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Background and Study Object Pedicle screw fixation has been widely used in surgical treatment for infective lumbar spondylodiskitis to prevent instability and deformity. The cortical bone trajectory pedicle screw (CBTPS) fixation is a minimally invasive posterior spinal fixation system that runs from the pedicle's entry point of the caudiomedial region toward the cephalad-divergent direction. Successful results with CBTPS fixation have been reported to treat degenerative and osteoporotic spinal diseases. This study aims to investigate the clinical feasibility of CBTPS in the surgical treatment of pyogenic lumbar spondylodiskitis. Patient and Methods We retrospectively retrieved 20 consecutive patients from two academic centers who were surgically treated for monosegmental lumbar pyogenic spondylodiskitis. The primary surgical treatment was the anterior lumbar interbody fusion with decompression, debridement, and reconstruction using an autogenous iliac strut bone graft. One to 2 weeks after the primary surgery, patients underwent a second surgery for posterior instrumentation using conventional pedicle screws (CPS; group I) and CBTPS (group II). Radiographic parameters of the deformity angle at the fusion segment and clinical parameter of visual analog scale (VAS) scores were assessed preoperatively, postoperatively, and at the last follow-up. Results There were 10 patients in each group. The mean follow-up periods of groups I and II were 51.10 ± 6.95 and 28.60 ± 9.31 months, respectively. Intergroup analysis indicated the two groups area age-matched (p = 0.38), but initial C-reactive protein (CRP; mg/dL, p = 0.04), CRP normalization (months, p = 0.00), and follow-up duration (months, p = 0.00) were heterogeneous. Meanwhile, deformity angles (segmental lordosis) between the two groups were not significantly different preoperatively (p = 0.25), postoperatively (p = 0.13), and at last follow-up (p = 0.38). The intragroup analysis indicated a significant postoperative increase of lordosis in both group I and II (p = 0.00 and 0.04, respectively) with subsequent subsidence. Lordosis remained increased at the last follow-up with or without significance (group I, p = 0.02; group II, p = 0.62). Both groups showed significant improvement in VAS scores (group I, p = 0.00; group II, p = 0.00). Conclusion In monosegmental lumbar spondylodiskitis, posterior stabilization of the anterior strut bone graft by CBTPS and CPS was comparable via the radiographic parameter of segmental lordosis or deformity angle. Our observation suggests the clinical feasibility of CBTPS in the treatment of relatively mild monosegmental pyogenic lumbar spondylodiskitis.

Βackground Both limb length inequality and scoliosis are associated with pelvic obliquity. Methods This is an observational study of adolescents with growth potential presenting for evaluation of thoracic or thoracolumbar idiopathic scoliosis at an outpatient pediatric orthopedic clinic. Patients were evaluated for limb length discrepancy (LLD) (using bilateral femoral head height difference), pelvic obliquity (using bilateral iliac crest height difference and sacral takeoff angle), and scoliotic curve (using Cobb angle and rotation) on full spine standing radiographs. The same radiographic parameters were measured at a follow-up visit at least 2 years later. Results Seventy-three consecutive patients with a mean (SD) age of 13.3 (0.2) years at initial examination were included in the study. Scoliosis (major curve Cobb angle ≥ 10°) was confirmed in all 73 patients, pelvic obliquity (iliac crest height difference > 1 cm or sacral takeoff angle > 5°) appeared in 23 (31.5%) patients with scoliosis, and LLD (> 1 cm femoral head height difference) was identified in 6 (8.2%) patients with scoliosis and pelvic obliquity. At a subsequent visit, a mean of 2.8 (range 2–5.8) years later, no significant change (p > 0.05) in limb length inequality was observed but a statistically significant increase (p

Objective We utilized a spectral and network analysis technique with an integrated support vector classification algorithm for the automated detection of cognitive capacity using resting state electroencephalogram (EEG) signals. Methods An eyes-closed resting EEG was recorded in 158 older subjects, and spectral EEG parameters in seven frequency bands, as well as functional brain network parameters were, calculated. In the feature extraction stage, the statistical power of the spectral and network parameters was calculated for the low-, moderate-, and high-performance groups. Afterward, the highly-powered features were selected as input into a support vector machine classifier with two discrete outputs: low- or high-performance groups. The classifier was then trained using a training set and the performance of the classification process was evaluated using a test set. Results The performance of the Support Vector Machine was evaluated using a 5-fold cross-validation and area under the curve values of 70.15% and 74.06% were achieved for the letter numbering task and the spatial span task. Conclusion In this study, reliable results for classification accuracy and specificity were achieved. These findings provide an example of a novel method for parameter analysis, feature extraction, training, and testing the cognitive function of elderly subjects based on a quantitative EEG signal.

Rationale: Herpes zoster frequently causes dermatomal vesicular rash accompanied by severe neuralgia, and reaching a differential diagnosis may be challenging before the appearance of the vesicular rash. Patient concerns: A 40-year-old male patient visited the emergency department with a complaint of sudden onset motor weakness and ipsilateral radiating neuralgia to the Lt. thigh. He had suffered from chickenpox during childhood. Diagnoses: No skin lesion was present at the initial visit. The reverse Straight Leg Raise test was negative. Magnetic resonance imaging showed asymmetrically swollen dorsal root ganglion with Gadolinium enhancement. The vesicular rash that appeared on the sixth day after the symptom onset led to the diagnosis of herpes zoster. Interventions: Antiviral agent of valacyclovir (1000 mg t.i.d.) was administered for 7 days. Outcomes: The patient recovered from motor weaknesses by 2 weeks from the onset of the symptom. Mild degree post-herpetic neuralgia recovered by 2 months. Lessons: A high index of suspicion is necessary to differentiate early herpes zoster radiculitis before the appearance of vesicular rash from compressive radiculopathy. In L2–3 ipsilateral radiating pain along the dermatome or myotome, the absence of reverse Straight Leg Raise sign may be a possible factor in differentiating herpes zoster radiculitis from compressive radiculopathy.

Background and Study Aim Cortical screws were proposed as an alternative to the traditional pedicle screws. Diverse experimental results support the biomechanical superiority of cortical screws compared to pedicle screws. Laminectomy is often part of multilevel lumbar surgeries. Laminectomy might weaken the medial bony edge at the entry of the divergently oriented screw and, thereby, the screw purchase. This study investigated the biomechanical strength of lumbar cortical screw after laminectomy. Objective To compare the fixation strength of cortical screws and traditional pedicle screws after lumbar laminectomy. Material and Methods A total of 120 pedicles from 60 lumbar vertebrae of 12 cadavers (8 men, 4 women) were assessed. The mean age of the cadavers was 73.4 ± 6.2 years (range: 62–82 years). Using a posterior midline approach, we inserted the traditional pedicle screws into one and the cortical screws into the other side of each vertebra. Laminectomy was performed after screw insertion. Vertical pullout strength and toggle strength testing were performed to compare the fixation strength between the two sides. Results After laminectomy, the pullout strength of the cortical screws was 718.92 ± 340.76 N, and that of the pedicle screws was 625.78 ± 287.10 N (p = 0.183). The toggle strength of the cortical screws was 544.83 ± 329.97 N; that of the pedicle screws was 613.17 ± 311.70 N (p = 0.145). No significant difference was found in biomechanical strength between the two types of screws. Conclusion Despite laminectomy, lumbar cortical screws offers comparable pullout and toggle biomechanical strength as traditional pedicle screws.

Objective The treatment of atrophy or increased fat infiltration of the lumbar paraspinal muscles of patients with back pain, lumbar radiculopathy, or lumbar degenerative kyphosis is controversial. We review the literature on changes in the lumbar paraspinal muscles of these patients. Methods We searched Medline for relevant English-language articles and retrieved 25 articles published from 1993 to 2017 on changes in the lumbar paraspinal muscles; 21 met our study criteria. We categorized each article into three groups: randomized clinical trial, nonrandomized prospective study, or retrospective study. Results We found 1 randomized prospective, 3 nonrandomized prospective, and 17 retrospective studies. Atrophies of the multifidus muscle are found at the level of the L5 vertebral body in patients with back pain, lumbar radiculopathy, and lumbar degenerative kyphosis. Increased fat infiltration to the multifidus muscle was found in the patients with lumbar radiculopathy or lumbar degenerative kyphosis. However, there are controversies over fat infiltration to the multifidus muscle in the patients with back pain and the efficiency of a paramedian surgical approach to prevent the atrophy of the multifidus muscle. Conclusions Atrophy of the multifidus muscle was found in patients with back pain, lumbar radiculopathy, and lumbar degenerative kyphosis. There was increased fat infiltration to the multifidus muscle in those patients with lumbar radiculopathy or lumbar degenerative kyphosis.

Jae-Hyuk Shin Kyoung-Chul Kim In-Hwan YangAbstractGalvanizing is one of the method used to solve the problem of corrosion of reinforcement in concrete structures. There few research reported in the literature regarding the effect of galvanized coating on the behavior of lap splices in concrete beams. Theobjective of this study was to determine whether galvanized rebar adversely affects lap splice behavior and bond strength. Concretebeams reinforced with black or galvanized rebar were tested in flexure. The test variables included the presence of galvanized rebarsteel diameter, and lengths of lap splices. The study concentrated on comparing crack, failure pattern, and bond strength. The ultimate behavior of beams reinforced with galvanized rebar was not significantly different from that of black steel reinforced beams. Therefore, the test results indicated that the use of galvanizing-coated rebar had no adverse effect on behavior in lap splices of rebar compared to the use of black rebar.Keywords : Galvanized rebar, Concrete, Lap slice, Bond stress, Crack

The purpose of this study was to prospectively evaluate clinical and radiographic outcomes following anatomic medial patellofemoral ligament (MPFL) reconstruction using patellar suture anchor fixation for recurrent patellar instability. Twenty patients (20 knees) were enrolled in this study. The median age was 21 years, and the median follow-up was 34.5 months. Reconstruction was performed using a hamstring autograft fixed with two suture anchors at native patellar site of the MPFL. No patient had undergone additional medial tibial tuberosity transfer. Clinical scores (Kujala, Lysholm, and Tegner score) and apprehension test were completed preoperatively and at the follow-up. Preoperative and follow-up radiographic assessments included modified Insall-Salvati ratio, congruence angle, and lateral patellofemoral angle. The preoperative Kujala and Lysholm scores were 52.6 ± 12.4 and 49.2 ± 10.7, and at follow-up visits, corresponding values were 90.9 ± 4.5 (p

Little is known about the coupled motions of the spine during functional dynamic motion of the body. This study investigated the in vivo characteristic motion patterns of the human lumbar spine during a dynamic axial rotation of the body. Specifically, the contribution of each motion segment to the lumbar axial rotation and the coupled bending of the vertebrae during the dynamic axial rotation of the body were analyzed.Eight asymptomatic subjects (M/F, 7/1; age, 40-60 years) were recruited. The lumbar segment of each subject was MRI scanned for construction of 3D models of the vertebrae from L2 to S1. The lumbar spine was then imaged using a dual fluoroscopic system while the subject performed a dynamic axial rotation from maximal left to maximal right in a standing position. The 3D vertebral models and the fluoroscopic images were used to reproduce the in vivo vertebral motion. In this study, we analyzed the primary left-right axial rotation, the coupled left-right bending of each vertebral segment from L2 to S1 levels.The primary axial rotations of all segments (L2-S1) followed the direction of the body axial rotation. Contributions of each to the overall segment axial rotation were 6.7° ± 3.0° (27.9 %) for the L2-L3, 4.4° ± 1.2° (18.5 %) for the L3-L4, 6.4° ± 2.2° (26.7 %) for the L4-L5, and 6.4° ± 2.6° (27.0 %) for the L5-S1 vertebral motion segments. The upper segments of L2-L3 and L3-L4 demonstrated a coupled contralateral bending towards the opposite direction of the axial rotation, while the lower segments of L4-L5 and L5-S1 demonstrated a coupled ipsilateral bending motion towards the same direction of the axial rotation. Strong correlation between the primary axial rotation and the coupled bending was found at each vertebral level. We did not observe patterns of coupled flexion/extension rotation with the primary axial rotation.This study demonstrated that a dynamic lumbar axial rotation coupling with lateral bendings is segment-dependent and can create a coordinated dynamic coupling to maintain the global dynamic balance of the body. The results could improve our understanding of the normal physiologic lumbar axial rotation and to establish guidelines for diagnosing pathological lumbar motion.

OBJECTIVE Percutaneous vertebroplasty (PVP) is usually carried out under three-dimensional (2D) fluoroscopic guidance. However, operative complications or bone cement distribution might be difficult to assess on the basis of only 2D radiographic projection images. We evaluated the feasibility of performing an intraoperative and postoperative examination in patients undergoing PVP by using three-dimensional (3D) reconstructive C-arm. METHODS Standard PVP procedures were performed on 14 consecutive patients by using a Siremobil Iso-C(3D) and a multidetector computed tomography machine. Post-processing of acquired volumetric datasets included multiplanar reconstruction (MPR) and surface shaded display (SSD). We analyzed intraoperative and immediate postoperative evaluation of the needle trajectory and bone cement distribution. RESULTS THE MALE : female ratio was 2 : 12; mean age of patients, 70 (range, 77-54) years; and mean T score, -3.4. The mean operation time was 52.14 min, but the time required to perform and post-process the rotational acquisitions was 7.76 min. The detection of bone cement distribution and leakage after PVP by using MPR and SSD was possible in all patients. However, detection of the safe trajectory for needle insertion was not possible. CONCLUSION 3D rotational image acquisition can enable intra- or post-procedural assessment of vertebroplasty procedures for the detection of bone cement distribution and leakage. However, it is difficult to assess the safe trajectory for needle insertion.

Since ubiquitous technology is an emerging paradigm in healthcare, we wanted to evaluate its feasibility in the healthcare area. As a first step, we evaluated the feasibility of the smart bed. In this study, a series of experiments were conducted to evaluate the smart bed.Smart bed is a continuous ballistocardiogram monitoring device developed by Seoul National University. Eleven healthy subjects participated in the study. Each subject slept in the smart bed for two nights. To measure meaningful sleep periods, noisy sections were removed from the original signal. The subject's heart activity was obtained by automatic peak detection, using the AF2 peak detection algorithm. In this study, the feasibility of the smart bed was evaluated in terms of the meaningful sleep periods and the accuracy of automatic peak detection.On an average, 92.8% of sleep duration was meaningful. The accuracy of peak detection algorithm was also evaluated. The algorithm proved to have an accuracy of 95%; thus, we observe that 95% of the peak detection results were correct in comparison with the manual results.Based on the experimental results, we conclude that the smart bed can be a useful device for long-term monitoring in ubiquitous healthcare environments.

Purpose With increasing concern for well-being and recent advances in biomedical technology, healthcare is extending beyond the realm of hospitals. Nonintrusive home healthcare monitoring is essential for ensuring long-term use and preservation of an uninterrupted daily life. Herein, we describe recent progress in nonintrusive measurements of ECG, PPG, respiration and blood pressure using sensors installed in everyday household equipment.

A photoplethysmography (PPG) signal provides very useful information about a subject's hemodynamic status in a hospital or ubiquitous environment. However, PPG is very vulnerable to motion artifacts, which can significantly distort the information belonging to the PPG signal itself. Thus, the reduction of the effects of motion artifacts is an important issue when monitoring the cardiovascular system by PPG. There have been many adaptive techniques to reduce motion artifacts from PPG signals. In the present study, we compared a method based on the fixed-interval Kalman smoother with the usual adaptive filtering algorithms, e.g. the normalized least mean squares, recursive least squares and the conventional Kalman filter. We found that the fixed-interval Kalman smoother reduced motion artifacts from the PPG signal most effectively. Therefore, the use of the fixed-interval Kalman smoother can reduce motion artifacts in PPG, thus providing the most reliable information that can be deduced from the reconstructed PPG signals.

STUDY DESIGN A retrospective radiographic analysis. PURPOSE To estimate the accurate trajectory in the axial plane for iliac screw insertion in 200 Korean patients using radiographic images. OVERVIEW OF LITERATURE Several complications have been encountered after fusion to the lumbosacral junction, including pseudarthrosis, S1 screw loosening, and sacral fractures. Iliac screw fixation is considered an efficient method for augmenting sacral screw fixation but there are few reports on the trajectory of iliac screw insertion. The trajectory in the sagittal plane can be visualized by intraoperative fluoroscopy. However, there is no method to check the accuracy of the trajectory in the axial plane during surgery. METHODS Between January 2007 and February 2009, 200 patients (107 men and 93 women) who underwent L-spine computed tomography were enrolled in this study. The mean age of the patients was 55.6 +/- 18.3 years (range, 13 to 92 years). The spino-iliac angle (SIA) was measured on the axial image at the S1 level, which was defined as the angle between a vertical line through the center of the spinous process and an oblique line that passed through the center of the outer and inner cortices of the ilium. RESULTS The group mean SIA was 30.1 degrees +/- 7.8 degrees ; 30.1 degrees +/- 7.7 degrees for men and 29.9 degrees +/- 81.1 degrees for women. There was no significant difference according to gender or age (p > 0.05). CONCLUSIONS The SIA for the axial trajectory of iliac screws is approximately 30 degrees in Korean patients.

We evaluated the performance of a bed-type sensor system using the air-mattress with balancing tube (AMBT) method to noninvasively monitor the signals of heartbeat, respiration, and events of snoring, sleep apnea and body movement of subject on the system. The proposed system consists of multiple cylindrical air cells, two sensor cells and 18 support cells, and the small physiological signals were measured by the changes in pressure difference between the sensor cells, and the dc component was removed by balancing tube that is connecting the sensor cells. Using newly developed AMBT method, heartbeat, respiration, snoring, and body movement signals were clearly measured. For the concept of a home healthcare system, two automatic processing algorithms were developed: one is to estimate the mean heart and respiration rates for every 30 s, and another one is to detect the snoring, sleep apnea, and body movement events from the measured signals. In the beat-to-beat heart rate and breath-by-breath respiration rate analyses, the correlation coefficients of the heart and respiration rates from the proposed AMBT method compared with reference methods, electrocardiogram, and respiration effort signal from piezoelectric belt, were 0.98 (p < 0.01) and 0.96 (p < 0.01), respectively. Sensitivity and positive predictive value (PPV) of the detection algorithm for snoring event were 93%, 96%, for sleep apnea event were 93%, 88%, and for body movement event were 86%, 100%, respectively. These findings support that ABMT method provides an accurate and reliable means to monitor heartbeat, respiration activities and the sleep events during sleep.

In this study, we developed a novel technique for estimating non-constrained and cuffless blood pressure (BP) that was based on electrocardiogram (ECG) and ballistocardiogram (BCG). The BCG was non-invasively measured using a common electronic weighing scale when a subject was standing on it. The ECG was measured using three different methods: on the chest using Ag/AgCl electrodes, on the hands using dry electrodes and on the feet also using dry electrodes. For a BP correlated parameter, a time interval parameter, which was defined as the time difference between the ECG R-peak and BCG J-peak, was employed for evaluating and estimating beat-to-beat BP. Under a BP varying experiment with a Valsalva manoeuvre, the R-J intervals were extracted at every beat cycle and a systolic blood pressure (SBP) estimation equation was established using linear regression analysis for each subject. In the case of feet delivered ECG (F-ECG), an ensemble average technique synchronized at the BCG J-peak point was applied to extract the ECG signal from the feet. The performance of the proposed method was evaluated using Finapres, a non-invasive blood pressure measurement system, as a reference BP signal, and a scatter plot was used to find the regression line between the reference values and estimated BPs. A moving-window averaging technique was applied to remove the high-frequency noise in the R-J intervals and was applied to enhance the accuracy of the SBP estimation. For all individuals, the estimated SBP was similar to the measured SBP with a reliable correlation, which makes the proposed method suitable for use in a home healthcare system to monitor blood pressure on a weighing scale at the same time as measuring weight.

The object of this study is to review the early clinical results and radiographic outcomes following insertion of the Bryan Cervical Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN), together with its effect on maintaining sagittal alignment of the functional spinal unit (FSU) and overall sagittal balance of the cervical spine for the treatment of single-level or two-level symptomatic disc disease. Forty-seven patients with symptomatic single or two-level cervical disc disease who received the Bryan Cervical Artificial Disc were reviewed prospectively. A total of 55 Bryan disc were placed in 47 patients. A single-level procedure was performed in 39 patients and a two-level procedure in the other eight. Radiographic and clinical assessments were made preoperatively and at 1.5, 3, 6, 9, 12, and 18 and up to 33 months postoperatively. Mean follow-up duration was 24 months, ranging from 13 to 33 months. Periods were categorized as early follow up (1.5-3 months) and late follow up (6-33 months). The visual analogue scale (VAS), neck disability index(NDI), Odom's criteria were used to assess pain and clinical outcomes. Static and dynamic radiographs were measured by hand and computer to determine the range of motion (ROM), the angle of the functional segmental unit (FSU), and the overall cervical alignment (C2-7 Cobb angle). With all of these data, we evaluated the change of the preoperative lordosis (or kyphosis) of the FSU and Overall sagittal balance of the cervical spine during the follow-up period. There was a statistically significant improvement in the VAS score from 7.0 +/- 2.6 to 2.0 +/- 1.5 (paired-t test, P = 0.000), and in the NDI from 21.5 +/- 5.5 to 4.5 +/- 3.9 (paired-t test P = 0.000). All of the patients were satisfied with the surgical results by Odom's criteria. The postoperative ROM of the implanted level was preserved without significant difference from preoperative ROM of the operated level. Only 36% of patients with a preoperative lordotic sagittal orientation of the FSU were able to maintain lordosis following surgery. However, the overall sagittal alignment of the cervical spine was preserved in 86% of cases at the final follow up. Interestingly, preoperatively kyphotic FSU resulted in lordotic FSU in 13% of patients during the late follow-up, and preoperatively kyphotic overall cervical alignment resulted in lordosis in 33% of the patients postoperatively. Clinical results are encouraging, with significant improvement seen in the Bryan Cervical Artificial disc. The Bryan disc preserves motion of the FSU. Although the preoperative lordosis (or kyphosis) of the FSU could not always be maintained during the follow-up period, the overall sagittal balance of the cervical spine was usually preserved.

A retrospective clinical study.To assess the results of anterior strut grafting and the loss of the reduction in anterior interbody fusion and anterior interbody fusion combined with posterior instrumental fusion in pyogenic spondylodiscitis.Resorption of the anterior graft is an ominous sign following most anterior surgery. Thus, additional posterior instrumentation has been used to prevent collapse of the anterior graft. However, its effect is controversial, and few studies have examined the fate of the anterior strut graft.Twenty-four consecutive patients underwent surgical treatment for pyogenic spondylodiscitis. The patients were divided into Group I (anterior interbody fusion) and Group II (anterior interbody fusion + posterior instrumented fusion). The sagittal angle, intervertebral height, and complications relating to the anterior graft were compared.Solid bone fusion was achieved in 23 (95.8%) patients. The sagittal angle and the intervertebral height were similar in Groups I and II (P = 0.61, P = 0.89, respectively). In Groups I and II, the postoperative sagittal angle was maintained until 1 month after surgery (P0.05), but it decreased significantly by 3 months after surgery (P0.05). In Groups I and II, intervertebral height correction was maintained until 1 month after surgery (P0.05), but by 3 months after surgery, it had collapsed significantly (P0.05). Subsidence of the graft occurred through the damaged endplate. Group I included 1 case of graft dislodgement necessitating revision; there were no such cases in Group II. There were no recurrences of infection in either group.Reduction of intervertebral height and loss of sagittal profile occurred in both groups. Complications relating to the bone graft were more common in Group I than in Group II. Despite loss of correction, both groups had a high fusion rate without recurrence of infection. The reduction of intervertebral graft height appears to be the result of destruction of the endplate either due to surgical debridement or the infective process.

Controlled laboratory study.To investigate the in vivo biomechanical effect of degenerative lumbar spondylolisthesis (DLS) on the motion of the facet joint during various functional weight-bearing activities.Although the morphologic changes of the facet joints in patients with DLS have been reported in a few studies, no data have been reported on the kinematics of these facet joints.Ten patients with DLS at L4-L5 were studied. Each patient underwent a magnetic resonance imaging scan to obtain 3-dimensional models of the lumbar vertebrae from L2-L5 and a dual fluoroscopic imaging scan in different postures: flexion-extension, left-right bending, and left-right torsion. The positions of the vertebrae were reproduced by matching the magnetic resonance imaging-based vertebral models to the fluoroscopic images. The kinematics of the facet joint and the ranges of motion were compared with those of healthy subjects and those of patients with degenerative disk diseases (DDD) previously published.In DLS patients, the range of rotation of the facet joints was significantly less at the DLS level (L4-L5) than that at the adjacent levels (L2-L3 and L3-L4), whereas the range of translation was similar at all levels. The range of rotation at the facet joints of the DLS level decreased compared with those of both the DDD patients and healthy subjects at the corresponding vertebral level (L4-L5), whereas no significant difference was found in the range of translation. The range of motion of facet joints in DLS and in DDD patients was similar at the adjacent levels (L2-L3 and L3-L4).The range of rotation decreased at the facet joints at the DLS level (L4-L5) in patients compared with those in healthy subjects and DDD patients. This decrease in range of rotation implies that the DLS disease may cause restabilization of the joint. The data may help the selection of conservative treatment or different surgical techniques for the DLS patients.

Using the Ballistocardiogram(BCG) measured on weighing scale, heart rate variability(HRV) and blood pressure were estimated. BCG was measured while subjects were on weighing scale in resting state and under the Valsalva maneuver and static exercise condition to induce the change in cardiac autonomic rhythm. Time domain, frequency domain and nonlinear HRV parameters were estimated from the measured BCG and compared with the ones calculated from ECG measured simultaneously. For blood pressure(BP) estimation, ECG was measured additionally on the feet using dry electrodes simultaneously installed on weighing scale and R-J intervals were extracted as a BP correlated parameter at every beat cycle. HRV estimation results shows the correlation higher than 0.97, and the estimated BP was similar to the measured BP with a reliable correlations.

Background In sleep efficiency monitoring system, actigraphy is the simplest and most commonly used device. However, low specificity to wakefulness of actigraphy was revealed in previous studies. In this study, we assumed that sleep/wake estimation using actigraphy and electromyography (EMG) signals would show different patterns. Furthermore, each EMG pattern in two states (sleep, wake during sleep) was analysed. Finally, we proposed two types of method for the estimation of sleep/wake patterns using only EMG signals from anterior tibialis muscles and the results were compared with PSG data. Methods Seven healthy subjects and five patients (2 obstructive sleep apnea, 3 periodic limb movement disorder) participated in this study. Night time polysomnography (PSG) recordings were conducted, and electrooculogram, EMG, electroencephalogram, electrocardiogram, and respiration data were collected. Time domain analysis and frequency domain analysis were applied to estimate the sleep/wake patterns. Each method was based on changes in amplitude or spectrum (total power) of anterior tibialis electromyography signals during the transition from the sleep state to the wake state. To obtain the results, leave-one-out-cross-validation technique was adopted. Results Total sleep time of the each group was about 8 hours. For healthy subjects, the mean epoch-by-epoch results between time domain analysis and PSG data were 99%, 71%, 80% and 0.64 (sensitivity, specificity, accuracy and kappa value), respectively. For frequency domain analysis, the corresponding values were 99%, 73%, 81% and 0.67, respectively. Absolute and relative differences between sleep efficiency index from PSG and our methods were 0.8 and 0.8% (for frequency domain analysis). In patients with sleep-related disorder, our proposed methods revealed the substantial agreement (kappa > 0.61) for OSA patients and moderate or fair agreement for PLMD patients. Conclusions The results of our proposed methods were comparable to those of PSG. The time and frequency domain analyses showed the similar sleep/wake estimation performance.

We introduced a novel non-constrained technique for estimating heart rate variability (HRV) using a ballistocardiogram (BCG). To assess whether the BCG signal can be used to analyse the cardiac autonomic modulation, HRV parameters derived from the BCG signal (ballistocardiographic HRV, B-HRV) were statistically compared with the HRV parameters from the ECG signal during rest and under two different experimental conditions that induce cardiac autonomic rhythm changes: the Valsalva manoeuvre and static exercise. Time domain, frequency domain and nonlinear analyses were individually performed on 15 healthy subjects to assess whether the BCG can be used to analyse the cardiac autonomic modulation under each condition. For all subjects, the proposed method had averages of relative errors of 5.01 ± 4.72, 5.64 ± 4.83 and 5.98 ± 5.80% for resting, Valsalva and post-exercise sessions, respectively, and the correlation coefficients between the reference (ECG) and proposed (BCG) methods are 0.97, 0.98 and 0.98, for resting, Valsalva and post-exercise sessions, respectively. During cardiac autonomic changes, the B-HRV parameters changed in a pattern that is very similar to the variations in the HRV parameters based on Student's t-test results. In addition, some of the B-HRV parameters changed according to cardiac autonomic rhythms controlled by sympathetic and parasympathetic activities during the experiments. These findings indicate that BCG can provide an accurate and reliable means to evaluate autonomic system activation by HRV in its unconstrained way.

STUDY DESIGN Comparative genomic hybridization (CGH) microarrays. OBJECTIVE To identify genomic copy number variations (CNVs) in degenerative lumbar scoliosis (DLS) patients, and investigate the possibility of genetic predisposition in DLS. SUMMARY OF BACKGROUND DATA Genome scanning technology enables search for presence of CNVs. CGH microarray is a useful procedure in a genome-wide study. METHODS Among 45 consecutive patients who were diagnosed as DLS, 15 patients who manifested greatest Cobb's angle were selected for the array-CGH based CNV analysis. Control group was blood samples from 58 individuals without DLS. Oligonucleotide CGH microarray was utilized to analyze the CNV. Gene searches were performed for CNV DNA with significant gene-dosage difference. Validation qualitative PCR(qPCR) was performed at 3 genetic loci: at chromosome 2--TMEM163 gene, at chromosome 16--ANKRD 11 gene, and at chromosome 18--NFATC1 gene. RESULTS Genomic gains and losses were observed using the oligonucleotide CGH microarray. Identified CNVs were 446 ± 129 per individual. Gain- and loss-CNVs were identified as 196 ± 24 and 250 ± 110, respectively. The length of total CNV per individual was 30,946,730 ± 31,658,175 bp, and mean CNV-length was 61,017 ± 40,620 (median length 6411 ± 1994). Comparison with control group revealed 260 CNVs, which were significant (P < 10(-3)). Validation qPCR for gene-dosage comparison of DLS group DNA versus control group DNA in TMEM163 (P < 0.001); ANKRD 11 (P = 0.000); and NFATC1 (P = 0.000) gene showed significant difference. CONCLUSION Various whole-genome CNVs specific to DLS patients were observed. Validation qPCR confirmed significantly different gene-dosages for TMEM163, ANKRD 11, and NFATC1 genes. We consider that the expression of DLS is supported by various typical CNV-associated structural variants of the genome.

In this study, we developed an automated behavior analysis system using infrared (IR) motion sensors to assist the independent living of the elderly who live alone and to improve the efficiency of their healthcare. An IR motion-sensor-based activity-monitoring system was installed in the houses of the elderly subjects to collect motion signals and three different feature values, activity level, mobility level, and nonresponse interval (NRI). These factors were calculated from the measured motion signals. The support vector data description (SVDD) method was used to classify normal behavior patterns and to detect abnormal behavioral patterns based on the aforementioned three feature values. The simulation data and real data were used to verify the proposed method in the individual analysis. A robust scheme is presented in this paper for optimally selecting the values of different parameters especially that of the scale parameter of the Gaussian kernel function involving in the training of the SVDD window length, T of the circadian rhythmic approach with the aim of applying the SVDD to the daily behavior patterns calculated over 24 h. Accuracies by positive predictive value (PPV) were 95.8% and 90.5% for the simulation and real data, respectively. The results suggest that the monitoring system utilizing the IR motion sensors and abnormal-behavior-pattern detection with SVDD are effective methods for home healthcare of elderly people living alone.