William R Overall

US Patent:

6750651, Jun 15, 2004

Filed:

Jul 3, 2002

Appl. No.:

10/190139

Inventors:

William R. Overall - Menlo Park CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

International Classification:

G01V 300

US Classification:

324309

Abstract:

A method of generating MRI signals with fat suppressed steady state free precession (SSFP) contrast without requiring any additional scan time over standard SSFP procedures and with comparable signal to noise ratio (SNR) to other techniques. Oscillating steady state free precession is employed to achieve the fat suppressed MRI signals. In the oscillating steady state sequence, a pattern of tips and precession is repeated every N repetition time in order to produce useful contrasts. In a described embodiment, a specific oscillating sequence has four tips in a repetition interval with four steady states being produced. With equal precession in each repetition time, the sequence of complex tips can be determined by an inverse Shinnar-LeRoux (SLR) transform.

US Patent:

7445605, Nov 4, 2008

Filed:

Mar 30, 2006

Appl. No.:

11/394449

Inventors:

William Ryan Overall - Palo Alto CA, US
Daniel Francis - Los Altos CA, US
Aimee Brigitte Angel - Atherton CA, US
R. Hardwin Mead - Palo Alto CA, US

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Palo Alto CA

International Classification:

A61B 5/103
A61B 5/02
A61N 1/00

US Classification:

600595, 600483, 600527, 600587, 607 17, 607 19

Abstract:

Systems, devices and methods for detecting and monitoring cardiac dysfunction. The devices include motion sensors for detecting signals representative of the total movement of the heart, and of the apex of the heart in particular.

US Patent:

8294461, Oct 23, 2012

Filed:

Jan 15, 2009

Appl. No.:

12/354451

Inventors:

William R. Overall - Palo Alto CA, US
Greig C. Scott - Palo Alto CA, US

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Palo Alto CA

International Classification:

G01V 3/00
A61B 5/05

US Classification:

324309, 324318, 324314, 324313, 324311, 324307, 600410, 600422

Abstract:

A method for detecting coupled RF current magnetic resonance (MR) objects in a body and determining MR risk is provided. The body is scanned with reverse circularly polarized RF. MR signals generated by coupling of the reverse circularly polarized RF with the RF current MR objects are detected. The detected MR signals are used to determine a risk value.

US Patent:

20030062893, Apr 3, 2003

Filed:

Sep 28, 2001

Appl. No.:

09/967644

Inventors:

William Overall - Menlo Park CA, US

Assignee:

THE BOARD OF TRUSTEES OF THE LELAND STANDFORD JUNIOR UNIVERSITY - Palo Alto CA

International Classification:

G01V003/00

US Classification:

324/306000, 324/309000, 324/307000

Abstract:

A method of oscillating dual-equilibrium steady-state angiography (ODESSA), utilizes a modified steady state free precession (SSFP) pulse sequence. The SSFP sequence is modified such that flowing material reaches a steady state which oscillates between two equilibrium values, while stationary material attains a standard, non-oscillatory steady state. When alternating sequences are employed, subtraction of adjacent echoes results in large, uniform signal from all flowing spins and zero signal from stationary spins. Venous signal can be suppressed based on its reduced T. ODESSA arterial signal is more than three times as large as that of traditional phase-contrast angiography (PCA) in the same scan time, and also compares favorably with other techniques of MR angiography. Pulse sequences are implemented in 2D, 3D, and volumetric projection modes. Angiograms of the lower leg, generated in as few as 5 s, show high arterial SNR and full suppression of other tissues.

US Patent:

20040260346, Dec 23, 2004

Filed:

Jan 30, 2004

Appl. No.:

10/769405

Inventors:

William Overall - Menlo Park CA, US
Daniel Francis - Los Altos CA, US
Aimee Angel - Atherton CA, US
R. Mead - Palo Alto CA, US

International Classification:

A61N001/365

US Classification:

607/004000, 600/508000, 607/017000, 600/016000, 604/891100

Abstract:

Methods and devices for detection and monitoring of cardiac dysfunction and means for deployment of same are disclosed, including implanted sensor devices and methods for sensing one or more mechanical, electrical, hemodynamic, or chemical properties of cardiac tissue or blood, with apparatus and methods for analyzing or interpreting signals generated by the sensing elements, producing a physiologic or environmental effect or output as a result of the analysis, and methods and devices for the delivery of such sensors into the body. A preferred embodiment is integrated into a subcutaneously implantable medical device such as a pacemaker or defibrillator, and includes one or more electrical leads placed into the cardiac veins via the coronary sinus with motion and/or electrogram sensors at their ends. Another preferred embodiment is an implanted device residing entirely within the right-ventricular apex, with apparatus for communication with an external device for signal analysis, display, and patient notification.

US Patent:

20180120401, May 3, 2018

Filed:

Dec 6, 2017

Appl. No.:

15/833514

Inventors:

- Los Altos CA, US
- Palo Alto CA, US
William OVERALL - Los Altos CA, US
Juan Santos - Los Altos CA, US

International Classification:

G01R 33/56
G01R 33/385
G01R 33/48
G01R 33/561

Abstract:

This disclosure provides a computer-implemented method for sequencing magnetic resonance imaging waveforms using a multistage sequencing hardware. The method comprises creating, with the aid of a computer processor, an active memory region that includes waveforms and schedules being played, and creating one or more buffer memory regions that contain waveforms and schedules not currently being played. Next, the waveforms and schedules in the one or more buffer memory regions may be updated while waveforms may be played in the active memory region. Upon completion of the waveform playback in the active memory region, the active and buffer memory regions may be swapped so that the former buffer memory region becomes the active memory region, and the former active memory region becomes the buffer memory region. The method may be repeated as needed until the imaging process is completed or otherwise halted.