Stroboscopic Vocal Fold Examination Illumination Control
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Solution Overview
Problem
Current stroboscopic examination methods for repetitive processes, such as moving vocal folds, suffer from fluctuations in image brightness and associated flickering due to imperfect synchronization and regulation of illuminating flashes with the camera system.
Innovation Solution
An arrangement that controls an illumination device coupled with a CCD or CMOS camera system, using an electronic control unit to generate flash pulses with varying pulse widths, ensuring a constant sum of flash durations per frame, and generating asynchronous pulses when no stable trigger signal is present, thereby maintaining consistent image brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the camera exposure control is switched on to control brightness, then brightness control is improved, but flash suppression by exposure control causes differently exposed images and brightness fluctuations
Solution Approach 1:
The invention uses feedback by monitoring the camera's exposure control signal and using it to dynamically adjust the flash pulse generation. The control unit detects when the exposure control suppresses flash impulses and compensates by adjusting subsequent flash timing and duration, ensuring consistent exposure across all frames while maintaining the brightness control benefits of the exposure control system.
Solution Approach 2:
The invention changes parameters of the flash illumination system dynamically - specifically adjusting flash pulse duration and timing based on the camera's exposure control state. When exposure control suppresses certain flashes, the system compensates by extending other flash pulses or adjusting their timing to ensure each frame receives adequate illumination, thereby maintaining exposure consistency while preserving brightness control.
2Reliability
If the camera exposure control is switched off to avoid brightness fluctuations, then exposure consistency is improved, but brightness control is lost causing crossfades in bright areas and poor visibility of dark objects
Solution Approach 1:
The system continuously monitors the camera's exposure control signal and uses this feedback to intelligently manage flash pulse generation. By detecting the exposure control state, the system can coordinate flash timing and duration to work harmoniously with exposure control, achieving both brightness control and exposure consistency simultaneously rather than requiring one or the other to be switched off.
Solution Approach 2:
The invention merges the functions of exposure control and flash synchronization by integrating their operation under a unified control strategy. Instead of treating them as separate, potentially conflicting systems, the invention combines their control mechanisms so that flash pulse generation is coordinated with exposure control signals, achieving both brightness control and exposure consistency through integrated operation.
3Illumination intensity
If complete flash impulses are suppressed to achieve constant light per frame, then brightness uniformity is improved, but dark or noisy video images result especially at low fundamental frequencies
Solution Approach 1:
The invention applies dynamics by making flash pulse duration and timing adjustable rather than fixed or simply suppressed. The system dynamically adapts flash parameters based on the number of pulses needed per frame - when fewer pulses are required (low fundamental frequencies), individual pulse durations are extended to compensate, ensuring adequate illumination while maintaining brightness uniformity across all frames without producing dark or noisy images.
Solution Approach 2:
The system changes flash parameter settings dynamically - specifically adjusting pulse duration and timing based on the operational conditions and the number of flashes needed per frame. This parameter adaptation ensures that when flash suppression is necessary for brightness uniformity, the remaining or extended pulses provide sufficient illumination to maintain image quality, preventing dark or noisy video images even at low fundamental frequencies.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution eliminates image brightness fluctuations and flickering, ensuring consistent exposure and optimal brightness control in stroboscopic examinations, even with unstable or absent trigger signals, reducing the likelihood of dark or noisy video images.
Implementation Method 1
the image sensor (11) of the camera system (1) is able to record brightness information over a defined period of time per frame
Data Source
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AI summary
The invention relates to an arrangement for examining vocal folds, in particular for stroboscopically observing repeating processes of the moving vocal folds, and to a method for operating said arrangement. The aim of the invention, to specify a device for examining vocal folds and a method for operating said arrangement that avoid the large fluctuations in the image brightness of the camera system and thus the flickering, which is unpleasant for the user, is achieved in that the arrangement comprises a stroboscopic light source (1), a camera control unit (2) having a camera head (3), a microphone (4), an optical waveguide (5), and an optical assembly (6), wherein the stroboscopic light source (1) has a signal-conducting connection to the camera control unit (2), and the camera head (3) is placed on the optical assembly (6), wherein the camera head (3) and the microphone (4) have signal-conducting connections to the camera control unit (2), and the optical assembly (6) is connected to the light source (1) by means of the optical waveguide (5).