Christopher Y Chang

US Patent:

6826640, Nov 30, 2004

Filed:

Jun 4, 2003

Appl. No.:

10/454096

Inventors:

Christopher Chang - Medfield MA

Assignee:

Digi International Inc. - Minnetonka MN

International Classification:

G06F 1314

US Classification:

710107, 710240, 370438

Abstract:

A system includes a central processing unit (CPU), one or more input/output (I/O) ports designed to connect with external devices, a data bus connecting the CPU with the I/O ports, bus request and grant channels, and a bus arbiter that executes a repetitive series of the positive number of cycles, where for each cycle, for each of the bus request and grant channels that is assigned to a bus master and that has a weight equal or greater than a number of cycles already executed, if the bus master assigned to the bus request and grant channel has data waiting to be transferred on the bus then the bus arbiter grants bus access to the bus master to transfer a data packet from the data using the data bus.

US Patent:

7206928, Apr 17, 2007

Filed:

Jun 3, 2003

Appl. No.:

10/454388

Inventors:

Christopher Chang - Medfield MA, US

Assignee:

DIGI International Inc. - Minnetonka MN

International Classification:

G06F 9/24

US Classification:

713 1

Abstract:

A method includes powering up a system with a system control circuitry (SCC) that contains a central processing unit (CPU). The method includes holding the CPU in a reset condition. The method also includes retrieving, over a serial data bus using a serial communications protocol, information about a system memory configuration and a boot program from a first section of a programmable read only memory (PROM). The method also includes retrieving, over a serial data bus using a serial communications protocol, a first portion of the boot program from a second section of the PROM using the information about the system memory configuration and the boot program, writing the first portion of the boot program into a system memory, releasing the CPU from the reset condition, and booting the system using the boot program.

US Patent:

7265588, Sep 4, 2007

Filed:

Aug 17, 2005

Appl. No.:

11/205668

Inventors:

Christopher Chang - Medfield MA, US
Jeffrey Lewis Parker - Arlington MA, US

Assignee:

Digi International, Inc. - Minnetonka MN

International Classification:

H03K 19/00

US Classification:

326 93, 326 38

Abstract:

A clock change circuit includes enabling a clock change frequency to be accepted while a system is active and clock frequencies are at a low period. The circuit includes generating an enabling signal representing a window of time in which a frequency change is accomplished.

US Patent:

7488820, Feb 10, 2009

Filed:

Jan 19, 2005

Appl. No.:

11/039396

Inventors:

Stephen J. Lippard - Cambridge MA, US
Christopher J. Chang - Berkeley CA, US
Elizabeth M. Nolan - Cambridge MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

C07D 257/02
C07D 405/00
C07D 311/88

US Classification:

540474, 546256, 549225

Abstract:

The present invention is directed, in part, to naphthofluorescein-based ligands for detection of metal ions, and methods of making and using the same.

US Patent:

20040250147, Dec 9, 2004

Filed:

Jun 3, 2003

Appl. No.:

10/454189

Inventors:

Christopher Chang - Medfield MA, US

International Classification:

G06F001/26

US Classification:

713/323000

Abstract:

A method can be implemented on a computer control system for entering and exiting a power-save mode. The method includes storing a first state of a system, setting up a wake-up condition for the system, reducing power of and disabling a first portion of the system, waiting for the wake-up condition to be met, restoring operation of the first portion of the system, using a value of a power-up register to determine whether to set a current state of the system to the first state of the system, and continuing a normal operation of the system

US Patent:

20110082506, Apr 7, 2011

Filed:

Sep 30, 2010

Appl. No.:

12/894776

Inventors:

VITO LORE - SOMERVILLE MA, US
CHRISTOPHER A. CHANG - BEVERLY MA, US
CRAIG HENSHAW - CHARLESTOWN MA, US
KINGSLEY CHIN - Hallandale FL, US
MICHAEL CORDONNIER - MEMPHIS TN, US
BURL DANIEL - NEW ALBANY MS, US

Assignee:

SPINEFRONTIER, INC - BEVERLY MA

International Classification:

A61B 17/88
A61B 17/70
A61B 17/56

US Classification:

606279, 606246, 606104

Abstract:

An implantable cervical plate assembly for stabilization of two adjacent spinal vertebras includes a cervical plate and one or more bone fasteners. The cervical plate comprises an elongated asymmetric body having a first straight side surface, a second contoured side surface opposite to the first side surface, front and back surfaces and top and bottom surfaces. The elongated asymmetric body comprises one or more through-openings extending from the front surface to the back surface of the elongated asymmetric body. The one or more bone fasteners are configured to be inserted through the one or more through-openings, respectively, and to be attached to locations in the spinal vertebras, thereby attaching the cervical plate to the spinal vertebras. The through-openings comprise a first diameter at the front surface of the elongated body, a second diameter at the back surface of the elongated body and a third diameter in the area between the front and back surfaces of the elongated body. The first diameter is smaller than the third diameter, thereby forming a lip at the top of the through-openings. The third diameter is larger than the second diameter and the first diameter is larger than the second diameter, thereby forming a groove within the perimeter of the inner wall of the through-openings. The bone fasteners comprise a threaded main body and a head. The threaded main body comprises threads for engaging the spinal vertebras and the head comprises one or more flexible structures configured to be flexed and inserted into the groove and then unflex and remain captured within the groove.

US Patent:

20110106261, May 5, 2011

Filed:

Oct 27, 2010

Appl. No.:

12/913004

Inventors:

KINGSLEY CHIN - Hallendale FL, US
VITO LORE - SOMERVILLE MA, US
MICHAEL DRNEK - BOSTON MA, US
CHRISTOPHER CHANG - BEVERLY MA, US

Assignee:

SPINEFRONTIER, INC - BEVERLY MA

International Classification:

A61F 2/44
A61B 17/56
A61B 17/88

US Classification:

623 1716, 606 86 A, 606279

Abstract:

An intervertebral implant assembly includes and inserter tool and an implant having a U-shaped body shaped and dimensioned to be placed between two adjacent vertebras. The U-shaped body comprises a rounded front end, an open back end, first and second elongated components extending from the rounded front end, forming the U-shaped body and ending at the open back end and at least one rigid strut extending from and connecting opposite inner side surfaces of the first and second elongated components. A first through-opening is formed in the space between the front end, the rigid strut and the opposite inner side surfaces of the front portions of the first and second elongated components and a second through-opening is formed in the space between the open back end, the rigid strut and the opposite inner side surfaces of the back portions of the first and second elongated components. The inserter tool comprises a shaft, a middle sleeve and an outer sleeve that work together to attach and lock to the implant.

US Patent:

20130184749, Jul 18, 2013

Filed:

Mar 5, 2013

Appl. No.:

13/785279

Inventors:

VITO LORE - SOMERVILLE MA, US
CHRISTOPHER A. CHANG - BEVERLY MA, US
CRAIG HENSHAW - CHARLESTOWN MA, US
KINGSLEY R. CHIN - Hallandale FL, US
MICHAEL CORDONNIER - MEMPHIS TN, US
BURL DANIEL - NEW ALBANY MS, US

Assignee:

SPINEFRONTIER, INC - BEVERLY MA

International Classification:

A61B 17/70
A61B 17/88

US Classification:

606246, 606104

Abstract:

An implantable cervical plate assembly includes a cervical plate, one or more bone fasteners and a driver tool. The cervical plate comprises an elongated asymmetric body having one or more through-openings extending from the front surface to the back surface of the elongated asymmetric body. The one or more bone fasteners are configured to be inserted through the one or more through-openings, respectively. The bone fasteners comprise a threaded main body and a head that includes one or more flexible structures configured to be flexed and inserted into a groove and then unflex and remain captured within the groove. The driver tool includes an elongated shaft, a handle and a bone fastener-engaging. The bone fastener-engaging component comprises one or more structures that complement and engage at least one of grooves and lobes of the bone fastener opening.