Modular Optoelectronic System for Wireless, Programmable Neuromodulation During Free Behavior.

This work presents a modular, light-weight head-borne neuromodulation platform that achieves low-power wireless neuromodulation and allows real-time programmability of the stimulation parameters such as the frequency, duty cycle, and intensity. This platform is comprised of two parts: the main device and the optional intensity module. The main device is functional independently, however, the intensity control module can be introduced on demand. The stimulation is achieved through the use of energy-efficient µLEDs directly integrated in the custom-drawn fiber-based probes. Our platform can control up to 4 devices simultaneously and each device can control multiple LEDs in a given subject. Our hardware uses off-the-shelf components and has a plug and play structure, which allows for fast turn-over time and eliminates the need for complex surgeries. The rechargeable, battery-powered wireless platform uses Bluetooth Low Energy (BLE) and is capable of providing stable power and communication regardless of orientation. This presents a potential advantage over the battery-free, fully implantable systems that rely on wireless power transfer, which is typically direction-dependent, requires sophisticated implantation surgeries, and demands complex custom-built experimental apparatuses. Although the battery life is limited to several hours, this is sufficient to complete the majority of behavioral neuroscience experiments. Our platform consumes an average power of 0.5 mW, has a battery life of 12 hours.

EMG-based Real Time Facial Gesture Recognition for Stress Monitoring.

An electromyogram (EMG) signal acquisition system capable of real time classification of several facial gestures is presented. The training data consist of the facial EMG collected from 10 individuals (5 female/5 male). A custom-designed sensor interface integrated circuit (IC) consisting of an amplifier and an ADC, implemented in 65nm CMOS technology, has been used for signal acquisition [1]. It consumes 3.8nW power from a 0.3V battery. Feature extraction and classification is performed in software every 300ms to give real-time feedback to the user. Discrete wavelet transforms (DWT) are used for feature extraction in the time-frequency domain. The dimensionality of the feature vector is reduced by selecting specific wavelet decomposition levels without compromising the accuracy, which reduces the computation cost of feature extraction in embedded implementations. A support vector machine (SVM) is used for the classification. Overall, the system is capable of identifying several jaw movements such as clenching, opening the jaw and resting in real-time from a single channel EMG data, which makes the system suitable for providing biofeedback during sleeping and awake states for stress monitoring, bruxism, and several orthodontic applications such as temporomandibular joint disorder (TMJD).

MRI findings of globe and optic nerves in tilted disk syndrome.

We assessed the anatomical variations of the globe and optic nerve in tilted disk (TD) syndrome using magnetic resonance imaging (MRI) findings and compared them with a control group. Eleven patients diagnosed with TD syndrome during eye examination were referred for MRI of the sella and chiasm to exclude intracranial mass lesions. The shape of the globe, the chiasmal angle, the insertion angles of the optic nerve in axial and parasagittal planes determined by lines parallel to the optic nerve and tangent to the globe in TD syndrome were compared with a control group consisting of 53 cases. Gender ratios were 7/4 (F/M) for the TD group and 35/18 for the control group (p>0.05). The insertion angle of the optic disk to the globe was wider in the temporal quadrant (p<0.05) and narrower in the nasal quadrant (p<0.05) in TD syndrome than in the control group. There was no significant difference in the superior and inferior insertion angles between the groups. The anterior-posterior (AP) diameter of the globe was significantly longer in patients with TD (p<0.05). There was no significant difference between the optic chiasm angles. The relationships of the optic disk and the globe were significantly different in patients with TD syndrome in comparison to the control group. TD syndrome is related to the malalignment of optic nerve and globe in the horizontal plane.

Preoperative helical computerized tomography estimation of donor liver volume.

BACKGROUND: The purpose of this study was to evaluate the accuracy of spiral computed tomography (CT) and 3-D imaging models in measuring total and segmental liver volume in potential living donors. METHODS: A prospective study was undertaken to assess the correlation between the volumes of potential donor livers determined via helical CT and the actual volumes measured during operation in 150 donor candidates. Left-lateral segment (S2,3) or left-lobe (S2,3,4) transplantation was performed in 36 cases with 96 right-lobe liver transplants (S5,6,7,8). Ten donor candidates were refused owing to inadequate liver volumes, and 8 for other reasons. RESULTS: The regression analysis model showed a significant correlation between the preoperative CT estimates of graft volume and intraoperative weight measurement of harvested grafts in living liver donors (F: 5525.37; P < .05); 97.7% of changes in CT volume were explained by differences in graft mass (R2: 0.977). CONCLUSION: Preoperative estimation of segmental volumes of the donor liver is necessary to avoid donor-recipient size disparity, thereby preventing hepatic failure of donors after harvesting. It has a major impact on donor selection and type of surgical management. The accuracy of helical CT was high to determine total and segmental liver volumes.

Variations of hepatic veins: helical computerized tomography experience in 100 consecutive living liver donors with emphasis on right lobe.

Anatomical variations in the venous system of liver are not a rarity. A prospective helical computerized tomography (CT) study was undertaken to determine the prevalence of surgically significant hepatic venous anatomic variations among 100 consecutive living liver donors. The studies evaluated the ramification pattern of hepatic veins, the presence of accessory hepatic veins, and of segment 5 or 8 veins (or both) draining into middle hepatic vein. These data obtained by CT influenced surgical planning. Sixty-four donors donated their right lobes and 24 donors, left lateral segments. Only one donor candidate was refused due to combined hepatic and portal venous variations accompanied by multiple bile ducts. Eleven donors were also refused due to reasons other than anatomical variations. Seventeen segment 5 and 17 segment 8 veins draining into middle hepatic vein were anastomosed to inferior vena cava in 23 (36%) of the right lobe liver transplantations. The middle hepatic vein was harvested in only one of the donors. Among the 100 cases, 47 had accessory right inferior hepatic veins, 13 of which were multiple. Twenty-two of the right lobe grafts required surgical anastomoses of these accessory hepatic veins (34%). An isolated hepatic vein anomaly or the presence of accessory hepatic veins are not contraindications to be a living liver donor candidate. However, preoperative knowledge of vascular variations alters surgical management. Helical CT is a valuable tool to delineate the hepatic venous anatomy for surgical planning in living liver donors.

Bilateral metastatic carcinoma of the breast from primary ovarian cancer.

We report a case of ovarian cancer with metastasis to both breasts and axillary lymph nodes and the vaginal cuff. A 41-year-old previously hysterectomized women presented with pelvic mass and malignant pleural effusion. During the courses of chemotherapy; bilateral breast nodules, and bilateral axillary lymphadenopathies and a nodule in the vaginal cuff were identified. The biopsy of both breasts, axillary lymph nodes and the nodule in the vaginal cuff revealed papillary serous cystadenocarcinoma. Immunohistochemical staining of breast specimens were positive for ovarian tumor marker CA-125.

Bilateral large Bochdalek hernias in an adult. CT demonstration.

Bochdalek hernia is a congenital posterior diaphragmatic defect resulting from failure of the retroperitoneal canal membrane to fuse with the dorsal esophageal mesentery and the body wall. A recent computed tomography study indicated that these defects frequently can be identified on routine chest and abdominal images, and classified them as small, medium, and large, the large ones being identifiable on five or more contiguous axial scans consisting of 1-cm-thick sections. Although the overall prevalence of Bochdalek hernias is 6%, and that of bilateral hernias is 0.9%, to date only a few patients with unilateral or bilateral large hernias have been reported. This article describes an adult with asymptomatic, bilateral, large Bochdalek defects containing herniated retroperitoneal fat.