Catheter Joystick Interlock Using Capacitive Touch Enable Signals
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Solution Overview
Problem
Robotic catheter procedure systems face issues with joystick failures, leading to unintended movement of medical devices when the joystick is stuck or not touched, posing a risk during precise medical procedures.
Innovation Solution
An interlocking system for joysticks in catheter procedure systems, utilizing a capacitive touch detection circuit and signal enable circuit to generate voltage output signals based on user interaction, ensuring the device remains stationary if the joystick is not touched, thereby preventing unintended actuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a robotic catheter procedure system uses a joystick for precise control of medical devices, then the ease of operation is improved, but the reliability deteriorates due to potential joystick failures causing unintended movement
Solution Approach 1:
The system performs preliminary detection of joystick touch status before executing device movement commands. The capacitive touch detection circuit continuously monitors whether the user is touching the joystick, and the control circuit is pre-configured to disable device motion when no touch is detected, preventing unintended actuation before it can occur
Solution Approach 2:
A capacitive touch detection circuit is introduced as an intermediary between the joystick and the device control system. This intermediary detects changes in capacitance caused by user touch and generates touch output signals that mediate whether the joystick commands are transmitted to move the medical device, adding a safety layer without complicating the user interface
2Reliability
If the system continuously monitors joystick touch status to prevent unintended movement, then the reliability is improved, but the device complexity increases due to additional detection circuits and control logic
Solution Approach 1:
The system replaces complex mechanical interlocking mechanisms with electronic capacitive touch detection. Instead of using mechanical switches or physical interlocks that would add mechanical complexity, the invention uses changes in electrical capacitance caused by user touch to detect joystick activation, simplifying the overall system architecture while maintaining reliability
Solution Approach 2:
The system detects user touch by monitoring changes in electrical capacitance parameters of the joystick. The capacitive touch detection circuit measures capacitance variations that occur when a user's body (with its inherent capacitance) comes into proximity with or touches the joystick, converting a physical interaction into an electrical signal for control purposes
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 provides a single fault-safe joystick interface, rapidly disabling device motion when not in use, enhancing procedural safety and precision by ensuring that medical devices only move when intentionally activated by the user.
Implementation Method 1
a capacitive touch detection circuit coupled to the electrode plating of the upper portion of the joystick cover, the capacitive touch detection circuit mounted on the inner surface of the lower portion of the joystick cover and configured to detect a proximal change in capacitance in the electrode plating of the upper portion of the joystick cover
Data Source
AI summary
An interlocking system for a joystick in a catheter procedure system includes a joystick configured to generate a first voltage output signal based on a linear activation of the joystick and a second voltage output signal based on a rotational activation of the joystick. A joystick cover is disposed over the joystick and includes an upper portion having an electrode plating on an inner surface of the upper portion and a lower portion having an inner surface. A capacitive touch detection circuit is coupled to the electrode plating of the upper portion of the joystick cover and is mounted on the inner surface of the lower portion of the joystick cover. The capacitive touch detection circuit is configured to detect a proximal change in capacitance in the electrode plating of the upper portion of the joystick cover and to generate a touch output signal to indicate whether a change in capacitance has been detected. A signal enable circuit is coupled to the joystick and the capacitive touch detection circuit and is configured to generate a linear enable voltage output signal and a rotational enable voltage output signal based on whether a change in capacitance has been detected.