Surgical Simulator Camera Shaft Rotation Detection via Roller Amplifier

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional rotational sensors used in surgical simulation systems, such as camera simulators, often lack the necessary resolution for accurate rotational detection, leading to bulky designs when higher-resolution sensors are employed, and small sensors provide insufficient accuracy.

Innovation Solution

A user interface device with a frame and suspension portion that utilizes a small rotational sensor detecting a roller engaged with a guiding surface, optimizing space to achieve high resolution while maintaining a compact design, and additional sensors for detecting translation and rotation of the shaft, eliminating the need for extra space-consuming sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a larger rotational sensor is used to improve resolution, then measurement precision is improved, but the device becomes larger and bulkier

Engineering Contradiction:
Improverotational detection resolutionVSAvoidjoint size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

A roller element is introduced as an intermediary between the guiding surface and the rotational sensor. The roller converts the rotational movement of the suspension portion into rotational movement of the sensor through frictional engagement, allowing a small sensor to achieve high resolution by multiple rotations per suspension portion rotation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The solution moves from directly measuring the rotation of the suspension portion to measuring the rotation of the roller that is frictionally engaged with the guiding surface. This dimensional transformation allows the sensor to rotate multiple times for each rotation of the suspension portion, amplifying the measurement resolution without increasing sensor size

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If conventional rotational sensors are used, then the device remains compact, but measurement precision is insufficient for accurate rotational detection

Engineering Contradiction:
Improvejoint sizeVSAvoidrotational detection resolution
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The roller acts as a mechanical intermediary that amplifies the rotational movement. By engaging the roller with the guiding surface at a distance from the rotation axis, the system converts a single rotation of the suspension portion into multiple rotations of the roller, thereby multiplying the effective resolution without requiring a larger sensor

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the parameter of rotational resolution by introducing a mechanical transmission ratio through the roller-guiding surface engagement. The resolution is enhanced by the ratio of the roller's rotation path radius to its own radius, allowing small sensors to achieve high effective resolution through parameter transformation

Inventive Principle:
Principle #35Parameter changes

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 high-resolution rotational detection with small, inexpensive sensors, maintaining a compact size suitable for surgical simulation systems, particularly beneficial for camera simulators, allowing precise control of the field of view without increasing the joint's size.

Implementation Method 1

a first roller arranged between the first axis and the guiding surface. The first roller is frictionally engaged with the guiding surface, so as to rotate when the suspension portion is rotated around the first axis

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2811479B1A user interface for a surgical simulation system
Publication Date: 2017.08.02 SURGICAL SCI SWEDEN
  • EP2811479B1 patent drawingFigure 1
  • EP2811479B1 patent drawingFigure 2
  • EP2811479B1 patent drawingFigure 3

AI summary

A user interface device (1) comprising a frame (11) with a support (15) and a suspension portion (16) rotatable around a first axis (A). Further comprising a camera simulator (10) having a rigid shaft (21) with a primary extension along a longitudinal axis (C), being suspended by the suspension portion (16) so that it can translate along the longitudinal axis (C). A first rotational sensor (25) arranged to detect rotation of the suspension portion (16) around the first axis (A) by a guiding surface (18a) arranged at a distance from the first axis (A), and a first roller (30) arranged between the axis (A) and the guiding surface (18a) to rotate when the suspension portion (16) is rotated around the first axis (A) wherein the first rotational sensor (25) is arranged to detect rotation of the first roller (30). This solution enables satisfactory measured resolution at more reasonable price.