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.

Quantitative Evaluation of Efficacy of Intraoperative Examination Monitor for Awake Surgery.

BACKGROUND: When brain tumors are located near the language area, a test to assess language function is required. During the test, it is practical to display combined information obtained from all the equipment so that the surgeon can confirm the patient's response to the tasks. We developed the intraoperative examination monitor for awake surgery (IEMAS) mainly to combine all information so that the language function test could be performed efficiently. The IEMAS has proved to be useful in clinical settings; however, no quantitative evaluation has been performed. This study aimed to demonstrate the clinical usefulness of the IEMAS through comparison of cases with and without IEMAS use in language function test simulation. METHODS: The language function test simulator was created to eliminate any uncertain factors, such as symptoms, which vary among patients. Neurosurgeons participated in the test, and the usefulness of the IEMAS was investigated. We analyzed test duration and number of information exchanges between surgeon and examiner. RESULTS: Total test duration with IEMAS use was significantly shorter than without IEMAS use (116.1 ± 23.1 seconds vs. 147.8 ± 48.7 seconds; P < 0.02). The number of information exchanges between surgeon and examiner was significantly lower with IEMAS use than without IEMAS use (0.2 ± 0.6 times vs. 16.1 ± 15.6 times; P < 0.02). CONCLUSIONS: We compared cases with and without IEMAS use. Total test duration decreased with IEMAS use, and number of information exchanges was reduced, thus demonstrating the usefulness of the IEMAS.

A novel four-wire-driven robotic catheter for radio-frequency ablation treatment.

PURPOSE:    Robotic catheters have been proposed to increase the efficacy and safety of the radio-frequency ablation treatment. The robotized motion of current robotic catheters mimics the motion of manual ones-namely, deflection in one direction and rotation around the catheter. With the expectation that the higher dexterity may achieve further efficacy and safety of the robotically driven treatment, we prototyped a four-wire-driven robotic catheter with the ability to deflect in two- degree-of-freedom motions in addition to rotation. METHODS:    A novel quad-directional structure with two wires was designed and developed to attain yaw and pitch motion in the robotic catheter. We performed a mechanical evaluation of the bendability and maneuverability of the robotic catheter and compared it with current manual catheters. RESULTS:    We found that the four-wire-driven robotic catheter can achieve a pitching angle of 184.7[Formula: see text] at a pulling distance of wire for 11 mm, while the yawing angle was 170.4[Formula: see text] at 11 mm. The robotic catheter could attain the simultaneous two- degree-of-freedom motions in a simulated cardiac chamber. CONCLUSION:    The results indicate that the four-wire-driven robotic catheter may offer physicians the opportunity to intuitively control a catheter and smoothly approach the focus position that they aim to ablate.

Development and initial clinical testing of "OPECT": an innovative device for fully intangible control of the intraoperative image-displaying monitor by the surgeon.

BACKGROUND: During surgery, various images as well as other relevant visual information are usually shown upon request with the help of operating staff. However, the lack of direct control over the display may represent a source of stress for surgeons, particularly when fast decision making is needed. OBJECTIVE: To present the development and initial clinical testing of an innovative device that enables surgeons to have direct intangible control of the intraoperative image-displaying monitor with standardized free-hand movements. METHODS: The originally developed intangible interface named "OPECT" is based on the commercially available gaming controller KINECT (Microsoft) and dedicated action-recognizing algorithm. The device does not require any sensors or markers fixed on the hands. Testing was done during 30 neurosurgical operations. After each procedure, surgeons completed the 5-item questionnaire for evaluation of the system performance, scaling several parameters from 1 (bad) to 5 (excellent). RESULTS: During surgical procedures, OPECT demonstrated high effectiveness and simplicity of use, excellent quality of visualized graphics, and precise recognition of the individual user profile. In all cases, the surgeons were well satisfied with performance of the device. The mean score value of answers to the questionnaire was 4.7 ± 0.2. CONCLUSION: OPECT enables the surgeon to easily have intangible control of the intraoperative image monitor by using standardized free-hand movements. The system has promising potential to be applied for various kinds of distant manipulations with the displaying visual information during human activities.

Wireless modification of the intraoperative examination monitor for awake surgery.

The dedicated intraoperative examination monitor for awake surgery (IEMAS) was originally developed by us to facilitate the process of brain mapping during awake craniotomy and successfully used in 186 neurosurgical procedures. This information-sharing device provides the opportunity for all members of the surgical team to visualize a wide spectrum of the integrated intraoperative information related to the condition of the patient, nuances of the surgical procedure, and details of the cortical mapping, practically without interruption of the surgical manipulations. The wide set of both anatomical and functional parameters, such as view of the patient's mimic and face movements while answering the specific questions, type of the examination test, position of the surgical instruments, parameters of the bispectral index monitor, and general view of the surgical field through the operating microscope, is presented compactly in one screen with several displays. However, the initially designed IEMAS system was occasionally affected by interruption or detachment of the connecting cables, which sometimes interfered with its effective clinical use. Therefore, a new modification of the device was developed. The specific feature is installation of wireless information transmitting technology using audio-visual transmitters and receivers for transfer of images and verbal information. The modified IEMAS system is very convenient to use in the narrow space of the operating room.

Information-guided surgical management of gliomas using low-field-strength intraoperative MRI.

BACKGROUND: Contemporary technological developments revolutionized management of brain tumors. The experience with information-guided surgery of gliomas, based on the integration of the various intraoperative anatomical, functional, and histological data, is reported. METHODS: From 2000 to 2009, 574 surgeries for intracranial gliomas were performed in our clinic with the use of intraoperative MRI (ioMRI) with magnetic field strength of 0.3T, updated neuronavigation, neurochemical navigation with 5-aminolevulinic acid, serial intraoperative histopathological investigations of the resected tissue, and comprehensive neurophysiological monitoring. Nearly half of patients (263 cases; 45.8%) were followed more than 2 years after surgery. FINDINGS: Maximal possible tumor resection, defined as radiologically complete tumor removal or subtotal removal leaving the residual neoplasm within the vital functionally-important brain areas, was attained in 569 cases (99.1%). The median resection rate constituted 95%, 95%, and 98%, for WHO grade II, III, and IV gliomas, respectively. Actuarial 5-year survival was significantly worse in WHO grade IV gliomas (19%), but did not differ significantly between WHO grade III and II tumors (69% vs. 87%). CONCLUSIONS: Information-guided management of gliomas using low-field-strength ioMRI provides a good opportunity for maximal possible tumor resection, and may result in survival advantage, particularly in patients with WHO grade III neoplasms.

Development of modified intraoperative examination monitor for awake surgery (IEMAS) system for awake craniotomy during brain tumor resection.

Gliomas represent the most frequent type of primary intracranial tumors, which originate from the brain tissue itself, have infiltrative growth, unclear borders, and usually affect functionally-important cerebral structures. From March 2000 till March 2010, 839 neurosurgical procedures directed on resection of such neoplasms were performed in the intelligent operating theater of Tokyo Women's Medical University with the use of intraoperative MRI, real-time updated neuronavigation system, and Hi-vision operative microscope. To facilitate maximal possible tumor resection with minimal risk of neurological morbidity a special device, called Intraoperative Examination Monitor for Awake Surgery (IEMAS) was developed by us. It provides an opportunity to visualize a wide spectrum of inraoperative information related to condition of the patient, nuances of the surgical procedure, and details of the cortical mapping. The wide set of both anatomical and functional parameters, such as view of the patient's mimic and face movements during answering on the specific questions, type of examination test, position of the surgical instruments, parameters of the bispectral index monitor, and general view of the surgical field through the operating microscope and/or endoscope, is presented compactly in one screen with several displays, which allows fast integrated real-time analysis of the multiple data, nearly without interruption of the surgical manipulations. All members of the surgical team can share this information using several in-room liquid crystal displays. However, the initially designed IEMAS system was occasionally affected by interruption or detachment of the connecting cables, which could interfere with effective advancement of the surgical procedure. To avoid this problem a modified device was created. Its specific feature is wireless information transmitting function attained by incorporation of transmitters with a frequency range of 2.4 GHz. The clinical testing of t- - his system was initiated on February 1, 2010, but quickly revealed crossed line effect between transmitters and receivers. To overcome this obstacle and to isolate transmitters, one channel was changed from wireless connection into wired, which resulted in significant improvement of the clearness of both transmitted images and sounds, and provides an opportunity for effective clinical use of the device. In perspective we wish to make IEMAS system fully wireless, using several types of frequency range transmitters.

Intraoperative multichannel audio-visual information recording and automatic surgical phase and incident detection.

Identification, analysis, and treatment of potential risk in surgical workflow are the key to decrease medical errors in operating room. For the automatic analysis of recorded surgical information, this study reports multichannel audio visual recording system, and its review and analysis system. Motion in operating room is quantified using video file size without motion tracking. Conversation among surgical staff is quantified using fast Fourier transformation and frequency filter without speech recognition. The results suggested the progression phase of surgical procedure.