Patents by Inventor Shalabh Chandra
Shalabh Chandra has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9835363Abstract: Evaporative heat transfer system. The system includes a substrate and a plurality of substantially parallel, spaced-apart ridges extending from the substrate forming vertical liquid manifolds therebetween. A nanoporous membrane is supported on the ridges and a pump delivers a dielectric fluid across the ridges. The fluid is drawn through the liquid manifolds via capillarity provided by the nanoporous membrane and evaporates to dissipate heat flux through the substrate. A preferred dielectric fluid is pentane. It is preferred that membrane porosity vary across the membrane to tailor thermal resistances to limit temperature rises.Type: GrantFiled: January 10, 2014Date of Patent: December 5, 2017Assignee: Massachusetts Institute of TechnologyInventors: Rong Xiao, Rishi Raj, Shankar Narayanan, Evelyn N. Wang, Ryan Enright, Shalabh Chandra Maroo
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Publication number: 20140196498Abstract: Evaporative heat transfer system. The system includes a substrate and a plurality of substantially parallel, spaced-apart ridges extending from the substrate forming vertical liquid manifolds therebetween. A nanoporous membrane is supported on the ridges and a pump delivers a dielectric fluid across the ridges. The fluid is drawn through the liquid manifolds via capillarity provided by the nanoporous membrane and evaporates to dissipate heat flux through the substrate. A preferred dielectric fluid is pentane. It is preferred that membrane porosity vary across the membrane to tailor thermal resistances to limit temperature rises.Type: ApplicationFiled: January 10, 2014Publication date: July 17, 2014Inventors: Rong Xiao, Rishi Raj, Shankar Narayanan, Evelyn N. Wang, Ryan Enright, Shalabh Chandra Maroo
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Patent number: 7289841Abstract: In a diagnostic cardiac imaging session of a patient's heart using a computed tomography imaging scanner (10) and a cardiac cycle monitor (42), a diagnostic objective (100) is received. Survey imaging (104) of the heart is performed to determine optimized imaging parameter values for the received diagnostic objective (100). Monitor imaging (108) of a limited portion of the heart is performed during influx of a contrast agent (22) using a low patient x-ray exposure condition to detect a trigger condition. Volume imaging (110) of the heart responsive to detection of the trigger condition is performed using the optimized imaging parameter values to obtain volumetric imaging data. Cardiac cycle data is recorded during at least a portion of the survey imaging (104), the monitor imaging (108), and the volume imaging (110). High resolution reconstructing (130) of at least some volumetric imaging data is performed to produce high resolution image representations (132).Type: GrantFiled: October 25, 2002Date of Patent: October 30, 2007Assignee: Koninklijke Philips Electronics N.V.Inventors: Peter C. Johnson, Shalabh Chandra, Uri Shreter, Ammon Steinberg, Dominic J. Heuscher
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Publication number: 20050184988Abstract: An apparatus and graphical method for tracking image volume review is provided. An image volume data set is stored in a memory and selected portions of the image volume data set is displayed on a human readable display. A mapping of the displayed portion of the image volume data set is performed relative to a volume completion data set. The volume completion data set with the first portion thereof identified according to the mapping is colorized using a shading function to visually differentiate first portions of the volume completion data set reviewed by a radiologist from remaining portions of the volume completion data set. In that way, a complete review of the image volume can be conducted without missing portions thereof and without redundancy.Type: ApplicationFiled: April 11, 2003Publication date: August 25, 2005Inventors: Jeffrey Yanof, Melinda Steinmiller, Shalabh Chandra, Himanshu Shukla
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Patent number: 6782284Abstract: An apparatus for measuring parameters preparatory to a stent replacement of an aneurytic blood vessel in a patient (26) includes a computed tomography (CT) scanner (10) that acquires image data (28) corresponding to multiple two-dimensional image slices. A reconstruction processor (32) reconstructs a three-dimensional image representation (34) from the image data (28). A tracking processor (40) produces a tracked vessel (92) including at least a centerline (80) and selected vessel boundaries (86). A user interface (44) displays a rendering (242) of the image representation to an associated user (42), measures selected vascular parameters corresponding to the stent parameters (276), and graphically superimposes the measured parameters on the rendering of the image representation (270, 272).Type: GrantFiled: November 21, 2001Date of Patent: August 24, 2004Assignee: Koninklijke Philips Electronics, N.V.Inventors: Krishna Subramanyan, Shalabh Chandra, Scott Kenneth Pohlman
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Patent number: 6745066Abstract: A CT scanner (10) for obtaining a medical diagnostic image of a subject includes a stationary gantry (12), and a rotating gantry (14). The detected radiation is reconstructed and divided into sub-portions, which sub-portions are aligned by a registration processor (56). The registered images are stored in a high resolution memory (58) and a maximum artery enhancement value is calculated from the high resolution images. A resolution reducer (82) reduces the resolution of the high resolution images. Time-density curves are found for the voxels of the images, which time-density curves are truncated to eliminate unwanted data, and analyzed to determine characteristic values. A perfusion calculator (106) calculates perfusion by using the maximum artery enhancement value and the characteristic values. A diagnostician can view any one of a low resolution image, a high resolution image, and a perfusion image on a video monitor (112).Type: GrantFiled: November 21, 2001Date of Patent: June 1, 2004Assignee: Koninklijke Philips Electronics, N.V.Inventors: Zhongmin Steve Lin, Scott Kenneth Pohlman, Shalabh Chandra
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Publication number: 20040082846Abstract: In a diagnostic cardiac imaging session of a patient's heart using a computed tomography imaging scanner (10) and a cardiac cycle monitor (42), a diagnostic objective (100) is received. Survey imaging (104) of the heart is performed to determine optimized imaging parameter values for the received diagnostic objective (100). Monitor imaging (108) of a limited portion of the heart is performed during influx of a contrast agent (22) using a low patient x-ray exposure condition to detect a trigger condition. Volume imaging (110) of the heart responsive to detection of the trigger condition is performed using the optimized imaging parameter values to obtain volumetric imaging data. Cardiac cycle data is recorded during at least a portion of the survey imaging (104), the monitor imaging (108), and the volume imaging (110). High resolution reconstructing (130) of at least some volumetric imaging data is performed to produce high resolution image representations (132).Type: ApplicationFiled: October 25, 2002Publication date: April 29, 2004Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Peter C. Johnson, Shalabh Chandra, Uri Shreter, Ammon Steinberg, Dominic J. Heuscher
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Patent number: 6728566Abstract: Computed tomography (CT) data (28) is collected for a plurality of slices by a CT scanner (10). At least a portion of the CT data is reconstructed (32) to form a volume image (34) defined by a plurality of two-dimensional image slices. At least one starting point is identified (72) within a blood vessel imaged in the three-dimensional image volume (34). The blood vessel is recursively tracked (70) to form a blood vessel representation (92).Type: GrantFiled: November 21, 2001Date of Patent: April 27, 2004Assignee: Koninklijke Philips Electronics, N.V.Inventors: Krishna Subramanyan, Shalabh Chandra
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Publication number: 20030097055Abstract: A diagnostic medical imaging system (10) includes an imaging apparatus (100) having an examination region (112) in which a subject (20) being examined is portioned. The imaging apparatus (100) obtains, at first resolution, a plurality of first image slices of the subject (20). The first image slices are loaded into a storage device, and a data processor combines subsets of first image slices to generate a plurality of second image slices having a second resolution lower than the first resolution. The subsets each includes a number n of contiguous first image slices. A display (152) having a plurality of view ports including a first view port which depicts one or more selected second image slices and a second view port which depicts one or more first image slices which are constituents of one of the second image slices depicted in the first view port.Type: ApplicationFiled: November 21, 2001Publication date: May 22, 2003Applicant: Philips Medical Systems(Cleveland), Inc.Inventors: Jeffrey Harold Yanof, David Morgan Kwartowitz, Shalabh Chandra
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Patent number: 6510337Abstract: A method of cardiac gating for use in an imaging apparatus includes monitoring a patient's cardiac cycle, and determining a cardiac cycle time for the patient. A desired cardiac phase of interest is selected, and a delay from a reference point in the cardiac cycle is determined. The delay is a function of the selected cardiac phase and the cardiac cycle time. Finally, the selected cardiac phase is located in the cardiac cycle using the delay. This cardiac gating method compensates for non-uniform changes in the patient's cardiac cycle corresponding to a non-uniform distribution of cardiac phases in the patient's cardiac cycle.Type: GrantFiled: November 15, 2000Date of Patent: January 21, 2003Assignee: Koninklijke Philips Electronics, N.V.Inventors: Dominic J. Heuscher, Shalabh Chandra
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Patent number: 6496560Abstract: A CT scanner (10) for obtaining a medical diagnostic image of a subject includes a stationary gantry (12), and a rotating gantry (14) rotatably supported on the stationary gantry (12) for rotation about the subject. A plurality of temporally displaced volume images are gathered, divided into slices, and stored in slice memories (541, 542, . . . 54n). A slice comparitor (58) compares each slice to a selected reference slice. The slices are transformed by a slice transformer (60) to align the slices thereby correcting for movement of the subject over the scan period.Type: GrantFiled: November 21, 2001Date of Patent: December 17, 2002Assignee: Koninklijke Philips Electronics, N.V.Inventors: Zhongmin Steve Lin, Shalabh Chandra
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Patent number: 6245028Abstract: A needle biopsy system (10) includes a biopsy needle (210), and a needle support assembly (200). The needle support assembly (200) holds the biopsy needle (210) and manipulates the biopsy needle (210) in response to received control signals. A needle simulator (250) having an input device (252) generates the control signals in response to manipulation of the input device (252) by an operator. The operator, in turn, receives feedback from the needle simulator (250) in accordance with forces experienced by the biopsy needle (210). In a preferred embodiment, the feedback received by the operator includes tactile sensations experienced by the operator as the operator manipulates the input device (252). The tactile sensations mimic those the operator would have received had the operator directly manipulated the biopsy needle (210). Optionally, a curved needle guide (280) is employed to restrict the biopsy needle's progression longitudinally therethrough.Type: GrantFiled: November 24, 1999Date of Patent: June 12, 2001Assignee: Marconi Medical Systems, Inc.Inventors: Daniel S. Furst, Shalabh Chandra, Dominic J. Heuscher, Raj Shekhar
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Patent number: 6154516Abstract: A cardiac gated spiral CT scanner (10) has a source of penetrating radiation (20) arranged for rotation about an examination region (14) having a central axis extending in a z direction. The source (20) emits a beam of radiation (22) that passes through the examination region (14) as the source (20) rotates. A patient support (30) holds a patient within the examination region (14) and translates the patient through the examination region (14) in the z direction while this source (20) is rotated such that the source (20) follows a helical path relative to the patient. A control processor (90) implements a patient-specific scan protocol in response to measured patient characteristics (for example, the patient's heart rate, the patient's breath hold time, and/or the range of coverage in the z direction based on the patient's anatomy) and scanner characteristics (for example, the number of detector rings, and/or the scan rate).Type: GrantFiled: September 18, 1998Date of Patent: November 28, 2000Assignee: Picker International, Inc.Inventors: Dominic Heuscher, Shalabh Chandra, Raj Shekhar, Dave Hoffmeyer
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Patent number: 5730144Abstract: An apparatus and method for predicting the efficacy of cardioversion as a dality for reverting a patient with atrial fibrillation to normal sinus rhythm. Blood flow through the patient's atrium is measured, converted and processed using nonlinear or chaotic processing to obtain a differential radius signal. The number of excursions of the differential radius beyond a threshold value indicates whether cardioversion will be successful.Type: GrantFiled: July 10, 1996Date of Patent: March 24, 1998Assignee: The United States of America as represented by the Secretary of the NavyInventors: Richard A. Katz, Shalabh Chandra, Richard A. Grimm, James D. Thomas