David T Luce

US Patent:

6419631, Jul 16, 2002

Filed:

Apr 20, 2000

Appl. No.:

09/553111

Inventors:

David A. Luce - Clarence Center NY

Assignee:

Leica Microsystems Inc. - Depew NY

International Classification:

A61B 500

US Classification:

600401

Abstract:

During corneal deformation induced by a fluid pulse, observations associated with an inward first state of applanation and an outward second state of applanation are processed to provide a final reported intra-ocular pressure value that is substantially without error due to corneal thickness effects.

US Patent:

6616609, Sep 9, 2003

Filed:

Nov 8, 2001

Appl. No.:

10/010323

Inventors:

Bruce Siskowski - Orchard Park NY
David A. Luce - Clarence Center NY

Assignee:

Reichert, Inc. - Depew NY

International Classification:

A61B 505

US Classification:

600401

Abstract:

A fluid pump system of a non-contact tonometer is numerically simulated through its compression stroke by a simulation software program. System dynamic behavior is modeled for a variety of piston diameters, whereby an optimal piston diameter or range of piston diameters is selected in view of stoke length limitations and target applanation pressure requirements.

US Patent:

6623429, Sep 23, 2003

Filed:

Nov 6, 2001

Appl. No.:

09/992875

Inventors:

Christopher J. Percival - Williamsville NY
Douglas H. Hoover - Corfu NY
David A. Luce - Clarence Center NY

Assignee:

Reichert, Inc. - Depew NY

International Classification:

A61B 316

US Classification:

600399, 600561

Abstract:

A hand-held non-contact tonometer comprises a housing having a handle portion for enclosing a rechargeable D. C. power source and an upper head portion for enclosing alignment and tonometric measurement systems of the tonometer. An operator can directly view the patients eye along an optical axis extending through the head portion of the housing, and an instructional display image is superimposed with the directly viewed image of the eye to guide the operator in X-Y-Z alignment based on data supplied by an afocal position detection system. A transceiver for wireless data exchange and a recharging support stand are also provided.

US Patent:

6679842, Jan 20, 2004

Filed:

Apr 15, 2002

Appl. No.:

10/122807

Inventors:

David A. Luce - Clarence Center NY

Assignee:

Reichert, Inc. - Depew NY

International Classification:

A61B 316

US Classification:

600398, 600401, 73 101

Abstract:

An apparatus for calibrating a non-contact tonometer comprises an electronic eye having a damped pressure sensor for receiving a tonometer air pulse and providing a pressure signal in response to the air pulse, and an applanation simulator connected to the pressure sensor for providing a pseudo-applanation event when the pressure signal reaches a predetermined level corresponding to a known IOP measurement standard. A method for calibrating a non-contact tonometer using the inventive calibration apparatus is also described.

US Patent:

6726625, Apr 27, 2004

Filed:

Apr 5, 2002

Appl. No.:

10/117510

Inventors:

David A. Luce - Clarence Center NY

Assignee:

Reichert, Inc. - Depew NY

International Classification:

A61B 316

US Classification:

600401

Abstract:

A non-contact tonometer of a type having a cylinder, a piston received by the cylinder for axially directed movement relative to the cylinder, and a driven member for causing the piston to move relative to the cylinder in a compression stroke to generate a fluid pulse for transfiguring a cornea is improved by decoupling the piston from the driven member to eliminate the need for critical alignment between the driven member and piston and allow the piston to be self-aligning with respect to the cylinder.

US Patent:

6817981, Nov 16, 2004

Filed:

Jul 1, 2002

Appl. No.:

10/186540

Inventors:

David A. Luce - Clarence Center NY

Assignee:

Reichert, Inc. - Depew NY

International Classification:

A61B 316

US Classification:

600399

Abstract:

A novel tonometry method wherein measured intraocular pressure corresponding to inward applanation of the cornea and corneal hysteresis derived from a pressure differential associated with inward and outward applanation events in the same measurement pulse allows comparison with a predetermined population normality function to avoid corneal effects so that the actual status of intraocular pressure can be ascertained. A dual mode non-contact tonometer allows selection between a standard measurement mode for patient comfort and an alternate measurement mode wherein pressure-time characteristics of the fluid pulse are varied to allow additional observation of corneal hysteresis associated with the dynamic measurement process for carrying out the novel tonometry method. Corresponding tonometry method embodiments include a method adapted for a contact tonometer and a method based on a pair of non-contact tonometer measurements taken using different air pulse pressure ramp rates.

US Patent:

6875175, Apr 5, 2005

Filed:

Jul 1, 2002

Appl. No.:

10/186572

Inventors:

David A. Luce - Clarence Center NY, US

Assignee:

Reichert, Inc. - Depew NY

International Classification:

A61B003/16

US Classification:

600398

Abstract:

A dual mode non-contact tonometer allows selection between a standard measurement mode for patient comfort and an alternate measurement mode wherein pressure-time characteristics of the fluid pulse are varied to allow additional observation of corneal hysteresis associated with the dynamic measurement process. In the alternate measurement mode, measured intraocular pressure corresponding to inward applanation of the cornea and corneal hysteresis derived from a pressure differential associated with inward and outward applanation events in the same measurement pulse allows comparison with a predetermined population normality function to avoid corneal effects so that the actual status of intraocular pressure can be ascertained.

US Patent:

7004902, Feb 28, 2006

Filed:

Mar 21, 2003

Appl. No.:

10/394833

Inventors:

David A. Luce - Clarence NY, US

Assignee:

Reichert, Inc. - Depew NY

International Classification:

A61B 3/16

US Classification:

600398, 600405, 600587

Abstract:

A method for measuring a biomechanical characteristic of corneal tissue of a cornea comprises the steps of measuring a geometric parameter of the cornea, measuring hysteresis associated with deformation of the cornea, and evaluating the measured geometric parameter and hysteresis. In an ophthalmic system for practicing the method, a pachometer is used to measure corneal thickness and a tonometer is used to measure hysteresis, and the measurement data is supplied to a computer for evaluation. A related method for prequalifying LASIK patients comprises the steps of establishing a multi-dimensional space wherein a first dimension is a geometric corneal parameter and a second dimension is hysteresis associated with corneal deformation, measuring the geometric corneal parameter and hysteresis of the patient's cornea, registering the geometric corneal parameter and corneal hysteresis in a data point in the multi-dimensional space, and evaluating a location of the data point in the multi-dimensional space.