Finger Segment Tracker for Minimally Invasive Bone Topography Mapping

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Solution Overview

Problem

Current surgical methods require large surgical openings to map the topography of bones during orthopedic surgery, which is not suitable for minimally invasive procedures, and existing technologies obstruct the finger pad or require direct skin contact.

Innovation Solution

A sensor array worn on a user's finger segment with multiple strain gauges and a positioning sensor that measures deformation and contact force, allowing for accurate 3D mapping of surfaces without obstructing the finger pad and allowing for minimally invasive procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a long physical contact stylus is used to digitize the bone surface, then the topography can be mapped, but a large surgical opening is required which is not desired for minimally invasive surgery

Engineering Contradiction:

Improvetopography mapping accuracyVSAvoidsurgical opening size

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the mechanical contact stylus system with a sensor array integrated into a finger-worn device. The sensor array includes multiple strain gauges that detect bone surface topography through tactile contact, eliminating the need for a long mechanical stylus and large surgical opening while maintaining measurement precision

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The finger-worn device serves multiple functions: it acts as both a tracking device for computer-assisted surgery and a topography mapping tool. The sensor array can detect bone surface features while the positioning sensor tracks finger location, combining navigation and measurement capabilities in a single minimally invasive device

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If existing finger-based technologies are used, then contactless measurement is possible, but the finger pad is obstructed which reduces tactile sensitivity

Engineering Contradiction:

Improvefinger pad accessibilityVSAvoidtactile sensitivity

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The device segments the sensing functions by placing strain gauges at the periphery of the finger segment rather than on the finger pad itself. This allows the finger pad to remain unobstructed for tactile exploration while the peripheral sensors detect deformation caused by contact with bone surfaces, preserving both accessibility and measurement precision

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The device uses the finger segment as an intermediary between the user and the bone surface. The strain gauges mounted on the finger segment detect deformation transmitted through the finger pad during tactile exploration, allowing indirect measurement that preserves direct finger pad contact with the bone surface

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If direct skin contact is required for measurement, then accurate topography data can be obtained, but minimally invasive procedures cannot be performed

Engineering Contradiction:

Improvetopography measurement accuracyVSAvoidsurgical invasiveness

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent substitutes direct skin contact measurement with strain gauge detection on the finger segment. The strain gauges measure deformation of the finger segment pad during tactile exploration, providing accurate topography data without requiring direct contact between the measurement device and skin, thereby enabling minimally invasive procedures

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables accurate 3D positional and force data collection in a minimally invasive manner, allowing surgeons to digitize bone surfaces through touch alone, improving surgical precision and reducing the need for large surgical openings.

Implementation Method 1

The multiple strain gauges are deployed around the periphery or sides of the finger segment. Each strain gauge measures the deformation of the finger segment pad as the finger segment passes over the surface topography.

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The positioning sensor determines the array's orientation as well as its location relative to a predetermined global frame of reference

Methodology Applied

Scientific EffectElectromagnetic positioning: Electromagnetic Induction

Data Source

PatentUS11589779B2Finger segment tracker and digitizer

Publication Date: 2023.02.28 FERREIRA LOUIS

AI summary

Systems, methods, and devices relating to a sensor array for use with a user's finger segment and which indirectly maps the topography of a surface under the finger segment. Each sensor array is worn on a user's finger segment and has multiple sensitive strain gauges as well a positioning sensor. The multiple strain gauges are deployed around the periphery or sides of the finger segment. Each strain gauge measures the deformation of the finger segment pad as the finger segment passes over the surface topography. The relative ratios of the deformation detected indicates the location of a feature or contact point on the topography relative to the group of strain gauges. The positioning sensor determines the array's orientation as well as its location relative to a predetermined global reference frame.