다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The analysis of medical images has been woven into the fabric of the pattern analysis and machine intelligence (PAMI) community since the earliest days of these Transactions. Initially, the efforts in this area were seen as applying pattern analysis and computer vision techniques to another interesting dataset. However, over the last two to three decades, the unique nature of the problems presented within this area of study have led to the development of a new discipline in its own right. Examples of these include: the types of image information that are acquired, the fully three-dimensional image data, the nonrigid nature of object motion and deformation, and the statistical variation of both the underlying normal and abnormal ground truth. In this paper, we look at progress in the field over the last 20 years and suggest some of the challenges that remain for the years to come.

https://hal.inria.fr/inria-00615100/document

Medical image analysis: progress over two decades and the challenges ahead

http://ee.sharif.edu/~miap/Files/A%20Survey%20of%20Medical%20Image%20Registration.pdf

A survey of medical image registration.

An image guided catheter navigation system for navigating a region of a patient includes an imaging device, a tracking device, a controller, and a display. The imaging device generates images of the region of the patient. The tracking device tracks the location of the catheter in the region of the patient. The controller superimposes an icon representing the catheter onto the images generated from the imaging device based upon the location of the catheter. The display displays the image of the region with the catheter superimposed onto the image at the current location of the catheter.

Navigation system for cardiac therapies

The complexity, diversity, and heterogeneity of tumors seriously undermine the therapeutic potential of treatment. Therefore, the current trend in clinical research has gradually shifted from a focus on monotherapy to combination therapy for enhanced treatment efficacy. More importantly, the cooperative enhancement interactions between several types of monotherapy contribute to the naissance of multimodal synergistic therapy, which results in remarkable superadditive (namely “1 + 1 > 2”) effects, stronger than any single therapy or their theoretical combination. In this review, state-of-the-art studies concerning recent advances in nanotechnology-mediated multimodal synergistic therapy will be systematically discussed, with an emphasis on the construction of multifunctional nanomaterials for realizing bimodal and trimodal synergistic therapy as well as the intensive exploration of the underlying synergistic mechanisms for explaining the significant improvements in synergistic therapeutic outcome. Furtherm...

Nanotechnology for Multimodal Synergistic Cancer Therapy

Ferroelectric and piezoelectric thin films are gaining more and more importance for the integration of high performance devices in small modules. High-K 'Integrated Discretes' devices have been developed, which are based on thin film ferroelectric capacitors integrated together with resistors and ESD protection diodes in a small Si-based chip-scale package. Making use of ferroelectric thin films with relative permittivity of 950–1600 and stacking processes of capacitors, extremely high capacitance densities of 20–520 nF/mm2, high breakdown voltages up to 140 V and lifetimes of more than 10 years at operating voltages of 5 V and 85°C are achieved. Thin film high-density capacitors play also an important role as tunable capacitors for applications such as tuneable matching circuits for RF sections of mobile phones. The performance of thin film tuneable capacitors at frequencies between 1 MHz and 1 GHz is investigated. Finally thin film piezoelectric ultrasound transducers, processed in Si– related processes, are attractive for medical imaging, since they enable large bandwidth (>100%), high frequency operation and have the potential to integrate electronics. With these piezoelectric thin film ultrasound transducers real time ultrasound images have been realized. Finally, piezoelectric thin films are used to manufacture galvanic MEMS switches. A model for the quasi-static mechanical behaviour is presented and compared with measurements.

https://iopscience.iop.org/article/10.1088/1757-899X/8/1/012008/pdf

Ferroelectric and piezoelectric thin films and their applications for integrated capacitors, piezoelectric ultrasound transducers and piezoelectric switches

The invention relates to a method and a device for adapting a radiation dose of an X-ray source (1). The X-ray source (1) irradiates an object to be examined, for example, a patient (4), so as to form an X-ray image (7) on an X-ray detector (5). The X-ray image (7) is subdivided into image regions (A-I) and each time the brightest image region is successively separated from the remaining image regions in an iterative method if its mean grey value forms an indication of the presence of direct radiation (2 b) in the relevant image region. The image regions still remaining at the end of the iteration operation correspond to an image region of interest which can be taken into account by a control unit (6) so as to calculate the optimum radiation dose.

Device and method for adapting the radiation dose of an X-ray source

When applying quantitative ultrasound (QUS) measurements to bone for predicting osteoporotic fracture risk, the multipath transmission of sound waves frequently occurs. In the last 10 years, the interest in separating multipath QUS signals for their analysis awoke, and led to the introduction of several approaches. Here, we compare the performances of the two fastest algorithms proposed for QUS measurements of bone: the modified least-squares Prony method (MLSP), and the space alternating generalized expectation maximization algorithm (SAGE) applied in the frequency domain. In both approaches, the parameters of the transfer functions of the sound propagation paths are estimated. To provide an objective measure, we also analytically derive the Cramer-Rao lower bound of variances for any estimator and arbitrary transmit signals. In comparison with results of Monte Carlo simulations, this measure is used to evaluate both approaches regarding their accuracy and precision. Additionally, with simulations using typical QUS measurement settings, we illustrate the limitations of separating two superimposed waves for varying parameters with focus on their temporal separation. It is shown that for good SNRs around 100 dB, MLSP yields better results when two waves are very close. Additionally, the parameters of the smaller wave are more reliably estimated. If the SNR decreases, the parameter estimation with MLSP becomes biased and inefficient. Then, the robustness to noise of the SAGE clearly prevails. Because a clear influence of the interrelation between the wavelength of the ultrasound signals and their temporal separation is observable on the results, these findings can be transferred to QUS measurements at other sites. The choice of the suitable algorithm thus depends on the measurement conditions.

Estimation of multipath transmission parameters for quantitative ultrasound measurements of bone

Photoacoustics (PA) is a new imaging modality based on the generation of ultrasound due to laser irradiation Instead of commonly used Q-switched Nd:YAG lasers the application of pulsed laser diodes as light sources for photoacoustic imaging is proposed The high pulse repetition frequency of laser diodes enables the usage of coded excitation schemes for SNR improvement Therefore, the performance of photoacoustic coded excitation (PACE) using Golay Codes is evaluated by a simulation study based on experimental data Golay Codes consist of 2 bipolar, complementary code sequences For PACE the codes must be split into 4 unipolar sequences and processed further First, experiments are conducted to provide the PA impulse response of the system under investigation by irradiating a spherical absorber by a pulsed laser diode and acquiring the acoustic response Then, based on these measurements, the acoustic response to a coded laser excitation is simulated by the superposition of PA impulse responses according to the coding scheme For each code length the acquisition duration is computed, the equivalent number of possible averages is determined, and the coding gain compared to averaging is calculated The SNR gain of the Golay Codes with respect to a single impulse response ranges from 587 dB for a 4 bit sequence to 2697 dB for a 512 bit sequence No range sidelobes are detectable and the acoustic response of the optical absorber is equivalent to the signal obtained from averaging Assuming an acquisition depth of 9 cm, the comparison of the coding schemes with equivalent averaging procedures shows that for coding PRFs lower than 60 kHz Golay coding exhibits a lower SNR than averaging for sequences up to 512 bit For a PRF of 250 kHz and a coding length of 512 bit the coding gain rises to 620 dB Additionally, the coding gain is theoretically derived and is in good agreement with the simulations Since state of the art high power laser diode drivers exhibit PRF up to 1 MHz, using coded excitation for photoacoustic imaging can improve the SNR in future set-ups

Simulation study of photoacoustic coded excitation using Golay Codes

The invention relates to an X-ray examination apparatus which includes an X-ray source, an X-ray detector, absorption means arranged between the X-ray source and the X-ray detector, a control unit for adjusting the absorption degree of the absorption means, an image processing unit and a display unit In order to perform an automatic adjustment of the absorption means, the absorption degree therein is optimized in dependence on user-specific parameters ( r ) and/or apparatus-specific parameters ( s ) and/or structure parameters ( C ) and/or parameters ( r ) classifying the subject matter of the image

Georg Schmitz

Papers

Ferroelectric and piezoelectric thin films and their applications for integrated capacitors, piezoelectric ultrasound transducers and piezoelectric switches

Device and method for adapting the radiation dose of an X-ray source

Estimation of multipath transmission parameters for quantitative ultrasound measurements of bone

Simulation study of photoacoustic coded excitation using Golay Codes

X-ray examination apparatus