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This paper discusses the motivations and initial design specifications relating to a custom experimental apparatus for the investigation of ultrasound as an active enhancement method in transdermal drug delivery. The motivations for such an apparatus are: the high standard deviations in published results; the expected discrepancies between inputted parameter values to a specific test setup and the values of those variables at the skin surface during experimentation; and the potentially low validity of empirical relationships due to apparatus inadequacies. Preliminary numerical modelling has indicated that, for ultrasound enhanced transdermal experimentation, an apparatus made of polypropylene and submerged in water will have superior functionality to a standard glass Franz diffusion cell surrounded by air. A novel donor chamber has been made that is capable of accommodating a 50cm diameter ultrasound probe in a Franz diffusion cell setup.

Different industrial mixing methods and some of their combinations (1) ultrasound; (2) stirring; (3) (4) by roller machine, (5) by gears machine (6) Ultrasound radiation + high stirring were investigated for incorporating Multi walled Carbon nanotubes (MWCNT) into a resin based on an aeronautical epoxy precursor, cured with 4,4′ diamine-dibenzylsulfone (DDS). The effect of different parameters, ultrasound intensity, number of cycles, type of blade, gears speed on the nanofiller dispersion were analyzed. The inclusion of the nanofiller in the resin causes a drastic increase in the viscosity, preventing the homogenization of the resin and a drastic increase in temperature in the zones closest to the ultrasound probe. To overcome these challenges, the application of high speed agitation simultaneously with the application of ultrasonic radiation was used. This allows on the one hand a homogeneous dispersion, on the other hand an improvement of the dissipation of heat generated by ultrasonic radiation. A comprehensive study with parameters like viscosity and temperature was performed. It is necessary a balance between viscosity and temperature. Viscosity must be low enough to facilitate the dispersion and homogenization of the nanofillers, whereas the temperature cannot be too high because of re-agglomerations

Fractional flow reserve (FFR) is the golden standard for making decision on surgical treatment of coronary vessels with multiple stenosis. Clinical measurements of FFR require expensive invasive procedure with endovascular ultrasound probe. In this work a method of FFR simulation is considered. It is based on modelling 1D haemodynamics in patient-specific coronary vessels network reconstructed from CT scans. In contrast to our previous studies we used explicit minimum oscillating 2nd order characteristic method for internal nodes and 2nd order approximation of compatibility conditions for discretization of boundary conditions in junctions. The model is applied for simulating the change of FFR due to variability of the vessels elasticity and autoregulation response rate.

A novel ultrasound imaging system based on endoscopic array probe is presented in this paper. The system utilizes an endoscopic linear-array probe instead of the conventional single-element probe to implement ultrasound scanning in vivo. For the system, a micro linear-array ultrasound probe sized Φ10mm×20mm is firstly designed. And then the excitation circuit, gating circuit and echo receiving and processing circuit are all designed cored by a center control unit FPGA. Finally the research of d/2 focusing algorithm is implemented on the basis of the system. After processed, the gray image of echoes reflected by a glass jar’s wall is obtained and shown on a computer.

Objectives: Accurate tumor identification during partial nephrectomy is essential for successful tumor control. Intraoperative laparoscopic ultrasonography is useful for tumor localization, but the ultrasound probe is controlled by the assistant rather than the surgeon. We evaluated our initial experience using a robotic ultrasound probe that is controlled by the console surgeon. Methods: Partial nephrectomy was carried out in 22 consecutive patients between November 2010 and March 2011. A robotic ultrasound probe under console surgeon control was used in all the cases. All patients had at least 1 year follow up. Results: Mean patient age was 59 years and mean tumor size was 2.7 cm. There were six hilar tumors (27%) and 21 (95%) endophytic tumors. Mean R.E.N.A.L. nephrometry score was 6.9 (range 6–9). Mean operative time was 205.7 min and mean warm ischemia time was 17.9 min (range 6–28 min). All patients had negative tumor margins and were free of disease recurrence at a mean follow up of 13 months. Conclusion: The use of a robotic ultrasound probe during partial nephrectomy allows the surgeon to optimize tumor identification with maximal autonomy, and to benefit from the precision and articulation of the robotic instrument during this key step of the partial nephrectomy procedure.

Recent trends in minimally invasive brain surgery aim at using the joint acquisition of endoscopic and ultrasound images, a technique called endoneurosonography (ENS). Endoscopic images are useful, but they cannot provide information beyond opaque structures; therefore, it is necessary to complement them with other medical images. In this sense, ultrasound images provide a good option because they are cheap and easy to acquire in intraoperative scenarios. This paper presents a methodology for acquiring 3D information on brain structures using endoneurosonography. The endoscopic cameras and the ultrasound sensor are inserted into the brain during surgery. The information from the endoscopic cameras is used for stereo reconstruction, while the ultrasound information is used to segment regions of interest. The aim of this work is solving four specific problems: calibration of the endoscopic system; tracking of the ultrasound probe through endoscopic images; segmentation of brain structures from ultrasound images; and 3D reconstruction of brain tumors. At the end of the paper, the complete methodology is explained and experiments are done on an ENS database of brain phantoms.

A 51-year-old man presented to our emergency department with persistent right cervical pain. Neurologic examination was unremarkable, and no anisocoria was reported. Using a linear ultrasound probe, the pupillary diameters were measured at rest, under direct/consensual light stimulus, and after elicitation of the ipsilateral ciliospinal reflex (CR), evoked by applying a painful stimulation (pinching) at the base of the neck on the trapezius muscle.1,2

Background The aim of this study was to evaluate a novel ultrasound probe specifically developed for robotic surgery by determining its efficiency in identifying renal tumors. Methods The study was carried out using the Da Vinci™ surgical system in one female pig. Renal tumor targets were created by percutaneous injection of a tumor mimic mixture. Single-port and standard robotic partial nephrectomy were performed. Intraoperative ultrasound was performed using both standard laparoscopic probe and the new ProART™ Robotic probe. Probe maneuverability and ease of handling for tumor localization were recorded. Results The standard laparoscopic probe was guided by the assistant. Significant clashing with robotic arms was noted during the single-port procedure. The novel robotic probe was easily introduced through the assistant trocar, and held by the console surgeon using the robotic Prograsp™ with no registered clashing in the external operative field. The average time for grasping the new robotic probe was less than 10 s. Once inserted and grasped, no limitation was found in terms of instrument clashing during the single-port procedure. Conclusions This novel ultrasound probe developed for robotic surgery was noted to be user-friendly when performing porcine standard and especially single-port robotic partial nephrectomy. Copyright © 2011 John Wiley & Sons, Ltd.

The purpose of this study was to describe detailed sonographic anatomy of the parasacral area for rapid and successful identification of the sciatic nerve. Fifty patients scheduled for knee surgery were included in this observational study. An ultrasound-guided parasacral sciatic nerve block was performed in all patients. The ultrasound probe was placed on an axial plane 8 cm lateral to the uppermost point of the gluteal cleft. Usually, at this level the posterior border of the ischium (PBI), a characteristically curved hyperechoic line, could be identified. The sciatic nerve appeared as a hyperechoic structure just medial to the PBI. The nerve lies deep to the piriformis muscle lateral to the inferior gluteal vessels, and if followed caudally, it rests directly on the back of the ischium. After confirmation with electrical stimulation, a 20-mL mixture of 1% ropivacaine and 1% lidocaine with epinephrine was injected. The sciatic nerve was identified successfully in 48 patients (96%). In those patients, the median time required for its ultrasonographic identification was ten seconds [interquartile range, 8-13.7 sec], and the block success rate was 100%. The described sonographic details of the parasacral area allowed for rapid and successful identification of the sciatic nerve.

Purpose : In this paper a new, easy-to-manufacture and easy-to-use ultrasound(US) probe calibration phantom for 3D freehand scanning is presented and evaluated, together with a new method for achieving an accurate and user-robust calibration using virtual plane. Methods : The phantom allows the optically tracked US probe to perform two rotations and two translations while keeping the image of a tensioned wire in the image plane. This approach allows obtaining a sharp image of the wire independently from the probe pose. The virtual plane allows the calibration algorithm to converge minimizing the required number of US probe tracked poses. The USimage and position data are synchronized via a CORBA interface, created within the Image Guided Surgery Toolkit (IGSTK) framework. The calibration algorithm and the calibration protocol were evaluated in a set of experiments carried out by different test-users. Results : The calibration method proved to be accurate and precise: 3D point reconstruction accuracy resulted 0.2 mm as mean value, while the precision was 0.4 mm as standard deviation. Conclusions : The technique showed to be suitable for medical applications from morphological diagnosis to intraoperative surgical planning adaption.

To determine suitable procedures for decontaminating ultrasound probes. We investigated bacterial transmission via ultrasound probes that were not wiped, wiped with a plain paper towel, or wiped with an ethanol-soaked paper towel. The unwiped probes transmitted large numbers of bacteria, which were markedly reduced by wiping the probes with a plain paper towel, and almost completely eliminated by wiping with an ethanol-soaked paper towel. Improperly decontaminated ultrasound probes can transmit bacteria among patients. Ultrasound probes should be decontaminated by wiping with a paper towel after examinations to prevent bacterial transmission. Plain or ethanol-soaked paper towels should be used depending on the situation.

A robotic wrist has been developed for physicians to perform ultrasound imaging on patients located at remote sites. Detailed design, kinematic analysis, prototyping, and preliminary clinical tests of the wrist are reported in this paper. The wrist has certain characteristics which make it novel from mechanical point of view and with respect to its suitability for ultrasound imaging. It is a four degree-of-freedom device and uses parallel mechanisms in its configuration to provide a remote center-of-motion. All four actuators are located on the ground, and each actuator is responsible for one required motion of the ultrasound probe. The wrist has been prototyped. Successful remote ultrasound imaging of kidney and liver has been done on a few volunteers to show the applicability of the proposed device.

This paper presents results of evaluating different concepts of haptic and visual force feedback interfaces using a force-reflecting hand-controller designed to guide an ultrasound probe held by a robotic device. Experiments were conducted that resemble the type of path alignment and force regulating tasks that are needed to perform ultrasound examinations, remotely. In the first experiment, the effectiveness of visual force feedback, augmented haptic feedback and augmented haptic plus visual force feedback was tested. In the second experiment, the tasks were executed under communication network delays. The results confirm the expected observation that long variable communication delays degrade force regulating tasks using only the visual force feedback approach. The introduction of passive haptic feedback that constructs forces locally, allows participants to improve their performance, without causing instability due to variable or long network delays.

We present an innovative compact dual-modality detector, which integrates an ultrasound probe with a scintigrafic γ -camera for molecular imaging in medicine, in order to get both morphological and functional information in a single three-dimensional image. The scintigraphic detector consists of a 2 × 2 array of a multi-anode PMT Hamamatsu H8500-Mod8 and a 4.0 mm thick continuous LaBr 3 (Ce) crystal equipped with four segment slant-hole collimators for single photon imaging (SPET). The collimator permits to recover the depth of a lesion by rotating around its vertical axis (z) without the need of rotating the camera around the investigated object. This detector can take advantage from being positioned close to the object and overcome the intrinsic limitations in spatial resolution arising from the geometry of SPET/CT gantry. The aim of this work is to describe preliminary phantom analysis and to provide a 3D US/SPET image.

Objective: To describe the anatomic features of the equine trochanteric bursa and to evaluate 4 techniques for bursa centesis. Study Design: Prospective, randomized design. Animals: Equine cadavers (n=2) and 20 live horses. Methods: The trochanteric bursae of 2 equine cadavers were injected with latex to identify the boundaries of the bursae. Four techniques for centesis of the trochanteric bursa were evaluated by attempting to inject dye into both trochanteric bursae of 20 live horses. Techniques included injection of the bursa with the limb-bearing weight and injection with the limb nonweight bearing and supported on a block, with or without ultrasonographic guidance of the needle. Ultrasonographic guidance of the needle was performed with or without the use of a guide channel attached to the ultrasound probe. Each of the 4 techniques was used to inject 10 bursae. The region of the bursa was dissected after horses were euthanatized to determine the location of the dye. Results: The trochanteric bursa was most successfully injected with the limb positioned caudally with the foot on a block, even though topographic landmarks for centesis were more difficult to identify when the limb was in this position. The highest incidence of success was achieved when the needle was inserted using ultrasonographic guidance with the foot in a Hickman block. Conclusion: Positioning the limb caudally with the foot nonweight bearing and on a block facilitated centesis of the trochanteric bursa.

Background: Controversy exists on stretching and warm-up in injury prevention. We hypothesized that warm up has a greater effect on Achilles tendon biomechanics than static stretching. This study investigated static stretching and warm-up on Achilles tendon biomechanics in recreational athletes, in vivo. Materials and Methods: Ten active, healthy subjects, 5 males, 5 females, With a mean age of 22.9 years with no previous Achilles tendon injuries were recruited. Typical stretching and warm-up routines were created. Testing was performed in a randomized cross-over design. A custom-built dynamometer was utilized to perform controlled isometric plantarflexion. A low profile ultrasound probe was utilized to visualize the musculotendinous junction of the medial gastrocnemius. An eight-camera motion capture system was used to capture ankle motion. Custom software calculated Achilles tendon biomechanics. Results: Achilles tendon force production was consistent. No statistically significant differences were detected in stretch, stiffness, and strain between pre-, post-stretching, and post-warm-up interventions. Conclusion: Stretching or warm-up alone, and combined did not demonstrate statistically significant differences. Stretching and warm-up may have an equivalent effect on Achilles tendon biomechanics. Prolonged and more intense protocols may be required for changes to occur. Clinical Relevance: Stretching and warm-up of the Achilles before exercise are commonly practiced. Investigating the effect of stretching and warm-up may shed light on potential injury prevention.

Labor epidural is commonly used to provide both regional anesthesia and postoperative pain relief. Epidural space is supposed to be narrower and deeper in a parturient than that in a nonpregnant woman. The aim of this study was to explore the difference of epidural spaces between parturient and nonpregnant women by ultrasound assessment. Thirty nonpregnant female volunteers and 30 parturients undergoing labor epidurals were enrolled to receive ultrasound examination. A low-frequency (2-5 MHz) curved-array ultrasound probe was used to obtain spinal sonoanatomy for each subject. The longitudinal paramedian scanning plane was used to obtain optimal ultrasound image for spinal sonoanatomy. Primary outcome was evaluated by the diameter and depth of epidural space at three lumbar interspaces (from L2 to L5). The quality of ultrasound images was also compared between the groups by a numerical scoring system (from 0 to 3). The mean diameters of lumbar epidural spaces were 3.03 ± 0.45 mm and 4.44 ± 0.49 mm (p0.05) for parturients and nonpregnant women, respectively. The mean depths of lumbar epidural spaces for parturients and nonpregnant women were 3.53 ± 0.62 cm and 3.25 ± 0.63 cm, respectively (p0.05). The mean scores for epidural space image quality were 2.58 ± 0.58 and 2.63 ± 0.53 for parturients and nonpregnant women, respectively (p=0.08). Epidural space is narrower and deeper at lumbar interspaces in obstetrics by ultrasound examination. The quality of ultrasound images did not differ significantly between the groups. These quantitative results improve the understanding of the differences between two groups that have been previously known qualitatively and may help in avoiding complications.

One of the important tasks required for sonographers is an accurate positioning of ultrasound probe. Especially, the measurement of the diameter of the blood vessel is affected by the positioning error of the probe. For this purpose, we have been developing a robot system for the medical ultrasound diagnosis, which composed of a 6-DOFs probe manipulator and supporting arm. In this paper, we present an implementation of fully automated positioning algorithm of the ultrasound probe on the carotid artery, by means of image feedback. A probe holding robot firstly detects the patient skin, then scans and detects the longitudinal section of the carotid artery, guide the probe towards the position where the tissue layers of the artery walls are most clearly observed. Furthermore, a new method of the visual servoing for tracking the out-of-plane motion for the medical ultrasound is presented. Automated positioning algorithm is tested in eleven volunteers and the results show that the system successfully completed the task in 91% of the trials. Visual servoing algorithm is also tested and the experimental results show its effectiveness.

Ultrasound guidance is recommended for cannulation of the internal jugular vein. Use of ultrasound allows you to identify relevant anatomy and possible anatomical anomalies. The most common approach is performed while visualizing the vein transversely and inserting the needle out of plane to the probe. With this approach needle tip visualization may be difficult. We report the use of a new biplane ultrasound probe which allows the user to simultaneously view the internal jugular vein in transverse and longitudinal views in real time. Use of this probe enhances needle visualization during venous cannulation.

In this study, in order to overcome the weakness of acoustic field analysis which is generally used for ultrasonic probe performance evaluation, automatic acoustic field measurement system and evaluation parameters were proposed. The comparisons between acoustic field simulation and measured acoustic distribution data of normal and abnormal channels were conducted to evaluate the availability of proposed system and evaluation parameters. First, the impulse response characteristic of sample probe was investigated to classify the normal elements and abnormal elements. And then, normal channels and abnormal channels with abnormal element were chosen. The suggested 12 evaluation parameters were calculated using the acoustic fields of these channels. The availability of proposed automatic acoustic field measurement system and evaluation parameters was confirmed. And the performance evaluation of ultrasonic probe using acoustic field analysis could be easier and faster.

Since its introduction into the operating room in the early 1980s, transesophageal echocardiography (TEE) has gained widespread use during cardiac, major vascular, and transplantation surgery, as well as in emergency and intensive care medicine. Moreover, TEE has become an invaluable diagnostic tool for the management of patients with cardiovascular disease in a nonoperative setting. In comparison with other diagnostic modalities, TEE is relatively safe and noninvasive. However, the insertion and manipulation of the ultrasound probe can cause oropharyngeal, esophageal, or gastric trauma. Here, the authors review the safety profile of TEE by identifying complications and propose a set of relative and absolute contraindications to probe placement. In addition, alternative echocardiographic modalities (e.g., epicardial echocardiography) that may be considered when TEE probe placement is contraindicated or not feasible are discussed.

Summary We performed a study of 85 consenting anaesthetists to assess their ability to locate the right internal jugular vein using a landmark technique. Initially, a questionnaire was completed ascertaining previous user experience. An ultrasound probe, using the midpoint as an ‘imaginary needle’, was placed on the neck of a healthy volunteer (with previously confirmed normal anatomy) and the image recorded. Both anaesthetist and volunteer were blinded to the screen until the image was stored. Anaesthetists were grouped into those in training before 2002 (Pre-2002, n = 58), when National Institute for Health and Clinical Excellence guidelines recommending ultrasound guidance were published, and those training after this time point (Post-2002, n = 27). The success rate for identifying the internal jugular vein using the landmark technique was 36 ⁄ 58 (62%) in the Pre-2002 group and 6 ⁄ 27 (22%) in the Post-2002 group (p < 0.001). Three participants in each group would have hit the carotid artery (5% Pre-2002 and 11% Post-2002 respectively; p = 0.2). The advent of routine use of ultrasound has resulted in a cohort of anaesthetists who are unable to use a landmark technique effectively or safely. This has significant training implications.

We have developed a scanning method of the ultrasound probe on body surface to construct visual servo system based on acquired echogram by the standalone medical robot, which is developed in our laboratory to move the ultrasound probe on patient abdomen in three-dimension. The visual servo system detects local change of brightness in time series echogram, which is stabilized the position of the probe by conventional force servo system in the robot, to compensate not only periodical respiration motion but also body motion. Then we integrated control method of the visual servo with the force servo as a hybrid control in both of position and force. To confirm the feasibility of application, we experimented tracking the gallbladder in echogram by minimizing abdominal response variations.

Muscular strength can be estimated by quantification of muscle area. For this purpose, we developed a flexible measuring system for muscle area using ultrasonography. This method is completely safe and is particularly suitable for elderly people because the subjects are not required to perform any muscular contraction during measurement. The ultrasound probe is installed on a mechanical arm, and continuously scans fragmental images along the body surface. A wide-area cross-sectional image is then constructed using the measured images. The link mechanism is very flexible, enabling the operator to measure images for any body posture and body site. Use of the spatial compounding method reduces speckle and artifact noise in the resultant cross-sectional images. The operator can observe individual muscles (extensor, flexor muscle, etc.) in detail. We conducted experiments to evaluate the performance of the system. In the experiments, the position of the ultrasound probe was calculated with high accuracy according to the link posture. In addition, a high degree of correlation was verified between MR images and those of the developed system. We observed a reduction in noise due to use of the spatial compounding method, and propose a new calibration method for correcting the measured muscle area, which were slightly deformed by the contact pressure of the ultrasound probe. Finally, we examined the relation between muscular area and muscular strength in young and middle-aged subjects. The results of these experiments confirm that the developed system can estimate muscular strength based on muscular area.

Purpose: A prototype ultrasound-based probe for use in ureteroscopy was used for in vitro measurements of stone fragments in a porcine kidney. Methods: Fifteen human stones consisting of three different compositions were placed deep in the collecting system of a porcine kidney. A 2 MHz, 1.2 mm (3.6F) needle hydrophone was used to send and receive ultrasound pulses for stone sizing. Calculated stone thicknesses were compared with caliper measurements. Results: Correlation between ultrasound-determined thickness and caliper measurements was excellent in all three stone types (r2 = 0.90, p

The objective of this study is to demonstrate in vivo the feasibility of optoacoustic temperature imaging during cryotherapy of prostate cancer. We developed a preclinical prototype optoacoustic temperature imager that included pulsed optical excitation at a wavelength of 805 nm, a modified clinical transrectal ultrasound probe, a parallel data acquisition system, image processing and visualization software. Cryotherapy of a canine prostate was performed in vivo using a commercial clinical system, Cryocare® CS, with an integrated ultrasound imaging. The universal temperature-dependent optoacoustic response of blood was employed to convert reconstructed optoacoustic images to temperature maps. Optoacoustic imaging of temperature during prostate cryotherapy was performed in the longitudinal view over a region of 30 mm (long) × 10 mm (deep) that covered the rectum, the Denonvilliers fascia, and the posterior portion of the treated gland. The transrectal optoacoustic images showed high-contrast vascularized regions, which were used for quantitative estimation of local temperature profiles. The constructed temperature maps and their temporal dynamics were consistent with the arrangement of the cryoprobe and readouts of the thermal needle sensors. The temporal profiles of the readouts from the thermal needle sensors and the temporal profile estimated from the normalized optoacoustic intensity of the selected vascularized region showed significant resemblance, except for the initial overshoot, that may be explained as a result of the physiological thermoregulatory compensation. The temperature was mapped with errors not exceeding ±2 °C (standard deviation) consistent with the clinical requirements for monitoring cryotherapy of the prostate. In vivo results showed that the optoacoustic temperature imaging is a promising non-invasive technique for real-time imaging of tissue temperature during cryotherapy of prostate cancer, which can be combined with transrectal ultrasound-the current standard for guiding clinical cryotherapy procedure.

Lung ultrasound surface wave elastography (LUSWE) was developed as a non-invasive tool for assessing pulmonary fibrosis. In this research, the effect of the fleural fluid on surface wave speed measurement of the lung is studied. Low-cost sponges [J. Ultrasound Med. 2017; 36, 2133], as good lung phantoms, were used in this study. The ultrasound transmission gel was used to simulate the pleural fluid. A harmonic vibration was generated at sponge surfaces using a shaker at 100, 150, and 200 Hz. The sponge surface wave speeds were measured with a 6 MHz ultrasound probe for both with and without a thin layer gel. The ultrasound features of A and B-lines were clearly observed in every sponge model in our experiment. The surface wave speeds for the sponges with the gel were indistinguishable from those without the gel for each frequency. The surface wave speeds were faster at higher excitation frequencies which is consistent with our patient study results. It was conclude that the pleural fluid may not affect th...

Background. Ultrasound evaluation of articular cartilage is not accurate if the ultrasound probe is not perpendicular to the cartilage surface. However a probe angle adjustment is difficult because of the manual procedure and the lack of angle index for the measurer. The aim of this study is to propose “Rise-to-Peak time” as an index of probe angle and to evaluate its effectiveness in evaluating articular cartilage surfaces. Methods. The “Rise-to-Peak time” is defined as the time interval between the rise of the first peak (50% amplitude of the first peak) and the first positive peak following the minimum peak of the echo. The relationship between the Rise-to-Peak time and probe angle was evaluated using several reflection surfaces including that of articular cartilage. Findings. The “Rise-to-Peak time” increased monotonically with increases in the angle between the probe and the reflection surface, and showed good agreement with calculated values for small angle changes (

To determine suitable methods for evaluating bacterial contamination of ultrasound probes.We compared probe imprinting, swab streaking, and swab suspension methods for evaluating bacterial contamination of ultrasound probes.Experimental and clinical investigations showed that the sensitivity for detecting bacterial contamination of ultrasound probes was higher with probe imprinting than with swab methods. Probe imprinting was very simple and required only agar plates.Probe imprinting was the most suitable method for evaluating bacterial contamination of ultrasound probes.

Contains fulltext : 81509.pdf (Publisher’s version ) (Closed access) BACKGROUND AND OBJECTIVES: The sciatic nerve block represents one of the more difficult ultrasound-guided nerve blocks. Easy and reliable internal ultrasound landmarks would be helpful for localization of the sciatic nerve. Earlier, during ultrasound-guided posterior approaches to the infragluteal sciatic nerve, the authors recognized a hyperechoic structure at the medial border of the long head of biceps femoris muscle (BFL). The present study was performed to determine whether this is a potential internal landmark to identify the infragluteal sciatic nerve. METHODS: The depth and the thickness of this hyperechoic structure, its relationship with the sciatic nerve and the ultrasound visibility of both were recorded in the proximal upper leg of 21 adult volunteers using a linear ultrasound probe in the range of 7-13 MHz. The findings were verified by an anatomical study in two cadavers. RESULTS: The hyperechoic structure at the medial border of the BFL extended in a dorsoventral direction between 1.4+/-0.6 cm (mean+/-SD) and 2.8+/-0.8 cm deep from the surface, with a width of 2.2+/-0.9 mm. Between 2.6+/-0.9 and 10.0+/-1.5 cm distal to the subgluteal fold, the sciatic nerve was consistently identified directly at the ventral end of the hyperechoic structure in all volunteers. The anatomical study revealed that this hyperechoic structure corresponds to tendinous fibres inside and at the medial border of the BFL. CONCLUSION: The hyperechoic BFL tendon might be a reliable soft tissue landmark for ultrasound localization of the infragluteal sciatic nerve.

Real-time ultrasound-assisted guidance for catheterization of the internal jugular vein (IJV) is known to be useful, especially for a small-sized vein, which is difficult to catheterize. However, one of the problems with real-time ultrasound-assisted guidance is that the ultrasound probe itself can collapse the vein. We have developed a novel "skintraction method (STM)", in which the puncture point of the skin over the IJV is stretched upwards with several pieces of surgical tape in the cephalad and caudal directions with the aim being to facilitate catheterization of the IJV. We examined whether this method increased the compressive force required to collapse the IJV.In ten volunteers, the compressive force required to collapse the right IJV, and the cross-sectional area and anteroposterior and transverse diameters of the IJV were measured with ultrasound imaging in the supine position (SP) with or without the STM or in the Trendelenburg position of 10 degrees head-down (TP) without the STM.The compressive force to required to collapse the vein was increased significantly with the STM, while the crosssectional area and anteroposterior diameter of the vein in the SP with STM were similar to those in the TP without the STM.With the STM, not only the cross-sectional area but also the compressive force required to collapse the IJV increased. Thus, the STM may facilitate real-time ultrasoundassisted guidance for catheterization of the IJV by maintaining the cross-sectional area of the vein during the guidance.

Resume La question de l’asepsie des sondes d’echographie est hautement d’actualite. Le probleme est d’evaluer le risque de contamination et la necessite d’une procedure specifique de traitement des sondes lorsqu’elles sont munies de gaine de protection a usage unique. Puisqu’il n’existe pas de referentiel pour les criteres de qualite des gaines de protection, il faut verifier qu’elles sont marquees CE par leur fabricant. L’usage d’un preservatif pour les sondes vaginales n’est pas recommande bien qu’ils soient moins sujets aux dechirures que les gaines protectrices commercialisees. Bien que le taux global de perforation des gaines varie selon les publications de 1 a 9 %, aucun cas d’infection liee a une echographie abdominale ou vaginale n’a ete rapporte. Cependant, tout patient doit etre considere comme une source potentielle d’infection. Les recommandations francaises classent les sondes d’echographie endovaginale dans la categorie semi-critique et conseillent la desinfection de niveau intermediaire. Les recommandations americaines, canadiennes et australiennes exigent toujours une desinfection de haut niveau en raison du risque de rupture de la gaine. Tout echographiste devrait des lors respecter des regles de conduite raisonnables afin de pouvoir totalement rassurer les patientes sur les risques de contamination individuelle lies a une echographie diagnostique pratiquee en suivant les regles d’hygiene.

BACKGROUND: The sciatic nerve block by the posterior approaches represents one of the more difficult ultrasound-guided nerve blocks. Our clinical experiences with these blocks indicated a point slightly distal to the subgluteal fold as an advantageous position to allow good ultrasonic visibility. In this study, we systematically scanned the sciatic nerve from the subgluteal fold to the popliteal crease, to determine an optimal point for ultrasonographic visualization. METHODS: After institutional approval and written informed consent, we recruited 15 volunteers to visualize the sciatic nerve from the subgluteal fold to the popliteal crease using a linear ultrasound probe in the range of 7-13 MHz. The ultrasonographic visibility of the sciatic nerve, nerve diameter (width and thickness), and skin-to-nerve distance at 20 equidistant points between the subgluteal fold and the popliteal crease were recorded. RESULTS: The sciatic nerve could be successfully visualized in cross-section as a hyperechoic structure on ultrasound in all volunteers. In the course from subgluteal to the popliteal area, the shape of the sciatic nerve changed from flat to round, while the skin-nerve distance varied with the smallest skin-nerve distances at the popliteal crease and at 5.4 cm (on average) distal to the subgluteal fold. The best ultrasonographic visibility scores were found between 7.2 and 10.8 cm (on average) distal to the gluteal fold. CONCLUSION: Between 5.4 and 10.8 cm from the subgluteal fold seems to be the best area to scan the sciatic nerve in terms of superficial nerve position and good ultrasonic visibility.

A sonication process was developed by means of which the deagglomeration of the particles of commercial densified silica fume (CSF) was achieved: an increase in the amount of submicrometric particles was obtained, which finally yielded a larger specific surface area. Sonicated silica fume (SSF) (prepared with an ultrasound probe, working in a water/silica fume suspension) was obtained starting from different tests in which parameters such as treating time and power level of sonication were varied. After sonication treatment, the commercial CSF (with 59.64 μm mean particle diameter) was converted to samples with mean particle diameter of about 5 μm, with an increase of the volume percentage of particles with diameter lower than 1 μm (more than 50%). With a longer sonication time and higher sonication power level it was possible to obtain a greater quantity of submicrometric particles. A threshold power level was identified below which the sonication process was not effective

The aim of this study was to observe the effect of ultrasound and sonication on whey proteins in order to improve their functional properties. Effect of ultrasound treatment on physicochemical and functional properties was examined by pH, conductivity and solubility measurements and foaming properties. In this work, low-intensity ultrasound (500 kHz) and the high-intensity ultrasound (20 kHz probe and 40 kHz bath) were used. 10 wt.% protein model suspensions of whey protein isolate (WPI); whey protein concentrate (WPC-60); and whey protein hydrolysate (HWP) were treated with ultrasound probe (20 kHz for 15 and 30 min) and ultrasound baths (40 kHz and 500 kHz for 15 and 30 min). pH did not change significantly upon ultrasound treatments. Ultrasound affected functional properties (using 20 kHz probe) of whey proteins like solubility and foaming ability by sample exposure at high temperatures caused by sonication. Using ultrasound of 40 kHz frequency had less effect on protein properties and better results were obtained with 15 min treatment than with 30 min treatment. Ultrasound treatment with 500 kHz bath did not had effect on foaming properties of whey protein model solutions. Conductivity decreased for ultrasound treatments with 40 kHz and 500 kHz bath for all samples. Temperature of protein model solutions increased after all ultrasound treatments.

Within a few years 3-dimensional prenatal ultrasound has achieved such a high standard that this technique opens up a new way of image rendering in prenatal diagnosis both for the examiner and for the patient. Using a 3-D ultrasound probe, data acquisition and storage of defined volumes is possible under routine conditions. Within the stored volume every dimension can be visualised and high quality 3-D surface and translucency images can also be provided rapidly. In prenatal diagnosis the advantages are not only in demonstrating precisely the extent of a defect, especially of the surface, but also to convince the parents concerned by clear demonstration of the absence of a specific defect. In 3-D technology there are still some problems to be solved: in severe oligohydramnios, no surface images can be provided, and in the examination of moving objects movement artifacts can occur. On the other hand, improvements in computer technology will soon provide an accelerated image rendering.

Ultrasound and electromyography (EMG) are two of the most commonly used diagnostic tools for the assessment of muscles. Recently, many studies reported the simultaneous collection of EMG signals and ultrasound images, which were normally amplified and digitized by different devices. However, there is lack of a systematic method to synchronize them and no study has reported the effects of ultrasound gel to the EMG signal collection during the simultaneous data collection. In this paper, we introduced a new method to synchronize ultrasound B-scan images, EMG signals, joint angles and other related signals (e.g. force and velocity signals) in real-time. The B-mode ultrasound images were simultaneously captured by the PC together with the surface EMG (SEMG) and the joint angle signal. The deformations of the forearm muscles induced by wrist motions were extracted from a sequence of ultrasound images, named as Sonomyography (SMG). Preliminary experiments demonstrated that the proposed method could reliably collect the synchronized ultrasound images, SEMG signals and joint angle signals in real-time. In addition, the effect of ultrasound gel on the SEMG signals when the EMG electrodes were close to the ultrasound probe was studied. It was found that the SEMG signals were not significantly affected by the amount of the ultrasound gel. The system is being used for the study of contractions of various muscles as well as the muscle fatigue.

Nephrologists have to place temporary dialysis catheters for hemodialysis in emergency situations. Since there is a dearth of literature on this subject, the authors have written guidelines for the safe and successful placement of these catheters. These instructions should be of help to nephrology trainees who want to master the art of central venous line placement. Based on their experience, the authors have provided a number of tips and techniques for temporary catheter placement in the femoral, internal jugular, and subclavian veins, with and without ultrasound guidance. Patient positioning, preparation of the catheter insertion tray, handling of ultrasound probe, cannulation of the central veins, and guide wire and dilator insertion are described in detail. These guidelines should assist the novice in placing temporary catheters with ease and with minimal complications.

The purpose of this paper was to examine how muscle architecture parameter (MAP) measurements made using brightness-mode ultrasonography (BMU) differ based on probe orientation. The human tibialis anterior muscle was imaged from nine different probe orientations during concentric contractions at four joint angles to determine the effect of probe orientation on the measurement of muscle architecture parameters. Ankle dorsi-flexion torque, tibialis anterior electromyography (EMG), and measures of MAP including fascicle length (FL), pennation angle (PA) and muscle thickness (MT) were collected. Statistically significant differences were found between joint angles for measures of FL and PA and between probe orientations for measures of FL and MT. A comparison of actual MAP values to a geometric model used by researchers to determine an ideal probe orientation show that the actual values vary to a greater extent and do not follow the trend predicted by the model. The results suggest that ultrasound probe orientation affects measures of MAP but the effect either cannot be predicted from a geometric model and/or the error in the measurement technique does not allow a comparison.

We integrated electrocardiogram (ECG) leads onto the face of a cardiac ultrasound transducer and the exterior chassis of a simulated small, portable scanner to minimize the number of devices needed to collect cardiac information. Since the ECG leads were not placed on their standard locations, a precordial ECG was recorded.

Purpose of review In this chapter we will discuss two bronchoscopic advances in the diagnosis and staging of lung cancer. Recent findings Endobronchial ultrasound utilizes a flexible ultrasound probe fed through the working channel of a bronchoscope to image and biopsy lesions and lymph nodes beyond the wall of the bronchus. Electromagnetic navigation and guidance involves a specialized electromagnetic table with a computer program that maps the endobronchial tree and then helps navigate a bronchoscope to a particular lesion or lymph node. Summary We review a number of recent studies that utilize endobronchial ultrasound and electromagnetic navigation and guidance and analyze their performance characteristics for lung cancer diagnosis and staging as well the clinical applications of both technologies. Both are likely to play an increasing and integral role in the diagnosis and staging of lung cancer in the near future. Endobronchial ultrasound will likely have its greatest impact on mediastinal lymph node staging while electromagnetic registration may impact both staging and diagnosis of peripheral lesions.

Following 183 ultrasound examinations, a randomized trial was conducted to compare three procedures for disinfection of probes under routine conditions: dry wiping with a soft, dry, non-sterile paper towel, antiseptic wiping with a towel impregnated with disinfectant spray and dry wiping followed by a 10 min ultraviolet C (UVC) cycle in a disinfection chamber. After ultrasonography, swabs were taken from transducer heads before and after cleaning and streaked onto plates that were then cultured. The number of colonies per plate was counted and organisms identified. The median microbial reduction was 100% for UVC, 98.4% for antiseptic wiping and 87.5% for dry wiping (P