Sasidhar Vajha

US Patent:

8467739, Jun 18, 2013

Filed:

Sep 10, 2008

Appl. No.:

12/208198

Inventors:

Sasidhar Vajha - Brooklyn Park MN, US
Timothy T. Childs - Minnetonka MN, US
Daniel C. Eller - Silver Lake MN, US

International Classification:

H04B 1/40

US Classification:

455 75, 455 76, 455 84, 331107 R

Abstract:

A variable operational mode transceiver device formed with an integrated circuit having a semiconductor material substrate supporting a feedback oscillator having a signal power divider electrically coupled to said feedback oscillator output, and a signal frequency multiplier electrically coupled to said signal power divider. A signal mixer has a pair of inputs of which one is electrically coupled to that remaining one of said pair of outputs of said signal power divider.

US Patent:

20040061565, Apr 1, 2004

Filed:

Sep 15, 2003

Appl. No.:

10/662748

Inventors:

Zahilya Austin - St. Paul MN, US
Timothy Childs - Eden Prairie MN, US
Sasidhar Vajha - Minneapolis MN, US

Assignee:

TLC Precision Wafer Technology, Inc. - Minneapolis MN

International Classification:

H03B001/00

US Classification:

331/17700V

Abstract:

A feedback oscillator device formed with an integrated circuit having a semiconductor material substrate on a ground plane. The circuit has an amplifier having an input and an output is provided at least in part on said semiconductor material substrate. A directional coupler is used to couple the amplifier output signal to the amplifier input through a parallel separated transmission lines transfer system and a capacitor such as a varactor. The substrate can be of gallium arsenide.

US Patent:

20080021521, Jan 24, 2008

Filed:

May 22, 2007

Appl. No.:

11/751966

Inventors:

Yogendra A. Shah - Blaine MN, US
Sasidhar Vajha - Brooklyn Park MN, US

Assignee:

CARDIAC PACEMAKERS, INC. - St. Paul MN

International Classification:

A61N 1/02

US Classification:

607 60

Abstract:

A medical communication system for providing remote communications with an active implantable medical device. In one embodiment, a medical communication system includes an active implantable medical device (AIMD) that is configured to transmit and receive a wireless signal from within a human body, and a non-implantable programmer that includes a retrodirective antenna. The programmer is configured to scan in multiple directions for signals received from the AIMD and to identify the direction of the signal having the highest signal power.

US Patent:

20110166629, Jul 7, 2011

Filed:

Dec 23, 2010

Appl. No.:

12/977166

Inventors:

Philip G. Dion - Blaine MN, US
Dennis E. Larson - White Bear Lake Township MN, US
Sasidhar Vajha - Brooklyn Park MN, US

International Classification:

A61N 1/08
H04B 1/40

US Classification:

607 60, 455 901

Abstract:

This document discusses, among other things, an implantable telemetry system including an RF transceiver configured to drive an antenna and a matching circuit, configured to be coupled to the antenna, the matching circuit including a control parameter configured to adjust the impedance of the matching circuit. The implantable telemetry system also includes a control circuit configured to receive an indication of the RF transceiver current draw and to control the control parameter of the matching circuit using the received indication of current draw. In an example, the control parameter is controlled to decrease the RF transceiver current draw.

US Patent:

20120130206, May 24, 2012

Filed:

Nov 22, 2011

Appl. No.:

13/302282

Inventors:

Sasidhar Vajha - Brooklyn Park MN, US
Keith R. Maile - New Brighton MN, US
Dennis E. Larson - White Bear Township MN, US
David A. Chizek - Brooklyn Park MN, US
John M. Edgell - Plymouth MN, US

International Classification:

A61B 5/07
H01P 11/00
A61N 1/36

US Classification:

600302, 607 60, 29600

Abstract:

Subject matter such as a method or apparatus can include an implantable antenna assembly, comprising a dielectric shell including first and second substantially parallel outer face portions, and a third outer face portion extending between the first and second portions, a spiral conductor extending along the first, second, and third portions on a surface of the dielectric shell. The dielectric shell and spiral conductor can be configured to be mechanically attached to a dielectric compartment, such as configured to be coupled to a housing of an implantable medical device. In an example, the implantable antenna assembly is configured to be electrically coupled to an implantable telemetry circuit configured to wirelessly transfer information electromagnetically using the implantable telemetry antenna, such as included as a portion of an implantable medical device.

US Patent:

20120130450, May 24, 2012

Filed:

Nov 22, 2011

Appl. No.:

13/302202

Inventors:

Sasidhar Vajha - Brooklyn Park MN, US
Keith R. Maile - New Brighton MN, US
Dennis E. Larson - White Bear Township MN, US
David A. Chizek - Brooklyn Park MN, US
John M. Edgell - Plymouth MN, US

International Classification:

A61N 1/36

US Classification:

607 60

Abstract:

In an example, an apparatus can include an implantable medical device comprising a housing, an implantable telemetry circuit carried within the housing, a dielectric compartment mechanically coupled to the housing, the dielectric compartment including first and second substantially parallel face portions and a third face portion extending between the first and second face portions, and an implantable telemetry antenna, located at least partially within the dielectric compartment. The implantable telemetry circuit can be electrically coupled to the implantable telemetry antenna and configured to wirelessly transfer information electromagnetically using the implantable telemetry antenna. In an example the implantable telemetry antenna comprises a spiral conductor portion extending along the first, second, and third face portions. In an example the spiral conductor includes a cross section having a lateral width that can be greater than a sidewall height of the cross section

US Patent:

20120130451, May 24, 2012

Filed:

Nov 22, 2011

Appl. No.:

13/302324

Inventors:

Sasidhar Vajha - Brooklyn Park MN, US
Keith R. Maile - New Brighton MN, US
Dennis E. Larson - White Bear Township MN, US
David A. Chizek - Brooklyn Park MN, US
John M. Edgell - Plymouth MN, US

International Classification:

A61N 1/36

US Classification:

607 60

Abstract:

Subject matter such as a method or apparatus can include an implantable medical device comprising a housing, an implantable telemetry circuit carried within the housing, and a dielectric compartment, mechanically coupled to the housing an implantable telemetry antenna, such as located at least partially within the dielectric compartment. The implantable telemetry circuit can be electrically coupled to the implantable telemetry antenna and configured to wirelessly transfer information electromagnetically using the implantable telemetry antenna. The implantable telemetry antenna can include a spiral conductor portion extending along a face portion of the dielectric compartment, and a loading portion configured to adjust an input impedance of the implantable telemetry antenna, to provide a specified input impedance range within a specified range of operating frequencies to be used for wireless information transfer.

US Patent:

20170272873, Sep 21, 2017

Filed:

Mar 15, 2016

Appl. No.:

15/071107

Inventors:

Trevor Webster - Eden Prairie MN, US
Sasidhar Vajha - Eden Prairie MN, US
Jeffrey Paul Solum - Greenwood MN, US
Gregory John Haubrich - Champlin MN, US

International Classification:

H04R 25/00

Abstract:

A hearing assistance device such as a hearing aid includes an antenna system that has an adaptive antenna configuration that can be dynamically optimized for communicating with one or more other devices at different locations. The hearing assistance device determines an approximately optimal antenna configuration and adjusts the antenna configuration to that approximately optimal antenna configuration using one or more switches coupled between the antenna system and a communication circuit of the hearing assistance device.