Search Results (53)

It has been demonstrated that needle guidance systems can enhance the precision and safety of ultrasound-guided punctures in human medicine. Systems that permit the utilization of commercially available standard needles, instead of those that necessitate the acquisition of costly, proprietary needles, are of particular interest. The objective of this phantom study is to evaluate the reliability and accuracy of magnet-based ultrasound needle guidance systems, which superimpose the position of the needle tip and a predictive trajectory line on the live ultrasound image. We conducted fine-needle aspiration cytology of thyroid nodules. The needles utilized in these procedures are of a slender gauge (21–27G), with lengths ranging from 40 to 80 mm. A dedicated training workstation with integrated software-based analyses of the movement of the needle tip was utilized in 240 standardized phantom punctures (angle: 45°; target depth: 20 mm). No system failures occurred, and the target achieved its aim in all cases. The analysis of the software revealed stable procedural parameters with minor relative deviations from the predefined reference values regarding the distance of needle tip movement (−4.2% to +6.7%), needle tilt (−6.4% to +9.6%), and penetration depth (−7.5% to +4.5%). These deviations appeared to increase with the use of thin needles and, to a lesser extent, long needles. They are attributed to the slight bending of the needle inside the (phantom) tissue. The training workstation we employed is thus suitable for use in educational settings. Nevertheless, in intricate clinical puncture scenarios—for instance, in the case of unfavorable localized small lesions near critical anatomical structures, particularly those involving thin needles—caution is advised, and the system should not be relied upon exclusively. Full article

Background: Patellar tendinopathy is a musculoskeletal pain condition capable of impairing physical or sport activities. Preliminary evidence supports the efficacy of percutaneous electrolysis (PE) in reducing pain and related disability in patients with patellar tendinopathy. Objective: This study proposes a theoretical model for the application of a percutaneous electrolysis approach targeting the deep zone of the proximal and distal parts of the patellar tendon in both human (ultrasound-guided) and fresh cadaver (not ultrasound-guided) models. Methods: A filiform solid needle was inserted from the lateral side of the patellar tendon targeting two areas: 1, the deep proximal interface of the Hoffa’s fat pad; and 2, the distal insertion of the patellar tendon at the tibial tuberosity in 10 fresh cadavers and in 10 healthy individuals. The patellar tendon, the saphenous nerve, and the infrapatellar nerve and its branches were identified by dissecting fresh cadavers to determine the anatomical trajectory of the infrapatellar nerve branches in relation to the needle. Results: The cadaveric model shows an anatomical relationship between the patellar tendon and infrapatellar nerve branches at the medial part of the knee. Infrapatellar nerve branches ran subcutaneously obliquely from the medial to the anterior and lateral parts of the knee, crossing in front of the patellar tendon. In all cadavers, the superior and inferior infrapatellar branches ran through the superior or inferior parts of the medial knee area. Only in 2/10 knees infrapatellar nerve branches reached the lateral part of the knee, specifically the superior lateral part. No neurovascular bundle of infrapatellar nerve branches was pierced in any insertion when the needle was inserted from the lateral part of the knee. Conclusion: This anatomical model supports the use of a lateral approach as a potentially safe approach to apply in needling interventions, e.g., percutaneous electrolysis for patellar tendinopathies. The infrapatellar nerve branches are vulnerable to needle procedures applied through the anteromedial side of the knee. Full article

Background: S1 nerve roots are difficult to approach during percutaneous procedures for the diagnostic and treatment procedures of low back pain with radicular symptoms. This is harder in older patients with obscure anatomies, due to the low bone density with overimposing degenerative changes in the facets and deformations. The otherwise straightforward procedure for the lumbar nerve roots, placing the needle in the proximity of the S1 under fluoroscopic guidance, becomes quite a challenge. Case presentation: In the proposed technique, the initial target for the needle is the lower part of the S1 facet in the convergent trajectory of the needle. After achieving contact with the bone the tip of the needle is moved caudally as, in proximity, it reaches the dorsal foramina of the S1/S2 segment—this is named “wandering to the hole”. The convergent trajectory of the needle ensures the success of the procedure with a minimal risk of intravenous drug administration, which is characteristic for the suprapedicular technique. Conclusions: The proposed technique is straightforward and reproducible due to the combination of the understanding of the surgical and radiological anatomy of this region, in spite of degenerative changes in the spine. Full article

Background/Objectives: Virtual reality (VR), a component of extended reality (XR), has shown promise in pre-procedural planning by providing immersive, patient-specific simulations. In pain management, where precise anatomical understanding is critical for interventions such as peripheral nerve stimulation (PNS), nerve blocks, and intrathecal pump placement, the application of VR remains underexplored. This case series examines the role of VR in enhancing pre-procedural planning for complex chronic pain interventions. Methods: From August 2022 to December 2024, six patients with anatomically challenging conditions underwent VR-assisted pre-procedural planning at Weill Cornell Medical Center. Patient-specific 3D models were created using the manual or automatic segmentation of imaging data and reviewed in VR to optimize procedural strategies by the surgeons performing the case. Procedures were then performed using conventional fluoroscopic or ultrasound guidance. Results: In all cases, VR facilitated the improved visualization of complex anatomies and informed optimal procedural trajectories. In patients with a complex cancer anatomy, previous surgical changes, or hardware, VR enabled precise PNS lead or needle placement, resulting in significant pain reductions postoperatively. In certain cases where previous interventional pain procedures had failed, VR allowed for a “second opinion” to develop an alternative approach with improved outcomes. Finally, in one case, VR served to potentially prevent patient harm by providing insight to the proceduralists regarding an alternative approach. Across the series, VR enhanced the spatial awareness, procedural accuracy, and confidence in navigating challenging anatomical scenarios. Conclusions: This case series demonstrates the utility of VR in pre-procedural planning for chronic pain interventions. By enabling detailed anatomical visualization and trajectory optimization, VR has the potential to improve outcomes in complex cases. Further studies are needed to evaluate its broader clinical applications and cost-effectiveness in pain management. Full article

Biopsy remains the gold standard for diagnosing lung cancer, with high-quality tissue samples being critical for accurate results. To improve puncture accuracy, reduce reliance on CT imaging, and minimize procedural complications, it is essential to address the challenges of tracking the biopsy needle’s trajectory and providing real-time positional guidance to physicians. In this study, we propose a tracking model based on a rectangular toroidal current distribution to determine the biopsy needle’s relative position within the electromagnetic tracking system. A printed circuit board (PCB) is used as the platform for generating the rectangular circulating magnetic field. An alternating electromagnetic field (~70 kHz) is modeled based on the Biot–Savart law. Induced voltages from multiple transmitting coils are processed using Fourier transform algorithms to separate frequencies, enabling the independent extraction of each coil’s signal. A least squares method is employed to solve the five-degree-of-freedom electromagnetic positioning equations for the receiving coils. The objective is to establish a precise and computationally efficient electromagnetic localization model for the biopsy needle. An experimental setup simulating lung biopsy procedures is implemented, utilizing the proposed rectangular toroidal current configuration. Results demonstrate an average localization error of less than 1.76 mm, validating the effectiveness of the system in addressing the challenges of real-time biopsy needle tracking. Full article

Optimal needle trajectory selection is critical in biopsy procedures to minimize tissue damage and ensure diagnostic accuracy. Timely trajectory planning is essential, as it relies on preoperative CT imaging. Prolonged processing times increase the risk of patient movement, rendering the planned path invalid. Traditional methods relying on clinician expertise or slow algorithms struggle with complex anatomical modeling for structures such as blood vessels. We introduce a novel method that reframes trajectory planning as an optimal puncture site identification problem by leveraging optical principles and computer rendering. A 3D model of key anatomical structures is reconstructed from CT images and segmented using SegResNet (average Dice similarity coefficient of 0.9122). A virtual light source positioned at the target illuminates the space, assigning distinct absorption coefficients to tissues based on needle permissibility and risk. Diffuse reflection simulates needle angle, and accumulated absorption represents depth, capturing puncture constraints. This simulation generates a grayscale map on the skin surface, highlighting candidate puncture sites. Furthermore, we employ a random forest-based method to model clinician preferences. This model analyzes an RGB image derived from the grayscale distribution to automatically select the optimal path and determine the needle entry point. The experimental evaluation demonstrates an average computation time of just 1.905 s per sample, which is significantly faster than traditional methods that require seconds to minutes. Moreover, clinical assessment by a thoracic surgeon found that 78% of the recommended paths met clinical standards, with 0% deemed unsatisfactory. These findings suggest that our method provides a rapid, intuitive, and reliable decision-support tool, improving biopsy safety and efficiency. Full article

Background/Objectives: Primary brain tumors are difficult to identify intraoperatively due to their infiltrative character in the marginal zone. Several optical methods have been suggested. Of these, 5-ALA-induced fluorescence visualized through a microscope is the most common. The aim is to present an investigational probe-based optical system and its translation for clinical use, summarize previous studies, and give examples of clinical implementations during resection and burr hole biopsies. Methods: The FluoRa system combines 5-ALA fluorescence spectroscopy with laser Doppler flowmetry (LDF). Probe designs are available for brain tumor resection (hand-held probe) or burr hole needle biopsies (frame-based or navigated). The outer cannulas of biopsy needles are modified with an opening at the tip for simultaneous use with optical probes during insertion along the trajectory. An updated version of FluoRa is introduced and experimentally investigated. Results: Probe-based fluorescence spectroscopy has been successfully translated for clinical use and applied during brain tumor resection (n = 75) and burr hole needle biopsies (n = 47). Forward-looking optical measurements through the biopsy needle reduce the number of trajectories (28/27) compared to prior to insertion (28/20), at the same time that the target for tissue sampling can be identified in situ. Additionally, increased microcirculation is identified along the trajectory with LDF. This is accomplished with FluoRa. Conclusions: Intraoperative probe-based spectroscopic measurements quantify 5-ALA fluorescence and thus identify glioblastoma and lymphoma tissue in situ during resection and burr hole needle biopsies. Full article

Ultrasound imaging provides real-time guidance during needle interventions, but localizing the needle in ultrasound videos remains a challenging task. This paper introduces a novel machine learning-based method to localize the needle in ultrasound videos. The method comprises three phases for analyzing the image frames of the ultrasound video and localizing the needle in each image frame. The first phase aims to extract features that quantify the speckle variations associated with needle insertion, the edges that match the needle orientation, and the pixel intensity statistics of the ultrasound image. The features are analyzed using a machine learning classifier to generate a quantitative image that characterizes the pixels associated with the needle. In the second phase, the quantitative image is processed to identify the region of interest (ROI) that contains the needle. In the third phase, the ROI is processed using a custom-made Ranklet transform to accurately estimate the needle trajectory. Moreover, the needle tip is identified using a sliding window approach that analyzes the speckle variations along the needle trajectory. The performance of the proposed method was evaluated by localizing the needle in ex vivo and in vivo ultrasound videos. The results show that the proposed method was able to localize the needle with failure rates of 0%. The angular, axis, and tip errors computed for the ex vivo ultrasound videos are within the ranges of 0.3–0.7°, 0.2–0.7 mm, and 0.4–0.8 mm, respectively. Additionally, the angular, axis, and tip errors computed for the in vivo ultrasound videos are within the ranges of 0.2–1.0°, 0.3–1.0 mm, and 0.3–1.1 mm, respectively. A key advantage of the proposed method is the ability to achieve accurate localization of the needle without altering the clinical workflow of the intervention. Full article

Background: Fluoroscopy-guided PTNB for fluoroscopy-identifiable lung lesions has been suggested as a useful method for the pathological diagnosis of lung lesions; however, it is lacking in accuracy and safety compared to CT-guided PTNB. Thus, we aimed to investigate the diagnostic accuracy and complications of fluoroscopy-guided percutaneous transthoracic needle biopsy (PTNB) with the aid of pre-procedural planning cone-beam computed tomography (CBCT) in order to take advantage of their respective strengths. Methods: A total of 255 fluoroscopy-guided PTNBs with the aid of planning CBCT were performed. Pre-procedural planning CBCT was conducted to calculate the shortest length from the skin puncture site to the margin of the target lesion for the needle trajectory. No intra-procedural CBCT was performed. The diagnostic performance of fluoroscopy-guided PTNB with the aid of planning CBCT was calculated. The prognostic factors for diagnostic failures and complications were evaluated using logistic regression analysis. Results: The accuracy, sensitivity, specificity, PPV, and NPV were 97.3%, 88.0%, 90.9%, 100%, and 62.5%, respectively. There were 29 diagnostic failures (11.8%), and the multivariable analysis showed that a longer lesion depth on CBCT and a shorter specimen length were each associated with diagnostic failure (p = 0.010 and 0.012, respectively). Complications occurred in 34 PTNBs (13.3%). The multivariable analysis showed that an increased total number of biopsies per lesion, a longer length of lung aeration via needle insertion, a smaller lesion size on CT imaging (≤20 mm), and the presence of an air bronchogram were associated with the occurrence of complications (p = 0.027, <0.001, 0.003, and 0.020, respectively). Conclusions: Excellent diagnostic accuracy was obtained by fluoroscopy-guided PTNB with the aid of planning CBCT. Compared to that of CT- or CBCT-guided PTNB, the procedure-related complication rate was acceptably low, but the radiation dose to patients could be potentially reduced. Full article

Robotic needle steering has become a topic of interest in intervention surgery. Yet, this surgical procedure poses challenges due to external disturbances and tissue movement. To address these challenges, several novel steering algorithms have been developed to guide the needle precisely from the entry point to the target point. However, some of these algorithms may cause additional trauma to patients. In this paper, we present a 3D optimal control algorithm for a curvature-controllable steerable (CCS) needle, aiming to achieve effective operations with minimal trauma. We derive a kinematics without duty cycle control strategy (needle shaft spin), propose a novel intraoperative motion planner for path replanning, and design a full-state feedback controller for accurate path tracking. A dynamic environment was simulated, and the optimal controller showed a better result (0.01 ± 0.01 mm) than the case (3.86 ± 1.32 mm) using a full-state feedback controller. The demonstration indicates that the optimal control system can safely, effectively, and accurately steer the needle to the target point in a dynamic environment. Full article

(1) Background: Our team has previously introduced the Single-Step Pedicle Screw System (SSPSS), which eliminates the need for K-wires, as a safe and effective method for percutaneous minimally invasive spine (MIS) pedicle screw placement. Despite this, there are ongoing concerns about the reliability and accuracy of screw placement in MIS procedures without traditional tools like K-wires and Jamshidi needles. To address these concerns, we evaluated the accuracy of the SSPSS workflow by comparing the planned intraoperative screw trajectories with the final screw positions. Traditionally, screw placement accuracy has been assessed by grading the final screw position using postoperative CT scans. (2) Methods: We conducted a retrospective review of patients who underwent lumbar interbody fusion, using intraoperative 3D navigation for screw placement. The planned screw trajectories were saved in the navigation system during each procedure, and postoperative CT scans were used to evaluate the implanted screws. Accuracy was assessed by comparing the Gertzbein and Robbins classification scores of the planned trajectories and the final screw positions. Accuracy was defined as a final screw position matching the classification of the planned trajectory. (3) Results: Out of 206 screws, 196 (95%) were accurately placed, with no recorded complications. (4) Conclusions: The SSPSS workflow, even without K-wires and other traditional instruments, facilitates accurate and reliable pedicle screw placement. Full article

Interventional radiologists mainly rely on visual feedback via imaging modalities to steer a needle toward a tumor during biopsy and ablation procedures. In the case of CT-guided procedures, there is a risk of exposure to hazardous X-ray-based ionizing radiation. Therefore, CT scans are usually not used continuously, which increases the chances of a misplacement of the needle and the need for reinsertion, leading to more tissue trauma. Interventionalists also encounter haptic feedback via needle–tissue interaction forces while steering a needle. These forces are useful but insufficient to clearly perceive and identify deep-tissue structures such as tumors. The objective of this paper was to investigate the effect of enhanced force feedback for sensing interaction forces and guiding the needle when applied individually and simultaneously during a virtual CT-guided needle insertion task. We also compared the enhanced haptic feedback to enhanced visual feedback. We hypothesized that enhancing the haptic feedback limits the time needed to reach the target accurately and reduces the number of CT scans, as the interventionalist depends more on real-time enhanced haptic feedback. To test the hypothesis, a simulation environment was developed to virtually steer a needle in five degrees of freedom (DoF) to reach a tumor target embedded in a liver model. Twelve participants performed in the experiment with different feedback conditions where we measured their performance in terms of the following: targeting accuracy, trajectory tracking, number of CT scans required, and the time needed to finish the task. The results suggest that the combination of enhanced haptic feedback for guidance and sensing needle–tissue interaction forces significantly reduce the number of scans and the duration required to finish the task by 32.1% and 46.9%, respectively, when compared to nonenhanced haptic feedback. The other feedback modalities significantly reduced the duration to finish the task by around 30% compared to nonenhanced haptic feedback. Full article

Rationale and Objectives: To evaluate the targeting accuracy of a novel robot-assisted guidance technique relying on one pair of 2D C-arm images. Material and Methods: In total, 160 punctures were carried out semi-automatically by using a novel robotic device. The needle’s paths were planned based on one pair of 2D fluoroscopic images from different angles. Conically shaped aluminum tips inside a gelatin-filled plexiglass phantom served as targets. The accuracy of the needle placement was assessed by taking control CTs and measuring the Euclidean distance (ED) and normal distance (ND) between the needle and the target point. In addition, the procedural time per needle placement was evaluated. Results: The accomplished mean NDs at the target for the 45°, 60°, 75° and 90° angles were 1.86 mm (SD ± 0.19), 2.68 mm (SD ± 0.18), 2.19 mm (SD ± 0.18) and 1.86 mm (SD ± 0.18), respectively. The corresponding mean EDs were 2.32 mm (SD ± 0.16), 2.68 mm (SD ± 0.18), 2.65 mm (SD ± 0.16) and 2.44 mm (SD ± 0.15). The mean duration of the total procedure, including image acquisition, trajectory planning and placement of four needles sequentially, was 12.7 min. Conclusions: Robotic guidance based on two 2D fluoroscopy images allows for the precise placement of needle-like instruments at the first attempt without the need for using an invasive dynamic reference frame. This novel approach seems to be a valuable tool for the precise targeting of various anatomical structures that can be identified in fluoroscopic images. Full article

To address the issues of low visibility, poor real-time performance, and weak interaction capabilities in the operation of magnetic levitation circular knitting needles, an online monitoring method based on digital twin technology for magnetic levitation knitting needles is proposed. This method first conducts an in-depth analysis of the digital twin five-dimensional model of the magnetic levitation knitting needle to monitor the operational status of the equipment in real time. Additionally, an online monitoring system based on the Unity3D engine and a digital twin-based architecture for magnetic levitation knitting needles are designed. On this basis, the comprehensive monitoring, operation, and maintenance of the magnetic levitation knitting needles are achieved through the design of virtual models, visual interfaces, and real-time data acquisition and driving technology. Finally, this method takes a 5-inch 32-needle magnetic levitation circular knitting machine as the application research object. By analyzing the movement trajectory and real-time current feedback data of the three working positions of the magnetic levitation knitting needles, the rationality, effectiveness, and accuracy of the proposed method and model are demonstrated, achieving online monitoring of the magnetic levitation knitting needles and reflecting the full lifecycle process of the magnetic levitation knitting needles. Full article

Objectives: The purpose of this study was to assess the performance of an optically tracked robot for computed-tomography (CT)-guided needle placements in a phantom study. Methods: In total, 240 needle punctures were carried out with the help of an optically tracked robotic device (Micromate) based on CT image datasets at three different slice thicknesses (1, 3, and 5 mm). Conically shaped targets inside a gelatin-filled plexiglass phantom were punctured. The target positioning error between the planned and actual needle trajectory was assessed by measuring the lateral positioning error (ND) between the target and the puncture needle and the Euclidean distance (ED) between the needle tip and target in control CTs. Results: The mean ND and ED for the thinnest CT slice thickness were 1.34 mm (SD ± 0.82) and 2.1 mm (SD ± 0.75), respectively. There was no significant impact of target depth on targeting accuracy for ND (p = 0.094) or ED (p = 0.187). The mean duration for the planning of one trajectory and for needle positioning were 42 s (SD ± 4) and 64 s (SD ± 7), respectively. Conclusions: In this ex vivo study, the robotic targeting device yielded satisfactory accuracy results at CT slice thicknesses of 1 and 3 mm. This technology may be particularly useful in interventions where the accurate placement of needle-like instruments is required. Full article