Tim R Majoch

44495285, May 22, 1984

Jul 20, 1981

6/285366

David C. Auth - Bellevue WA
Dale M. Lawrence - Lynnwood WA
Tim R. Majoch - Tacoma WA

University of Washington - Seattle WA

A61B 1736

1283031

A miniaturized, endoscopically deliverable thermal cautery probe for cauterizing internal vessels. The probe is applied to tissues cold, and a large number of electric heating pulses of equal energy are then applied to an internal heating element in the probe. The probe has an internal heating element in direct thermal contact with an active heat-transfer portion that has a low heat capacity to insure quick heating and subsequent cooling, thereby adequately coagulating tissue while minimizing heat penetration and resulting tissue damage. The electrical power applied to the probe is continuously measured and is terminated when the energy delivered reaches a preset value. The number of such pulses applied to the probe (and hence the total energy delivered) may be preset while the duration of the period during which the pulses were applied is displayed. Alternatively, the duration of the period during which such pulses are applied to the probe may be preset while the number of pulses applied (and hence the total energy delivered) is displayed. The heating element for the probe is a controlled breakdown diode which has a breakdown voltage that is a function of its temperature so that the temperature can be controlled.

52084850, May 4, 1993

Oct 24, 1991

7/781963

Jeffrey A. Krinsky - Renton WA
Tim R. Majoch - Puyallup WA

The Boeing Company - Seattle WA

H02J 300

307 41

Disclosed is an electrical control circuit (10) for controlling current through a plurality of resistive loads (14(1), 14(2). . . 14(N)). The control circuit includes a plurality of current control stages (12(1), 12(2),. . . 12(N)), a comparator circuit (18), and a plurality of diodes D. sub. 1, D. sub. 2. . . D. sub. N-1 in serial connection with the current control stages. The comparator circuit controls the current that is drawn collectively through the loads. The diodes ensure that all preceding current control stages in the series are conducting a predetermined level of current before the next current control stage begins to source current through its respective load. Each current control stage includes an operational amplifier (30), a pass transistor (34), a sense resistor (R. sub. s), and a feedback resistor (R. sub. f). The operational amplifiers are a pre-drive to the pass transistors to allow smaller sense resistors to be used, thereby providing greater efficiency.

46917039, Sep 8, 1987

Apr 25, 1986

6/856573

David C. Auth - Redmond WA
Dale M. Lawrence - Lynnwood WA
Tim R. Majoch - Kent WA

Board of Regents, University of Washington - Seattle WA

A61B 1736

1283031

A thermal cautery system having an endoscopically deliverable probe connected to a power supply and display unit. The power supply and display unit, when triggered by a footswitch, energizes a voltage regulator having a current limited output that supplies power to the probe. The current limiting function of the voltage regulator is disabled for a predetermined period that power is initially applied to said probe to minimize the heating time of said probe. The current through said probe is sensed and used to increase the voltage at the output of the voltage regulator as the current increases to compensate for the voltage drop in the conductors connecting the probe to the power supply. A manually selected portion of the sensed current through the probe is also integrated and used to terminate the flow of current through the probe when the integral of the current with respect to time has reached a predetermined value. A tone generator provides an audible indication when power is being applied to the probe and for a predetermined period thereafter to allow the probe to cool before the absence of the tone signals the removal of the probe from tissue being coagulated.

52006921, Apr 6, 1993

Sep 23, 1991

7/764000

Jeffrey A. Krinsky - Renton WA
Tim R. Majoch - Puyallup WA

The Boeing Company - Seattle WA

G05F 159
G05F 1573

323269

Disclosed is an electrical control circuit (10) for controlling current through a furnace coil or other resistive load (14). The control circuit includes a plurality of current control stages (12(1), 12(2),. . . 12(N)), a minimum circuit (16), and a control system (22) which provides feedback from the load. The control circuit utilizes a signal conditioner (20) and a sensor (18) to provide information regarding the load to the minimum circuit. The minimum circuit provides the minimum of inputs from the control system and a limit circuit (24) to the current control stages, thereby controlling the current that is drawn through the load. Each current control stage includes an operational amplifier (30), a pass transistor (34), a sense resistor (R. sub. s), and a feedback resistor (R. sub. f). The sense resistors ensure that there is current sharing through each of the current control stages.

45820570, Apr 15, 1986

Nov 21, 1983

6/553855

David C. Auth - Bellevue WA
Dale M. Lawrence - Lynnwood WA
Tim R. Majoch - Tacoma WA

Regents of the University of Washington - Seattle WA

A61B 1736

1283031

A miniaturized, endoscopically deliverable thermal cautery probe for cauterizing internal vessels. The probe is applied to tissues cold, and a large number of electric heating pulses of equal energy are then applied to an internal heating element in the probe. The probe has an internal heating element in direct thermal contact with an active heat-transfer portion that has a low heat capacity to insure quick heating and subsequent cooling, thereby adequately coagulating tissue while minimizing heat penetration and resulting tissue damage. The electrical power applied to the probe is continuously measured and is terminated when the energy delivered reaches a preset value. The number of such pulses applied to the probe (and hence the total energy delivered) may be preset while the duration of the period during which the pulses were applied is displayed. Alternatively, the duration of the period during which such pulses are applied to the probe may be preset while the number of pulses applied (and hence the total energy delivered) is displayed. The heating element for the probe is a controlled breakdown diode which has a breakdown voltage that is a function of its temperature so that the temperature can be controlled.