Using Akaike information criterion and minimum mean square error mode in compensating for ultrasonographic errors for estimation of fetal weight by new operators.

OBJECTIVES: The accuracy of ultrasound (US) measurements is operator dependent. In order to decrease the operator-dependent errors in estimated fetal weight (EFW), a model selection analysis was undertaken to select significant compensation weighting factors on ultrasonographic parameters to support artificial neural network (ANN), and thus to enhance the accuracy of fetal weight estimation. MATERIALS AND METHODS: In total, 2127 singletons were examined by prenatal US within 3 days before delivery for ANN development, and another 100 cases were selected from new operators for evaluation. First, correlation analysis was used to analyze the differences between the prenatal and postnatal parameters. Second, Akaike information criterion (AIC) was used to determine the number of database partition and optimal weightings for compensating the input parameters of the ANN model. Finally, minimum mean squared error (MMSE) mode was utilized to determine the optimal EFW. RESULTS: EFW of the proposed compensation model using AIC and MMSE showed mean absolute percent error of 5.1 ± 3.1% and mean absolute error of 158.9 ± 96.2 g. When comparing the accuracy of EFW, our model using AIC and MMSE was superior to those conventional EFW formulas (all p < 0.05). CONCLUSION: We proved that performing the parameter compensation (by AIC) and model compensations (by MMSE) for the ANN model can improve EFW accuracy. Our AIC-MMSE model of EFW will contribute to the improvement of accuracy when adding new US datasets measured by new operators.

Percutaneous vertebroplasty for symptomatic osteoporotic vertebral compression fracture adjacent to lumbar instrumented circumferential fusion.

The purpose of this study was to evaluate the efficacy and safety of percutaneous vertebroplasty for patients with symptomatic osteoporotic vertebral compression fractures adjacent to lumbar instrumented circumferential fusion. Between January 2005 and June 2010, eighteen patients in the authors' institution with lumbar instrumented circumferential fusion had adjacent symptomatic osteoporotic vertebral compression fractures. The patients received percutaneous vertebroplasty using polymethylmethacrylate bone cement augmentation. Radiographs and magnetic resonance imaging were used. The visual analog pain scale and modified Brodsky's criteria were used to compare clinical outcomes pre- and postoperatively. Minimum follow-up was 18 months. Dual-energy x-ray absorptiometry scan confirmed osteoporosis in all patients. The average interval between fusion surgery and sustaining osteoporotic vertebral compression fractures was 24.8 months. The average interval between sustaining osteoporotic vertebral compression fractures and undergoing percutaneous vertebroplasty was 49.3 days. One-level percutaneous vertebroplasty was performed in 13 patients, and 2 levels were performed in 5 patients. The patients' visual analog pain scale scores improved by an average of 53 points postoperatively. Fifteen patients returned to preinjury activities of daily living. The average restoration of the fractured vertebral body height was 12.1%. No major surgery-related complications, occurred except asymptomatic cement leakage in 3 patients. Elderly patients undergoing lumbar instrumented fusion surgery should be aware of the possibility of adjacent vertebral compression fractures. Percutaneous vertebroplasty is a minimally invasive and effective procedure to treat such adjacent segment disease.

Clinical evaluation of repeat percutaneous vertebroplasty for symptomatic cemented vertebrae.

BACKGROUND: Percutaneous vertebroplasty (PV) with polymethylmethacrylate is widely used to treat osteoporotic vertebral compression fracture and satisfactory clinical outcomes have been reported in the literature. However, recurrent or persistent back pain after PV is not uncommon. Sometimes, the pain may result from pathogenesis within the previously treated vertebra. In this study, we evaluated the efficacy and safety of repeat PV for treating patients with recurrent back pain caused by the previously cemented vertebrae. METHODS: We retrospectively reviewed the medical records of 18 patients who underwent repeat PV to treat symptomatic cemented vertebrae. Patients were categorized into 3 groups based on clinical presentation and imaging studies: those with refracture (RF), residual vacuum (RV), and osteonecrosis (ON) along the bone-cement interface. A bipedicle approach was used for repeat PV in all patients. The visual analogue scale (VAS) and modified Brodsky criteria were used to evaluate clinical outcomes before and after surgery. The Kruskal-Wallis test, Wilcoxon signed-rank test, and Spearman correlation analyses were used to analyze patient surgical prognosis and radiologic findings. RESULTS: Nine patients were diagnosed with RF, 5 with RV, and 4 with ON. The average VAS score was 77.1 (range, 62-90) before repeat PV (80.1, 72.4, and 76.3 for the RF, RV, and ON groups, respectively) and 34.4 (range, 25-45) after repeat PV treatment (33.1, 36.8, and 34.3 for the RF, RV, and ON groups, respectively). The VAS score significantly decreased in all 3 groups. The vertebral body height was significantly restored by a mean of 13.9% across all groups (17.8%, 12.7%, and 6.8% in the RF, RV, and ON groups, respectively). Fifteen patients recovered from vertebral compression fracture and regained their preinjury activities of daily living. No surgery-related complications occurred except asymptomatic cement leakage in 5 patients. CONCLUSIONS: The results of this research demonstrate that repeat PV may be an effective method for relieving recurrent or persistent pain in patients with symptomatic cemented vertebrae, allowing them to regain functional activity.

Efficient fetal size classification combined with artificial neural network for estimation of fetal weight.

OBJECTIVES: A novel analysis was undertaken to select a significant ultrasonographic parameter (USP) for classifying fetuses to support artificial neural network (ANN), and thus to enhance the accuracy of fetal weight estimation. METHODS: In total, 2127 singletons were examined by prenatal ultrasound within 3 days before delivery. First, correlation analysis was used to determine a significant USP for fetal grouping. Second, K-means algorithm was utilized for fetal size classification based on the selected USP. Finally, stepwise regression analysis was used to examine input parameters of the ANN model. RESULTS: The estimated fetal weight (EFW) of the new model showed mean absolute percent error (MAPE) of 5.26 ± 4.14% and mean absolute error (MAE) of 157.91 ± 119.90 g. Comparison of EFW accuracy showed that the new model significantly outperformed the commonly-used EFW formulas (all p < 0.05). CONCLUSION: We proved the importance of choosing a specific grouping parameter for ANN to improve EFW accuracy.

Sliding and pressure evaluation on conventional and V-shaped seats of reclining wheelchairs for stroke patients with flaccid hemiplegia: a crossover trial.

BACKGROUND: Reclining wheelchairs are commonly used to transport elderly stroke patients in Taiwan. However, there is concern that the patient's body in the wheelchair often slides forward when they return to a seated position, increasing the sitting pressure. Therefore, a novel reclining wheelchair with an ergonomic "V-Seat" was designed to prevent forward sliding and pressure sores. The use of these reclining chairs by stroke patients has not yet been studied. Thus, we investigated the effects of V-shaped and conventional seats in reclining wheelchairs on the extent of forward sliding and on the sitting pressure of stroke patients with flaccid hemiplegia and of able-bodied elders. METHODS: We recruited 13 able-bodied elders and 11 stroke patients with flaccid hemiplegia and performed 5 reclining cycles in both types of wheelchair. The amount of sliding along the backrest (BS) plane and the seat (SS) plane, the mean sitting pressure (MP), and the sacral peak pressure (SPP) of the subjects were recorded. We used the Wilcoxon signed-rank test to compare the BS, SS, MP, and SPP in wheelchairs with conventional and V-shaped seats, and we used the Wilcoxon rank sum test to compare the differences in BS and SS between stroke patients and able-bodied elders in both types of reclining wheelchair. RESULTS: The BS, SS, and SPP of stroke patients were significantly lower in the wheelchairs with V-shaped seats than in conventional wheelchairs in most comparisons; however, the BS of able-bodied elders was higher in V-shaped seats than in conventional seats. The SS and SPP of stroke patients were significantly higher than those of able-bodied elders in both types of reclining wheelchair, and the BS of stroke patients was significantly higher than that of able-bodied elders only in conventional reclining wheelchairs. CONCLUSIONS: The use of V-shaped seats in reclining wheelchairs can help reduce the forward sliding and sacral peak pressure of stroke patients with flaccid hemiplegia. The back displacement of able-bodied subjects when using both conventional and V-shape seats in reclining positions differs from the back displacement of stroke patients with flaccid hemiplegia when using such seats. These results are of paramount value and should be considered when prescribing the use of reclining wheelchairs to subjects with flaccid hemiplegia.

Insertion of the ProSeal™ laryngeal mask airway is more successful with the Flexi-Slip™ stylet than with the introducer.

PURPOSE: The ProSeal™ laryngeal mask airway (PLMA™) may be difficult to insert because of its large soft cuff, even when using a dedicated introducer tool. The purpose of this study was to investigate whether introduction of a stylet (Flexi-Slip™) in the drainage tube improved insertion characteristics compared with the standard introducer. METHODS: In this randomized controlled trial, 160 adults were allocated randomly to either the Introducer group (n = 80) or to the Flexi-Slip stylet group (n = 80). In the Introducer group, the PLMA was inserted with an introducer as described in the manufacturer's instructions. In the Flexi-Slip stylet group, a Flexi-Slip stylet was inserted into the drainage tube of the PLMA and bent to form a near 90° angle at the junction of the cuff and the airway tube. The primary outcome measurement was the success rate at first attempt. Insertion time, visible blood staining, and complications were also noted. RESULTS: Success at first attempt was more frequent with the Flexi-Slip stylet than with the introducer (100% vs 86%, respectively; P = 0.001). Overall time (mean ± standard deviation) taken for successful placement was shorter with the Flexi-Slip stylet than with the introducer (19.9 ± 5.6 sec vs 28.4 ± 15.2 sec, respectively; P < 0.001). The incidences of blood staining and postoperative sore throat were lower in the Flexi-Slip stylet group than in the Introducer group (4% vs 15%, respectively; P = 0.015 and 8% vs 23%, respectively; P = 0.008). CONCLUSION: Insertion of the PLMA with a Flexi-Slip stylet has a higher success rate at first attempt, requires less time, and results in fewer airway complications than the introducer technique.

Use of the Rusch Flexi-Slip stylet for patients with difficult insertion of the ProSeal laryngeal mask airway.

The ProSeal laryngeal mask airway (PLMA) offers a more effective seal and is easier for gastric tube placement to prevent aspiration than the classical laryngeal mask airway. However, it is more difficult to insert with the digital and introducer tooling techniques. The Rusch Flexi-Slip stylet (RFSS) is an accessory intubation tool that consists of a malleable coated wire and a soft atraumatic tip. It has been reported that it can facilitate easier insertion of the PLMA. Here, we report two cases in which the PLMA could not be inserted correctly on the initial attempts, and with successful placement of the PLMA after using an RFSS. In the first case, three attempts to insert the PLMA with the digital and introducer tooling techniques were unsuccessful. The second case was known to be difficult for PLMA placement because, in a previous operation, PLMA insertion for general anesthesia was unsuccessful, and in that instance required endotracheal intubation for general anesthesia. In both cases, the PLMA was successfully inserted using the RFSS technique, without difficulty. The RFSS technique offers several advantages for PLMA insertion, including the provision of effective support and a soft tip for the PLMA insertion. Other techniques to facilitate the insertion of the PLMA, including priming the drain tube with a guide are discussed. We recommend that the RFSS technique offers an effective method for cases with difficult insertion of the PLMA.

Impact of cement leakage into disks on the development of adjacent vertebral compression fractures.

STUDY DESIGN: A retrospective study assessing new adjacent vertebral compression fracture (VCF) after percutaneous vertebroplasty (PV). OBJECTIVE: To evaluate the relationship between cement leakage into the disk during initial PV and development of subsequent new adjacent VCF. SUMMARY OF BACKGROUND DATA: Cement leakage outside the vertebral body during PV has been reported and usually responds to conservative treatment. Sometimes bone cement may leak into the intervertebral disk and result in painful new adjacent VCF that usually requires another PV for pain relief. METHODS: From January 2002 to December 2002, a total of 106 consecutive patients underwent PVs for osteoporotic VCFs. The risk of new fractures of adjacent vertebral bodies, the amount of cement injection, and the duration of development of new adjacent fractures in relation to cement leakage into the disk were retrospectively assessed and statistically compared. RESULTS: New adjacent VCFs occurred in 20 (18.9%) of 106 patients at 22 adjacent vertebral bodies after PVs during at least 24 months of follow-up. The difference in number of new adjacent fractures between both patients and vertebral bodies with cement leakage and those without leakage into the disk were statistically significant (P<0.001 and P<0.001). Amounts of cement injected and duration to development of new adjacent fractures differed between patients with or without cement leakage (P<0.001 and P=0.005, respectively). CONCLUSIONS: PV is a simple and effective, but not risk-free or complication-free procedure for the treatment of osteoporotic VCF. Patients undergoing PV should be informed of the possibility of new adjacent fractures and the higher risk if cement leaks into the disk.

The impact of timing and dose of rehabilitation delivery on functional recovery of stroke patients.

BACKGROUND: To investigate the impact of both timing and dose of rehabilitation delivery on the functional recovery of stroke patients. METHODS: From chart review, we included 76 patients who were admitted to a regional hospital for first-ever stroke, and who had received multidisciplinary rehabilitation programs including physical therapy (PT) and occupational therapy (OT) at the inpatient department, and continuous rehabilitation therapy at the outpatient department for at least 3 months. The collected data included age, sex, type of stroke (hemorrhage/infarction), onset of stroke, initial motor status by Brunnstrom's motor recovery stages, time to rehabilitation intervention (from onset of stroke), length of stay, existence of aphasia, craniotomy (yes/no), and total units of rehabilitation. Main outcome measures were serial Barthel Index (BI) at initial assessment, 1 month, 3 months, 6 months, and 1 year post-stroke. RESULTS: Age was inversely correlated with BI and BI improvement at 3 months and 6 months post-stroke. Rehabilitation intervention time from onset was negatively correlated with BI improvement at 1 month and 1 year, and with BI at 1 month, 3 months, 6 months, and 1 year post-stroke. The total units of inpatient PT and/or OT were positively correlated with BI improvement at 1 month, 3 months, and 6 months post-stroke. The total units of PT and/or OT were positively correlated with BI improvement at 3 months and 6 months post-stroke. And the initial BI was positively correlated with BI at 1 month, 3 months, and 6 months post-stroke. The total units of OT can significantly predict BI improvement at 3 months and 6 months post-stroke, while the initial BI capacity can significantly predict BI status at 1 month, 3 months, and 6 months post-stroke. CONCLUSION: There is a dose-dependent effect of rehabilitation on functional improvement of stroke patients for the first 6 months post-stroke, and earlier delivery of rehabilitation has lasting effects on the functional recovery of stroke patients up to 1 year.

Revision strategies for complications and failure of vertebroplasties.

Percutaneous vertebroplasty is widely discussed in the management of osteoporotic spinal compression fracture, but few reports are available concerning salvage procedures after failure of this technique. We studied 22 percutaneous vertebroplasty patients who required revision surgery upon presentation of new symptoms postoperatively. The indications for revision surgery included recurrent intractable back pain with no response to medical treatment, infectious spondylitis, cement leakage with neurologic deficit, and cement dislodgement and/or fragmentation. Five patients underwent repeated percutaneous vertebroplasty of the initially cemented vertebrae. Seventeen patients underwent anterior, posterior, or combined anterior and posterior surgery. Four patients required a third surgical procedure because of poor augmentation with cement, subsidence of the anterior bone graft, or pullout of the instrumentation. Finally, four (18%) patients underwent repeat vertebroplasty, two (9%) patients underwent anterior surgery only, one (5%) patient underwent posterior surgery only, and 15 (68%) patients underwent combined anterior and posterior surgery; all but one regained ambulatory status equivalent to that prior to surgery. In conclusion, percutaneous vertebroplasty is a simple and effective, but not risk- or complication-free procedure for the treatment of osteoporotic spinal compression fracture. The spine surgeon should be familiar with varied approaches and techniques for revision surgery. Combined anterior and posterior surgery seems to be the most secure salvage method to treat severely osteoporotic patients in whom percutaneous vertebroplasty initially failed.

A two-stage approach to positioning and identification of tracheal intubation using LED-based lightwand and acoustic models.

This paper proposes a two-stage approach to positioning and identifying tracheal intubations by computer-assisted diagnosis system. First, an innovated LED-based lightwand is developed for positioning the opening of the trachea and inserting the endotracheal tube rapidly. The proposed LED-based lightwand instrument significantly reduces the effects of temperature reaction without changing transillumination through the tissue. After intubation, breath sound analysis instrumentation is developed and assists for identifying the accurate tube position. To overcome the fast and overstepped variations of amplitude, a high sensitivity omni dimensional microphone and an automatic gain control device with linear phase property are calibrated and conducted into experiments of operating intubations. User-friendly interface software is also developed to analyze and transcribe the physiological characteristics of the collected breath sound corpus. Several subjective and objective experiments are performed to examine the practicability of the proposed approach and systems. The preliminary results show that the proposed LED-based lightwand instrument outperformed in the tip temperature without the influence on transillumination. The proposed parameters of average vibration parameter variance (AVPV) and frequency-domain energy variance (FEV) revealed the potential for distinguishing between the tracheal and esophageal intubations.

Effectiveness of two forms of feedback on training of a joint mobilization skill by using a joint translation simulator.

BACKGROUND AND PURPOSE: Joint mobilization is a complicated task to learn and to teach and is characterized by great intersubject variability. This study's purpose was to investigate whether quantitatively augmented feedback could enhance the learning of joint mobilization and, more specifically, to compare the effects of training with concurrent or terminal feedback by using a joint translation simulator (JTS). SUBJECTS: Thirty-six undergraduate physical therapist students were randomly assigned to control (no feedback), concurrent feedback, and terminal feedback groups. METHODS: The JTS was designed to simulate tissue resistance based on load-displacement relationships of glenohumeral joint specimens. Subjects applied specific mobilization grades of force on the JTS while quantitative feedback was given to the feedback groups either during a trial (ie, concurrent feedback) or after a trial (ie, terminal feedback). The skill acquisition phase lasted a total of 40 minutes, and a total of 75 repetitions were performed for each grade of each joint model. Pretest and no-feedback retention tests were conducted. RESULTS: During acquisition and retention, both feedback groups performed more accurately than did the control group. No obviously superior performance was shown by the terminal feedback group compared with concurrent feedback group during retention testing. DISCUSSION AND CONCLUSION: Subjects who trained with augmented feedback had less variability, and thus more consistency, than the control group subjects who received no feedback. Augmented feedback provides the student with a reference force and the status of his or her performance. The effectiveness of the JTS feedback compared with no feedback was clearly demonstrated. Skill acquisition in mobilization can be enhanced by either concurrent or terminal feedback.

Relationships among speech perception, self-rated tinnitus loudness and disability in tinnitus patients with normal pure-tone thresholds of hearing.

Exactly how speech perception and tinnitus perception are related remains unclear. This study investigated how tinnitus alone affects speech perception and the relationship between speech perception, tinnitus loudness, and tinnitus disability. The Mandarin Speech Perception in Noise Test (MSPIN), Tinnitus Loudness Scaling (TLS), and Tinnitus Handicap Inventory (THI) were utilized to assess 20 tinnitus patients with normal hearing. The tinnitus group had a significantly lower MSPIN score than the control group (p < 0.01). TLS and THI scores were strongly correlated (r(2): 0.534 approximately 0.627, p < 0.05). Correlations between MSPIN and TLS or THI scores were not significant. Tinnitus loudness correlated well with tinnitus-related disability. Neither tinnitus loudness nor disability was strongly correlated with speech perception. In noisy environments, tinnitus sufferers had significantly poorer ability to recognize speech than control subjects.

Evaluation of the mixing point in tinnitus sound therapy by a psychoacoustic matching protocol with a digital tinnitus evaluation system.

Directive counseling and sound therapy have been reported to effectively alleviate tinnitus suffering. Without objective evaluation, researchers doubt the real effect of sound therapy. This study was designed to evaluate the frequency and intensity of the theoretical 'mixing point' (MP) in sound therapy and to investigate its relationship with the minimal masking level (MML) of tinnitus. The tinnitus tones of 133 patients were successfully matched in frequency (dominant in 4-10 kHz) and loudness (83.09 +/- 12.04 dB) using a psychoacoustic matching protocol and a newly designed tinnitus evaluation system. The matching rate was 83%. The relationship between the MP and MML is described by a linear regression equation: MP = 0.90 x MML + 1.98 (r2 = 0.82, p < 0.0001). The results of matching and correlation analysis confirmed the consistency of the MP in sound therapy. The psychoacoustic characteristics of tinnitus can be objectively evaluated with our matching protocol and evaluation system.