Pathfinder Therapeutics Inc.

Metropolitan Government of Nashville-Davidson (balance), TN, United States

Pathfinder Therapeutics Inc.

Metropolitan Government of Nashville-Davidson (balance), TN, United States
SEARCH FILTERS
Time filter
Source Type

Simpson A.L.,Vanderbilt University | Simpson A.L.,Sloan Kettering Cancer Center | Geller D.A.,University of Pittsburgh | Hemming A.W.,University of California at San Diego | And 9 more authors.
Journal of the American College of Surgeons | Year: 2014

Background Postoperative or remnant liver volume (RLV) after hepatic resection is a critical predictor of perioperative outcomes. This study investigates whether the accuracy of liver surgical planning software for predicting postoperative RLV and assessing early regeneration. Study Design Patients eligible for hepatic resection were approached for participation in the study from June 2008 to 2010. All patients underwent cross-sectional imaging (CT or MRI) before and early after resection. Planned remnant liver volume (pRLV) (based on the planned resection on the preoperative scan) and postoperative actual remnant liver volume (aRLV) (determined from early postoperative scan) were measured using Scout Liver software (Pathfinder Therapeutics Inc.). Differences between pRLV and aRLV were analyzed, controlling for timing of postoperative imaging. Measured total liver volume (TLV) was compared with standard equations for calculating volume. Results Sixty-six patients were enrolled in the study from June 2008 to June 2010 at 3 treatment centers. Correlation was found between pRLV and aRLV (r = 0.941; p < 0.001), which improved when timing of postoperative imaging was considered (r = 0.953; p < 0.001). Relative volume deviation from pRLV to aRLV stratified cases according to timing of postoperative imaging showed evidence of measurable regeneration beginning 5 days after surgery, with stabilization at 8 days (p < 0.01). For patients at the upper and lower extremes of liver volumes, TLV was poorly estimated using standard equations (up to 50% in some cases). Conclusions Preoperative virtual planning of future liver remnant accurately predicts postoperative volume after hepatic resection. Early postoperative liver regeneration is measureable on imaging beginning at 5 days after surgery. Measuring TLV directly from CT scans rather than calculating based on equations accounts for extremes in TLV. © 2014 by the American College of Surgeons.


Dumpuri P.,Vanderbilt University | Clements L.W.,Pathfinder Therapeutics Inc. | Dawant B.M.,Vanderbilt University | Miga M.I.,Vanderbilt University
Progress in Biophysics and Molecular Biology | Year: 2010

The current protocol for image guidance in open abdominal liver tumor removal surgeries involves a rigid registration between the patient's operating room space and the pre-operative diagnostic image-space. Systematic studies have shown that the liver can deform up to 2. cm during surgeries in a non-rigid fashion thereby compromising the accuracy of these surgical navigation systems. Compensating for intra-operative deformations using mathematical models has shown promising results. In this work, we follow up the initial rigid registration with a computational approach that is geared towards minimizing the residual closest point distances between the un-deformed pre-operative surface and the rigidly registered intra-operative surface. We also use a surface Laplacian equation based filter that generates a realistic deformation field. Preliminary validation of the proposed computational framework was performed using phantom experiments and clinical trials. The proposed framework improved the rigid registration errors for the phantom experiments on average by 43%, and 74% using partial and full surface data, respectively. With respect to clinical data, it improved the closest point residual error associated with rigid registration by 54% on average for the clinical cases. These results are highly encouraging and suggest that computational models can be used to increase the accuracy of image-guided open abdominal liver tumor removal surgeries. © 2009.


Pheiffer T.S.,Vanderbilt University | Lennon B.,Pathfinder Therapeutics Inc. | Simpson A.L.,Vanderbilt University | Miga M.I.,Vanderbilt University
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2011

Laser range scanning an organ surface intraoperatively provides a cost effective and accurate means of measuring geometric changes in tissue. A novel laser range scanner with integrated tracking was designed, developed, and analyzed with the goal of providing intraoperative surface data during neurosurgery. The scanner is fitted with passive spheres to be optically tracked in the operating room. The design notably includes a single-lens system capable of acquiring the geometric information (as a Cartesian point cloud) via laser illumination and charge-coupled device (CCD) collection, as well as the color information via visible light collection on the same CCD. The geometric accuracy was assessed by scanning a machined phantom of known dimensions and comparing relative distances of landmarks from the point cloud to the known distances. The ability of the scanner to be tracked was first evaluated by perturbing its orientation in front of the optical tracking camera and recording the number of spheres visible to the camera at each orientation, and then by observing the variance in point cloud locations of a fixed object when the tracking camera is moved around the scanner. The scanning accuracy test resulted in an RMS error of 0.47 mm with standard deviation of 0.40 mm. The sphere visibility test showed that four diodes were visible in most of the probable operating orientations, and the overall tracking standard deviation was observed to be 1.49 mm. Intraoperative collection of cortical surface scans using the new scanner is currently underway. © 2011 SPIE.


Kingham T.P.,Sloan Kettering Cancer Center | Scherer M.A.,Pathfinder Therapeutics Inc. | Neese B.W.,Pathfinder Therapeutics Inc. | Clements L.W.,Pathfinder Therapeutics Inc. | And 2 more authors.
HPB | Year: 2012

Background: Ultrasound (US) is the most commonly used form of image guidance during liver surgery. However, the use of navigation systems that incorporate instrument tracking and three-dimensional visualization of preoperative tomography is increasing. This report describes an initial experience using an image-guidance system with navigated US. Methods: An image-guidance system was used in a total of 50 open liver procedures to aid in localization and targeting of liver lesions. An optical tracking system was employed to localize surgical instruments. Customized hardware and calibration of the US transducer were required. The results of three procedures are highlighted in order to illustrate specific navigation techniques that proved useful in the broader patient cohort. Results: Over a 7-month span, the navigation system assisted in completing 21 (42%) of the procedures, and tracked US alone provided additional information required to perform resection or ablation in six procedures (12%). Average registration time during the three illustrative procedures was <1 min. Average set-up time was approximately 5 min per procedure. Conclusions: The Explorer™ Liver guidance system represents novel technology that continues to evolve. This initial experience indicates that image guidance is valuable in certain procedures, specifically in cases in which difficult anatomy or tumour location or echogenicity limit the usefulness of traditional guidance methods. © 2012 International Hepato-Pancreato-Biliary Association.


Patent
Pathfinder Therapeutics Inc. | Date: 2012-09-21

An ultrasound tracking adapter assembly that attaches to an ultrasound transducer in a repeatable, rigid, and tool-less manner. When used with a tracked body, the position of the tracking technology devices and the ultrasound transducer is fixed, so intraoperative calibration is not necessary. This permits a 3D guidance system and 2D ultrasound to be used together. The adapter provides a secure, rigid hold between the ultrasound transducer body and the clamping body. The ultrasound probe clamp assembly is attached to specific probe instruments used in the operating room that are to be tracked using 3D positioning technology.


A method includes scanning a bodily tissue of a patient with an imaging device and prior to an interventional procedure to produce an image of a surface of an organ. At least a portion of a registration path associated with the organ is defined. The method further includes surgically exposing the organ and placing a probing instrument in contact with the organ at a starting point associated with the registration path and moving the probing instrument substantially along the registration path to define a registration surface of the organ. The method further includes mapping the registration surface of the organ to the image of the surface of the organ based at least in part on the registration path.


Systems, apparatus and methods for localizing and/or determining the relative position of surgical instruments during a surgical procedure are disclosed. A method includes capturing an image depicting at least a portion of a first surgical instrument disposed at a first position with respect to a target tissue, and at least a portion of a second surgical instrument disposed at a second position with respect to the target tissue, the second position different from the first position. The method includes transforming the image to a three-dimensional model so the first position of the portion of the first surgical instrument is rendered with the three-dimensional model, and the second position of the portion of the second surgical instrument is rendered with the three-dimensional model. The method includes calculating distance between the portion of the first surgical instrument and the portion of the second surgical instrument based on the three dimensional model.


Patent
Pathfinder Therapeutics Inc. | Date: 2012-09-21

An IRE guidance collar assembly used to support an IRE needle or other ablation-type devices, comprising a guidance collar eye component and a guidance collar tube component. The collar eye component is movable, and slides freely along the guidance collar tube. This provide rigidity to the IRE needle while allowing various depths of insertion. The IRE needle body is seated in the receiving end of the guidance collar tube, with the needle inserted into and through the tube end of the guidance collar tube. One end of the guidance collar eye component snaps onto and fits over the tube end of the guidance collar tube, while the other end has a needle holder through which the IRE needle is inserted. The collar eye end slides along the tube end of the guidance collar tube, moving the needle holder of the collar end close to or away from the end of the guidance collar tube, as desired.


Trademark
Pathfinder Therapeutics Inc. | Date: 2011-11-15

intraoperative guidance system comprised of a digital imaging apparatus to be used by radiologists and surgeons while in the operating room that allows real-time medical instrument tracking and three dimensional visualization of the human liver.


Trademark
Pathfinder Therapeutics Inc. | Date: 2012-01-24

imaging software to guide surgeons in performing liver surgery.

Loading Pathfinder Therapeutics Inc. collaborators
Loading Pathfinder Therapeutics Inc. collaborators