The increasing availability of portable ultrasound systems motivates exploration of novel approaches to respiratory signal assessment. In this in-vitro study, we investigate whether pulsed-wave (PW) Doppler ultrasound can capture structured spectral patterns from replayed lung sound recordings.Digitized respiratory sounds were replayed through a tissue-mimicking ultrasound phantom, generating 1,478 PW Doppler spectral images from recordings associated with healthy subjects and several externally labeled disease categories. Exploratory classification experiments using a ResNet-18 architecture demonstrated that these Doppler representations contain learnable differences under controlled conditions.These findings motivate further investigation into PW Doppler as a potential representation of respiratory acoustics.

Abdominal ultrasound is a core component of residency training in ultrasound medicine, yet opportunities for repetitive and standardized bedside practice are often limited in routine clinical settings. Although simulation-based teaching may help address this gap, evidence remains limited regarding the role of abdominal ultrasound phantom training in standardized residency curricula. This study evaluated whether integrating structured phantom-assisted simulation into routine residency teaching was associated with improved early abdominal ultrasound skill acquisition and clinically oriented performance among novice residents. We conducted a quasi-experimental study with a historical comparison cohort at a tertiary teaching hospital. Consecutive postgraduate year 2 residents in ultrasound medicine were included. The intervention cohort (2023-2025) received the routine curriculum supplemented with a 4-week structured phantom-assisted training module, whereas the historical comparison cohort (2020-2022) underwent the conventional bedside apprenticeship-based curriculum alone. The primary outcome was total score on a standardized patient-based abdominal ultrasound objective structured clinical examination (OSCE). The secondary outcome was learner-reported self-assessment measured using a 6-item questionnaire. Standard-view acquisition and embedded-lesion recognition were assessed as intervention-process measures within the intervention cohort. A total of 58 residents were included (intervention, n = 32; historical comparison, n = 26). Baseline characteristics were comparable between cohorts. The intervention cohort achieved significantly higher OSCE scores than the historical comparison cohort (87.16 ± 3.81 vs. 84.04 ± 4.00), with a mean difference of 3.12 points (95% CI 1.06-5.18; P = 0.004; Cohen's d = 0.80). Inter-rater reliability for OSCE scores was good (ICC[2,1] = 0.746). Among residents in the intervention cohort, 71.9% completed all required standard views, and lesion-recognition task performance ranged from 78.6% to 86.5% across assessed domains. Compared with the historical comparison cohort, the intervention cohort also reported higher learner-reported scores in understanding of ultrasound anatomy, perceived skill mastery, and clinical readiness (all P < 0.05). Integration of a structured phantom-assisted simulation module into residency teaching was associated with improved abdominal ultrasound OSCE performance and better learner-reported outcomes in selected domains. Structured phantom-assisted training may serve as a useful supplementary approach for early abdominal ultrasound skill development, although its long-term transfer value requires further study.

This phantom is designed to instruct emergency medicine residents in ultrasound-guided fascia iliaca (FI) nerve blocks but could also be used for medical students and attending physicians. Ultrasound-guided regional nerve blocks are increasingly used in the emergency department for pain management. The FI block, used for pain management in patients with hip fractures, have been shown to provide pain relief for up to eight hours with rare complications and to decrease need for parenteral pain medication.1,2 It is considered best practice to train physicians in ultrasound-guided procedures such as FI blocks by using phantoms, which are objects designed to mimic human tissue and anatomy relevant to the specific ultrasound-guided procedure. Commercial trainers are available but are quite expensive with those designed to mimic femoral anatomy priced at or over $5,000 USD, and they still lack some of the anatomical landmarks useful in FI blocks.3,4 Several lower cost FI models have been described made from a variety of perishable items including gelatin, tofu, chicken, konnyaku jelly, pork and meat glue.5-10 However, these models have the downside of limited uses due to the nature of perishable materials, and most are also lacking in block specific landmarks and durability. By the end of the training session using the FI phantom and bedside ultrasound, learners should be able to: 1) discuss indications, contraindications, and complications of FI blocks; 2) identify anatomy relevant to performing an FI block on ultrasound; and 3) independently perform an FI block or demonstrate proper needle position for FI block on ultrasound of the phantom. This low-cost FI block phantom was developed using ballistics gel to create the fascia layers and muscles, bungee cord for nerve, and latex balloons for vessels. Ballistics gel was also used as the base medium for the phantom. Participants completed a short electronic survey following the educational session using five-point Likert scale questions to evaluate the phantom based on ultrasound image quality, anatomical accuracy, and perceived durability. An additional question asked participants if they felt more confident performing an FI block after practicing on the phantom. Twenty-four emergency medicine residents completed the training session and the post-training survey. All learners were able to successfully demonstrate proper needle placement on ultrasound for the FI block. On a five-point Likert scale, ranging from 1 (very poor) to 5 (excellent), participants rated the phantom in durability, anatomical accuracy, and ultrasound image quality. Most participants agreed that the phantom was anatomically accurate (median 4) and durable (median 4). The phantom performed the best in the category of ultrasound image quality (median 5). Most participants agreed that practicing with the phantom increased their confidence in performing FI blocks (median 4). The phantom held up to 100 needle sticks with only mild degradation in image quality. The phantom presented here effectively taught EM residents proper needle placement for an FI block since all participants were able to demonstrate appropriate needle placement. The phantom was low cost, particularly compared to commercial trainers, and held up to a large number of needle sticks. Nerve blocks, ultrasound phantom, pain management, hip fractures, point of care ultrasound.

Ultrasound imaging optimization via frequency-dependent weighting for angular field-of-view.

Tissue-mimicking materials are essential for developing realistic ultrasound phantoms in medical training and device calibration. This study systematically evaluates the acoustic and physical properties of 15 materials, including gelatin-based formulations, synthetic gels, and rubbers, to assess their suitability for simulating human soft tissues. The investigation focused on ultrasound propagation speed, attenuation coefficients, and temporal stability, with measurements conducted under controlled conditions to ensure consistency. Results revealed that organic gelatins exhibited propagation speeds (1508-1626 m/s) and attenuation coefficients (0.21-1.10 dB/cm) closely aligned with soft tissue benchmarks (1540 m/s and 0.54 dB/cm MHz, respectively), with minimal variations (<5%) over 15 days. However, their susceptibility to dehydration and mold growth necessitates protective measures. Synthetic gels, such as ballistic gel and PVC-Plastisol, demonstrated superior long-term stability but required more complex fabrication processes. Rubbers, while durable, exhibited acoustic properties that deviated significantly from tissue standards, limiting their utility. The study quantitatively highlights trade-offs between material categories: gelatins offer cost-effectiveness and acoustic fidelity for short-term use, whereas synthetic gels provide durability for repeated applications. These findings provide a comprehensive framework for selecting materials tailored to specific phantom requirements, balancing acoustic accuracy, stability, and manufacturability. The work advances the development of high-fidelity, cost-effective phantoms, with implications for improving ultrasound training and diagnostic tool validation. Future research should explore hybrid materials and extended stability assessments to further optimize phantom performance.

Ultrasound phantom is an important tool in simulation, training, and calibration of ultrasound devices. This study aims to compare the performance of agar and oil-based ultrasound phantoms using vertical distance and horizontal distance parameters. Both types of phantoms are made by embedding test objects in the form of nylon ropes in their respective media. Evaluation is carried out by measuring the vertical and horizontal distances displayed on the ultrasound image, then compared with the actual distance. The results show that the oil phantom produces measurement deviations that are still within acceptable tolerance limits. The oil-based phantom shows more stable and accurate results. Thus, the oil-based phantom is considered superior and more recommended for use in simulation and testing of ultrasound devices.

Ultrasound-guided femoral vascular access (UFVA) is a crucial step in cardiovascular intervention, yet training models remain costly, anatomically limited, or insufficiently durable. This research aimed to develop and evaluate a reusable, self-healing vascularised leg phantom in collaboration with clinicians. This bifurcating vascular model was cast in Plastisol using a customisable silicone mould design. The material exhibited a Shore OO hardness of 18.0 ± 2.2, a speed of sound of 1454 ± 15 m/s, an acoustic attenuation of 1.66 ± 0.02 × 106 kg/m2s, and healed 18G needle lesions within 3 h. Training capabilities were evaluated in a workshop involving 18 medical students: FVA times improved by more than 60% after 5 min of free practice. Qualitative feedback was collected from 31 medical educators via a seven-question Likert survey, with most reporting they would adopt the phantom for teaching. Phantoms cost £7.87 for materials, yet educators valued the models at £100–£500, underscoring its perceived utility. Compared to commercial alternatives, this in-house production approach reduced costs by 10–60 times, achieving comparable durability and anatomical fidelity. This study establishes a scalable, ultra-low-cost method for producing anatomically realistic, self-healing vascular phantoms, validated for effective skill acquisition in both educational and research settings.

Introduction: Ultrasound image guidance and quality assurance (QA) of imaging and needle placement are important for safe and accurate prostate brachytherapy. However, the QA phantoms recommended by AAPM TG-128 are very costly and difficult to obtain in low-resource settings. This study aimed to design and test a low-cost, tissue-like ultrasound phantom that follows the main requirements of TG-128. Methodology: The phantom was made using a agar-based gel with added silica powder, graphite and glycerol to match soft-tissue ultrasound properties. Simple geometric structures, including spherical and cylindrical targets, were incorporated to represent key anatomical regions relevant to prostate brachytherapy QA, as recommended in AAPM TG-128. The phantom was evaluated on a clinical transrectal ultrasound system to check image quality, geometric accuracy, and repeatability of needle insertion. Distance measurements, contrast visibility, and needle tracking were compared with TG-128 recommendations. Results: Ultrasound images showed clear visibility of all internal structures. The size measurements were within ±1 mm of the intended design. Repeated needle insertions showed a consistent accuracy within 1.5 mm. The phantom remained stable for routine QA use, and the total fabrication cost was very low compared with commercial phantoms. Conclusion: This study shows that a simple, low-cost prostate brachytherapy ultrasound phantom can be made locally while still meeting key TG-128 requirements. It provides reliable performance for QA, commissioning, and training. Future work will focus on making longer-lasting versions using stronger gels or urethane materials, as well as using replaceable inserts to increase durability.

Ultrasound-guided fascial plane blocks are increasingly used as part of multimodal peri-operative analgesia, yet opportunities for structured training in deliberate targeting of fascial planes remain limited. We describe a low-cost ultrasound phantom designed to teach core technical skills required for fascial plane blocks, including ultrasound recognition of tissue layers, tactile feedback on plane entry and accurate needle-tip positioning. The phantom combines readily available soft tissue analogues with a compliant film layer to simulate fascial resistance and a simple electrical circuit that provides objective confirmation of needle contact with defined anatomical boundaries. The design is material-agnostic, reproducible and adaptable to simulate techniques with or without bony end points. This ultrasound phantom provides an accessible educational tool which integrates sonographic, haptic and objective feedback for training in ultrasound-guided fascial plane blocks across a range of teaching environments.

【目的】超音波検査において検者は，実患者への検査の前に一定の走査訓練が必要となるが，十分な機会が得られない場合も多い．その際に，走査練習用ファントムは有用であると考えられるが，そのニーズに関する調査の報告はない．本研究は，開発中の頸動脈超音波ファントムを提示しながら超音波検査を施行している医療機関にアンケート調査を行う形で，超音波ファントムに対するニーズを明らかにすることを目的とした．【対象と方法】超音波検査を施行している医療機関に勤務する20代から70代の医療従事者118名を対象に超音波ファントムに関するアンケート調査を実施した．【結果と考察】さらに頸動脈超音波検査を訓練した方がよいと思う人の割合は75％，技術向上を目的として頸動脈超音波ファントムを使用したい人の割合は53.6％であった．以上より，走査練習の機会を求めるニーズは高く，その機会の一端として超音波練習用ファントムは有用となる可能性がある．【結論】実際にファントムを使用している施設は少ないが，配備されれば使用する検者は多いことが予測され，走査技術向上の一助となることが期待できる．

The complexity of biological tissues calls for imaging techniques capable of measuring complementary tissue characteristics in 3-D. Multiparametric imaging is a fast-growing field, especially for applications such as cancer diagnosis. Developing multiparametric imaging sequences and the associated post-processing often requires finding trade-offs between the constraints of different techniques, imaging quality and imaging time. As a consequence, phantoms capable of capturing different tissue parameters in the same location are becoming crucial to testing and optimizing such sequences without a change in setup. Thanks to recently developed techniques, ultrasound imaging today enables the measurement of tissue rigidity, structure and blood flow, but concurrent imaging is still under development. The aim of this study was therefore to design and evaluate an ultrasound phantom combining these different aspects into the same field of view; to our knowledge the first in the field of ultrasound imaging. A gel-based phantom was built with a rigid inclusion controlled by the proportion of agar. Blood flow was generated inside a looped wall-less vessel made by delicately removing a thin catheter after gel-setting. Tissue orientation was obtained by mixing magnetic particles in the phantom gel and controlling their orientation during setting with external magnets. The phantom was characterized in terms of tissue rigidity values measured with shear wave elastography, vessel diameter measured with ultrasensitive Doppler imaging and tissue orientation measured with backscatter tensor imaging. Excellent image contrast was obtained for rigidity and flow imaging, and clearly oriented tissue structure was visible with backscatter tensor imaging. The tissue rigidity ratio between the 3-D inclusion and matrix was within 12% of the theoretical value, the vessel diameter measured in 3-D was within 3% of the true value and tissue scatterer orientation was validated visually against histological phantom slabs. This phantom provides not only a framework for 3-D multiparametric ultrasound evaluation, but could also be used as a more clinically realistic alternative to some standard phantoms.

Objective: The aim of this study was to evaluate the consistency and reproducibility of attenuation coefficient (AC) measurements using different commercial ultrasound (US) across via a phantom experiment to investigate the relationship between the AC and MRI-derived proton density fat fraction (MRI-PDFF) values and the conversion equation. Methods: Twelve phantoms containing varying fat proportions (0-100%) were constructed. Phantom ACs were estimated via three US attenuation systems, including attenuation imaging (ATI), ultrasound attenuation analysis (USAT), and the US-guided attenuation parameter (UGAP), along with MRI-PDFF. Agreement among the AC values from the three ultrasonic attenuation systems was evaluated. Linear correlation analysis was used to explore the ACs, fat concentrations of the phantom, and MRI-PDFF measurements, from which a linear conversion formula between the ultrasonic attenuation parameters and the MRI-PDFF was derived. Results: MRI-PDFF and phantom fat concentration measurements appeared with a strong linear correlation (R2 = 0.996, p < 0.001). For the three US attenuation parameters, both inter-operator and intra-operator intraclass correlation coefficients (ICCs) ranged from 0.990 to 0.995 and 0.989 to 0.995, respectively. Bland-Altman analysis revealed no significant differences between the above three (all p > 0.05). Significant linear relationships were demonstrated between ultrasound attenuation parameters and phantom fat concentration (r = 0.938-0.986; all p < 0.001), as well as between ultrasound attenuation parameters and MRI-PDFF values (r = 0.922-0.982; all p < 0.001). A conversion formula (fat proportions ≤ 50%) was derived: US (dB/cm/MHz) = 0.501 + 0.012 MRI-PDFF (%). Conclusions: AC across different commercial ultrasound devices demonstrated significant diagnostic value in fat concentrations that appeared good consistency in measuring phantom fat concentration both between and within groups. The linear relationship between AC and MRI-PDFF enables the application of a conversion formula.

Due to high cost, training phantoms are often inaccessible and their manufacturing technologies are quite sophisticated. The purpose of this paper is to develop an inexpensive and reproducible technology for creating ultrasound training phantoms. These phantoms are a 3D printed porous medium composed of 156-µm-thick photopolymer resin fibers and include models of cysts ranging from 4 to 8mm in diameter, effectively simulating a muscle tissue with anechoic lesions. A custom software generates a virtual phantom model, enabling precise control over its properties. We believe that the results of the acoustic characteristics' measurements for the designed phantoms provide an opportunity to mimic muscle (1547m/s) and breast (1510m/s) tissues. Following the creation of the phantom, a series of assessments were conducted to evaluate its efficacy for needle insertion (involving 3 observers) and to identify its mimicked tissue type (with 29 observers participating). The findings revealed that the phantom is capable of enduring up to 300 punctures in a single location without exhibiting significant decline in image quality. A subsequent survey of ultrasound specialists, who possessed a range of professional experiences, indicated that the ultrasound images produced by the phantom predominantly corresponded to those of muscle tissues upon visual examination. The 3D printing process for the phantom 60mm × 60mm × 30mm in size was completed in 3h and 23min. The proposed technology allows creating low-cost, long-lasting phantoms for training in ultrasound diagnostics and ultrasound-guided procedures. The phantom designed using widely available photopolymer resin, while the custom software and high-resolution 3D printing ensures reproducibility of the shape and positions of the fibers and inclusions. The phantom mimics muscle tissues with multiple cysts and can be used to develop basic coordination and navigation skills required for ultrasound diagnostics.

Introduction: Ultrasound (USS) guided regional anaesthesia is a core skill in anaesthetic training. However, access to high-fidelity phantoms is often restricted by cost. Simulation-based training is well recognised for improving clinical performance [1] and low-cost phantoms offer significant educational value [2]. We developed an affordable, realistic, and reusable gelatine-based phantom in collaboration with the simulation team at our hospital. We evaluated its effectiveness through user feedback across different training levels. Methods: The aim of our project was to assess the educational value, realism and usability of a low-cost USS Needling phantom that we developed in-house, amongst anaesthetic trainees and consultants.The phantom was made using gelatine, glycerine, silicon tubing (to simulate nerves or vessels), and a silicone skin to mimic anatomical realism as seen in Figure 1. It was used in a hands-on training workshop conducted in October 2024 with anaesthetic trainees (ST1-7), clinical fellows and consultants. Post workshop feedback was collected through surveys with questions focusing on realism, needle feel, ultrasound clarity and overall training value. Results: Our gelatine models were successfully used for ultrasound imaging and needling practice for cannulation and nerve blocks. Feedback was given by anaesthetists across on clarity, realistic resistance and educational value, with 96% (25/26) of respondents rating the model as a useful tool for needling practice. The selected combination of ingredients resulted in a model with excellent needle visibility, minimal track mark retention, and ease of ultrasound use, all while maintaining structural integrity and durability. The total cost of consumable materials for a single model was under £40, making it an affordable training tool. Additionally, our models are reusable and can be stored in the freezer for up to six weeks, then thawed for reuse without compromising quality. Discussion: Over the past decade, USS has become an indispensable tool in anaesthesia and intensive care, with NICE guidelines recommending its use for procedures such as central venous cannulation and peripheral nerve blocks. However, gaining competency in USS imaging and needle visualisation can be challenging. Our model is an affordable, reusable, durable, and high-functional fidelity alternative to both existing gelatine models and expensive commercial phantoms. It provides a practical solution for ultrasound training in anaesthesia and critical care, and other junior trainee doctors in various specialities, ensuring accessibility without compromising educational value. The model also aligns with national curriculum goals on USS proficiency [3].Feedback from trainees and experienced clinicians highlights its strong educational impact. Ethics Statement: As the submitting author, I can confirm that all relevant ethical standards of research and dissemination have been met. Additionally, I can confirm that the necessary ethical approval has been obtained, where applicable.

Method for Developing Tissue-mimicking Ultrasound Imaging Phantoms of Organs using Polyvinyl Alcohol and 3-D Printed Moulds.

Infertility is a major global health concern, with fallopian tube blockages contributing to up to 35% of female infertility cases, and highlighting the critical need for effective tubal patency diagnostics. Hysterosalpingo-contrast sonography (HyCoSy) is a noninvasive ultrasound technique for assessing fallopian tube patency, crucial in infertility diagnostics. Despite its advantages over x-ray and laparoscopic methods, its clinical use is limited due to operator dependence and the need for specialized training. However, existing ultrasound phantoms lack compatibility with microbubble-based contrast agents, restricting their effectiveness for HyCoSy training. This study presents a low-cost, anatomically representative ultrasound phantom of the female reproductive system designed to support contrast agent infusion. The phantom replicates the uterus and fallopian tubes using tissue-mimicking materials with acoustic and mechanical properties approximating human muscle and serous membrane tissues. Fabrication was performed using 3D-printed molds. Materials were selected and characterized based on density, Young's modulus, acoustic velocity, and attenuation slope, and compared with literature-reported physiological ranges. Reproducibility was assessed through multiple independent fabrications, and statistical analysis was conducted to evaluate inter-batch variability. Among 15 tested material formulations, muscle-mimicking sample 6 exhibited a Young's modulus of 24.3±4.8kPa, an acoustic velocity of 1550±5m/s, and an attenuation slope of 0.055±0.002dB/mm/MHz-closely matching reported values for human muscle tissue (13-32kPa, 1547m/s, 0.05-0.054dB/mm/MHz, respectively). Serosa-mimicking sample 15 showed a Young's modulus of 60.7±7.3kPa, velocity of 1598±5m/s, and attenuation slope of 0.079±0.002dB/mm/MHz, closely aligning with reported ranges for serous tissue (50-500kPa, 1575-1595m/s, 0.048-0.157dB/mm/MHz). Computed tomography and B-mode ultrasound confirmed the structural integrity and formation of internal cavities in the phantom, while fluorescence and ultrasound imaging demonstrated effective retention of contrast agents during microbubble infusion. Both B-mode and non-linear contrast ultrasound imaging enabled clear visualization of the uterine and tubal structures. The phantom demonstrates validated mechanical and acoustic properties that closely match those of human muscle and serosa, supporting its suitability for illustrating core principles of HyCoSy, including contrast agent infusion and tubal visualization. The low cost and structural reproducibility of the model make it a practical option for simulation-based radiology training.

Purpose: This study aims to assess the preparedness of faculty in the Nursing, Clinical Medicine, and Radiography and Imaging Sciences departments in Kenya to teach Obstetric Point-of-Care Ultrasound (O-POCUS) and Postpartum Hemorrhage (PPH) management, in light of the 2024 National Guidelines requiring structured training in these areas. The purpose is to identify training gaps among educators and propose solutions to improve maternal health outcomes. Methods: A descriptive cross-sectional design with a quantitative approach was employed to gather data from health educators using a structured self-administered questionnaire. The survey targeted tutors and clinical instructors across the three departments. The questionnaire, aligned with the 2024 O-POCUS guidelines, covered areas such as training gaps, resource availability, teaching methods, and institutional readiness. Data were analyzed using SPSS, with descriptive statistics and chi-square tests used to identify relationships between various factors. Findings: The study revealed significant gaps in faculty training and resources. In the Nursing and Clinical Medicine departments, over 80% of educators had not received training in O-POCUS, and 60% in PPH management. The Radiography and Imaging Sciences department showed a similar trend, with 89% of respondents reporting a lack of training in both areas. Additionally, limited access to ultrasound machines and teaching materials hindered effective teaching. Respondents favored hands-on workshops, mentorship, and simulation-based scenarios as the most effective teaching methods. Curriculum inclusion of O-POCUS and PPH management was inadequate across all departments, with many respondents uncertain or unaware of its integration. Unique Contributions to Theory, Policy and Practice: The study concluded that faculty members in the Nursing, Clinical Medicine, and Radiography and Imaging Sciences departments are inadequately trained to teach O-POCUS and PPH management, leading to gaps in student preparedness. Despite strong leadership support, there is insufficient resource allocation and curriculum integration of these critical topics. This lack of preparation impacts the quality of maternal healthcare education and hinders the implementation of effective practices in obstetric emergencies. To address these gaps, it is recommended that a comprehensive faculty development program be implemented, focusing on both theoretical knowledge and hands-on training in O-POCUS and PPH management. Curricula across all departments should integrate these topics with clear guidelines and balance between theory and practical application. Institutions must prioritize resource allocation, including the provision of portable ultrasound machines, phantoms, and standardized teaching materials.

ABSTRACTUltrasonography in veterinary medicine serves a vital role in the diagnosis and management of various medical conditions by allowing noninvasive visualization of internal structures. Veterinary students face many challenges in gaining hands‐on experience with ultrasound equipment and developing competencies in ultrasonography. This is largely due to the limited access and ethical dilemmas of live animal models and the high cost of commercial phantoms. To solve these issues, the niche of cost‐effective amateur models has exponentially increased. However, while these at‐home models solve the financial issues associated with commercial phantoms, they still lack the realism and fidelity necessary to simulate the real‐time feedback needed to gain the spatial awareness of this dynamic imaging modality. To foster successful day‐one‐ready veterinary students, The Ohio State University College of Veterinary Medicine acknowledged that a better solution should be possible. A prospective anatomic study was performed to recognize the imaging anatomy and usability of a new model termed the Danny Phantom. This model was developed by testing various amateur phantom materials from both the literature and self‐discovered. These materials were analyzed and deemed satisfactory versus unsatisfactory based on fulfillment of predetermined criteria of an ideal phantom model. It was determined that real fixed organs can be encased in traditional bovine gelatin to produce an ultrasound phantom with recognizable parenchyma. Other additives can be included to give the phantom an imitated peritoneal space and prevent spoilage of the gelatin for an extended period of time.

Free-hand 3D ultrasound imaging for vascular access.

Medical phantoms are essential to imaging calibration, clinician training, and the validation of therapeutic procedures. However, most ultrasound phantoms prioritize acoustic realism while neglecting the viscoelastic and anisotropic properties of fibrous soft tissues. This gap limits their effectiveness in modeling realistic biomechanical behavior, especially in wave-based diagnostics and therapeutic ultrasound. Current materials like gelatine and agarose fall short in reproducing the complex interplay between the solid and fluid components found in biological tissues. To address this, we developed a soft, anisotropic composite whose dynamic mechanical properties resemble fibrous biological tissues such as skin and skeletal muscle. This material enables wave propagation and vibration studies in controllably anisotropic media, which are rare and highly valuable. We demonstrate the tunability of damping and stiffness aligned with fiber orientation, providing a versatile platform for modeling soft-tissue dynamics and validating biomechanical simulations. The phantoms achieved Young’s moduli of 7.16–11.04 MPa for skin and 0.494–1.743 MPa for muscles, shear wave speeds of 1.51–5.93 m/s, longitudinal wave speeds of 1086–1127 m/s, and sound absorption coefficients of 0.13–0.76 dB/cm/MHz, with storage, loss, and complex moduli reaching 1.035–6.652 kPa, 0.1831–0.8546 kPa, and 2.138–10.82 kPa. These values reveal anisotropic response patterns analogous to native tissues. This novel natural fibrous composite system affords sustainable, low-cost ultrasound phantoms that support both mechanical fidelity and acoustic realism. Our approach offers a route to next-gen tissue-mimicking phantoms for elastography, wave propagation studies, and dynamic calibration across diverse clinical and research applications.