standing, sitting, lying, walking, running, and falling. Specially, we implemented an integrated solution for various physical activities monitoring using a mobile phone and PC. METHODS: We put the iPod touch has built in a tri-axial accelerometer on the waist of the subjects, and measured change in acceleration signal according to change in ambulatory movement and physical activities. First, we developed of programs that are aware of step counts, velocity of walking, energy consumptions, and metabolic equivalents based on iPod. Second, we have developed the activity recognition program based on PC. iPod synchronization with PC to transmit measured data using iPhoneBrowser program. Using the implemented system, we analyzed change in acceleration signal according to the change of six activity patterns. RESULTS: We compared results of the step counting algorithm with different positions. The mean accuracy across these tests was 99.6 +/- 0.61%, 99.1 +/- 0.87% (right waist location, right pants pocket). Moreover, six activities recognition was performed using Fuzzy c means classification algorithm recognized over 98% accuracy. In addition we developed of programs that synchronization of data between PC and iPod for long-term physical activity monitoring. CONCLUSIONS: This study will provide evidence on using mobile phone and PC for monitoring various activities in everyday life. The next step in our system will be addition of a standard value of various physical activities in everyday life such as household duties and a health guideline how to select and plan exercise considering one's physical characteristics and condition.

Electro-Mechanical Safety Testing of Portable ECG Devices for Home Healthcare Usage / 대한의료정보학회지

OBJECTIVES: This paper suggests the experimental guidelines to evaluate the electro-mechanical safety of belt type equipment. The electro-mechanical safety was determined by using the International Electrotechnical Commission guidelines, which are widely used as important factors for assessing the electro-mechanical safety of belt type equipment. However, the local guidelines on wearable healthcare sensors are currently not well-established. Therefore, safety guidelines suited for the actual circumstances in Korea are required, and this paper attempts to try a new experimental safety test procedure of the wearable healthcare sensor. METHODS: This belt type device measures the electrocardiogram (ECG) and heart rates by attaching to the chest. Examination lists were selected by analyzing the common standards ofelectro-mechanical safety (IEC 60601-1) and environment tests (IEC 60068-1, IEC 60068-2) of home-healthcare equipment. RESULTS: The essential electrical safety, which was required for the RS300G3 as a medical device, was evaluated, and most of the examination lists were selected by considering the circumstances of the users. The device passed all the selected examinable lists that are applicable to the Korean environment. CONCLUSIONS: This study has limitations to estimate and to conduct electro-mechanical safety experiments because our study focused on the belt type of heart-rates equipment. We are not taking into account the overall electro-mechanical home-healthcare measurements. According to industrial and technological development, there are infinite possibilities for the advancement of home-healthcare equipment, so more examination lists for safety are being added in addition to what we have done.

Non-linear Analysis of Single Electroencephalography (EEG) for Sleep-Related Healthcare Applications / 대한의료정보학회지

OBJECTIVES: Soft-computing techniques are commonly used to detect medical phenomena and to help with clinical diagnoses and treatment. The purpose of this paper is to analyze the single electroencephalography (EEG) signal with the chaotic methods in order to identify the sleep stages. METHODS: Data acquisition (polysomnography) was performed on four healthy young adults (all males with a mean age of 27.5 years). The evaluated algorithm was designed with a correlation dimension and Lyapunov's exponent using a single EEG signal that detects differences in chaotic characteristics. RESULTS: The change of the correlation dimension and the largest Lyapunov exponent over the whole night sleep EEG was performed. The results show that the correlation dimension and largest Lyapunov exponent decreased from light sleep to deep sleep and they increased during the rapid eye movement stage. CONCLUSIONS: These results suggest that chaotic analysis may be a useful adjunct to linear (spectral) analysis for identifying sleep stages. The single EEG based nonlinear analysis is suitable for u-healthcare applications for monitoring sleep.

Ubiquitous-Severance Hospital Project: Implementation and Results / 대한의료정보학회지

OBJECTIVES: The purpose of this study was to review an implementation of u-Severance information system with focus on electronic hospital records (EHR) and to suggest future improvements. METHODS: Clinical Data Repository (CDR) of u-Severance involved implementing electronic medical records (EMR) as the basis of EHR and the management of individual health records. EHR were implemented with service enhancements extending to the clinical decision support system (CDSS) and expanding the knowledge base for research with a repository for clinical data and medical care information. RESULTS: The EMR system of Yonsei University Health Systems (YUHS) consists of HP integrity superdome servers using MS SQL as a database management system and MS Windows as its operating system. CONCLUSIONS: YUHS is a high-performing medical institution with regards to efficient management and customer satisfaction; however, after 5 years of implementation of u-Severance system, several limitations with regards to expandability and security have been identified.

Performance Test of Web Based 3D Medical Image System using Image Streaming Technique / 대한의료정보학회지

OBJECTIVE: It is still the important subject that 3D visualizing of medical images to help patient diagnose. There were many challenges for fast 3D visualization but it has some limitations that volume rendering without high price's hardware and software. Some techniques through the web were suggested to construct high quality's 3D visualization even though it was an only poor personal computer. This technique could share the volume rendering board and diagnose 3D images together. However there are some problems to construct web based 3D visualization. These are network delay, optimized visualization and security etc. The purpose of this paper was to visualize and control the 3D medical image having a high quality on the web. METHODS: To construct this system, we used mainly three tools which were VolumePro1000 board, WMV9(Windows Media Video 9 Codec) and socket functions based on TCP(Transmission Control Protocol). VolumePro1000 board could calculate quickly heavy matrixes of 3D images using phong's shading and shear-warp factorization. WMV9 was able to compress efficiently live images and to apply image streaming technique. Socket functions based on TCP transmitted messages to control the 3D images. RESULTS: We developed 3D visualization system and evaluated about image qualities and transmission conditions of different compression rates on unfixed network condition. CONCLUSION: It was big advantages that WMV9 encoder could decode automatically in many platforms(desk top, PDA, notebook, cellular phone, etc) without installing specific decoding programs if they only have Windows Media player. We expect 3D visualization system to be utilized various biomedical fields such as IIGS(Interactive Image Guided Surgery), CAD(Computer Aided Diagnosis) and Tele-medicine technologies.

A Size Change of Bone Defect Area after Autogenous Calvarial Bone Graft

Calvarial bone grafting in craniomaxillofacial trauma and facial reconstructive surgery is now widely recognized and accepted as a standard procedure. One of the commonly reported problems of calvarial bone graft is the contour defect caused by partial resorption of the graft. But, there are few reports that discuss the fate of the calvarial bone graft based on the quantitative data. In this article, the changes of grafted calvarial bone were evaluated using 3-dimensional computed tomography(CT). 9 patients were observed with the CT scans at 2mm thickness immediately after operation and at the time of last follow-up. The area of the bone defect was segmented on the 3-dimensional CT image and calculated by AnalyzeDirect 5.0 software. The immediate postoperative bone defect area of the recipient site and the donor site were 612.9mm2 and 441.5mm2, respectively, which became 1028.1mm2 and 268.8mm2, respectively at the last follow-up. In conclusion, the bone defect area was less increased on the donor site of calvarial bone graft than on the recipient site. And the CT scan is a valuable imaging method to assess and follow-up the clinical outcome of calvarial bone grafting.

Bone Growth after Distraction Osteogenesis in Patients with Craniosynostosis

The pathogenesis of craniosynostosis is the early bone fusion of the sutures. Conventional treatment focused on creating a bony gap in which distraction osteogenesis could be a contradictive procedure. There are few reports on the long-term follow-up of distraction in craniosynostosis and into the continuity of bone tissue. This study was performed to investigate if this continuity of the regenerated bone tissue, which can possibly have inhibitory potentials for bone growth, affects growth after distraction osteogenesis with long- term follow-up results. For the study, the authors realigned all CT scans into a same position using a software program using landmarks from the image for comparison in terms of growth ratio for patients with craniosynostosis. From January 2000 to October 2002, the authors performed distraction osteogenesis on 5 patients with craniosynostosis. Three patients had unilateral coronal craniosynostotis and 2 with unilambdoidal craniosynostosis. The follow-up period was from 13 months to 33 months after full distraction. 3D CT images were obtained preoperatively, after full distraction and at the last follow-up. The result was that the regenerated calvarial bone seems to grow in the same growth ratio as the normal side up to 2 years on follow-up in the patient with unilateral craniosynostosis. According to these results, we conclude that the regenerated bone grows as normal bone even after distraction osteogenesis.

Automatic Simulation Surgery Process of the 3D Computed Tomographic Data in the Unilateral Orbital Hypoplasia

Computer-assisted medical imaging has shown tremendous improvements in definition of in vivo anatomy of patients with craniofacial anomalies. In accordance with developments of simulation surgery, preoperative surgical simulation can now be performed more accurately and interactively within the environment of computer graphic workstation and can also provide the best solution for surgery by displaying the 3 dimensional simulation images. The interactive surgical simulation approach is based on digitally osteotomized objects which have been translocated manually by an operator who visually determines the amount of movement required until the desired end result is achieved. However, this approach depends upon subjective assessment and may not consistently provide optimal simulation in all directions due to manual movement of the osteotomized object by mouse or trackball. In addition, this procedure is time and labor intensive due to repetitive processing to obtain a satisfactory end result. This study demonstrates a method of surface matching of digitally osteotomized objects, by simulating the deformed orbit to the assumed ideal position of mirror image without manual manipulation of simulation objects. This process can move the osteotomized object to the preset end results-mirror image- automatically by computer module. The single processing of the osteotomized segment changes the position of simulated segments with certainty. This procedure allows more accurate and reliable result of simulation surgery. However, it will be valuable only when one can determine the ideal end results such as mirror image of this article as a normal template.

Significance of the Position of the Craniofacial Computed Tomographic Scanning

The computer imaging process is becoming a popular procedure in the research of the craniofacial skeleton. In acquisition of the digital data of computer tomography (CT), the position of the head is likely to vary each time. The difference in head position results in different orientations on actual images, which in turn may result in misinterpretation of the image. The purpose of this study is to point out the importance of position alignment between CT databases before pursuing research by comparing the images of different position alignment To show the significance of the alignment of CT scan, eleven target points were selected from CT scan and the coordinates were obtained from the different position of the aligned CT scan by the nasion, basion, and bilateral external auditory meatus. The target points were divided into three groups-the central points, the lateral points, and the mid points groups, depending on their positional configuration from the mid- sagittal plane. The alignment of CT scan was processed by volume rendering method and the coordinates of target points were taken from the three dimensional images with different position. The aligned CT images rotated by 10 degrees with respect to the X-axis, the (X- and Y-axes), and the (X-, Y-, and Z axes), respectively. Eleven target points were measured from these rotated images one per day, for 10 days, by a plastic surgeon. The mean coordinates from the 10 trials were defined as the gold standard values for the other 10 times measurement. The measurement error(ME) of the central points group was lower than that of the mid points group, and the ME of the mid points group was lower than that of the lateral points group. The ME increased as the distance from the center to target point increased. However the ME of aligned CT images was the lowest of all the rotated cases. For the mean ME of the 11 points, aligned image, the X-axis(X- and Y-axes), and (X-, Y-, and Z-axes) rotation were 0.97, 1.53, 1.62 and 1.77 mm, respectively. Among three rotated cases, ME of the(X-, Y-, and Z-axes) rotation had the highest one. Above results mean that the chance of incorrectly localizing the target points could be significantly reduced if the skull CT images were aligned, in the research of the measurement of craniofacial skeleton from CT scan.

Multiagent System using Data Mining Technique for the Management of Asthma in Mobile Computing Environments / 대한의료정보학회지

OBJECTIVE: In the mobile computing environments, doctors or patients with mobile devices can access services at any time, any place. It makes chronic diseases, such as asthma care successively and in long-term. This paper presents a new multiagent system using data mining technique for the management of asthma in mobile computing environments. METHODS: In mobile computing environments, mobile communication is prone to disconnection. To use the services when disconnected, we locally store the recommendation information in mobile devices. Then, when user reconnects network, the new information is delivered in mobile devices. Because mobile devices have a limitation of resource, we store only patterns and recent data. We adopted data mining technique from the large pool of accumulated patients data can be utilized to summarize observed correlations and trends. RESULTS: We propose multiagent system composed of a Pattern Agent, a Selection Agent and a Recommendation Agent. They make asthmatic-caring system access effectively in mobile computing environments. We describe the underlying architecture and the process. Then we make a prototype with asthmatic patients data in the Severance Hospital in Korea. CONCLUSION: The results of our study can be contributed to aid management of asthma in mobile computing environments.

Prediction of the Postoperative Changes of the Cranial Base in Unicoronal Craniosynostosis using CT Scan

Three unilateral craniosynostosis (plagiocephaly) patients who had undergone the cranial vault surgery in 4,9,18 months after birth were evaluated. The CT scans were obtained with high resolution. The CT scan data were reconstructed three dimensionally via Analyze AVW software, and visualized as volume rendering mode. The reconstructed volume data was realigned using 4 anatomical landmarks, nasion, basion, left and right external auditory meatus. After all data sets were realigned with same orientation, the target axial slice was obtained. The target slices are determined that is passing the center of the sellar trucica. The anterior, posterior and lateral distances were measured and the midsagittal angles were measured on the selected target slices. The pre- and post-operative data of measurement were compared. As results, the growth of affected side was seemed to be more rapid than that of normal side in patients who had undergone surgery at the time of 4 and 9 months old. Midsagittal angle was also increased up to about 180 degrees. However it was not definite in the 18month old patient. These results can be an evidence of the compensatory growth of the synostotic cranial base of synostosed side as same as other previous reports, however, much more cases should be examined to make the results to be more objective.

Three-dimensional image analysis of the skull using variable CT scanning protocols-effect of slice thickness on measurement in the three-dimensional CT images / 대한구강악안면방사선학회지

PURPOSE: To evaluate the quantitative accuracy of three-dimensional (3D) images by means of comparing distance measurements on the 3D images with direct measurements of dry human skull according to slice thickness and scanning modes. MATERIALS AND METHODS: An observer directly measured the distance of 21 line items between 12 orthodontic landmarks on the skull surface using a digital vernier caliper and each was repeated five times. The dry human skull was scanned with a Helical CT with various slice thickness (3, 5, 7 mm) and acquisition modes (Conventional and Helical). The same observer measured corresponding distance of the same items on reconstructed 3D images with the internal program of V-works 4.0 TM (Cybermed Inc., Seoul, Korea). The quantitative accuracy of distance measurements were statistically evaluated with Wilcoxons' two-sample test. RESULTS: 11 line items in Conventional 3 mm, 8 in Helical 3 mm, 11 in Conventional 5 mm, 10 in Helical 5 mm, 5 in Conventional 7 mm and 9 in Helical 7 mm showed no statistically significant difference. Average difference between direct measurements and measurements on 3D CT images was within 2 mm in 19 line items of Conventional 3 mm, 20 of Helical 3 mm, 15 of Conventional 5 mm, 18 of Helical 5 mm, 11 of Conventional 7 mm and 16 of Helical 7 mm. CONCLUSION: Considering image quality and patient's exposure time, scanning protocol of Helical 5 mm is recommended for 3D image analysis of the skull in CT.

Evaluation of Web-Based Real-Time Telemedicine Application Using ActiveX ontrols for Medical Moving Picture Analysis / 대한의료정보학회지

Telemedicine is described as combination of topics from the fields of telecommunication, medicine, and information and literally telemedicine means medicine at a distance. In this study, we present a web based real-time telemedicine application(WEBRETA) that was designed for patients who needs diagnosis on the Internet. The WEBRETA system is supporting transmitting of MPEG-4 video format(640*480)that was appropriate for Internet and designed with ActiveX controls technology that is also suitable for telecommunication link such as ADSL, VDSL and Cable modem which are very popular communication link in Korea. To improve the reliability and the usefulness of this prototype we involved the PSNR method and subjective score measuring from doctors. Futhermore, we will evaluate the WEBRETA with various communication network environment to improve how this system can contribute the diagnosis of patients and to analysis.

Migration of Digital Medical Image Data Stored through Mini-PACS to Full-PACS / 대한의료정보학회지

The purpose of this study was to evaluate the migration of medical image data stored thorough mini-PACS to full-PACS at Yonsei University Medical Center (YUMC). The image data to be migrated were 2.7 TB stored through approximately 4,500 CD archives at Yongdong Severance hospital and 4.7 TB (2:1 compression) stored through 196 digital linear tape (DLT) archives at Severance hospital. Prior to carrying out the migration, principles, methods and expected practical affairs for the migration were discussed and planned to optimize the migration work by considering the cost and the effectiveness of migration work. Migration gateway workstations were set up and a migration software tool was developed. Real migration works were performed based on the results of several migration simulations. Severance hospital decided to migrate all stored image data. The CD image data of 2.7 TB were estimated total 2,250 hr (about 94 days) migration time, but the practical migration work was completed within 3 months by using maximum 5 workstations. The DLT data of 4.7 TB were estimated total 100 days migration time by applying 16 hr working time per day with single workstation, however, the practical migration work was taken 5 months. Meanwhile, 20% of the DLT image data were not able to migrate because the DLT were partially damaged due to frequent access. In conclusion, a migration plan should be carefully prepared by considering the individual hospital environments because the server system, archival media, the network, and the policy of data management may be unique.

Design of a Multimedia Telemedicine System for Inter-hospital Emergency Consultation

PURPOSE: The telemedicine systems for both timely decision of patient transfer and accurate direction of patient treatment through remote consultation are required for better patient care in emergency situation. In this paper, we present noble design methods to implement the emergency telemedicine system suitable for emergency consultation. METHODS: The prototype system designed can encompass multimedia components including radiological images, medical record, biological signals, video conferencing and full-quality video, as well as can transmit changing data in real-time. In the first stage, experimental tests at the local networks analyzed the technical aspects of designed systems, and optimize the parameters subjectively to run them with affordable error. In the Second stage, two medical emergency cases were examined between two hospitals, the first was advanced airway management, and second was the management a patient with cardiac problem. RESULTS: Experimental tests at the local networks, all multimedia components can be represented to both terminals without any problems. Two cases of clinical experiment have performed to demonstrate the clinical usefullness. Orotracheal Intubation was done successfully by local hospital physician who was directed by specialist at distant hospital. The second case, a patient with cardiac problem was good managed by specialist via this telemedicine system without any problems. CONCLUSION: Inter-hospital experiments demonstrate the feasibility to be effectively used at emergency department.

Web-Based Asthma Care System / 대한의료정보학회지

Asthma is a chronic disease, which requires a successive and long-term management. In this paper, we implemented a web-based caring system for a more effective management of the asthmatics. The service of this asthmatic-caring system targeted on both the doctor and the patient. The patient connects to the asthma management server through the Internet everyday and inputs his or her daily condition and dosage. Then the doctor will give a proper comment or order to the patient according to the data that patient has filled in. By merely connecting to this web-site, doctors can manage asthmatics everyday and the patient can be under the doctor's management without frequently visiting the hospital. The test verifying the user's satisfaction of the implemented system has been taken by both the doctor- and the patient-groups. The doctor-group pointed out the successive management, an easy inspection of the patient condition, and the accumulation of clinical data for future researches as advantages. The patientgroup pointed out being under the daily management without visiting hospital and the active attitude they can have toward their diseases as advantages.

Design of Mobile Emergency Telemedicine System Based on CDMA2000 1X-EVDO / 대한의료정보학회지

Using a high bandwidth cellular communication network is appropriate to implement a high-quality mobile emergency telemedicine system. In Korea, the commercial service of CDMA2000 1X-EVDO has been providing since 2002. In this paper, we designed the system that transfers the biological signal and the video information of a patient simultaneously based on this CDMA2000 1X-EVDO network environment. In CDMA2000 1X-EVDO, the maximum speed of its reverse link can be observed within 153.6Kbps. Before the system design, several field tests had been performed using commercial CDMA2000 1X-EVDO reverse link with the UDP data segments. The test had been taken under several velocity and tunnel areas of Seoul. With the test result we implemented an efficient emergency telemedicine system fitted to the features of CDMA2000 1X-EVDO reverse link using UDP packets. Additional header information is added to the UDP packet data. With the header information the emergency system can transmits the ECG signal prior to the video data and controls the transmission error. The designed system has the ability to transmit both the biological signals and MPEG4 video of 640x480 spatial resolution at the same time. We set up the ambulance with this system and test it on the road.

The Design Of Multimedia Emergency Telemedicine System Between Inter-Hospital / 대한의료정보학회지

In this paper, the real-time telemedicine system based on multimedia data was designed. In order to describe patients to medical specialists, the system included multimedia data. The prototype system designed in this paper effectively integrated multimedia components in a single computer, as well as compromise the compression, interface, medical imaging standards and modular software architectures. The mobile bed was manufactured to improve the movement of the system. Two experiments had been conducted to evaluate the technical functionality and clinical usability. Using the data compression and priority control, the telemedicine system transmitted multimedia data in real-time at the internet and the ethernet network. Inter-hospital experiments and Sang-Am World-Cup Stadium experiments demonstrate the feasibility to be effectively used.