Image-guided Breast Biopsy of MRI-visible Lesions with a Hand-mounted Motorised Needle Steering Tool

A biopsy is the only diagnostic procedure for accurate histological confirmation of breast cancer. When sonographic placement is not feasible, a Magnetic Resonance Imaging(MRI)-guided biopsy is often preferred. The lack of real-time imaging information and the deformations of the breast make it challenging to bring the needle precisely towards the tumour detected in pre-interventional Magnetic Resonance (MR) images. The current manual MRI-guided biopsy workflow is inaccurate and would benefit from a technique that allows real-time tracking and localisation of the tumour lesion during needle insertion. This paper proposes a robotic setup and software architecture to assist the radiologist in targeting MR-detected suspicious tumours. The approach benefits from image fusion of preoperative images with intraoperative optical tracking of markers attached to the patient's skin. A hand-mounted biopsy device has been constructed with an actuated needle base to drive the tip toward the desired direction. The steering commands may be provided both by user input and by computer guidance. The workflow is validated through phantom experiments. On average, the suspicious breast lesion is targeted with a radius down to 2.3 mm. The results suggest that robotic systems taking into account breast deformations have the potentials to tackle this clinical challenge.Comment: Submitted to 2021 International Symposium on Medical Robotics (ISMR

Needle and Biopsy Robots: a Review

Purpose of the review Robotics is a rapidly advancing field, and its introduction in healthcare can have a multitude of benefits for clinical practice. Especially, applications depending on the radiologist\u2019s accuracy and precision, such as percutaneous interventions, may profit. This paper provides an overview of recent robot-assisted percutaneous solutions. Recent findings Percutaneous interventions are relatively simple and the quality of the procedure increases a lot by introducing robotics due to the improved accuracy and precision. The success of the procedure is heavily dependent on the ability to merge pre- and intraoperative images, as an accurate estimation of the current target location allows to exploit the robot\u2019s capabilities. Summary Despite much research, the application of robotics in some branches of healthcare is not commonplace yet. Recent advances in percutaneous robotic solutions and imaging are highlighted, as they will pave the way to more widespread implementation of robotics in clinical practic

Performance and application of an open source automated magnetic optical density meter for analyzing magnetotactic bacteria

We present a spectrophotometer (optical density meter) combined with electromagnets dedicated to the analysis of magnetotactic bacteria. We have ensured that our system, called MagOD, can be easily reproduced by providing the source of the 3D prints for the housing, electronic designs, circuit board layouts, and microcontroller software. We compare the performance of this novel system to existing adapted commercial spectrophotometers. In addition, we demonstrate its use by analyzing the absorbance of magnetotactic bacteria as a function of their orientation with respect to the light path and their speed of reorientation after the field has been rotated by 90o. We continuously monitored the development of a culture of magnetotactic bacteria over a period of five days, and measured the development of their velocity distribution over a period of one hour. Even though this dedicated spectrophotometer is relatively simple to construct and cost-effective, a range of magnetic field-dependent parameters can be extracted from suspensions of magnetotactic bacteria. Therefore, this instrument will help the magnetotactic research community to understand and apply this intriguing micro-organism

An open-source automated magnetic optical density meter for analysis of suspensions of magnetic cells and particles

We present a spectrophotometer (optical density meter) combined with electromagnets dedicated to the analysis of suspensions of magnetotactic bacteria. The instrument can also be applied to suspensions of other magnetic cells and magnetic particles. We have ensured that our system, called MagOD, can be easily reproduced by providing the source of the 3D prints for the housing, electronic designs, circuit board layouts, and microcontroller software. We compare the performance of our system to existing adapted commercial spectrophotometers. In addition, we demonstrate its use by analyzing the absorbance of magnetotactic bacteria as a function of their orientation with respect to the light path and their speed of reorientation after the field has been rotated by 90°. We continuously monitored the development of a culture of magnetotactic bacteria over a period of 5 days and measured the development of their velocity distribution over a period of one hour. Even though this dedicated spectrophotometer is relatively simple to construct and cost-effective, a range of magnetic field-dependent parameters can be extracted from suspensions of magnetotactic bacteria. Therefore, this instrument will help the magnetotactic research community to understand and apply this intriguing micro-organism

Design of an end-effector for robot-assisted ultrasound-guided breast biopsies

Purpose: The biopsy procedure is an important phase in breast cancer diagnosis. Accurate breast imaging and precise needle placement are crucial in lesion targeting. This paper presents an end-effector (EE) for robotic 3D ultrasound (US) breast acquisitions and US-guided breast biopsies. The EE mechanically guides the needle to a specified target within the US plane. The needle is controlled in all degrees of freedom (DOFs) except for the direction of insertion, which is controlled by the radiologist. It determines the correct needle depth and stops the needle accordingly. Method: In the envisioned procedure, a robotic arm performs localization of the breast, 3D US volume acquisition and reconstruction, target identification and needle guidance. Therefore, the EE is equipped with a stereo camera setup, a picobeamer, US probe holder, a three-DOF needle guide and a needle stop. The design was realized by prototyping techniques. Experiments were performed to determine needle placement accuracy in-air. The EE was placed on a seven-DOF robotic manipulator to determine the biopsy accuracy on a cuboid phantom. Results: Needle placement accuracy was 0.3 ± 1.5 mm in and 0.1 ± 0.36 mm out of the US plane. Needle depth was regulated with an accuracy of 100 µm (maximum error 0.89 mm). The maximum holding force of the stop was approximately 6 N. The system reached a Euclidean distance error of 3.21 mm between the needle tip and the target and a normal distance of 3.03 mm between the needle trajectory and the target. Conclusion: An all in one solution was presented which, attached to a robotic arm, assists the radiologist in breast cancer imaging and biopsy. It has a high needle placement accuracy, yet the radiologist is in control like in the conventional procedure

Production and clinical evaluation of breast lesion skin markers for automated three-dimensional ultrasonography of the breast: a pilot study

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Quantitative evaluation of automated robot-assisted volumetric breast ultrasound

Adding volumetric ultrasound (3DUS) to MRI improves cancer detection rate in a breast. However, the fusion of 3DUS and MRI is challenging due to the different position (supine versus prone, respectively) and high deformation of a breast in the existing 3DUS scanners. In this study, we present and quantitatively evaluate a novel robot-assisted breast scanning system for 3D US acquisitions. Since the breast is scanned in a prone position with minimal and measurable deformation, this can facilitate MRI - 3DUS fusion. For quantitative evaluation, a breast-shaped rigid polyvinyl-alcohol phantom was constructed containing spherical lesions (15 mm diameter) with different echogenicity (-22 dB, -5 dB, -4 dB, 3 dB, 7 dB). First, the phantom was scanned with a Siemens Skyra 3T MRI (Siemens Healthcare, Erlangen, Germany). Next, the phantom was scanned by a robotic arm (KUKA, Augsburg, Germany) (Fig. 1a.) following a pre-planned spiral trajectory, determined from the MRI volume. The flange of the robot was equipped with an L10-5v US transducer attached to a P500 system (Siemens, Mountain View, CA, US). 2D B-mode US data were acquired for 3 minutes at 12 fps. The imaging depth was 5 cm, and the focal depth was set at 2 cm. A volume of 77 × 77 × 69 mm3 was reconstructed with an isotropic sampling distance of 0.2 mm utilizing a voxel nearest neighbor method with a subsequent 'hole filling' step, i.e. interpolation. The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated per lesion and compared to reference values from the originally acquired 2D B-mode images. The 3D US volume was registered to the MRI volume by using 4 lesions as landmark, using rigid registration. The distance between the centers of the remaining lesion in MRI and 3DUS after the registration was calculated. The measurement was repeated for 5 combinations between lesions and landmarks. The average distance was used as a measure of registration accuracy. For the reconstructed volume only 24 % of the data were obtained by interpolation. On average, the CNR and SNR were 24% and 6% higher, respectively, for the 3DUS compared to the reference. The registration accuracy was 3.4 mm; hence, the presented scanning approach enables ultrasound breast 3D imaging in prone position facilitating MRI - 3D US fusion

Deformation Compensation in Robotically-Assisted Breast Biopsy

A major challenge of current breast biopsy procedures is lesion displacement due to needle-tissue interaction, respiration and involuntary motions, possibly causing the needle to miss the target. These deformations are intrinsically ac- counted for when the procedure is performed under ultrasound (US) guidance, but the low US resolution makes target visualization often impossible. By con- trast, MRI-guided biopsies provide high-resolution images with excellent sensi- tivity, but they do not account in any ways for breast deformations. The MRI and Ultrasound Robotic Assisted Biopsy (MURAB) project aims to solve this challenge by the use of a combination of technologies