2,759 research outputs found

    Color-Shift Compensation for Foldable OLED Display

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    This publication describes techniques for off-angle color-shift compensation that accommodates a user’s viewing direction and use cases for devices including foldable OLED displays, particularly, foldable displays configured in an intermediate mode with a first display portion positioned in a first plane (e.g., as a display) and a second display portion positioned in a second plane at an angle to the first plane (e.g., as an input screen). The techniques include generating a Color Compensation lookup table (LUT) relating display input values with corresponding display output values (target color space), based on angle measurements between the first display portion and the second display portion. The Color Compensation LUT is stored on a computer-readable medium (CRM) of the device as device data. A Display Manager implemented on the CRM utilizes sensor data from sensors (e.g., radar sensors, gyroscope sensors, hinge sensors) to enable off-angle color-shift compensation that compensates for a color difference between the first display portion and the second display portion

    Nano-Watt Modular Integrated Circuits for Wireless Neural Interface.

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    In this work, a nano-watt modular neural interface circuit is proposed for ECoG neuroprosthetics. The main purposes of this work are threefold: (1) optimizing the power-performance of the neural interface circuits based on ECoG signal characteristics, (2) equipping a stimulation capability, and (3) providing a modular system solution to expand functionality. To achieve these aims, the proposed system introduces the following contributions/innovations: (1) power-noise optimization based on the ECoG signal driven analysis, (2) extreme low-power analog front-ends, (3) Manchester clock-edge modulation clock data recovery, (4) power-efficient data compression, (5) integrated stimulator with fully programmable waveform, (6) wireless signal transmission through skin, and (7) modular expandable design. Towards these challenges and contributions, three different ECoG neural interface systems, ENI-1, ENI-16, and ENI-32, have been designed, fabricated, and tested. The first ENI system(ENI-1) is a one-channel analog front-end and fabricated in a 0.25µm CMOS process with chopper stabilized pseudo open-loop preamplifier and area-efficient SAR ADC. The measured channel power, noise and area are 1.68µW at 2.5V power-supply, 1.69µVrms (NEF=2.43), and 0.0694mm^2, respectively. The fabricated IC is packaged with customized miniaturized package. In-vivo human EEG is successfully measured with the fabricated ENI-1-IC. To demonstrate a system expandability and wireless link, ENI-16 IC is fabricated in 0.25µm CMOS process and has sixteen channels with a push-pull preamplifier, asynchronous SAR ADC, and intra-skin communication(ISCOM) which is a new way of transmitting the signal through skin. The measured channel power, noise and area are 780nW, 4.26µVrms (NEF=5.2), and 2.88mm^2, respectively. With the fabricated ENI-16-IC, in-vivo epidural ECoG from monkey is successfully measured. As a closed-loop system, ENI-32 focuses on optimizing the power performance based on a bio-signal property and integrating stimulator. ENI-32 is fabricated in 0.18µm CMOS process and has thirty-two recording channels and four stimulation channels with a cyclic preamplifier, data compression, asymmetric wireless transceiver (Tx/Rx). The measured channel power, noise and area are 140nW (680nW including ISCOM), 3.26µVrms (NEF=1.6), and 5.76mm^2, respectively. The ENI-32 achieves an order of magnitude power reduction while maintaining the system performance. The proposed nano-watt ENI-32 can be the first practical wireless closed-loop solution with a practically miniaturized implantable device.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/98064/1/schang_1.pd

    Image Data Compensation to Prevent Display Artifacts on an OLED Display

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    This publication describes techniques for image data compensation that prevent display artifacts on an organic light-emitting diode (OLED) display when the refresh rate and the clock speed of the display are changed. The OLED display may be implemented in a mobile device that supports multiple refresh rates. To conserve power, the mobile device may alter the refresh rate and clock speed of the OLED display from a first refresh rate and clock speed to a second refresh rate and clock speed. Image data intended to be displayed on a particular pixel row of the OLED display may be compensated based on the first refresh rate, the second refresh rate, and the location of the particular pixel row within the OLED display to generate compensated image data. Using the techniques described herein, the compensated image data may be output for use in preventing display artifacts while the image data is displayed in a first frame after the refresh rate and clock speed are changed

    Real-time measurement of the three-axis contact force distribution using a flexible capacitive polymer tactile sensor

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    In this paper, we report real-time measurement results of various contact forces exerted on a new flexible capacitive three-axis tactile sensor array based on polydimethylsiloxane (PDMS). A unit sensor consists of two thick PDMS layers with embedded copper electrodes, a spacer layer, an insulation layer and a bump layer. There are four capacitors in a unit sensor to decompose a contact force into its normal and shear components. They are separated by a wall-type spacer to improve the mechanical response time. Four capacitors are arranged in a square form. The whole sensor is an 8 _ 8 array of unit sensors and each unit sensor responds to forces in all three axes. Measurement results show that the full-scale range of detectable force is around 0–20 mN (250 kPa) for all three axes. The estimated sensitivities of a unit sensor with the current setup are 1.3, 1.2 and 1.2%/mN for the x- , y- and z -axes, respectively. A simple mechanical model has been established to calculate each axial force component from the measured capacitance value. Normal and shear force distribution images are captured from the fabricated sensor using a real-time measurement system. The mechanical response time of a unit sensor has been estimated to be less than 160 ms. The flexibility of the sensor has also been demonstrated by operating the sensor on a curved surface of 4 mm radius of curvature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90798/1/0960-1317_21_3_035010.pd

    A Parametric Study on the Immunomodulatory Effects of Electroacupuncture in DNP-KLH Immunized Mice

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    This study was conducted to compare the effects of low frequency electroacupuncture (EA) and high frequency EA at acupoint ST36 on the production of IgE and Th1/Th2 cytokines in BALB/c mice that had been immunized with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH), as well as to investigate the difference in the immunomodulatory effects exerted by EA stimulations at acupoint ST36 and at a non-acupoint (tail). Female BALB/c mice were divided into seven groups: normal (no treatments), IM (immunization only), ST36-PA (IM + plain acupuncture at ST36), ST36-LEA (IM + low frequency (1 Hz) EA at ST36), ST36-HEA (IM + high frequency (120 Hz) EA at ST36), NA-LEA (IM + low frequency (1 Hz) EA at non-acupoint) and NA-HEA (IM + high frequency (120 Hz) EA at non-acupoint). EA stimulation was performed daily for two weeks, and total IgE, DNP-KLH specific IgE, IL-4 and IFN-γ levels were measured at the end of the experiment. The results of this study showed that the IgE and IL-4 levels were significantly suppressed in the ST36-LEA and ST36-HEA groups, but not in the NA-LEA and NA-HEA groups. However, there was little difference in the immunomodulatory effects observed in the ST36-LEA and ST36-HEA groups. Taken together, these results suggest that EA stimulation-induced immunomodulation is not frequency dependent, but that it is acupoint specific

    Endometrial Stromal Sarcoma Presenting as Prevesical Mass Mimicking Urachal Tumor

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    Endometrial stromal sarcoma (ESS) is a mesenchymal neoplasm that usually occurs as a primary tumor of the uterine corpus, but rarely arises in other sites, such as the ovary, pelvic cavity, mesentery, omentum and intestine. Herein, we present a rare case of low-grade ESS presented as prevesical mass. A 60-yr-old woman who had undergone total hysterectomy for endometriosis eleven years ago was presented with incidentally detected prevesical pelvic mass. Since malignant transformation of urachal remnants was possible, the mass was suspected to be a urachal tumor. Extraction of the mass was performed, and the histopathologic diagnosis was low-grade ESS. In summary, prevesical tumor is rare but in patients with endometriosis, we suggest endometriosis and its possible malignant changes should be taken into account in the differential diagnosis of prevesical mass

    Microlensing Detections of Planets in Binary Stellar Systems

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    We demonstrate that microlensing can be used for detecting planets in binary stellar systems. This is possible because in the geometry of planetary binary systems where the planet orbits one of the binary component and the other binary star is located at a large distance, both planet and secondary companion produce perturbations at a common region around the planet-hosting binary star and thus the signatures of both planet and binary companion can be detected in the light curves of high-magnification lensing events. We find that identifying planets in binary systems is optimized when the secondary is located in a certain range which depends on the type of the planet. The proposed method can detect planets with masses down to one tenth of the Jupiter mass in binaries with separations <~ 100 AU. These ranges of planet mass and binary separation are not covered by other methods and thus microlensing would be able to make the planetary binary sample richer.Comment: 5 pages, two figures in JPG forma

    Clinical Features and Prognosis of HLA-B27 Positive and Negative Anterior Uveitis in a Korean Population

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    Clinical features and prognosis of HLA-B27 positive anterior uveitis (AU) were assessed compared with HLA-B27 negative AU in a Korean population, based on the medical records of AU patients seen at a university hospital. Twenty-seven HLA-B27 negative, idiopathic AU patients (group I) and 55 HLA-B27 positive AU patients (group II) were studied. HLA-B27 positive group was further divided into 29 with associated systemic disease (seronegative spondyloarthropathy) (group IIA) and 26 without associated systemic disease (group IIB). Significantly more severe anterior chamber inflammation in terms of anterior chamber cells (P=0.006) and hypopyon formation (P=0.034) was observed with higher frequency of AU attacks (P=0.007) in the HLA-B27 positive group than in the HLA-B27 negative group. Systemic/periocular steroids were required in significantly more patients in the HLA-B27 positive group than in the HLA-B27 negative group (P=0.015). However, no significant differences were observed for final ocular and visual outcomes between these two groups. Associated systemic disease made no significant difference in the clinical features and prognosis in the HLA-B27 positive AU patients. In conclusion, despite more severe inflammation and a higher recurrence rate, HLA-B27 positive AU shows similar good final ocular and visual outcomes compared to HLA-B27 negative, idiopathic AU in a Korean population

    Effect of Achyranthes bidentata

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    The present study investigated the antiobesity effect of Achyranthes bidentata Blume root water extract in a 3T3-L1 adipocyte differentiation model and rats fed with a high-fat diet. To investigate the effect of Achyranthes bidentata Blume on adipogenesis in vitro, differentiating 3T3-L1 cells in adipocyte-induction media were treated every two days with Achyranthes bidentata Blume at various concentrations (1 to 25 μg/mL) for eight days. We found that Achyranthes bidentata Blume root inhibited 3T3-L1 adipocyte differentiation without affecting cell viability, and Western blot analysis revealed that phospho-Akt expression was markedly decreased, whereas there was no significant change in perilipin expression. Furthermore, administration of Achyranthes bidentata Blume root (0.5 g/kg body weight for six weeks) to rats fed with a high-fat diet significantly reduced body weight gain without affecting food intake, and the level of triglyceride was significantly decreased when compared to those in rats fed with only a high-fat diet. These results suggest that Achyranthes bidentata Blume root water extract could have a beneficial effect on inhibition of adipogenesis and controlling body weight in rats fed with a high-fat diet
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