Patents by Inventor James M. Lepper
James M. Lepper has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6011986Abstract: The method and apparatus of the present invention provides a system wherein light-emitting diodes (LEDs) can be tuned within a given range by selecting their operating drive current in order to obtain a precise wavelength. The present invention further provides a manner in which to calibrate and utilize an LED probe, such that the shift in wavelength for a known change in drive current is a known quantity. In general, the principle of wavelength shift for current drive changes for LEDs is utilized in order to allow better calibration and added flexibility in the use of LED sensors, particularly in applications when the precise wavelength is needed in order to obtain accurate measurements. The present invention also provides a system in which it is not necessary to know precise wavelengths of LEDs where precise wavelengths were needed in the past. Finally, the present invention provides a method and apparatus for determining the operating wavelength of a light emitting element such as a light emitting diode.Type: GrantFiled: February 2, 1998Date of Patent: January 4, 2000Assignee: Masimo CorporationInventors: Mohamed Kheir Diab, Esmaiel Kiani-Azarbayjany, Charles Robert Ragsdale, James M. Lepper, Jr.
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Patent number: 5940182Abstract: An optical filter used in applications involving spectroscopic measurements is fabricated by depositing layers of optical coatings onto a substrate. The layers are deposited so as to have a substantially constant thickness in a first direction along the surface of the substrate, and a gradually increasing thickness along a direction perpendicular to the first direction. The structure of the optical filter allows for large scale production of the filter so that costs in producing the filter are greatly reduced. The filter may be used in a variety of applications including, but not limited to chemical analysis, blood glucose monitoring, and the like.Type: GrantFiled: June 1, 1998Date of Patent: August 17, 1999Assignee: Masimo CorporationInventors: James M. Lepper, Jr., Mohamed Kheir Diab
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Patent number: 5860919Abstract: A monitoring method is disclosed which provides for inducing an active pulse in a blood volume of a patient. The induction of an active pulse results in a cyclic, and periodic change in the flow of blood through a fleshy medium under test. By actively inducing a change of the blood volume, modulation of the volume of blood can be obtained to provide a greater signal to noise ratio. This allows for the detection of constituents in blood at concentration levels below those previously detectable in a non-invasive system. Radiation which passes through the fleshy medium is detected by a detector which generates a signal indicative of the intensity of the detected radiation. Signal processing is performed on the electrical signal to isolate those optical characteristics of the electrical signal due to the optical characteristics of the blood.Type: GrantFiled: April 17, 1997Date of Patent: January 19, 1999Assignee: Masimo CorporationInventors: Esmaiel Kiani-Azarbayjany, Mohamed Kheir Diab, James M. Lepper, Jr.
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Patent number: 5823950Abstract: The method and apparatus of the present invention provides a system wherein light-emitting diodes (LEDs) can be tuned within a given range by selecting their operating drive current in order to obtain a precise wavelength. The present invention further provides a manner in which to calibrate and utilize an LED probe, such that the shift in wavelength for a known change in drive current is a known quantity. In general, the principle of wavelength shift for current drive changes for LEDs is utilized in order to allow better calibration and added flexibility in the use of LED sensors, particularly in applications when the precise wavelength is needed in order to obtain accurate measurements. The present invention also provides a system in which it is not necessary to know precise wavelengths of LEDs where precise wavelengths were needed in the past. Finally, the present invention provides a method and apparatus for determining the operating wavelength of a light emitting element such as a light emitting diode.Type: GrantFiled: November 12, 1996Date of Patent: October 20, 1998Assignee: Masimo CorporationInventors: Mohamed Kheir Diab, Massi E. Kiani, Charles Robert Ragsdale, James M. Lepper, Jr.
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Patent number: 5760910Abstract: An optical filter used in applications involving spectroscopic measurements is fabricated by depositing layers of optical coatings onto a substrate. The layers are deposited so as to have a substantially constant thickness in a first direction along the surface of the substrate, and a gradually increasing thickness along a direction perpendicular to the first direction. The structure of the optical filter allows for large scale production of the filter so that costs in producing the filter are greatly reduced. The filter may be used in a variety of applications including, but not limited to chemical analysis, blood glucose monitoring, and the like.Type: GrantFiled: June 7, 1995Date of Patent: June 2, 1998Assignee: Masimo CorporationInventors: James M. Lepper, Jr., Mohamed Kheir Diab
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Patent number: 5758644Abstract: The method and apparatus of the present invention provides a system wherein light-emitting diodes (LEDs) can be tuned within a given range by selecting their operating drive current in order to obtain a precise wavelength. The present invention further provides a manner in which to calibrate and utilize an LED probe, such that the shift in wavelength for a known change in drive current is a known quantity. In general, the principle of wavelength shift for current drive changes for LEDs is utilized in order to allow better calibration and added flexibility in the use of LED sensors, particularly in applications when the precise wavelength is needed in order to obtain accurate measurements. The present invention also provides a system in which it is not necessary to know precise wavelengths of LEDs where precise wavelengths were needed in the past. Finally, the present invention provides a method and apparatus for determining the operating wavelength of a light emitting element such as a light emitting diode.Type: GrantFiled: June 7, 1995Date of Patent: June 2, 1998Assignee: Masimo CorporationInventors: Mohamed Kheir Diab, Massi E. Kiani, Charles Robert Ragsdale, James M. Lepper, Jr.
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Patent number: 5743262Abstract: A blood glucose monitoring system includes a broadband light source and a specially fabricated optical filter for modulating optical radiation to be transmitted through a fleshy medium. Optical radiation which passes through the fleshy medium is detected by an optical detector which generates an electrical signal indicative of the intensity of the detected light. Digital signal processing is performed on the electrical signal to extract those optical characteristics of the electrical signal due to the optical characteristics of the filter and constituents of the fleshy May 1, 1995 medium other than blood glucose concentration. The monitoring system employs a unique "double-log" transformation to minimize errors due to indeterminate path length variations of the optical radiation through the fleshy medium. The monitoring system further employs specialized signal processing to avoid inaccuracies due to the previously unidentified solvent effect which arises when glucose is dissolved into water.Type: GrantFiled: June 7, 1995Date of Patent: April 28, 1998Assignee: Masimo CorporationInventors: James M. Lepper, Jr., Mohamed Kheir Diab
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Patent number: 5638818Abstract: An optical probe for measurements, which is particularly suited to reduce noise in measurements taken on an easily compressible material, such as a finger, a toe, a forehead, an earlobe, or a lip. The probe includes a base having an aperture which leads to a chamber. The base is placed adjacent a portion of the material, the chamber being placed directly adjacent any easily compressible portion of the material. A photodetector is located within the chamber and does not contact the material. A light emitting diode (LED) is affixed to the material, opposite the photodetector and above the chamber. The material which is supported by the aperture and therefore rests above or has intruded into the chamber is inhibited from compression since nothing comes in contact with this portion of the material, even when the material moves. Thus, light from the LED is directed through a stabilized portion of the material, i.e.Type: GrantFiled: November 1, 1994Date of Patent: June 17, 1997Assignee: Masimo CorporationInventors: Mohamed Kheir Diab, Esmaiel Kiani-Azarbayjany, James M. Lepper, Jr.
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Patent number: 5638816Abstract: A blood glucose monitoring system is disclosed which provides for inducing an active pulse in the blood volume of a patient. The induction of an active pulse results in a cyclic, and periodic change in the flow of blood through a fleshy medium under test. By actively inducing a change of the blood volume, modulation of the volume of blood can be obtained to provide a greater signal to noise ratio. This allows for the detection of constituents in blood at concentration levels below those previously detectable in a non-invasive system. Radiation which passes through the fleshy medium is detected by a detector which generates a signal indicative of the intensity of the detected radiation. Signal processing is performed on the electrical signal to isolate those optical characteristics of the electrical signal due to the optical characteristics of the blood.Type: GrantFiled: June 7, 1995Date of Patent: June 17, 1997Assignee: Masimo CorporationInventors: Esmaiel Kiani-Azarbayjany, Mohamed Kheir Diab, James M. Lepper, Jr.
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Patent number: 4641658Abstract: Previously undesired artifacts in a color signal used in fiberoptic cardiac catheters to measure blood oxygenation levels are used to produce indications of blood flow and true pulse. For this purpose, the color signal is band-pass filtered to derive a DC mean signal level .mu. and an AC signal containing only those frequencies at which the signal is affected by blood flow variations. The RMS value of that band-pass-filtered AC signal (which corresponds to the standard deviation .sigma. of the AC signal) is divided by the DC value .mu. to produce a .sigma./.mu. signal representative of flood flow. By clipping the AC signal and using the resulting square wave to drive a one-shot multivibrator, an indication of the patient's true pulse can be obtained.Type: GrantFiled: October 1, 1984Date of Patent: February 10, 1987Assignee: American Hospital Supply Corp.Inventor: James M. Lepper
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Patent number: 4262191Abstract: Disclosed herein is a method and a digital electronic steam humidifier control for use with a humidifier system including an electrode boiler to provide a normally repetitive fill, boil, fill-on-drain cycle. The humidifier control includes circuitry for providing an analog signal proportional to the electrode current, and a comparator network which receives the analog signal and a reference voltage and scaled voltages provided by additional circuitry to establish predetermined levels of electrode current at which the control responds.Type: GrantFiled: March 28, 1979Date of Patent: April 14, 1981Assignee: Wehr CorporationInventors: James M. Lepper, John C. McNabney, James A. Haas
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Patent number: 4113386Abstract: The forward light scattering photometer for analyzing particles dispersed in a fluid includes a cylindrical housing enclosing a pair of axially spaced, spherical-surfaced, bi-convex lenses which provide axial focusing of the lamp image in an intermediate light scattering chamber through which the sample being analyzed is flowed. Such lenses provide axial focusing with no circumferential aberations and only radial aberations. Light traps having radial borders, such as semicircular blank off discs, are located on the upstream or lamp side of each lens to provide an image having sharp radial edges, thereby eliminating the need for high quality lenses adapted to correct for spherical aberations.The lenses are shielded from contamination by particles from the sample by a stream of purge air introduced into the housing at a location near each lens and tangentially with the housing bore so as to create a stable vortexing flow of the purge air in the vicinity of each lens.Type: GrantFiled: September 20, 1976Date of Patent: September 12, 1978Assignee: Climet Instruments CompanyInventor: James M. Lepper, Jr.