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Robotic puncture system has been widely used in modern minimally invasive surgery, which usually uses hand-eye calibration to calculate the spatial relationship between the robot and the optical tracking system. However, the hand-eye calibration process is time-consuming and sensitive to environmental changes, which makes it difficult to guarantee the puncture accuracy of the robot. This study proposes an uncalibrated positioning method for puncture robot based on optical navigation. The method divides the target path positioning into two stages, angle positioning and position positioning, and designs angle image features and position image features respectively. The corresponding image Jacobian matrix is constructed based on the image features and updated by online estimation with a cubature Kalman filter to drive the robot to perform target path localization. The target path positioning results show that the method is more accurate than the traditional hand-eye calibration method and saves significant preoperative preparation time by eliminating the need for calibration.
Subject(s)
Robotics , Robotic Surgical Procedures , Calibration , Minimally Invasive Surgical Procedures , Optical DevicesABSTRACT
Measuring eye movement is a fundamental approach in cognitive science as it provides a variety of insightful parameters that reflect brain states such as visual attention and emotions. Combining eye-tracking with multimodal neural recordings or manipulation techniques is beneficial for understanding the neural substrates of cognitive function. Many commercially-available and custom-built systems have been widely applied to awake, head-fixed small animals. However, the existing eye-tracking systems used in freely-moving animals are still limited in terms of their compatibility with other devices and of the algorithm used to detect eye movements. Here, we report a novel system that integrates a general-purpose, easily compatible eye-tracking hardware with a robust eye feature-detection algorithm. With ultra-light hardware and a detachable design, the system allows for more implants to be added to the animal's exposed head and has a precise synchronization module to coordinate with other neural implants. Moreover, we systematically compared the performance of existing commonly-used pupil-detection approaches, and demonstrated that the proposed adaptive pupil feature-detection algorithm allows the analysis of more complex and dynamic eye-tracking data in free-moving animals. Synchronized eye-tracking and electroencephalogram recordings, as well as algorithm validation under five noise conditions, suggested that our system is flexibly adaptable and can be combined with a wide range of neural manipulation and recording technologies.
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Abstract Introduction In the last 28 years, the scientific community has been using elastography to evaluate the mechanical properties of biological tissue. The aim of this work was the optimization of the UDmV method, presented in Part I of the series, by means of modifying the technique employed to generate the reference sine and cosine functions, used for phase-quadrature demodulation, and determining how this modification improved the performance of the method. Additionally, the UDmV was employed to characterize the acoustic and mechanical properties of a 7% gelatin phantom. Methods A focused transducer, T F, with a nominal frequency of 2.25 MHz, was used to induce the shear waves, with frequency of 97.644 Hz. Then, the modified UDmV method was used to extract the phase and quadrature components from ultrasonic RF echo-signals collected from four positions along the propagation path of the shear wave, which allowed the investigation of the medium vibration caused by wave propagation. The phase velocity, c s, and attenuation, α s, of the phantom were measured and employed in the calculation of shear modulus, μ, and viscosity, η. Results The computational simulation demonstrated that the modification in UDmV method resulted in more accurate and precise estimates of the initial phases of the reference sinusoidal functions used for phase-quadrature demodulation. The values for c s and μ of 1.31 ± 0.01 m·s-1 and 1.66 ± 0.01 kPa, respectively, are very close to the values found in the literature (1.32 m·s-1 and 1.61 kPa) for the same material. Conclusion The UDmV method allowed estimating of the acoustic and viscoelastic parameters of phantom.
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Resumen: El análisis de motilidad espermática es muy importante para la evaluación de fertilidad humana. A menudo este análisis se lleva a cabo de forma manual, pero puede ser susceptible a errores inherentes a la naturaleza del procedimiento. Además de conllevar largos periodos de tiempo, los resultados son subjetivos y carentes de repetitividad. Con el fin de mejorar esto, presentamos un algoritmo semi-automático que rastree de manera precisa el desplazamiento de los espermatozoides. La metodología implementada se basó en la aplicación de modelos gaussianos adaptativos para detectar los espermatozoides en movimiento y segmentarlos a lo largo de los fotogramas de un video, posteriormente fueron aplicadas operaciones morfológicas y análisis de componentes conectados para reducir ruido en la imagen y calcular los centroides respectivamente. Luego, el algoritmo de Munkres y el filtro de Kalman fueron utilizados con el propósito de asignar centroides a las trayectorias. Finalmente, las trayectorias son visualizadas en pantalla. Los resultados evidencian un 90.91% de precision con respecto al análisis manual por parte de un experto. La herramienta tiene como único objetivo detectar el movimiento y trazar el desplazamiento de los espermatozoides en vídeo para muestras espermáticas humanas. Por otra parte, permite a los expertos en andrología llevar a cabo un análisis más exacto de las características individuales de los espermaozoides, teniendo así un soporte tecnológico a bajo costo, preciso y con repetitividad en los resultados que les permita emitir un diagnóstico más acertado. Por lo tanto, este método puede ayudar a especialistas a reducir periodos de tiempo y realizar un análisis más objetivo de motilidad espermática. De esta manera, el diagnóstico de fertilidad será más confiable.
Abstract: Sperm motility analysis is very important for human fertility assessment. It is often carried on manually, but this could be susceptible to mistakes due to the nature of procedure. In addition to being time-consuming, results are merely subjective and non-repeatable. In order to overcome this, we present a semi-automated algorithm that tracks accurately the sperm movements. Adaptive Gaussian models are implemented for detecting moving spermatozoa and segment them throughout video frames. Morphological operators and connected-components labeling are applied to reduce noise and calculate centroids, respectively. Then, the Munkres algorithm along with the Kalman filter are used for the purpose of assigning centroids to tracks. Finally, tracks are displayed on screen. Outcomes show a 90.91 % of accuracy regarding to manual analysis. This algorithm aims only to detect spermatozoa movement and trace its displacement in video for human sperm samples. Moreover, it allows andrology experts to perform a more exact analysis of the individual characteristics of spermatozoa, having so a low cost, accurate and repetitive technological support that will allow them to emit more precise diagnosis. Thus, this method will help specialists to reduce time periods and make more objective analysis of sperm motility. In this way, fertility diagnosis will be more reliable.
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OBJECTIVE: To determine the contents of chlorzoxazone and paracetamol in compound chlorzoxazone tablets by Kalman Filter spectrophotometry. METHODS: The absorbabilities of the two components were detected in an interval of 1mn over a wavelength range of 248～296 nm. The data obtained were computed by Kalman Filter program. RESULTS: Good linear relations were achieved when the concentration ranges of chlorzoxazone and paracetamol were 2～20 ?g?mL-1 (r=0.999 9) and 3～30 ?g?mL-1 (r=0.999 7) respectively; the recovery rates were 99.1%(RSD=1.01%) and 100.3% (RSD=0.92%), respectively. CONCLUSION: This method is simple, rapid and accurate, and it can be used for the simultaneonsly determination of 2 components in compound chlorzoxazone tablets without separation.
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A data processing method for the sound power of the medical ultrasonic diagnostic equipment is introduced in this paper. The sound power for the transducer of a medical ultrasonic diagnostic equipment is measured for many times, and then the mathematical model based on the measurement data above is processed with Kalman filter.The output fluctuations for sound power of the equipment and its transducer as well as the measurement errors of sound power meter are eliminated to achieve the true value of sound power. Compared with other mean methods, the method above can improve the dicreteness of the measurements, and thus is worth being applied to processing other measured data.