Measurement of local tissue perfusion through a minimally invasive heating bead

A minimally invasive approach was proposed to measure local blood perfusion rate in living tissues, based on the well-known Pennes bioheat equation. The measuring probe consists of a heater covered with conductive epoxy and temperature sensor deposited on the probe–tissue interface. By monitoring the probe–tissue interface’s temperature response before and after employing the constant heat flux, the tissue blood perfusion rate can be obtained. A theoretical model was developed to describe the measurement system. In vivo experiments were performed on the rabbit’s thighs to validate this method. At last, uncertainties implied in the temperature measurement and voltage across the heater was evaluated. The results point out the way to improve the accuracy of the present method and its appropriate application occasion.     

Shock Hugoniot for Biological Materials

This paper presents shock Hugoniot compression data for several bio-related materials by using flat plate impact experiments. Shock pressure covered in this study ranges at least up to 1 GPa. It is emphasized here that spatial and temporal uniformity of pressure distribution behind a shock wave front is very important and it can be realized in these materials by the impact method, and their precise shock propagation characteristics have been obtained by the application of the procedure developed previously by our group. Hugoniot measurements for different and systematic data for various samples are compared with shock Hugoniot curve for water. Samples used in the experiment include water gel of gelatin, NaCl aqueous solution, and finally chicken breast meat. Several samples with different initial density were used for gelatin and NaCl solution. Shock Hugoniot function for all the specimens tested can be summarized as u _s =A+B u _p , B ~ 2Value of the intercept of the relationship, A, which has the meaning of the sound velocity, is apparently dependent on the material and ambient temperature. Physical meanings of the obtained results have been discussed.     

Intraosseous monitoring and guiding by ultrasound: A feasibility study

An efficient method for navigation within bone tissue boundaries is essential for performance of surgical procedures, e.g. without damaging of adjacent vulnerable organs. The application of sonographic measuring methods for this purpose promises to be effective in the ability to distinguish soft trabecular bone from dense cortical bone, owing to an order of magnitude difference in acoustic density between these structures. For this purpose, a specific method was developed that utilizes propagation of a 5 MHz ultrasonic wave through an aqueous milieu. Using this method a 0.2 mm resolution in measurements is achieved. This resolution is in an order of magnitude lower than is required for a clinical use. A three-stage experimental approach was adopted: measurements in a cubic “phantom” made of a transparent plastic material, in samples of fresh porcine femora, and in a clinical setting of drilling in the upper and lower jaw during dental implantation surgery in nine patients. Two patterns of the detected ultrasound wave reflections were found: low amplitude reflections from the aqueous surrounding and trabecular bone and highly reflected ultrasound waves from the cortical bone. We show that trabecular and cortical bones are distinguishable by real-time ultrasonic measurement. The distances of the drilled tracts, in the range of 58.0–122.0 mm for the “phantom” experiment, 22.6–35.5 mm for the ex vivo experiment and 10.0–11.5 mm in the clinical experiment, and residual distances to the opposite edge of the tested samples and organs, in the range of 21.0–82.0 mm for the “phantom” experiment, 3.8–11.36 mm for the ex vivo experiment and 2.1–6.9 mm in the clinical experiment, were measured by the presented sonographic method and compared statistically, using linear correlation and Bland Altman plot, to the mechanical and/or radiographic measurements in all three stages of the experiment. A correlation coefficient above 0.95 was considered an indication of high correlation, while a value of 0.75–0.94 was considered intermediate, and a value below 0.75 was considered poor.     

Ultrasonic scanning of straight micro tools in soft biological tissues: Methodology and implementation

The acoustical behaviour of straight micro tools (SMT), such as sub-millimetre needles or electrodes, is delicate and their automated maintaining in the image plane displayed to the practitioner must handle the extremely varying signal they backscatter. Because of the complex nature of the scattering by a narrow rod target, the localization process has to face two main tasks before being able to conduct 3D location: the reduction of the apparent diameter when this latter is visible, and the detection of the instrument and its real depth of penetration. In this paper, a methodology based on these steps is proposed, along with preliminary implementations of each of the steps. This methodology exploit the acoustic duality of those SMT and treat different acoustic aspects separately: first the apparent diameter is reduced through a deconvolution process, associating the backscattering to a purely linear acoustic process without attenuation; second, the imaging is treated as a pure attenuation process, and the signal is summed post-ROI to achieve the detection. Finally, the complete localisation is achieved by combining the two first steps with a previously tested global 3D straight line location technique: the Parallel Integral Projection. Experiments are conducted in vitro with 700 μm graphite rods and 150 μm in diameter tungsten electrode crossing gelatine and cryogel phantoms, and ex vivo on a porcine liver to assess the efficiency of the proposed implementations and of the whole methodology. The volumes were acquired with a Kretztechnic 530D scanner customized so as to provide the raw RF data. Results show that the combination of the different step-methods reduces progressively the apparent diameter, and that the detection step is essential to the proper localization of the micro tool. The final resolution improvement is at least of 3 and estimated to be typically of 12, for a final estimated apparent diameter reaching the average 400 μm resolution cell in the porcine liver.     

关于外科手术患者焦虑情绪的护理探索

目的探索外科手术患者焦虑情绪的护理。方法选取200例该类患者,均分为对照组（一般护理）和观察组（优质护理）,比较两组患者满意度。结果在患者满意度方面,观察组98%明显优于对照87%（P〈0.05）。结论行外科手术前后,应对患者予以优质护理,缓解其焦虑情绪,保证手术治疗质量。     

Support vector regression with digital band pass filtering for the quantitative analysis of near‐infrared spectra

This paper proposes a novel calibration technique based on combining support vector regression with a digital band pass (DBP) filter for the quantitative analysis of near‐infrared spectra. The efficacy of the proposed method is investigated and validated in the determination of glucose from near‐infrared spectra of a mixture composed of urea, triacetin and glucose. In this paper, the DBP filtering was implemented as a pre‐processing technique in the frequency domain as a Gaussian band pass filter and in the time domain as a Chebyshev filter. The grid‐search optimization method was used to optimize the filter parameters. The results demonstrate that utilization of the optimized DBP filters as a pre‐processing technique improved the performance of the predictive models. Copyright © 2013 John Wiley & Sons, Ltd.     

Applications of Biodegradable Magnesium-Based Materials in Reconstructive Oral and Maxillofacial Surgery: A Review

Reconstruction of defects in the maxillofacial region following traumatic injuries, craniofacial deformities, defects from tumor removal, or infections in the maxillofacial area represents a major challenge for surgeons. Various materials have been studied for the reconstruction of defects in the maxillofacial area. Biodegradable metals have been widely researched due to their excellent biological properties. Magnesium (Mg) and Mg-based materials have been extensively studied for tissue regeneration procedures due to biodegradability, mechanical characteristics, osteogenic capacity, biocompatibility, and antibacterial properties. The aim of this review was to analyze and discuss the applications of Mg and Mg-based materials in reconstructive oral and maxillofacial surgery in the fields of guided bone regeneration, dental implantology, fixation of facial bone fractures and soft tissue regeneration.     

考虑视轴方向的个性化眼模型的构建

包含更多人眼解剖学特性的个性化眼模型具有重要的实验和临床意义。由角膜地形图计算了8只人眼视轴与光轴之间的夹角,水平分量平均值为4.23°±1.51°,竖直分量平均值为-0.40°±1.27°。根据视轴与光轴之间的夹角、角膜地形数据、眼内各部分轴向间距和人眼波像差,运用光学设计软件Zemax分别为这8只人眼构建了考虑视轴方向的个性化眼模型。在此基础上,计算了波前引导的个性化角膜切削深度,并与光程差方法计算的切削深度进行了比较。在切削光区中心处,两者相差不大,平均值为(0.09±0.04)μm;随着半径增大,两者之间的差值逐渐增大。对于所研究的实例,光区外围处的最大差值为0.59μm。个性化眼模型为设计波前引导的个性化角膜切削方案提供了一个有效工具。     

Bak groups and equivariant surgery II

The previous paper showed that theG-surgery obstructions ofG-normal maps lie in the Bak groups. That paper remarked that in even-dimensional cases, theG-surgery obstruction is invariant under suitable cobordisms. This paper presents cobordism invariance theorems for theG-surgery obstruction not only in even-dimensional cases but also in odd-dimensional ones. We prove Theorems B-D by detaching equivariant issues from the singular sets and then by using arguments of C. T. C. Wall in ordinary surgery theory. We still need, however, to argue carefully, especially in the odd-dimensional cases. Actually, this paper contains details which are skipped over in Wall's work.Partially supported by Grant-in-aid for Development of Young Scientists.Dedicated to Kazutoshi Morioka on his 60th birthday     

On knot Floer homology and lens space surgeries

In an earlier paper, we used the absolute grading on Heegaard Floer homology HF⁺ to give restrictions on knots in S³ which admit lens space surgeries. The aim of the present article is to exhibit stronger restrictions on such knots, arising from knot Floer homology. One consequence is that the non-zero coefficients of the Alexander polynomial of such a knot are ±1. This information can in turn be used to prove that certain lens spaces are not obtained as integral surgeries on knots. In fact, combining our results with constructions of Berge, we classify lens spaces L(p,q) which arise as integral surgeries on knots in S³ with |p|?1500. Other applications include bounds on the four-ball genera of knots admitting lens space surgeries (which are sharp for Berge's knots), and a constraint on three-manifolds obtained as integer surgeries on alternating knots, which is closely to related to a theorem of Delman and Roberts.