Sherwood Services Ag

Radionics, Inc.

Radionics Software Applications, Inc.

Robert A Daniels

Eric R Cosman, Sr

Michael A Cundari

Barton L Guthrie

Christophe P Mauge

Robert J Ledoux

Jeffrey Labuz

This invention relates to a three-dimensional digitizer and a probe means associated with said digitizer that enables a virtual target point to be visualized and depth and range measurements to that target to be determined. In one embodiment, a mechanical articulated arm or other type of 3-D digitizer is used in conjunction with a graphics workstation which displays images from CT, MR, or other scanning means of the anatomy. By registration of the digitizer to the patient's physical anatomy, a representation of the digitizer on the display means of the graphics workstation is possible. The position of the digitizer will be displayed in its quantitative relationship to the patient's anatomy, including internal pathologies such as tumors. The end means of the 3-D digitizer could be a holder or fixation device which can accept a sliding probe. The probe, for example, could be a shaft which slides in a spring-loaded or non-spring-loaded fashion within the fixation means of the digitizer. The degree of extension of the probe from the fixation means can be read out by a scale, which might be engraved on the shaft of the sliding probe. The digitizer, when calibrated to the anatomy, would register a target point and also a direction of the probe as it would approach that point, as seen on the graphics workstation. There may be a pre-determined relationship of the virtual tip of a probe relative to the fixation means as it scans the anatomy with the probe moving in space. The physical probe might be the sliding rod, which will be retractile within the fixation means. Thus, by knowing the degree of retraction, one can gauge the distance from the tip of the sliding probe to the virtual target, as calculated in the 3-D graphic workstation.

Virtual probe for a stereotactic digitizer for use in surgery

This invention involves apparatus and methods for relating image scan data of a patient's anatomy from an imaging scanner to a device attached to said patient's anatomy or to an apparatus located nearby said patient's anatomy. In one embodiment it includes identification of fiducial points or markers on or near the patient's anatomy in the image scan data, and subsequently relating these fiducial points to reference points or structures connected to an apparatus attached to or nearby the patient's body. Such an apparatus might be a surgical head clamp or stereotactic frame or arc which has been attached to the patient's head at the time of surgery. A mapping is made between the coordinate frame data of the scan image to the coordinate reference frame of the patient attachment means or external apparatus by physically referencing the fiducial points to the patient attachment means or external apparatus. In one embodiment, such registration can be in the form of distance or coordinate measurements between the fiducial points on the patient's body and the reference points on the external apparatus. Applications are given in the field of frameless stereotaxy, radiosurgery, and stereotactic frame application.

Frameless to frame-based registration system

A skin-based band is fixed to a patient's skin in a repeatable position and includes reference markers which, attached to the skin band, can be visualized in tomographic image scanning. The reference markers appear as reference marker images in the image scan data from the image scan and correspond to coordinate positions in the image scan coordinate system. The reference markers also provide corresponding reference marker positions in the physical space of the patient's anatomy, which may correspond to a stereotactic coordinate system associated with a digitized navigator or frameless stereotactic reference system near the patient. The band can also be placed on the patient again at the time of surgical intervention, and the reference markers can be touched or referenced by the surgical navigator in the stereotactic coordinate system. A computer system assimilates the image scan data and calibration data and enables a mapping from the image scan coordinate system to the stereotactic coordinate system so that surgical instruments can be tracked by a surgical navigator so that their position can be referenced to the image scan data.

Head band for frameless stereotactic registration

This invention relates to apparatus for calibrating and recalibrating a digitized navigator or so-called frameless stereotactic instrument or device during a surgical operation. The apparatus enables calibration for the stereotactic digitizer to be recovered after sterile draping of the patient, movement of the patient's head during operation, relative movement of the patient's head and reference apparatus associated with the stereotactic digitizer, power failures, or other events which could compromise calibration of the stereotactic digitizer during the operation which would otherwise preclude continuations using the digitizer. It also provides convenient means for initial calibration or repeat calibration, should that be necessary. The apparatus is, in one embodiment, cooperatively coupled to, or coupled so as to move with, the portion of the patient's body which is being operated upon and enables the repositioning of the recalibration means after sterile draping. In exemplary embodiments, the apparatus would include a reference point structure or a reference holding structure that can be attached to, for example, a surgical head clamp in a neurosurgical operation and can be accessed for calibration positioning or calibration locationing by the digitizer during the operation. The apparatus could be removed, sterilized, and repositioned in an identical position relative to the head clamp, and therefore the patient's head during the operation, assuring that sterility and loss of calibration would not be compromised.

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Haverhill, MA, United States of America

Robert A Daniels