Sparse Shield Cable Design for Medical Device Cross-Talk Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In medical devices with base/remote unit arrangements, electrical cross-talk between conductors is a significant issue, particularly in advanced systems that require high information transfer, where increasing the thickness of insulating material and adding a braided shield reduces the number of conductors that can fit within a given cable diameter, leading to fragile conductors and increased attenuation.
Innovation Solution
A shielded cable design featuring a center conductor with an insulating layer, a conductive coating on the outside, and a sparse shield that partially surrounds the insulating layer, allowing for a higher number of conductors within a given diameter while reducing cross-talk and attenuation by controlling mutual capacitance and inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the thickness of insulating material is increased to reduce cross-talk, then cross-talk is reduced, but the number of conductors that can fit in a given cable diameter decreases
Solution Approach 1:
The cable structure is segmented into multiple functional layers: individual conductor insulation, a common insulating layer surrounding multiple conductors, and a sparse shield. This segmentation allows each layer to address specific requirements - individual insulation provides basic isolation, the common insulating layer reduces cross-talk between conductors, and the sparse shield provides additional electromagnetic interference protection, thereby enabling more conductors to fit while maintaining low cross-talk
Solution Approach 2:
The invention transitions from a two-dimensional arrangement (conductors side-by-side with individual insulation) to a three-dimensional hierarchical structure with multiple insulating layers and a sparse shield surrounding groups of conductors. This dimensional change allows for more efficient space utilization and better electromagnetic isolation without proportionally increasing the cable diameter
2Object-affected harmful factors
If a braided shield wire is added to improve cross-talk characteristics, then cross-talk is reduced, but the number of conductors that can fit in a given cable diameter decreases
Solution Approach 1:
The invention extracts only the essential shielding function from a traditional braided shield, creating a sparse shield that provides electromagnetic interference protection and cross-talk reduction without the bulk and complexity of a full braided structure. This extracted shielding approach maintains the beneficial cross-talk reduction while minimizing the space occupied, allowing more conductors to fit in the cable
Solution Approach 2:
The sparse shield is strategically positioned and configured to provide shielding where it is most needed - surrounding groups of conductors that communicate with each other. This localized shielding approach provides effective cross-talk reduction between adjacent conductors while occupying minimal space, unlike a uniform braided shield that would enclose the entire cable
3Quantity of substance
If higher gauge (thinner) conductors are used to increase the number of conductors, then the number of conductors increases, but the conductors become more fragile and cable attenuation increases
Solution Approach 1:
The cable structure provides beforehand cushioning and protection for thinner conductors through multiple layers: individual conductor insulation, a common insulating layer, and a sparse shield. These protective layers cushion the thinner conductors from mechanical damage and environmental factors, thereby maintaining their durability despite their reduced gauge
Solution Approach 2:
The invention uses composite material structures - combining different insulation materials with different protective properties, and combining the sparse shield with the insulating layers to create a composite protective system. This composite structure provides enhanced mechanical protection and electromagnetic shielding that allows thinner, more numerous conductors to be used without sacrificing reliability
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 design effectively decreases cross-talk and attenuation, allowing for more conductors in a cable of a given diameter, enhancing the durability and performance of medical device communication cables.
Implementation Method 1
decreases the mutual capacitance and inductance between adjacent wires
Implementation Method 2
decreases the mutual capacitance and inductance between adjacent wires
Implementation Method 3
The conductive coating and/or sparse shield decreases the mutual capacitance and inductance between adjacent wires and lessens the effects of electromagnetic interference on signals propagated over the wires
Data Source
AI summary
A cable (210) includes a center conductor (220). An insulating material in the form of a layer (225) surrounds the center conductor. A sparse shield (232) partially surrounds the insulating material. The sparse shield may include a plurality of conductors, which are grouped adjacent to one another within a space around the insulating layer that has a length that is less than 25% of the total circumference of the insulating layer. An insulating jacket (227) covers the sparse shield and the remainder of the cable. The cable may be used in a cable assembly (10).