Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 35
Filter
1.
Sensors (Basel) ; 22(20)2022 Oct 16.
Article in English | MEDLINE | ID: mdl-36298205

ABSTRACT

Convolutional neural networks (CNNs) play a key role in deep learning applications. However, the high computational complexity and high-energy consumption of CNNs trammel their application in hardware accelerators. Computing-in-memory (CIM) is the technique of running calculations entirely in memory (in our design, we use SRAM). CIM architecture has demonstrated great potential to effectively compute large-scale matrix-vector multiplication. CIM-based architecture for event detection is designed to trigger the next stage of precision inference. To implement an SRAM-based CIM accelerator, a software and hardware co-design approach must consider the CIM macro's hardware limitations to map the weight onto the AI edge devices. In this paper, we designed a hierarchical AI architecture to optimize the end-to-end system power in the AIoT application. In the experiment, the CIM-aware algorithm with 4-bit activation and 8-bit weight is examined on hand gesture and CIFAR-10 datasets, and determined to have 99.70% and 70.58% accuracy, respectively. A profiling tool to analyze the proposed design is also developed to measure how efficient our architecture design is. The proposed design system utilizes the operating frequency of 100 MHz, hand gesture and CIFAR-10 as the datasets, and nine CNNs and one FC layer as its network, resulting in a frame rate of 662 FPS, 37.6% processing unit utilization, and a power consumption of 0.853 mW.


Subject(s)
Algorithms , Neural Networks, Computer , Software , Gestures , Equipment Design
2.
Sensors (Basel) ; 22(14)2022 Jul 21.
Article in English | MEDLINE | ID: mdl-35891131

ABSTRACT

In this work, a two-dimensional (2D) position-detection device using a single axis magnetic sensor combined with orthogonal gradient coils was designed and fabricated. The sensors used were an induction coil and a GMR spin-valve sensor GF807 from Sensitec Inc. The field profiles generated by the two orthogonal gradient coils were analyzed numerically to achieve the maximum linear range, which corresponded to the detection area of the tracking system. The two coils were driven by 1-kHz sine wave currents with a 90° phase difference to generate the fields with uniform gradients along the x- and y-axis in the plane of the tracking stage. The gradient fields were detected by a single-axis sensor incorporated with a digital dual-phase lock-in detector to retrieve the position information. A linearity correction algorithm was used to improve the location accuracy and to extend the linear range for position sensing. The mean positioning error was found to be 0.417 mm, corresponding to the relative error of 0.21% in the working range of 200 mm × 200 mm, indicating that the proposed tracking system is promising for applications requiring accurate control of the two-dimensional position.

3.
Comput Methods Programs Biomed ; 219: 106762, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35378394

ABSTRACT

BACKGROUND AND OBJECTIVE: The automatic recognition of myocardial infarction (MI) by artificial intelligence (AI) has been an emerging topic of academic research and an existing classification method that can recognize conventional electrocardiogram (ECG) signals with high accuracy. However, they are employed to classify one-dimensional (1-D) ECG signals rather than three-dimensional (3-D) ECG images, and it is limited to provide physicians with significant recommendations to aid in diagnosis like highlighting abnormal leads. Other studies on 3-D ECG images either did not achieve high accuracy or did not employ an inter-patient classification scheme. By proposing a multi-VGG deep neural network, this study aims to develop an automatic classification method for identifying myocardial infarction with inter-patient high accuracy and proper interpretability using 3-D ECG image and a Grad-CAM++ method. METHODS: We apply a multi-VGG deep convolutional neural network to top-view images of 3-D ECG, which are generated from simply denoised standard 12 leads ECG signals for classification. The multi-network method, which separately classifies QRS areas, ST areas, and whole heartbeats, was applied to improve classification performance. Furthermore, the Grad-CAM++ method was used to provide visually interpretable heatmaps for user's attention to improve network interpretability and assist physicians in MI diagnosis RESULTS: The proposed method achieved 95.65% inter-patient accuracy and exactly perfect inner-patient accuracy in the Physikalisch-Technische Bundesanstalt (PTB) diagnostic ECG database experiment. In the PTB-XL diagnostic ECG database, the proposed method achieved 97.23% inter-patient accuracy. The Grad-CAM++ experiment results also showed that the highlighted areas matched the medical diagnosis criteria for myocardial infarction. CONCLUSIONS: Our method demonstrates that 3-D ECG images with AI classification can be efficiently employed for heart disease diagnosis with both high accuracy and visual interpretability.


Subject(s)
Artificial Intelligence , Myocardial Infarction , Algorithms , Databases, Factual , Electrocardiography/methods , Humans , Myocardial Infarction/diagnosis , Neural Networks, Computer
4.
Sensors (Basel) ; 21(4)2021 Feb 05.
Article in English | MEDLINE | ID: mdl-33562587

ABSTRACT

The optical characteristics of copper ion detection, such as the photometric absorbance of specific wavelengths, exhibit significant intensity change upon incident light into the aqueous solutions with different concentrations of metal ions due to the electron transition in the orbit. In this study, we developed a low-cost, small-size and fast-response photoelectric sensing prototype as an optic sensor for copper (Cu) ions detection by utilizing the principle of optical absorption. We quantified the change of optical absorbance from infra-red (IR) light emitting diodes (LEDs) upon different concentrations of copper ions and the transmitted optical signals were transferred to the corresponding output voltage through a phototransistor and circuit integrated in the photoelectric sensing system. The optic sensor for copper (Cu) ions demonstrated not only excellent specificity with other metal ions such as cadmium (Cd), nickel (Ni), iron (Fe) and chloride (Cl) ions in the same aqueous solution but also satisfactory linearity and reproducibility. The sensitivity of the preliminary sensing system for copper ions was 29 mV/ppm from 0 to 1000 ppm. In addition, significant ion-selective characteristics and anti-interference capability were also observed in the experiments by the proposed approach.

5.
Medicine (Baltimore) ; 99(47): e23083, 2020 Nov 20.
Article in English | MEDLINE | ID: mdl-33217809

ABSTRACT

In the present study, we retrospectively analyzed the records of surgical confirmed kidney cancer with renal cell carcinoma pathology in the database of the hospital. We evaluated the significance of cancer size by assessing the outcomes of proposed adaptive active contour model (ACM). The aim of our study was to develop an adaptive ACM method to measure the radiological size of kidney cancer on computed tomography in the hospital patients. This paper proposed a set of medical image processing, applying images provided by the hospital and select the more obvious cases by the doctors, after the first treatment to remove noise image, and the kidney cancer contour would be circled by using the proposed adaptive ACM method. The results showed that the experimental outcome has highly similarity with the medical professional manual contour. The accuracy rate is higher than 99%. We have developed a novel adaptive ACM approach that well combines a knowledge-based system to contour the kidney cancer size in computed tomography imaging to support the clinical decision.


Subject(s)
Kidney Neoplasms/diagnostic imaging , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Adult , Aged , Contrast Media , Female , Humans , Kidney Neoplasms/surgery , Male , Middle Aged , Quality Improvement , Retrospective Studies , Sensitivity and Specificity
6.
Sex Med ; 7(4): 451-458, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31540883

ABSTRACT

INTRODUCTION: The comorbidity between premature ejaculation (PE) and erectile dysfunction (ED) has not yet been clarified. AIM: To assess the comorbidity between PE and ED. METHODS: Male members of a shopping club in Taiwan aged 20-60 years with stable sexual relationships were invited to complete an online questionnaire. MAIN OUTCOME MEASURES: Self-estimated intravaginal ejaculatory latency time (IELT), Premature Ejaculation Diagnostic Tool, Sexual Health Inventory for Men, Self-Esteem and Relationship, and Hospital Anxiety and Depression Scale results were used. RESULTS: A total of 937 participants with a mean age of 41.1 ± 10.2 years were enrolled. The prevalence rates of ED (Sexual Health Inventory for Men ≤ 21), PE (Premature Ejaculation Diagnostic Tool ≥11), and IELT ≤1 minute were 24.7%, 6.3%, and 6.4%, respectively. Prevalence of acquired PE and IELT ≤1 minute increased marginally with age. Participants with ED had a greater prevalence of PE than those without ED (19.5% vs 2.0%, P < .001), and participants with PE had a greater prevalence of ED than those without PE (76.3% vs 19.4%, P < .001). Compared with participants without PE, participants with PE had greater adjusted odds of ED (odds ratio [OR] = 12.7, 95% CI = 6.7-24.2). Relative to participants without ED, participants with ED had increased adjusted odds of PE (OR = 7.2, 95% CI = 3.5-14.6 with mild ED and OR = 36.7, 95% CI = 16.2-83.0 with ED severity greater than a mild degree). Poor sexual relationships and self-esteem, depression, and anxiety were reported more frequently in those with PE or ED, especially in those with both problems compared with those without PE and ED. CONCLUSIONS: This study confirmed a high prevalence of PE and ED coexistence, indicating a complicated relationship between the 2 conditions and the importance of screening for their co-occurrence in practice. Tsai W-K, Chiang P-K, Lu C-C, et al. The Comorbidity Between Premature Ejaculation and Erectile Dysfunction-A Cross-Sectional Internet Survey. Sex Med 2019;7:451-458.

7.
J Surg Oncol ; 120(7): 1162-1168, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31556139

ABSTRACT

BACKGROUND: Vascularized lymph node transfer (VLNT) is an effective surgery for extremity lymphedema. This study evaluated a lymphatic drainage device (LDD) for the drainage of accumulated fluid into the venous system. METHODS: Micropore filtering membranes with pore sizes of 5, 0.65, and 0.22 µm polyvinylidene difluoride, and 0.8 µm Nylon Net Filter were evaluated to determine the in vitro efficiency of drainage flow of an LDD. The two superior membranes were further used for the evaluation of the inflow and outflow of the LDD in vivo using 5% albumin. RESULTS: At 5 minutes, the volumes drained with 5, 0.65, and 0.22 µm polyvinylidene difluoride and 0.8 µm nylon membranes were 15.2, 2.77, 2.37, and 0.59 mL, respectively (P < .01). At 10 minutes, the collected volumes of 5 and 0.65 µm polyvinylidene difluoride were 1788 and 1051 µL (P = .3). The indocyanine green fluorescence was detected at 50 seconds for the 5 µm polyvinylidene difluoride membrane but not for the 0.65 µm membrane. CONCLUSIONS: The study successfully demonstrated the proof-of-concept of the LDD prototype that mimicked VLNT with drainage of 5% albumin into the venous system in a rat model.


Subject(s)
Disease Models, Animal , Drainage/instrumentation , Drainage/methods , Lymphedema/therapy , Animals , Equipment Design , Indocyanine Green/metabolism , Infusion Pumps, Implantable , Male , Rats , Rats, Sprague-Dawley , Recovery of Function
8.
Sensors (Basel) ; 19(8)2019 Apr 20.
Article in English | MEDLINE | ID: mdl-31010005

ABSTRACT

A non-contact current measurement device comprised of a GMR sensor and a ferrite ring core was investigated. The sensor chip employed a high-sensitivity spin-valve full-bridge GMR sensor of which the direct output has non-negligible hysteresis and a limited linear range. By applying an AC modulation current to modulate the output of the GMR sensor, the hysteresis was reduced, and the linear range was over ±0.5 A. The resolution for DC and quasi-static current measurement was 0.1 mA at a 10 Hz bandwidth. The output in proportion to the measured current was obtained either by demodulating the current-sensitive AC signal or by employing the filtered output of the intrinsically nonlinear spin-valve response. The proposed current sensing scheme is suitable for quasi-static current measurement from DC to over 100 Hz.

9.
PLoS One ; 13(7): e0199620, 2018.
Article in English | MEDLINE | ID: mdl-29965977

ABSTRACT

Self-organized dendritic architecture is of fundamental importance and its application can be used in many natural and industrial processes. Nanopost arrays are usually used in the applications of reflecting grating and changing the material surface wettability. However, in recent research, it is found that nanopost arrays can be fabricated as passive components to induce the dendritic self-organizaed hierarchical architectures. Via this simplified Phase-Field based finite element simulation, the surface dendritic self-organized architecture morphology and expanding speed in the growing path can be controlled by nanopost structures. In addition, nanopost array arrangement on the surface affects the hierarchal architecture branching distribution. Finally, with an external applied force introduced to the system, it enables the nanopost as an active component. It is found that nanopost surroundings significantly impact the final distribution of dendritic architectures which is qualitatively in agreement with experiments and induce these dendritic architectures to form assigned character patterns after the external driving forces are introduced into the system. This novel study can fundamentally study the dynamic physics of dendritic self-organized architecutes provide an indicator for the development of smart self-organized architecture, and a great opportunity for the creation of large-scale hierarchical structures.


Subject(s)
Computer Simulation , Models, Theoretical , Algorithms
10.
Rev Sci Instrum ; 88(2): 025004, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28249502

ABSTRACT

In this work, an ASIC (application specific integrated circuits) transducer circuit for field modulated giant magnetoresistance (GMR) sensors was designed and fabricated using a 0.18-µm CMOS process. The transducer circuits consist of a frequency divider, a digital phase shifter, an instrument amplifier, and an analog mixer. These comprise a mix of analog and digital circuit techniques. The compact chip size of 1.5 mm × 1.5 mm for both analog and digital parts was achieved using the TSMC18 1P6M (1-polysilicon 6-metal) process design kit, and the characteristics of the system were simulated using an HSpice simulator. The output of the transducer circuit is the result of the first harmonic detection, which resolves the modulated field using a phase sensitive detection (PSD) technique and is proportional to the measured magnetic field. When the dual-bridge GMR sensor is driven by the transducer circuit with a current of 10 mA at 10 kHz, the observed sensitivity of the field sensor is 10.2 mV/V/Oe and the nonlinearity error was 3% in the linear range of ±1 Oe. The performance of the system was also verified by rotating the sensor system horizontally in earth's magnetic field and recording the sinusoidal output with respect to the azimuth angle, which exhibits an error of less than ±0.04 Oe. These results prove that the ASIC transducer is suitable for driving the AC field modulated GMR sensors applied to geomagnetic measurement.

11.
Medicine (Baltimore) ; 95(49): e5594, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27930581

ABSTRACT

The aim of this study was to investigate cancer risk in patients with a history of urolithiasis and to determine whether intervention for calculi attenuated the risk of subsequent urinary tract cancer (UTC).Using data from the National Health Insurance Research Database in Taiwan, we performed a nationwide cohort study enrolling participants (n = 42,732) aged > 30 years who were diagnosed with urinary tract calculi between 2000 and 2009. Age- and gender-matched insured individuals (n = 213,660) found in the health service records over the same period were recruited as the control group. The Cox proportional hazards model and competing risks regression model were used to examine the relationship between urolithiasis and UTC, as well as whether early intervention for urolithiasis decreased the subsequent cancer risk relative to late intervention.Participants with a previous diagnosis of urolithiasis (n = 695) had a 1.82-fold (95% CI: 1.66-1.99, P < 0.001) increased risk of developing UTC. Furthermore, the risk of UTC associated with urolithiasis was higher in women (adjusted HR: 2.43, 95% CI: 1.94-3.05) than in men (adjusted HR: 1.72, 95% CI: 1.55-1.90). When stratified by cancer site, the adjusted HR for bladder, renal pelvis/ureter, renal, and prostate cancers were 1.94 (95% CI: 1.62-2.33), 2.94 (95% CI: 2.24-3.87), 2.94 (95% CI: 2.29-3.77), and 1.45 (95% CI: 1.27-1.65), respectively. Patients who received interventions for urolithiasis within 3 months of detection had a decreased risk of subsequent UTC (adjusted HR: 0.53, 95% CI: 0.40-0.71, P < 0.001).The present study demonstrated that urolithiasis increased the risk of subsequent UTC, especially upper UTC. Hence, it is recommended that physicians administer the appropriate interventions as early as possible upon diagnosis of urolithiasis.


Subject(s)
Precancerous Conditions/pathology , Urolithiasis/epidemiology , Urolithiasis/surgery , Urologic Neoplasms/epidemiology , Adult , Age Distribution , Aged , Cohort Studies , Databases, Factual , Female , Follow-Up Studies , Humans , Incidence , Lithotripsy/methods , Logistic Models , Male , Middle Aged , Proportional Hazards Models , Reproducibility of Results , Retrospective Studies , Risk Assessment , Secondary Prevention , Sex Distribution , Taiwan , Treatment Outcome , Urolithiasis/diagnosis , Urologic Neoplasms/diagnosis
12.
Case Rep Urol ; 2016: 9317567, 2016.
Article in English | MEDLINE | ID: mdl-27872789

ABSTRACT

A mid-aged male presented with progressive lower urinary tract symptoms (LUTS) for years. Huge prostate with low serum prostate-specific antigen (PSA) level was detected. The specimen from transurethral resection revealed surprising pathology finding as malignant peripheral nerve sheath tumor (MPNST). Considering its huge size (more than 300 gm) and location, we prescribed neoadjuvant chemotherapy firstly. The tumor became regressive and then radical surgical resection was achieved. Adjuvant multimodality treatment including concurrent chemoradiotherapy (CCRT) and target therapy was given. However, he expired about one year later. MPNST originating from prostate is very rare and seldom reported before. We here present this extremely rare disease and share our treatment experience.

13.
BMC Microbiol ; 16(1): 175, 2016 08 02.
Article in English | MEDLINE | ID: mdl-27484120

ABSTRACT

BACKGROUND: Streptococcus agalactiae (GBS) is a common pathogen to infect newborn, woman, the elderly, and immuno-compromised human and fish. 37 fish isolates and 554 human isolates of the GBS in 2007-2012 were investigated in serotypes, antibiotic susceptibility, genetic difference and pathogenicity to tilapia. RESULTS: PCR serotyping determined serotype Ia for all fish GBS isolates and only in 3.2 % (3-4.2 %) human isolates. For fish isolates, all consisted a plasmid less than 6 kb and belonged to ST7 type, which includes mainly pulsotypes I and Ia, with a difference in a deletion at the largest DNA fragment. These fish isolates were susceptible to all antimicrobials tested in 2007 and increased in non-susceptibility to penicillin, and resistance to clindamycin and ceftriaxone in 2011. Differing in pulsotype and lacking plasmid from fish isolates, human serotype Ia isolates were separated into eight pulsotypes II-IX. Main clone ST23 included pulsotypes II and IIa (50 %) and ST483 consisted of pulsotype III. Human serotype Ia isolates were all susceptible to ceftriaxone and penicillin and few were resistant to erythromycin, azithromycin, clindamycin, levofloxacin and moxifloxacine with the resistant rate of 20 % or less. Using tilapia to analyze the pathogenesis, fish isolates could cause more severe symptoms, including hemorrhage of the pectoral fin, hemorrhage of the gill, and viscous black and common scites, and mortality (>95 % for pulsotype I) than the human isolates (<30 %); however, the fish pulostype Ia isolate 912 with deletion caused less symptoms and the lowest mortality (<50 %) than pulsotype I isolates. CONCLUSION: Genetic, pathogenic, and antimicrobial differences demonstrate diverse origin of human and fish serotype Ia isolates. The pulsotype Ia of fish serotype Ia isolates may be used as vaccine strains to prevent the GBS infection in fish.


Subject(s)
Fish Diseases/microbiology , Streptococcal Infections/microbiology , Streptococcal Infections/veterinary , Streptococcus agalactiae/classification , Streptococcus agalactiae/genetics , Animals , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Drug Resistance, Multiple, Bacterial , Female , Humans , Male , Microbial Sensitivity Tests , Streptococcus agalactiae/drug effects , Streptococcus agalactiae/isolation & purification , Taiwan
14.
J Microbiol Immunol Infect ; 49(5): 672-678, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26316010

ABSTRACT

BACKGROUND: Streptococcus agalactiae [group B Streptococcus (GBS)] has become more prevalent in nonpregnant women, the elderly, and people who are immunocompromised. We investigated the serotype and genomic changes of GBS human isolates from different hospitals from 2007 to 2012. METHODS: The serotype and genotype of 658 GBS human isolates were determined with multiplex polymerase chain reaction and pulsed field gel electrophoresis analysis. Multilocus sequence typing analysis determined the sequence type (ST) of the major clones of serotypes Ib, V, and VI. RESULTS: Most of the isolates were collected from urine samples (60.5%) with a reduction in the rate from 74.6% in 2007 to 34.5% in 2012 and from infected patients older than 30 years (72.6%). The female/male ratio differed depending on the source: 3.52 in the urine group, 0.48 in the wound group, and 0.43 in pus. Serotypes Ib (16.5%), III (16.9%), V (27.2%), and VI (17.6%) were the most predominant among the nine serotypes identified and were separated into two prevalence patterns: a decrease in serotypes Ib and V and an increase in serotypes III and VI from 2007 to 2012. The prevalence change was associated with the urine group. Additionally, serotype VI become more prevalent in blood samples in four hospitals. The pulsed field gel electrophoresis analysis demonstrated three genetic patterns: limited pulsotypes and a major clonal dissemination for serotypes Ib and V, diverse pulsotypes for serotypes III, and diverse pulsotypes with a major clonal dissemination for serotype VI. Multilocus sequence typing analysis of the major clones identified ST12 for serotype Ib and ST1 for serotypes V and VI. CONCLUSION: Rapid genomic variations with different evolutionary patterns have led to the establishment of serotypes III and VI as the predominant GBS serotypes.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Genetic Variation , Streptococcal Infections/drug therapy , Streptococcal Infections/epidemiology , Streptococcus agalactiae/genetics , Adolescent , Adult , Aged , Child , Child, Preschool , Drug Resistance, Multiple, Bacterial , Electrophoresis, Gel, Pulsed-Field , Female , Humans , Infant , Male , Middle Aged , Multilocus Sequence Typing , Multiplex Polymerase Chain Reaction , Serogroup , Serotyping , Streptococcus agalactiae/drug effects , Streptococcus agalactiae/isolation & purification , Taiwan/epidemiology , Young Adult
15.
Sensors (Basel) ; 15(10): 24961-76, 2015 Sep 25.
Article in English | MEDLINE | ID: mdl-26404283

ABSTRACT

A miniature intra-oral dental implant system including a built-in biosensor device is proposed in this article. The dental implant system, or platform, is replaced over maxilla and allows relatively non-invasive procedures for a novel biosensing scheme for human blood analysis. Due to placement of the implant fixture, periodontal ligaments and the pulp structure, which are regarded as the main origin of pain, are thus removed, and long-term, continuous blood analysis and management through maxillary bone marrow becomes achievable through the dental implant platform. The new pathway of biological sensing is for the first time presented to realize an accurate and painless approach without injections. The dental implant system mainly consists of an implant fixture and a prosthetic abutment, a biosensor module, a bluetooth 4.0 wireless module and a dc button cell battery. The electrochemical biosensor possesses three electrodes, including working, reference and counter ones, which are arranged to pass through the titanium implant fixture below the biosensor module. The electrodes are exposed to the blood pool inside the maxillary bone marrow and perform oxidation/reduction reactions with the coating of biosensing enzyme. To prove the proposed platform, the immobilization process of glucose oxidase (GOD) enzyme and in vitro detections of glucose levels are successfully carried out, and proven sensitivity, linearity and repeatability of the glucose biosensor system are obtained. Moreover, a preliminary canine animal model adopting the new pathway shows significant consistency with the traditional method through dermal pricks for blood sugar detection. Despite the prospective results, further challenges in engineering implementation and clinical practices are addressed and discussed. In brief, the novel biosensing pathway and intra-oral biosensor platform may increasingly reveal their promising value and feasibilities in current bio-medical analysis, diagnosis, drug release and even healthcare technologies.


Subject(s)
Biosensing Techniques/instrumentation , Blood Glucose/analysis , Dental Implants , Diabetes Mellitus/blood , Animals , Blood Glucose Self-Monitoring/instrumentation , Blood Glucose Self-Monitoring/methods , Dental Abutments , Dogs , Electrodes , Enzymes, Immobilized/metabolism , Feasibility Studies , Glucose Oxidase/metabolism , Humans
16.
Sensors (Basel) ; 15(6): 14727-44, 2015 Jun 19.
Article in English | MEDLINE | ID: mdl-26102496

ABSTRACT

A new class of tri-axial miniature magnetometer consisting of a planar fluxgate structure with an orthogonal ferromagnetic fluxguide centrally situated over the magnetic cores is presented. The magnetic sensor possesses a cruciform ferromagnetic core placed diagonally upon the square excitation coil under which two pairs of pick-up coils for in-plane field detection are allocated. Effective principles and analysis of the magnetometer for 3-D field vectors are described and verified by numerically electromagnetic simulation for the excitation and magnetization of the ferromagnetic cores. The sensor is operated by applying the second-harmonic detection technique that can verify V-B relationship and device responsivity. Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum. As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well. The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency. Compared with the previous tri-axis fluxgate devices, this planar magnetic sensor with an orthogonal fluxguide provides beneficial enhancement in both sensory functionality and manufacturing simplicity. More importantly, this novel device concept is considered highly suitable for the extension to a silicon sensor made by the current CMOS-MEMS technologies, thus emphasizing its emerging applications of field detection in portable industrial electronics.

17.
J Endourol Case Rep ; 1(1): 65-7, 2015.
Article in English | MEDLINE | ID: mdl-27579394

ABSTRACT

Renal-cell carcinoma (RCC) with synchronous metastasis to contralateral ureter is extremely rare with only four cases reported in the literature. We report a case of synchronous metastatic RCC to the contralateral ureter with effective robot-assisted retroperitoneoscopic nephron-sparing surgery that leads to favorable oncologic and functional outcome.

18.
Sensors (Basel) ; 14(8): 13815-29, 2014 Jul 30.
Article in English | MEDLINE | ID: mdl-25196107

ABSTRACT

This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB) substrate and electrically connected to each other similar to the current "flip chip" concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or "responsivity" for magnetometers) and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz) magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz(1/2) at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market.


Subject(s)
Electronics/instrumentation , Equipment Design/instrumentation , Magnetics/instrumentation , Electricity , Electromagnetic Phenomena , Magnetic Fields , Noise
19.
J Gastrointest Surg ; 18(6): 1138-45, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24733257

ABSTRACT

OBJECTIVE: The objective of this study was to explore volume-outcome associations after major hepatectomy for hepatocellular carcinoma (HCC). METHODS: This population-based cohort study retrospectively analyzed 23,107 major hepatectomies for HCC patients from 1998 to 2009. Relationships between hospital/surgeon volume and patient outcome were analyzed by propensity score matching (PSM). Five-year overall survival (OS) was estimated by Kaplan-Meier method, and differences were compared by log-rank test. RESULTS: The mean length of stay (LOS) after major hepatectomy was 18.1 days, and the mean hospital cost was US$5,088.2. After PSM, the mean OS in high- and low-volume hospitals was 71.1 months (standard deviation (SD) 0.7 months) and 68.6 months (SD 0.6 months), respectively; the mean OS in high- and low-volume surgeons was 78.5 months (SD 0.7 months) and 66.9 months (SD 0.7 months), respectively. The PSM analysis showed that treatment by high-volume hospitals and treatment by high-volume surgeons were both associated with significantly shorter LOS, lower hospital cost, and longer survival compared to their low-volume counterparts (P < 0.001). CONCLUSIONS: The results of this nationwide study support the regionalization of HCC treatment by hospital volume and by surgeon volume. High surgeon volume revealed both short- and long-term benefits. The applicability of PSM in volume-outcome analysis may also be confirmed.


Subject(s)
Carcinoma, Hepatocellular/surgery , Clinical Competence/statistics & numerical data , Hepatectomy/statistics & numerical data , Hospitals, High-Volume/statistics & numerical data , Hospitals, Low-Volume/statistics & numerical data , Liver Neoplasms/surgery , Adult , Aged , Carcinoma, Hepatocellular/mortality , Female , Hepatectomy/economics , Hepatectomy/mortality , Hospital Costs , Humans , Length of Stay , Liver Neoplasms/mortality , Male , Middle Aged , Propensity Score , Retrospective Studies , Survival Rate , Taiwan , Treatment Outcome
20.
ScientificWorldJournal ; 2012: 941685, 2012.
Article in English | MEDLINE | ID: mdl-22645476

ABSTRACT

This paper shows a new finding about the decrease of relaxative response to loperamide in prostate of spontaneously hypertensive rats (SHR) as compare to normal rats (WKY). Authors demonstrated the reduction of ATP-sensitive potassium channels is responsible for this change using immunoblotting analysis and the decrease of action induced by diazoxide. This view is not mentioned before and is the first one reporting this result.


Subject(s)
Loperamide/pharmacology , Prostate/drug effects , Adenosine Triphosphate/chemistry , Animals , Antidiarrheals/pharmacology , Diazoxide/chemistry , Dose-Response Relationship, Drug , Gene Expression Regulation/drug effects , KATP Channels/chemistry , Male , Potassium Channels/chemistry , Potassium Channels, Inwardly Rectifying/chemistry , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Receptors, Opioid/metabolism , Receptors, Opioid, mu/chemistry , Temperature
SELECTION OF CITATIONS
SEARCH DETAIL
...