Abstract: A compact device (20) for non-invasively monitoring concentration levels of blood constituents, including glucose, cholesterol, alcohol, blood gases and various ions. The device includes a finger receptor (140) having a channel for receiving a finger of a user. The channel has a light entrance and a light exit so that light can be passed from a light source (91) through a finger located in the channel in a direction generally normal to the finger. Certain heat generating components, including a stable power supply for the device, are external to the device housing so as to reduce heat generation and thereby increase stability of the device. The device includes a communications interface for interacting with a computer. The device can be used for clinical use or for home use and the memory of the computer can be used to assist with record keeping and with dosage calculations.

Abstract: Described is a method which uses spectral data simultaneously collected in a continuous array of discrete wavelength points of the visible spectrum adjacent to the infrared and near infrared part of the light spectrum. The spectral data is collected using a number of detectors with different sensitivity ranges. Some detectors may be sensitive to visible and possibly, to part of the near infrared portion of radiation. Spectral data from die infrared spectrum is collected with the infrared detectors, and are in some embodiments insensitive to the visible links.

Abstract: Described is a method for measuring the concentration of a blood constituent within a body part (80) of a living subject which comprises irradiating a body part of the subject with a continuum of a broad spectrum of radiation in adjacent and near infrared range of the electomagnetic spectrum; collecting the band of radiation after the radiation has been directed onto the part; dispersing the continuum of collected radiation into a dispersed spectrum of component wavelengths onto a detector (120) the detector taking measurements of at least one of transmitted or reflected radiation from the collected radiation; and transferring the measurements to a processor (300), and then measuring the same kind of absorbance or reflectance with respect to one or more a discrete wavelengths of radiation from the longer near infrared range and using the measurements to calculate the concentration of the constituent.

Abstract: A holographic diffuser provides a high degree of chromatic correction, or color balance, within a selected eyebox and the ability to generate more than one specific eyebox for multiple observer applications. The strength of these gratings can be varied to modify the diffraction efficiency for each color so that the balance of colors can be varied within the eyebox. This balancing of colors can be used, for example, to compensate for color imbalance within the light source or image generator. Illuminating a first holographic medium produces a first real image of a diffusing screen in a define eyebox. A second hologram is recorded in the holographic medium using the real image produced by the first hologram as an object such that when the holographic medium is illuminated, it produces a second real image of a diffusing screen in the define eyebox. A third hologram is recorded in the holographic medium using the second real image as an object.