DE102006027518A1 - Light source for fluorescence microscopy, has electronics regulating brightness of light and providing information about end of life span of source via acoustic or optical signal to user from detected brightness of light - Google Patents

Abstract

The light source has an LED (1) provided for producing light, where electronics (3) is provided for regulating the brightness of the light. A light-sensitive semiconductor (2) is provided for detecting the brightness of the light. The electronics informs about the end of the life span of the source through an acoustic or an optical signal to a user from the detected brightness of the light.

Description

object The invention is a light source for fluorescence microscopy with constant brightness.

State of the art

The Fluorescence microscopy is used in many areas of the medical Diagnosis used, It becomes the physical effect of fluorescence exploited: When irradiating a drug with light becomes this Light energy supplied. This energy can be absorbed by the atoms or molecules of the preparation. in the In the case of fluorescence microscopy, this absorption takes place in dyes, with which the drug dyed before viewing has been. These dyes are also referred to as fluorochromes.

Due to the supplied energy, the substance is put into an energetically higher state. Since a lower-energy state is usually the more stable state, the stimulated substance falls after a short time (10 ^-5 to 10 ^-8 sec) with release of energy in the lower energy state: The released energy is released in the fluorescence in the form of light and forms the basis for fluorescence microscopy.

The preparation is irradiated with light of a certain wavelength (excitation wavelength) and gives while the irradiation light of a larger wavelength (fluorescence wavelength) from.

at commercial Fluorescence microscopy becomes a source of fluorescence for a xenon lamp, Mercury vapor lamp or an LED used out of the white light The vapor lamp is activated by an excitation filter for the excitation of the Fluorochrome suitable wavelength (in which as "indirect Immunofluorescence " Application in medical laboratory diagnostics mostly blue light) filtered out When using LEDs, the wavelength is through the LED specified.

in the Inside the microscope becomes the light from a dichroic mirror on the drug reflected. This mirror reflects light of small wavelengths and is for Light with longer wavelength permeable. Of the Mirror is chosen that its critical wavelength between excitation and emission maximum of the fluorochrome. Thus, the excitation light is directed to the preparation, while the from the drug emitted long-wavelength light passes through the mirror and through the eyepiece is directed to the eye of the beholder.

All light sources have the property that they are during their Lifetime in their intensity decrease in different degrees. Already during normal operation Brightness fluctuations occur due to heating of the light source. Of others are also new sources of light due to e.g. manufacturing tolerances different bright.

brightness variations lead the light source in diagnostics to different results in one and the same Sample. If a sample with different intensities of Excitation wavelength irradiated, is also the intensity the emission is correspondingly heterogeneous. As the emission intensity of the analyte concentration is proportional, the reproducibility of the method is "indirect Immunofluorescence "strong limited. Comparability of results, both within the laboratory as well as between different laboratories, can with current Light sources are indicated only with unacceptable tolerances.

Object of the invention

The Invention is intended to contribute to the standardization of fluorescence microscopy, by creating a light source with constant brightness.

solution the task

When Light source, an LED is used. The brightness of the LED will be metrologically recorded and supplied as a control variable to a control loop ,. Of the Control circuit controls the brightness of the LED and thus ensures its Constance. Furthermore, the user is informed by the electronics, when the light source has reached the end of its life.

embodiment

An embodiment is based on 1 explained.

The light of a high power LED 1 is through a photosensitive semiconductor 2 (eg phototransistor) detected. The recorded measurement signal is an electronic 3 fed. This regulates the current of the LED 1 , so that a constant brightness of the LED is achieved. Due to aging processes of the LED, their light output decreases over the lifetime, so that the current has to be constantly readjusted (increased). The Electronic 3 detects the achievement of a preset current limit value and informs the user when this threshold is reached

The The innovation now is to regulate the brightness of the light source and thus to obtain a standardized light source. Furthermore the user is active on the end of the life of the light source called attention ,.

A constant brightness of the light source leads to a reproducible Fluorescent signal. Thereby can in the diagnostics better comparable results can be achieved as before, both at repeat measurements in a laboratory as also for measurements in different laboratories. The standardization the method "indirect Immunofluorescence "is a big step by this invention advanced.

Claims (6)

Light source for a fluorescence microscope, characterized in that it has a constant brightness. Light source according to claim 1, characterized in that the light is transmitted through an LED ( 1 ) is produced. Light source according to claims 1 or 2, characterized in that the brightness by an electronics ( 3 ) is regulated. Light source according to claim 3, characterized in that the brightness is controlled by a photosensitive semiconductor ( 2 ) is detected metrologically. Light source according to claim 3, characterized in that the electronics ( 3 ) informs the user about the end of the lifetime. Light source according to Claim 5, characterized that information by an acoustic or an optical signal he follows.