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A freehand three-dimensional (3D) ultrasound system is a method of acquiring images using a 3D ultrasound probe or conventional two-dimensional (2D) ultrasound probe to give a 3D visualization of an object inside the body. Ultrasounds are used extensively in clinical applications since they are advantageous in that they do not bring dangerous radiation effects and have a low cost. However, a probe calibration method is needed to transform the coordinate position into a 3D visualization display, especially for image-guided intervention. The current ultrasound probe calibration system usually uses the numerical regression method for the N-wire phantom, which has problems in accuracy and reliability due to nonlinear point scattered ultrasound image data. Hence, a method for ultrasound probe positional calibration of single-wire phantom using the Levenberg-Marquardt algorithm (LMA) was proposed to overcome this weakness. This experiment consisted of an optical tracking system setup, a 2D ultrasound probe with marker, an ultrasound machine, and a single-wire object in a water container equipped with a marker. The position and orientation of the marker in a 2D ultrasound probe and the marker in the water container were tracked using the optical tracking system. A 2D ultrasound probe was equipped with a marker connected wirelessly using an optical tracking system to capture the single-wire object. The resulting sequences of 2D ultrasound images were reconstructed and visualized into 3D ultrasound images using three transformations, ultrasound beam to ultrasound probe’s marker, single-wire phantom position to container’s marker, and the 3D visualization transformation. The LMA was used to determine the best optimization parameters for determining the exact position and representing that 3D visualization. The experiment result showed that the lowest mean square error (MSE), rotation error, and translation error were 0.45 mm, 0.25°, and 0.3828 mm, respectively.

The aim of the present study was to determine the reliability and differences between three fascicle length (FL) estimation methods when utilizing a 10-cm ultrasound (US) probe. Thirteen males (24.1 ± 3.8 years, 79.3 ± 14 kg, 179 ± 6.6 cm) participated. Bicep femoris long head (BFLH) US images were collected on two separate occasions. Three previously established extrapolation methods were utilized. Near-perfect reliability was observed for all methods. Criterion estimation resulted in a significant, trivial (p = 0.016,g = 0.17) increase in FL compared to the basic trigonometry equation with non-significant, trivial increase (p = 0.081,g = 0.10) between the criterion and partial measure method. The partial measure method was not significantly or meaningfully greater than the basic trigonometry method (p = 0.286,g = 0.08). Both alternative methods demonstrated unacceptable LOA (>5%), with heteroscedasticity. All methods of extrapolation are reliable and could be used over time. However, as methods are not comparable, there could be a rationale to utilize underestimated results to ensure a degree of cushioning.

Abstract Objectives To observe change in economy of 9 ultrasound probe movement metrics among internal medicine trainees during a 5-day training course in cardiac point of care ultrasound (POCUS). Methods We used a novel probe tracking device to record nine features of ultrasound probe movement, while trainees and experts optimized ultrasound clips on the same volunteer patients. These features included translational movements, gyroscopic movements (titling, rocking, and rotation), smoothness, total path length, and scanning time. We determined the adjusted difference between each trainee’s movements and the mean value of the experts’ movements for each patient. We then used a mixed effects model to trend average the adjusted differences between trainees and experts throughout the 5 days of the course. Results Fifteen trainees were enrolled. Three echocardiographer technicians and the course director served as experts. Across 16 unique patients, 294 ultrasound clips were acquired. For all 9 movements, the adjusted difference between trainees and experts narrowed day-to-day (p value

Abstract Medical imaging-based triage is a critical tool for emergency medicine in both civilian and military settings. Ultrasound imaging can be used to rapidly identify free fluid in abdominal and thoracic cavities which could necessitate immediate surgical intervention. However, proper ultrasound image capture requires a skilled ultrasonography technician who is likely unavailable at the point of injury where resources are limited. Instead, robotics and computer vision technology can simplify image acquisition. As a first step towards this larger goal, here, we focus on the development of prototypes for ultrasound probe securement using a robotics platform. The ability of four probe adapter technologies to precisely capture images at anatomical locations, repeatedly, and with different ultrasound transducer types were evaluated across more than five scoring criteria. Testing demonstrated two of the adapters outperformed the traditional robot gripper and manual image capture, with a compact, rotating design compatible with wireless imaging technology being most suitable for use at the point of injury. Next steps will integrate the robotic platform with computer vision and deep learning image interpretation models to automate image capture and diagnosis. This will lower the skill threshold needed for medical imaging-based triage, enabling this procedure to be available at or near the point of injury.

This article introduced the design and application of the ultrasound probe holder for ultrasound-guided venipuncture. The ultrasound probe holder has been designed to hold a variety of probes in different angles, and to provide more comfort with less fatigue for the operator. The components of the probe holder can be dismantled for cleaning or sterilization. (本文介绍一种用于超声引导静脉穿刺的超声探头固定装置的设计与应用。该装置操作简便, 能够灵活调整并固定超声探头, 提高操作者舒适度, 且可拆卸进行清洗或消毒。)

This paper presents a quantitative index introduced, ‘clarity,’ which can address both the ultrasound probe's brightness and full contact states to indicate ultrasound image quality for the robotic ultrasound system. Furthermore, it evaluates its performance through an experiment, a comparative analysis, and a questionnaire. The index is calculated based on pixel statistics within the predefined region of interest. Experimental validation is conducted by implementing a robotic ultrasound system and performing experiments using two phantoms. Notably, the Results demonstrate the distinction of the visible difference in ultrasound images but also show that it is hard to classify the tiny difference. Additionally, a questionnaire was carried out to ask about the recognition of good image quality. The opinions are the same trends and patterns. The 53.4 clarity value was determined from the answers as the boundary between good and bad-quality images. The experiment results, and questionnaire findings suggest that the proposed clarity index could be a reliable tool for evaluating ultrasound image quality in robotic systems, offering insights for improving diagnostic accuracy and efficiency. This research provides a clear framework for assessing ultrasound image quality in robotic applications, paving the way for advancements in the efficacy and precision of ultrasound imaging techniques. [ABSTRACT FROM AUTHOR]

Goal: Skeletal muscle mechanics can be assessed in vivo using shear wave elastography. However, the impact of pennation angle on shear wave velocity (SWV) remains unclear. This study aims to quantify the effect by automatically aligning the ultrasound probe with muscle fiber orientation. Methods: We propose an automatic ultrasound probe alignment system and compare it to manual and no alignment. SWV of the gastrocnemius medialis muscle of ten volunteers was measured during rest and isometric contractions. Results: The SWV was different between the conditions (p = 0.008). The highest SWV was obtained during the automatic alignment and differences between the conditions were most pronounced during high-level contractions. The automatic system yielded more accurate alignment compared to a manual operator (p = 0.05). Conclusions: The present study indicates that pennation angle affects SWV, hence muscle fiber orientation must be considered to reliably interpret SWV. Using automatic alignment systems allows for more accurate alignment, improving the methodology of ultrasound elastography in skeletal muscles.

Purpose Although the taller-than-wide (TTW) sign has been regarded as one of the most specific ultrasound (US) features of thyroid malignancy, uncertainty still exists regarding the US probe’s orientation when evaluating it. This study investigated which US plane would be optimal to identify the TTW sign based on malignancy risk stratification using a registry-based imaging dataset. Methods A previous study by 17 academic radiologists retrospectively analyzed the US images of 5,601 thyroid nodules (≥1 cm, 1,089 malignant and 4,512 benign) collected in the webbased registry of Thyroid Imaging Network of Korea through the collaboration of 26 centers. The present study assessed the diagnostic performance of the TTW sign itself and fine needle aspiration (FNA) indications via a comparison of four international guidelines, depending on the orientation of the US probe (criterion 1, transverse plane; criterion 2, either transverse or longitudinal plane). Results Overall, the TTW sign was more frequent in malignant than in benign thyroid nodules (25.3% vs. 4.6%). However, the statistical differences between criteria 1 and 2 were negligible for sensitivity, specificity, and area under the curve (AUC) based on the size effect (all P0.05, respectively). Conclusion A longitudinal US probe orientation provided little additional diagnostic value over the transverse orientation in detecting the TTW sign of thyroid nodules.

Author(s): Pratibha Deshmukh (corresponding author) [1]; Parag Sable [1]; Priyanka Deshmukh [1]; Anjali Borkar [1] INTRODUCTION The use of ultrasound (US) in anaesthesia and intensive care has evolved over time [...]

Ultrasound imaging is extensively used by both practitioners and researchers in assessing muscle thickness (MT); however, its use in the field is constrained by the transportability of stationary devices. New portable ultrasound probes pose as a cost‐effective and transportable alternative for field‐based assessments. This study evaluated the concurrent validity of a portable probe (Lumify) against a laboratory‐based device (Vivid S5) in measuring MT. Eighteen participants (nine males and nine females) visited the laboratory and their MT measurements were collected using each device at five different sites (anterior and posterior arm, anterior and posterior thigh, and posterior lower leg). Bland‐Altman plots (systematic and proportional bias, random error, and 95% limits of agreement), Pearson's product–moment correlation coefficient (r), and paired samples t‐tests with Cohen's d effect sizes (ES) were used to assess the concurrent validity of the Lumify device. Systematic bias was low at all sites ( ≤ 0.11 cm) while proportional bias was detected only at the posterior lower leg (r2 = 0.217 [r = 0.466]). The difference in MT between devices was significant only at the anterior thigh (p < 0.05); however, ES for all sites were considered trivial (ES ≤ 0.131). Linear associations were found between the devices at each site of measurement (r ≥ 0.95). These results highlight that the Lumify probe can be used interchangeably with the Vivid S5 for MT measurements, providing practitioners and researchers with a more cost‐effective and portable alternative for field‐based assessments. [ABSTRACT FROM AUTHOR]

Ultrasound measurements are a widely used instrument in clinical practice. For later traceability of the images, the position (and orientation) of the ultrasound probe must be recorded during the measurement. Until now this has to be done manually by the physician. An easier and more accurate approach would be the automatic tracking of the ultrasound probe. This contribution shows a first approach for automatically localizing the ultrasonic head during measurement. The proposed method is based on coils surrounding the patient bed and a 3D magnetic sensor placed on the ultrasound head. Besides some pre- and postprocessing steps, the proposed localization algorithm is based on trilateration followed by a least mean squares approach for refinement of the estimation. In a first proof-of-concept measurement with fixed positions and orientations of the ultrasound head a mean accuracy of 2.85 cm and 8.94 ◦was achieved. Additionally, a measurement with a moving ultrasound head is presented to demonstrate the real-time capability of the system. Finally, future steps for improving the automatic measurement are discussed, including a graphical user interface for the physician and the use of magnetoelectric sensors for measurement.

Transesophageal echocardiography (TEE) is becoming increasingly utilized by emergency medicine providers during cardiac arrest. Intra-arrest, TEE confers several benefits including shorter pauses in chest compressions and direct visualization of cardiac compressions. Many ultrasound probe manufacturers recommend against performing defibrillation with the TEE probe in the mid-esophagus for fear of causing esophageal injury or damage to the probe, however no literature exists that has investigated this concern. To assess this, we performed cardiopulmonary resuscitation (CPR) and multiple defibrillations in 8 swine with a TEE probe in place. We performed TEE on 8 adult swine during CPR and performed multiple 200 J defibrillations with the TEE probe in the mid-esophagus. Post-mortem, esophagi were dissected and inspected for evidence of injury. On macroscopic inspection of 8 esophagi, no evidence of hematoma, thermal injury, or perforation was noted. Our study suggests that performing defibrillation during CPR with a TEE probe in place in the mid-esophagus is likely safe and low risk for significant esophageal injury. This further bolsters the use of TEE in CPR and would enable continuous visualization of cardiac activity without the need to remove the TEE probe for defibrillation. [ABSTRACT FROM AUTHOR]

Abstract Background The recurrence of esophageal varices remains high in patients with hepatic portal hypertension after the endoscopic esophageal variceal eradication therapies, including endoscopic variceal band ligation (EVL), injection sclerotherapy (EIS) or EVL plus EIS. The aim of this study was to evaluate the endoscopic ultrasound probe examinations (EUP) findings in the prediction of recurrence following esophageal variceal eradication in a prospective cohort. Methods A total of 206 cirrhotic portal hypertension patients with esophageal variceal eradication, who underwent endoscopic variceal therapy (EVL or EIS or EVL plus EIS) were initially enrolled. All patients were scheduled for a follow-up every 6 months for up to 3 years. EUP was performed to evaluate peri-esophageal collateral veins (peri-ECVs), perforating veins (PFV) and para-esophageal collateral veins (para-ECVs). In addition, computed tomography (CT) were conducted to detect portal vein diameter, portal vein embolus, and major portosystemic collateral shunts. The relationship between esophageal variceal recurrence and EUP findings were analyzed. Results We found that as high as 93.5% of patients developed esophageal variceal recurrence in the 3-year follow-up. The time of esophageal variceal recurrence after variceal eradication was 13.4 months (13.4 ± 9.2 months). Furthermore, the median time of recurrence in patients who were undertaken EVL,EIS and EVL plus EIS was 10, 13 and 12 months, respectively. We identified that the risk factors, including EVL (OR 0.23, 95% CI 0.08–0.71, p

Objectives: Conventionally, an assistant would be required to hold the ultrasound probe during therapeutic hysteroscopy. To manage without a skilled assistant, Lin developed a self-retaining hands-free probe method that can be used to hold an abdominal ultrasound probe. One can now perform ultrasound-guided hysteroscopic procedures single-handedly. The purpose of this study is to report the successful development of a method to keep an abdominal ultrasound probe self-retained without an assistant's help. Materials and Methods: A technique derived from improvisation with available equipment. Results: The hands-free ultrasound probe was used successfully in 2680 cases needing therapeutic hysteroscopy management for various endometrial pathologies. We only encountered one case of latex allergy, which serves as a reminder to ask about latex allergy before the procedure. Upon notification, the handle can be improvised to a latex-free solution. Compression indentation marks were of negligible concern as they resolved spontaneously within 1–2 h postsurgery. We have used this method successfully and to good effect, particularly in guiding us to avoid uterine perforations during dilation of the cervix as well as during the therapeutic hysteroscopy surgery itself. This device facilitates efficient and safe therapeutic hysteroscopic surgeries. In addition, this method encourages the reuse and recycling of plastic water bottles. Conclusion: The usage of Lin's self-retaining ultrasound probe method is practical, cheap, and not dependent on an assistant's participation during procedures.

Intravascular ultrasound (IVUS) imaging has been extensively utilized to visualize atherosclerotic coronary artery diseases and to guide coronary interventions. To receive ultrasound signals within the vessel wall safely and effectively, miniaturized ultrasound transducers that meet the strict size constraints and have a simple manufacturing procedure are highly demanded. In this work, the first known IVUS probe that employs a backing-layer-shared dual-frequency structure and a single coaxial cable is introduced, featuring a small thickness and easy interconnection procedure. The dual-frequency transducer is designed to have center frequencies of 30 MHz and 80 MHz, and both have an aperture size of 0.5 mm × 0.5 mm. The total thickness of the dual-frequency transducer is less than 700 µm. In vitro phantom imaging and ex vivo porcine coronary artery imaging experiments are conducted. The low-frequency transducer achieves spatial resolutions of 40 µm axially and 321 µm laterally, while the high-frequency transducer exhibits axial and lateral resolutions of 17 µm and 247 µm, respectively. A bandpass filter is utilized to separate the ultrasound images. Combining in vitro phantom imaging analysis with ex vivo imaging validation, a comprehensive demonstration of the promising application of the proposed miniature ultrasound probe is established.