The objective of this work was to develop a robotic device to perform biopsy and therapeutic interventions in the breast with real-time magnetic resonance imaging (MRI) guidance. The device was designed to allow for (i) stabilization of the breast by compression, (ii) definition of the interventional probe trajectory by setting the height and pitch of a probe insertion apparatus, and (iii) positioning of an interventional probe by setting the depth of insertion. The apparatus is fitted with five computer-controlled degrees of freedom for delivering an interventional procedure. The entire device is constructed of MR compatible materials, i.e. nonmagnetic and non-conductive, to eliminate artifacts and distortion of the MR images. The apparatus is remotely controlled by means of ultrasonic motors and a graphical user interface, providing real-time MR-guided planning and monitoring of the operation. Joint motion measurements found probe placement in less than 50 s and sub-millimeter repeatability of the probe tip for same-direction point-to-point movements. However, backlash in the rotation joint may incur probe tip positional errors of up to 5 mm at a distance of 40 mm from the rotation axis, which may occur for women with large breasts. The imprecision caused by this backlash becomes negligible as the probe tip nears the rotation axis. Real-time MR-guidance will allow the physician to correct this error Compatibility of the device within the MR environment was successfully tested on a 4 Tesla MR human scanner

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We have developed a device to perform minimally invasive interventions in the breast with realtime MRI guidance for the early detection and treatment of breast cancer. The device uses five computer-controlled degrees of freedom to perform minimally invasive interventions inside a closed MRI scanner. Typically the intervention would consist of a biopsy of the suspicious lesion for diagnosis, but may involve therapies to destroy or remove malignant tissue in the breast. The procedure proceeds with: (a) conditioning of the breast along a prescribed orientation, (b) definition of an insertion vector by its height and pitch angle, and (c) insertion into the breast. The entire device is made of materials compatible with MRI, avoiding artifacts and distortion of the local magnetic field. The device is remotely controlled via a graphical user interface. This is the first surgical robotic device to perform real-time MRI-guided breast interventions in the United States.Index Terms-breast cancer, magnetic resonance imaging, medical diagnosis, robots, surgery.

The objective of this work was to develop a robotic device to perform biopsy and therapeutic interventions in the breast with real-time MRI guidance. This is the first US made surgical robotic device to perform real time MR-guided interventions in the breast. The device was designed to allow for (i) conditioning of the breast by compression, (ii) definition of the interventional probe trajectory, by setting the height and pitch of a probe insertion apparatus, and (iii) positioning of an interventional probe by setting the depth of insertion. The apparatus is fitted with five computer-controlled degrees of freedom for delivering an interventional procedure. The entire device is constructed of MR compatible materials, i.e. non-magnetic and non-conductive, to eliminate artifacts and distortion of the local magnetic field. The apparatus is remotely controlled by means of ultrasonic actuators and a graphical user interface, providing real-time MR-guided planning and monitoring of the operation.

A breast stabilization device or breast cradle has been developed for use in interventional procedures. The device is a three-dimensional collapsible linkage that, when actuated, lightly compresses the breast while pulling it away from the chest wall. The compression provides the pressure needed to hold the breast firm during needle biopsy, ablation, or other procedures while being more comfortable than bilateral compression plates. By collapsing radially in an open configuration, the cradle provides nearly full access to the breast, as compared to the restrictive two-dimensional layout of grid-based bilateral compression plates. By pulling the breast away from the chest wall, the breast cradle may reduce the incidence of lung puncture or other medical errors. Several iterations of the device were developed, including rigid-joint models and a compliant-joint model. The rigid models more precisely show the kinematics of the device, but the manufacturability and assembly of the joints may be tedious in a production environment. Conversely, the compliant model may be more easily mass-produced, although the design would be more complex and costly. To provide a proof-of-concept for the compliant-joint design, a rapid prototyping machine was used to quickly produce several models that could be produced by other means (i.e. vacuum forming or injection molding) in full production. These models will be tested with breast phantoms in a magnetic resonance imaging (MRI) environment to ensure compatibility. Other tests will be performed to ensure patient comfort amongst various breast sizes and shapes.