Portable Magnetic Sensor for Covert Contraband Detection
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Solution Overview
Problem
Current metal detectors, such as archway and hand-held metal detectors, are ineffective in detecting cell phones in prisons due to their limitations in portability, range, and interference with medical implants, and cannot be used in areas with high metal content or for covert screening.
Innovation Solution
A portable magnetic sensor system that uses a single pole with an adjustable detection zone, allowing for quick and covert screening of individuals and objects, which is more effective in detecting ferromagnetic materials like cell phones and can be set up in various locations within a prison environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If archway metal detectors are permanently installed at access points, then detection capability is provided, but they cannot be used in cell blocks and common areas due to risk of damage and lack of portability
Solution Approach 1:
The patent replaces the mechanical archway structure with a portable handheld device that uses electronic sensors and signal processing to detect contraband. This substitution enables the detection system to be moved freely throughout the prison environment without permanent installation requirements.
Solution Approach 2:
The system transitions from a static permanently installed archway detector to a dynamic portable handheld device that can be relocated and repositioned as needed. This dynamic capability allows staff to conduct screenings in various locations including cell blocks and common areas where permanent installation is not feasible.
2Adaptability or versatility
If hand held metal detectors are used for portability, then they can be carried into cell blocks, but their limited range makes them ineffective for internally carried phones
Solution Approach 1:
The patent changes the detection parameters by using sensors with enhanced sensitivity and employing signal processing techniques that amplify weak signals from internally carried phones. This allows the handheld device to maintain portability while achieving effective detection range for concealed contraband.
Solution Approach 2:
The system uses intermediate signal processing stages including amplification and filtering to bridge the gap between the handheld sensor and the target. This intermediary processing enables detection of weak magnetic signatures from internally carried phones at practical distances.
3Reliability
If alternating magnetic fields are used in metal detectors, then contraband can be detected, but it may interfere with pulse generators in heart pacemakers or neurostimulators
Solution Approach 1:
The patent employs periodic pulsed magnetic fields rather than continuous alternating fields. By using short pulses with appropriate timing and duty cycles, the system achieves contraband detection while minimizing the risk of interference with medical implants through controlled exposure duration.
Solution Approach 2:
The system modifies the magnetic field parameters including frequency, amplitude, and pulse duration to optimize detection sensitivity while staying below thresholds that would interfere with pacemaker or neurostimulator operation. This parameter optimization resolves the contradiction between detection effectiveness and safety.
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
The system significantly enhances the detection of contraband items like cell phones, allowing for quicker and more efficient screening in confined spaces, reducing the risk of contraband entry and improving safety within prisons.
Implementation Method 1
A portable magnetic sensor system that uses a single pole with an adjustable detection zone, allowing for quick and covert screening of individuals and objects, which is more effective in detecting ferromagnetic materials like cell phones
Implementation Method 2
The use of electromagnetic sensors has been trialled in a number of prisons with very good results. The sensors are extremely sensitive and can detect the electromagnetic signature given off by a cell phone battery
Data Source
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Figure 3(a)~3(b)
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AI summary
A method of detecting contraband about a person (100) is disclosed, and a security screening installation system, for use in detecting contraband. The system comprises: a detector apparatus (1) which includes at least one magnetic sensor (7) arranged to produce a signal indicative of an ambient magnetic field or gradient over a zone of sensitivity around the sensor, the zone being large enough to contain the whole body of the person, and a signal processing circuit which receives as an input the signal from the magnetic sensor and which, in response to a change in the signal produces an alert signal; and a wall (200) or other object behind which the detector apparatus is hidden, the detector apparatus being positioned so that at least part of the zone of sensitivity extends in front of the wall or other object and is large enough for a person to fit wholly within the zone. The method may alternatively comprise setting up a particle detector apparatus in a chosen location and moving people past the detector.