3D evaluation model of facial aesthetics based on multi-input 3D convolution neural networks for orthognathic surgery.

BACKGROUND: Quantitative evaluation of facial aesthetics is an important but also time-consuming procedure in orthognathic surgery, while existing 2D beauty-scoring models are mainly used for entertainment with less clinical impact. METHODS: A deep-learning-based 3D evaluation model DeepBeauty3D was designed and trained using 133 patients' CT images. The customised image preprocessing module extracted the skeleton, soft tissue, and personal physical information from raw DICOM data, and the predicting network module employed 3-input-2-output convolution neural networks (CNN) to receive the aforementioned data and output aesthetic scores automatically. RESULTS: Experiment results showed that this model predicted the skeleton and soft tissue score with 0.231 ± 0.218 (4.62%) and 0.100 ± 0.344 (2.00%) accuracy in 11.203 ± 2.824 s from raw CT images. CONCLUSION: This study provided an end-to-end solution using real clinical data based on 3D CNN to quantitatively evaluate facial aesthetics by considering three anatomical factors simultaneously, showing promising potential in reducing workload and bridging the surgeon-patient aesthetics perspective gap.

Precise Brain-shift Prediction by New Combination of W-Net Deep Learning for Neurosurgical Navigation.

Brain tissue deformation during surgery significantly reduces the accuracy of image-guided neurosurgeries. We generated updated magnetic resonance images (uMR) in this study to compensate for brain shifts after dural opening using a convolutional neural network (CNN). This study included 248 consecutive patients who underwent craniotomy for initial intra-axial brain tumor removal and correspondingly underwent preoperative MR (pMR) and intraoperative MR (iMR) imaging. Deep learning using CNN to compensate for brain shift was performed using the pMR as input data, and iMR obtained after dural opening as the ground truth. For the tumor center (TC) and the maximum shift position (MSP), statistical analysis using the Wilcoxon signed-rank test was performed between the target registration error (TRE) for the pMR and iMR (i.e., the actual amount of brain shift) and the TRE for the uMR and iMR (i.e., residual error after compensation). The TRE at the TC decreased from 4.14 ± 2.31 mm to 2.31 ± 1.15 mm, and the TRE at the MSP decreased from 9.61 ± 3.16 mm to 3.71 ± 1.98 mm. The Wilcoxon signed-rank test of the pMR TRE and uMR TRE yielded a p-value less than 0.0001 for both the TC and MSP. Using a CNN model, we designed and implemented a new system that compensated for brain shifts after dural opening. Learning pMR and iMR with a CNN demonstrated the possibility of correcting the brain shift after dural opening.

Surgery assistance system for continuous resection of brain tumors-proposal of continuous tumor resection forceps, tumor cell separation, dehydration, and isolation mechanism.

The tumor resection ratio must be improved due the increased possibility of recurrence or malignancy. The purpose of this study was to develop a system that includes forceps with a continuous suction function and flow cytometry to diagnose the malignancy of the tumor for safe, accurate, and effective surgery. A newly developed continuous tumor resection forceps consists of a triple pipe structure, which enables continuous suction of the tumor by integrating the reflux water and suction system. The forceps includes tip opening/closure detection switch to control the adsorption and suction strength when tip is opened and closed. To perform accurate tumor diagnosis using flow cytometry, a filtering mechanism was developed for dehydrating reflux water from continuous suction forceps. In addition, a cell isolation mechanism comprising a roller pump and shear force loading mechanism was also newly developed. By using a triple pipe structure, a significantly larger tumor collection ratio was observed compared to the previous double-pipe structure. By performing suction pressure control with the opening/closure detection switch, inaccurate suction can be prevented. By widening the filter area of dehydration mechanism, it was possible to improve the reflux water dehydration ratio. The most appropriate filter area was 85 mm2. By using a newly developed cell isolation mechanism, the processing time can be reduced to less than 1/10 of the original time, keeping the same cell isolation ratio, when compared to the existing pipetting method. Neurosurgery assistance system with continuous tumor resection forceps and a cell separation, dehydration and isolation mechanism was developed. An effective and safe tumor resection, accurate and fast diagnosis of malignancy can be achieved by using the current system.

Relationship between characteristics of glioma treatment and surgical site infections.

PURPOSE: Surgical site infections (SSIs) after neurosurgery are common in daily practice. Although numerous reports have described SSIs in neurosurgery, reports specific to gliomas are limited. This study aimed to investigate the relationship between SSIs and glioma treatment characteristics, such as reoperations, radiation therapy, and chemotherapy. METHODS: We examined 1012 consecutive patients who underwent craniotomy for glioma between November 2013 and March 2022. SSIs were defined as infections requiring reoperation during the observation period, regardless of their location. We retrospectively analyzed SSIs and patient factors. RESULTS: During the observation period, SSIs occurred in 3.1% (31/1012). In the univariate analysis, three or more surgeries (P = 0.007) and radiation therapy (P = 0.03) were associated with SSIs, whereas intraoperative magnetic resonance imaging (MRI) was not significantly associated (P = 0.35). Three or more surgeries and radiation therapy were significantly correlated with each other (P < .0001); therefore, they were analyzed separately in the multivariate analysis. Three or more surgeries were an independent factor triggering SSIs (P = 0.02); in contrast, radiation therapy was not an independent factor for SSIs (P = 0.07). Several SSIs localized in the skin occurred more than 1 year after surgery. CONCLUSIONS: Undergoing three or more surgeries for glioma is an independent risk factor for SSIs. Glioma SSIs can occur long after surgery. These results are considered characteristic of gliomas. We recommend careful long-term observation of patients at a high risk of SSIs.

Construction of brain area risk map for decision making using surgical navigation and motor evoked potential monitoring information.

PURPOSE: Surgical devices or systems typically operate in a stand-alone manner, making it difficult to perform integration analysis of both intraoperative anatomical and functional information. To address this issue, the intraoperative information integration system OPeLiNK® was developed. The objective of this study is to generate information for decision making using surgical navigation and intraoperative monitoring information accumulated in the OPeLiNK® database and to analyze its utility. METHODS: We accumulated intraoperative information from 27 brain tumor patients who underwent resection surgery. First, the risk rank for postoperative paralysis was set according to the attenuation rate and amplitude width of the motor evoked potential (MEP). Then, the MEP and navigation log data were combined and plotted on an intraoperative magnetic resonance image of the individual brain. Finally, statistical parametric mapping (SPM) transformation was performed to generate a standard brain risk map of postoperative paralysis. Additionally, we determined the anatomical high-risk areas using atlases and analyzed the relationship with each set risk rank. RESULTS: The average distance between the navigation log corresponding to each MEP risk rank and the anatomical high-risk area differed significantly between the with postoperatively paralyzed and without postoperatively paralyzed groups, except for "safe." Furthermore, no excessive deformation was observed resulting from SPM conversion to create the standard brain risk map. There were cases in which no postoperative paralysis occurred even when MEP decreased intraoperatively, and vice versa. CONCLUSION: The time synchronization reliability of the study data is very high. Therefore, our created risk map can be reported as being functional at indicating the risk areas. Our results suggest that the statistical risks of postoperative complications can be presented for each area where brain surgery is to be performed. In the future, it will be possible to provide surgical navigation with intraoperative support that reflects the risk maps created.

The actual status of drug prices and adjustment factors for drug price calculation: an analysis of ultra-orphan drug development in Japan.

BACKGROUND: Extremely high prices facilitate drug development for ultra-rare diseases (ultra-orphan drugs). However, various problems arise in terms of healthcare financing and fairness, and the status of ultra-orphan drug pricing remains ambiguous. In this study, we investigated ultra-orphan drug prices in Japan relative to that of other drugs. We examined the relationship between annual expected drug prices and expected sales, and the expected number of patients, for 393 drugs containing new active ingredients for therapeutic use that were listed on the National Health Insurance drug price list in Japan between April 16, 2010 and August 26, 2020. In addition, we compared prices, the drug price calculation method, and price calculation adjustment factors for ultra-orphan and other drugs. RESULTS: Drug prices tended to increase as the expected number of patients to whom the drug was administered decreased; however, this trend diminished when the expected number of patients was less than 1000. On the other hand, the expected sales tended to decrease as the number of expected patients decreased, and this tendency was reinforced when the expected number of patients was less than 1000. The cost accounting method tended to be used for the price calculation of ultra-orphan drugs, but there were no price differences based on the drug price calculation method. Regarding the price calculation adjustment factors, the premium for usefulness tended to be higher for ultra-orphan drugs. The premium for marketability was higher for non-orphan drugs but did not differ from that for orphan drugs, except for ultra-orphan drugs. CONCLUSIONS: The status of drug prices and expected sales differed beyond a threshold of 1000 expected patients, indicating that recovering the development cost for ultra-orphan drugs is difficult. In addition, the higher premium for usefulness for ultra-orphan drugs reflects the largely unmet need of the associated diseases. Scarcity among orphan drugs is not considered for marketability, highlighting the need for a new framework to promote the development of ultra-orphan drugs.

Temperature-controlled laser thermal therapy system using a newly developed laparoscopic system equipped with an ultra-compact thermographic camera.

Laser thermal therapy is one of the treatments for malignant tumors. We developed a thermal endoscope using an ultra-compact thermo-sensor and established a new laparoscopic laser thermal therapy system to heat cancer tissue at an appropriate temperature, focusing on the fact that thermographic cameras are capable of two-dimensional temperature mapping. Hepatocellular carcinoma (N1S1) cells were implanted into the livers of Sprague-Dawley rats (n = 13) to create orthotopic hepatocellular carcinoma. Six of the rats underwent laparoscopic laser thermotherapy (70 °C, 5 min) using the newly developed system, and the others underwent laparoscopic insertion only. Lesion volume measurement and histological evaluation were performed in all of the rats. The laparoscopic laser thermal therapy system provided stable temperature control. When a temperature of 70 °C was used for the set temperature, the temperature of the target cancer was maintained within the range of 68-72 °C for 93.2% of the irradiation time (5 min). The median volume of the tumors that were thermally treated was significantly smaller than that of the untreated tumors. The newly developed laparoscopic laser thermal therapy system was capable of maintaining the temperature of the tumor surface at any desired temperature and was proven to be effective in treatment of the rat hepatocellular carcinoma model.

A trial to visualize perforators images from CTA with a tablet device: experience of operating on minipigs.

A reliable method for precise perforator mapping can be extremely valuable in perforator flap surgery. In this study, we attempted to map perforator location using 3-dimensional computed tomography angiography (CTA), a newly developed application, and a tablet device. Preliminary examinations to test the device were conducted in mini-pigs. We used 5 female mini-pigs. Preoperative imaging of the vasculature was undertaken with CTA in the prone position, following Iopamidol (200 ml) injection via the internal jugular vein. Prior to the examination, we placed round markers on the backs of the mini-pigs. To assess accuracy, we compared the perforator positions acquired with an optical position measurement device with the perforator positions acquired with the tablet device. Furthermore, we compared the perforator positions with the tablet navigation device, which we measured directly. We measured 12 perforators with the optical position measurement device. The mean difference was 10 mm (minimum, 2 mm; maximum, 20 mm). We measured these perforators with the tablet navigation device. The mean difference was 5.4 mm (minimum, 0 mm; maximum, 20 mm). The perforator flaps were elevated safely. The perforator flaps could be elevated safely using our device, as the mean difference was only 10 mm, which is acceptable for navigating perforator flap operations. Pig backs are triangular in shape; therefore, we were unable to place markers on the contralateral side. Thus, for clinical applications of the device, we should determine the ideal marker locations.

The high incidence and risk factors of levetiracetam and lacosamide-related skin rashes in glioma patients.

OBJECTIVE: Antiseizure drug (ASD)-induced skin rash remains the main side effect of seizure management in patients with glioma. New generations of ASDs, such as levetiracetam (LEV) and lacosamide (LCM) are associated with less frequent skin rashes than conventional ASDs. However, there are few reports regarding the incidence of skin rashes by LEV and LCM in patients with glioma. Therefore, the aim of this study was to investigate the incidence and risk factors of LEV- and LCM-associated skin rashes in patients with glioma. METHODS: We compared the incidence of ASD-associated skin rash between 353 patients with glioma and 125 patients with meningioma, who received LEV or LCM and underwent surgery between 2017 and 2019 at our institution. Furthermore, to evaluate the association between potential risk factors and ASD-associated skin rashes, univariate and multivariate analyses were performed. RESULTS: The incidence of ASD-associated skin rash in patients with glioma was higher (11 %) than in those with meningiomas (1.6 %). The multivariate regression analysis showed that adjuvant treatment with radiotherapy (p = 0.023) and a history of drug allergy (p = 0.023) were significant risk factors for ASD-associated skin rash. The rate of ASD-related skin rashes in patients with glioma was also higher than the previously reported rates of 1-3 % in patients with epilepsy. CONCLUSION: Our results indicate that adjuvant treatment with radiotherapy and a history of drug allergy correlated with a high incidence of ASD-related skin rashes in patients with glioma who receive LEV and LCM. Patients with these two factors should be carefully checked for skin rashes.

Machine-learning-based approach for predicting postoperative skeletal changes for orthognathic surgical planning.

BACKGROUND: Manually surgical planning becomes an increasing workload of surgeons because of the fast-growing patient population. This study introduced a machine-learning-based approach to assist surgical planning in orthognathic surgery. METHODS: Both preoperative and one-year-later postoperative computerised tomography images of 56 patients were collected. A 12-layers cascaded deep neural network structure with two successive models was proposed to yield an end-to-end solution, where the first model extracts landmarks from 2D patches of 3D volume and the second model predicts postoperative skeletal changes. RESULTS: The experimental results showed that the model obtained a prediction accuracy of 5.4 mm at the landmark level in 42.9 s. It also represented 74.4% of 3D regions at volume level when compared with the ground truth of human surgeons. CONCLUSIONS: This study demonstrated the feasibility of predicting postoperative skeletal changes for orthognathic surgical planning by using machine learning, showing great potential for reducing the workload of surgeons.

Mixed Reality Needle Guidance Application on Smartglasses Without Pre-procedural CT Image Import with Manually Matching Coordinate Systems.

PURPOSE: To develop and assess the accuracy of a mixed reality (MR) needle guidance application on smartglasses. MATERIALS AND METHODS: An MR needle guidance application on HoloLens2, without pre-procedural CT image reconstruction or import by manually matching the spatial and MR coordinate systems, was developed. First, the accuracy of the target locations in the image overlay at 63 points arranged on a 45 × 35 × 21 cm box and needle angles from 0° to 80°, placed using the MR application, was verified. The needle placement errors from 12 different entry points in a phantom by seven operators (four physicians and three non-physicians) were compared using a linear mixed model between the MR guidance and conventional methods using protractors. RESULTS: The average errors of the target locations and needle angles placed using the MR application were 5.9 ± 2.6 mm and 2.3 ± 1.7°, respectively. The average needle insertion error using the MR guidance was slightly smaller compared to that using the conventional method (8.4 ± 4.0 mm vs. 9.6 ± 5.1 mm, p = 0.091), particularly in the out-of-plane approach (9.6 ± 3.5 mm vs. 12.3 ± 4.6 mm, p = 0.003). The procedural time was longer with MR guidance than with the conventional method (412 ± 134 s vs. 219 ± 66 s, p < 0.001). CONCLUSION: MR needle guidance without pre-procedural CT image import is feasible when matching coordinate systems, and the accuracy of needle insertion is slightly better than that of the conventional method.

Current Landscape of Sonodynamic Therapy for Treating Cancer.

Recent advancements have tangibly changed the cancer treatment landscape. However, curative therapy for this dreadful disease remains an unmet need. Sonodynamic therapy (SDT) is a minimally invasive anti-cancer therapy involving a chemical sonosensitizer and focused ultrasound. A high-intensity focused ultrasound (HIFU) beam is used to destroy or denature targeted cancer tissues. Some SDTs are based on unfocused ultrasound (US). In some SDTs, HIFU is combined with a drug, known as a chemical sonosensitizer, to amplify the drug's ability to damage cancer cells preferentially. The mechanism by which US interferes with cancer cell function is further amplified by applying acoustic sensitizers. Combining multiple chemical sonosensitizers with US creates a substantial synergistic effect that could effectively disrupt tumorigenic growth, induce cell death, and elicit an immune response. Therefore, the minimally invasive SDT treatment is currently attracting attention. It can be combined with targeted therapy (double-targeting cancer therapy) and immunotherapy in the future and is expected to be a boon for treating previously incurable cancers. In this paper, we will consider the current state of this therapy and discuss parts of our research.

A Three-dimensionally Printed Acrylonitrile Butadiene Styrene Model for the Reduction of Nasomaxillary Fracture.

The successful reduction of a nasomaxillary fracture was performed using a three-dimensional printed model. A 16-year-old boy was struck in the left orbit by a baseball; subsequently, he was diagnosed with the nasal bone fracture at a hospital, and was referred to the authors' department. A left nasomaxillary fracture and nasal bone fracture were diagnosed by computed tomography. Standard triangulated language data for the mirror image of the frontal process of the right maxilla were obtained from digital imaging and communications in medicine data for preparing a three-dimensional printed acrylonitrile butadiene styrene model. On postinjury day 13, the frontal process fracture was reduced via transconjunctival and intraoral approaches. After the reduction of the fracture, an absorbable plate fitting to the shape of three-dimensional printed acrylonitrile butadiene styrene model was molded, and the maxillary frontal process and infraorbital rim were reduced and fixed with an absorbable plate and screws. Postoperative computed tomography demonstrated a favorable reduction. The intraoperative use of the 3D printed acrylonitrile butadiene styrene model was helpful in the nasomaxillary fracture reduction and fixation.

Learning effectiveness of using augmented reality technology in central venous access procedure: an experiment using phantom and head-mounted display.

PURPOSE: Augmented reality (AR) technology improves the learning process in interventional radiology. This study hypothesized that using AR to train for central venous access is superior to using ultrasound alone. METHODS: This study used an AR central venous catheterization phantom with an internal jugular vein (IJV) and subclavian vein (SCV) made of resin body and soft tubing. Ten radiologists attempted to punctuate, using needle placement simulation, under three conditions (ultrasound-, augmented reality-, and ultrasound and AR-guided methods; US-only, AR-only, and US+AR, respectively) using a smart-glass device (HoloLens, Microsoft, Redmond, WA, USA). Subjective (anatomical understanding and self-confidence for procedure) and objective evaluations (optimized needle position and time) were recorded for each condition. RESULTS: The subjective IJV evaluation showed no difference among the guiding methods (p = 0.26 and p = 0.07 for anatomical understanding and self-confidence for procedure, respectively). Conversely, there were significant improvements in subjective and objective evaluations for SCV using the AR-only and US+AR methods (p < 0.05) and US+AR method (p < 0.05), respectively. The AR-only method reduced the time required to fix the needle position to puncture the SCV (p < 0.05), but its objective evaluation did not improve compared with the US-only method (p = 0.20). CONCLUSION: Adding the AR-guided method to the US-guided method improved subjective and objective evaluations in the SVC procedure. The AR technology-assisted training may be more beneficial for use in difficult procedures. Though the AR-only method saved time, no time saving is expected with AR+US method.

Locally operated assistant manipulators with selectable connection system for robotically assisted laparoscopic solo surgery.

PURPOSE: By integrating locally operated surgical assistant robots in a sterilized area, a surgeon can perform safe robotically assisted laparoscopic solo surgery while controlling a laparoscope-holding robot and a forceps robot. At present, there is no leader-follower control system with switchable connection for the leader device in which each assistant follower robot can provide the manipulation intuitively and easily. In the present study, a new locally operated leader-follower selectable control system has been developed. METHODS: The leader-follower system was developed to connect one leader operating device and one of two selectable follower assistant manipulator devices with different numbers of axes, kinematics models, sensors, and actuators for view stabilization and pulling organs. The system is constructed using the middleware of the ORiN-based medical robot architecture MRLink. The system is regulated by the robot integrator application with unilateral leader-follower PTP using the relative displacement between the leader device and the selected follower device through providers of device interface including the information and control commands. RESULTS: The execution cycle for updating the position was 50 ms, and the time delay to catch up with the same position was 100 ms. Two assistant manipulators controlled by the leader-follower selectable system could successfully produce the desired view and handle the target organ model for 17 min in a simulated laparoscopic cholecystectomy. CONCLUSIONS: A locally operated leader-follower selectable control system was constructed to facilitate minimally invasive, robotically assisted laparoscopic solo surgery by a doctor working near the patient. This system could be used for such applications.

Robotic Technology in Operating Rooms: a Review.

Purpose of Review: With the rapid growth and development of robotic technology, its implementation in medical fields has also been significantly increasing, with the transition from the period of mainly using surgical robots to the era with combinations of multiple types of robots. Therefore, this paper introduces the newest robotic systems and technology applied in operating rooms as well as their architectures for integration. Recent Findings: Besides surgical robots, other types of robotic devices and machines such as diagnostic and treatment devices with robotic operating tables, robotic microscopes, and assistant robots for surgeons emerge one after another, improving the quality of surgery from different aspects. With the increasing number and type of robots, their integration platforms are also proposed and being spread. Summary: This review paper presents state-of-the-art robot-related technology in the operating room. Robotic platforms and robot components which appeared in the last decade are described. In addition, system architectures for the integration of robots as well as other devices in operating rooms are also introduced and compared.

Effectiveness of drug postmarketing all-case surveillance as a safety measure in Japan.

INTRODUCTION: The drug pharmacovigilance system in Japan is similar to those in the European Union (EU) and the United States. As a unique Japanese pharmacovigilance program, postmarketing all-case surveillance (PMACS) is required. PMACS plays a key role for postmarketing activities, but there are challenges that place much burden on PMACS conduct. This study investigates the impact of PMACS on postmarketing activities in Japan and proposes its potential improvement. This study also seeks the possibility to expand PMACS beyond Japan. MATERIALS AND METHODS: Reexamination reports issued from 2017 to 2019 were identified in September 2020 by searching 'reexamination report' and '201701' to '201912' on the Pharmaceuticals and Medical Devices Agency website. The corresponding Package Insert (PI) change orders and premarketing review reports were also identified. Reviewing these regulatory documents allowed for investigation of the PMACS impact on postmarketing activities. RESULTS: More than half (57%) of the drugs with PMACS had 'Limited dosing experience in Japan' as a reason for the PMACS requirement. As a safety measure, no PI change orders were imposed on 33% and 28% of drugs with and without PMACS, respectively. The means of the number of PI change orders were 2.23 and 2.14 for drugs with and without PMACS, respectively. There were no reexamination reports mentioning any concerns related to efficacy. DISCUSSION AND CONCLUSION: PMACS should not be imposed only because of limited dosing experience in Japan at the premarketing stage. Rather, PMACS should focus on (1) collection of safety data (not efficacy), (2) necessity of distribution control, and/or (3) collection of case details for drugs with a limited treated population. PMACS also has the potential to be utilized in the EU and the United States, as their regulatory frameworks are acceptable for PMACS. Naglazyme (galsulfase) is a case where the PMACS-like studies have been required in each region. PLAIN LANGUAGE SUMMARY: Effectiveness of data collection for all patients who receive a new drug as a safety measure in Japan: Introduction:: In Japan, a drug company is obligated to conduct data collection after a new drug launch as an approval condition. The obligation is a unique Japanese requirement where a company must collect data from all patients receiving the drug in Japan in cooperation with hospitals. This is expected to contribute to intensive data collection and better drug distribution control and could potentially be useful in countries beyond Japan. However, no clear criteria have been established for decision making, despite the significant burden for companies and hospitals. Therefore, this study aimed to investigate the impact of the obligation on safety measures and efficacy data collection and propose a potentially improved drug scope to impose the obligation.Materials and Methods:: Reexamination of reports issued by the Pharmaceuticals and Medical Devices Agency between 2017-2019.Results:: More than half (57%) of the included drugs had 'Limited dosing experience in Japan' as a reason for the obligation being required. However, regulatory order to change drug label, an action based on safety signal identification, was imposed on 33% and 28% of drugs with and without the obligation, respectively. The means of the number of the label change orders were 2.23 and 2.14 for drugs with and without obligation, respectively. Meanwhile, some drugs were highlighted as potential factors for better application of the obligation.Conclusion:: According to these results, the obligation should be imposed on a limited number of drugs by focusing not on dosing experience in Japan but on safety (not efficacy) data collection, necessity of distribution control, and/or collection of case details for drugs with a limited treated population. The obligation also has the potential to be utilized in the EU and the United States, as their regulatory frameworks are acceptable for the obligation.

Development of a Semiautomatic Dura Mater Suturing Device for Preventing Cerebrospinal Fluid Leakage in Transsphenoidal Surgery.

Dural suturing in transsphenoidal surgery requires well-honed technical skills. We have developed a semiautomatic dural suturing device and confirmed its effectiveness by comparing it with the conventional method. This device significantly shortens the suturing time compared with the conventional method. The dural suturing time in transsphenoidal surgery could be decreased significantly by use of this novel device.

Video-based neonatal state assessment method for timing of procedures.

BACKGROUND: Procedures should be performed when an infant is most receptive to disruptions in order to reduce the stress on the infant. However, frequent direct observations place a heavy burden on medical staff. There is therefore a need for a method for quantitatively and automatically evaluating the neonatal state. METHODS: Ten infants in our hospital were enrolled in this study. The states of the infants were assessed by medical staff using the Brazelton Neonatal Behavioral Assessment Scale and were recorded on video at the same time. The recorded states were reclassified as activity levels, a new state classification method that includes middle activity, which is the appropriate time for a procedure. Using image analysis, motions of the infant were quantified as two indices: activity and pause time. Activity and pause time were compared for each activity level. The cutoff values of the indices were calculated, and the sensitivity and specificity of the middle activity were calculated. RESULTS: There was a significant difference between all groups of activity level (P < 0.01). The maximum sensitivity and specificity of middle activity were 71.7% and 51.2%, respectively. CONCLUSIONS: The neonatal state of infants can be quantitatively and automatically evaluated using video cameras, and the activity level can be used to determine an appropriate time for procedures in infants. This will reduce the burden on medical staff and lead to less stressful procedures for infants.

Reliability of Residual Tumor Estimation Based on Navigation Log.

The mass of residual tumors has previously been estimated using time-series records of the position of surgical instruments acquired from neurosurgical navigation systems (navigation log). This method has been shown to be useful for rapid evaluation of residual tumors during resection. However, quantitative analysis of the method's reliability has not been sufficiently reported. The effect of poor log coverage is dominant in previous studies, in that it did not highlight other disturbance factors, such as intraoperative brain shift. We analyzed 25 patients with a high log-acquisition rate that was calculated by dividing the log-available time by the instrument-use time. We estimated the region of resection using the trajectory of surgical instrument that was extracted from the navigation log. We then calculated the residual tumor region and measured its volume as log-estimation residual tumor volume (RTV). We evaluated the correlation between the log-estimation RTV and the RTV in the post-resection magnetic resonance (MR) image. We also evaluated the accuracy of detecting the residual tumor mass using the estimated residual tumor region. The log-estimation RTV and the RTV in the post-resection MR image were significantly correlated (correlation coefficient = 0.960; P <0.001). The presence of patient-wise residual tumor mass was detected with a sensitivity of 81.8% and a specificity of 92.9%. The individual residual tumor mass was detected with a positive predictive value of 72%. Estimation of residual tumor with adequate log coverage appears to be a suitable method with a high reliability. This method can support rapid decision-making during resection.