Laser Pointer Synchronization for Radiotherapy Positioning
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Solution Overview
Problem
Current navigation systems in surgical and radiotherapy procedures face challenges in accurately determining the position of a patient's body part during treatment, particularly in distinguishing light reflections from other sources, which can lead to misinterpretation and reduced accuracy.
Innovation Solution
A data processing method and laser pointer system that emit light pulses following a predefined emission pattern, synchronized with the camera system, allowing for the detection of reflections by analyzing the time-pattern of light mark portions in camera images to uniquely identify reflections originating from the laser pointer, thereby reducing interference from other light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser pointer is used to generate light marks on the patient's body surface for navigation, then the position determination capability is improved, but the ability to distinguish laser reflections from other light sources deteriorates due to interference from ambient light
Solution Approach 1:
The laser pointer emits light in periodic pulses rather than continuously. The camera system is synchronized to capture images only during specific time windows when laser pulses are expected. This temporal gating allows the system to distinguish laser-generated light marks from ambient light sources, resolving the contradiction between position determination capability and light source discrimination accuracy
Solution Approach 2:
The system employs a feedback mechanism where the camera detects light marks and their positions, which are then processed to determine the actual position of the laser pointer relative to the patient's body surface. This feedback loop enables continuous refinement of position data and verification that detected light marks originate from the laser pointer rather than other sources, thereby maintaining both measurement precision and reliability
2Duration of action of moving object
If continuous light emission is used to ensure continuous tracking, then the tracking coverage is improved, but the ability to synchronize with camera frames for accurate detection deteriorates
Solution Approach 1:
Both the laser pointer and camera operate in synchronized periodic cycles. The laser emits pulses at specific intervals that coincide with camera exposure windows. This periodic synchronization ensures that light marks are generated and captured at optimal moments, maintaining tracking continuity while maximizing detection accuracy by avoiding ambient light interference during camera exposure
Solution Approach 2:
The laser pointer is triggered to emit light pulses in advance of or in precise synchronization with the camera's exposure window. This preliminary action ensures that light marks are present on the patient's surface exactly when the camera captures the image, guaranteeing both continuous tracking capability and high detection accuracy without requiring continuous light emission
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 approach enhances the accuracy of position determination and registration of body parts during surgical navigation by reliably distinguishing reflections from the laser pointer, reducing errors and improving the precision of surface shape determination.
Implementation Method 1
detecting reflections of light pulses, such as (laser) light pulses emitted by a (laser) pointer
Data Source
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AI summary
The invention relates to a laser pointer system comprising a laser pointer element (1) comprising a detection element (1a), a laser controller (1b) and a laser (1c); a camera system comprising a transmission element (11) and at least one camera (5, 6); a camera control unit (9) controlling the camera system; wherein the camera control unit (9) can control the transmission element (11) of the camera system to emit a defined pattern of control pulses; and wherein the laser controller (1b) can receive a detection signal from the detection element (1a) including the defined pattern of control pulses and can control the laser (1c) to emit a pattern of pointer beams (2) being dependent on the detection signal and on a pre-defined emission pattern, so as to synchronize the pattern of pointer beams (2) to the defined pattern of control pulses emitted by the transmission element (11) of the camera system.