Flexible Circuit Sheet for Navigated Surgical Instrument Tracking

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Solution Overview

Problem

Surgical instruments with flexible elongated portions face challenges in navigating complex anatomical cavities, such as the ear, nose, and throat, due to obscured viewing angles and difficulties in accurately tracking the distal tip, especially when the instrument is bent or moved relative to the handle.

Innovation Solution

A flexible circuit assembly for medical devices, comprising a base layer, circuit traces, and an insulative layer, which forms a thin flexible sheet that can conform to non-planar surfaces, allowing for accurate tracking and bending without breaking lead wires, and is integrated with a tracking system for precise navigation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flexible elongated portion is used to navigate complex anatomical cavities, then the instrument can conform to internal cavities, but the instrument cannot retain a specific configuration

Engineering Contradiction:

Improveconformability to internal cavitiesVSAvoidconfiguration retention

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The instrument is divided into a flexible elongated portion and a separate configuration-retaining component. The flexible portion allows navigation through cavities while the separate component (such as a mandrel or shaping tool) provides the desired configuration when needed, resolving the contradiction between conformability and configuration retention.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The instrument transitions from a static configuration-retaining structure to a dynamic system where the flexible portion can adapt its shape during navigation, while configuration retention is achieved through active shaping during the procedure rather than passive structural memory.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If a tracking device is coupled to the distal tip of the instrument, then accurate tracking is achieved, but the tracking device becomes difficult to manipulate and cumbersome

Engineering Contradiction:

Improvetracking accuracyVSAvoidmanipulability of tracking device

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The tracking device is integrated with the flexible circuit sheet that is already coupled to the instrument's elongated portion. This merging eliminates the need for separate tracking device manipulation while maintaining accurate tracking of the distal tip throughout the procedure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The flexible circuit sheet serves as an intermediary that connects the tracking device to the instrument's flexible elongated portion. This intermediary allows the tracking device to follow the instrument's movements accurately without requiring direct manipulation of the tracking device itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If lead wires are used to connect tracking devices, then electrical coupling is achieved, but the lead wires break when the flexible elongated portion is bent

Engineering Contradiction:

Improveelectrical connectionVSAvoidwire flexibility

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The traditional lead wires are replaced with a flexible circuit sheet that has the properties of a flexible shell/thin film. This circuit sheet can bend with the instrument's elongated portion without breaking, maintaining electrical connection reliability while accommodating the flexible navigation requirements.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The flexible circuit sheet is constructed from composite materials that combine electrical conductivity with extreme flexibility. This composite structure allows the circuit to maintain electrical connections while bending repeatedly with the instrument, resolving the contradiction between connection reliability and wire flexibility.

Inventive Principle:

Principle #40Composite materials

4Ease of operation

If the tracking device is positioned in the handle, then manipulation is simplified, but tracking accuracy is lost when the distal tip moves relative to the handle

Engineering Contradiction:

Improvetracking device manipulationVSAvoiddistal tip tracking accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The tracking device is moved from the handle (proximal dimension) to the distal tip (distal dimension) along the length of the instrument. This dimensional relocation allows the tracking device to remain at the point of interest while the flexible circuit sheet provides the connection path back to the handle, maintaining both ease of operation and tracking accuracy.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2948090B1Navigated surgical instrument comprising a flexible circuit sheet

Publication Date: 2018.09.12 MEDTRONIC XOMED INC

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AI summary

A flexible circuit assembly can include a base layer (244), a plurality of circuit traces (350) and an insulative layer (362). The plurality of circuit traces can each be coupled to a pair of circuit pads, and the circuit traces can be formed on an upper side of the base layer. The insulative layer can be formed over the circuit traces to isolate the circuit traces from an external environment. The base layer, plurality of circuit traces and insulative layer can form a flexible circuit sheet (232). The base layer and the insulative layer can include material properties and a thickness configured to facilitate the flexible circuit sheet being flexible such that the flexible circuit sheet is adapted to conform to a non-planar surface of the medical device (100).