Abstract: An electrokinetic actuator for fluid flow titration including two chambers separated from one another by a porous dielectric disposed therebetween. A plurality of electrodes are disposed about a perimeter of the first and second chambers. Polar electrolyte disposed within the actuator is able to pass through the porous dielectric between the first and second chambers upon the application of an electric field or electric potential to the plural electrodes. A mechanical valve actuation mechanism connected to the second chamber allows for fine titration of fluid flow using electro-osmosis, including full-flow and/or complete cut-off. The polar electrolyte is isolated to prohibit intermixing with a fluid being titrated such as cerebrospinal fluid.

Abstract: An electrokinetic actuator for fluid flow titration including two chambers separated from one another by a porous dielectric disposed therebetween. A plurality of electrodes are disposed about a perimeter of the first and second chambers. Polar electrolyte disposed within the actuator is able to pass through the porous dielectric between the first and second chambers upon the application of an electric field or electric potential to the plural electrodes. A mechanical valve actuation mechanism connected to the second chamber allows for fine titration of fluid flow using electro-osmosis, including full-flow and/or complete cut-off. The polar electrolyte is isolated to prohibit intermixing with a fluid being titrated (such as cerebrospinal fluid).

Abstract: An electrokinetic actuator for fluid flow titration including two chambers separated from one another by a porous dielectric disposed therebetween. A plurality of electrodes are disposed about a perimeter of the first and second chambers. Polar electrolyte disposed within the actuator is able to pass through the porous dielectric between the first and second chambers upon the application of an electric field or electric potential to the plural electrodes. A mechanical valve actuation mechanism connected to the second chamber allows for fine titration of fluid flow using electro-osmosis, including full-flow and/or complete cut-off. The polar electrolyte is isolated to prohibit intermixing with a fluid being titrated (such as cerebrospinal fluid).

Abstract: 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.

Abstract: 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.

Abstract: The intraoperative calibration of an arbitrary surgical instrument relative to a surgical navigation digitizing system is achieved by a calibration guide. The calibration guide is established in position and orientation relative to the digitizing system coordinate system. The surgical instrument is aligned to the calibration guide during calibration to establish its probe and end orientation in the digitizer coordinates. The instrument carries a marker structure which is trackable in the digitizer coordinates to enable tracking by rigid-body transformation of the instruments probe and end position after calibration in the calibration guide.