Endoscopic Tool Power Control With Pulsed Heating Hold
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Solution Overview
Problem
Therapeutic tools with heating elements face challenges in maintaining optimal temperature control, as existing safeguards like polyfuses are unreliable and require manual intervention, leading to risks of overheating or underheating, which can damage the tool and adjacent tissues.
Innovation Solution
A direct current power control system that includes a first power control circuit for constant output power and a second power control circuit for pulsed output power, managing the heating element's temperature through specific time intervals to maintain it within a target range, thereby preventing excessive heating and ensuring consistent performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual power control is implemented using a switch or toggle, then the user can turn off power to prevent overheating, but the response time becomes unpredictable and inconsistent, potentially allowing overheating to occur
Solution Approach 1:
The patent implements self-service temperature control where the system automatically monitors its own temperature via the thermistor and adjusts power delivery without requiring user intervention. The control circuit autonomously responds to temperature conditions by modulating power output, eliminating the need for manual switching while ensuring consistent overheating prevention.
Solution Approach 2:
The system uses continuous temperature feedback from the thermistor to automatically regulate power delivery. When the heating element approaches the maximum target temperature, the control circuit reduces or interrupts power automatically based on the feedback signal, providing reliable overheating prevention without requiring unpredictable manual user response.
2Productivity
If constant power is supplied to the heating element to ensure effective tissue cutting and cauterizing, then the heating element reaches target temperature quickly, but the risk of excessive heat and collateral tissue damage increases
Solution Approach 1:
The patent implements periodic pulsed power delivery instead of continuous constant power. The control circuit delivers power in controlled pulses with adjustable duty cycles, allowing the heating element to reach effective temperatures quickly during the on-phase while the off-phase allows heat to dissipate, preventing excessive temperature buildup and collateral tissue damage.
Solution Approach 2:
The system dynamically changes power delivery parameters including pulse width, frequency, and duty cycle based on real-time temperature feedback from the thermistor. This allows the heating element to receive sufficient power for effective tissue cutting when needed while automatically reducing power when approaching temperature limits, balancing productivity with safety.
3Reliability
If the power limit is set to ensure quick response to overheating, then overheating is prevented, but the procedure cannot be completed in time; if set higher, then procedure completion is possible, but overheating risk increases
Solution Approach 1:
The patent implements dynamic parameter adjustment where the control circuit modifies power delivery characteristics based on real-time temperature conditions. The system can deliver high power quickly when the heating element is cool to enable rapid procedure completion, then automatically reduces power as temperature approaches the maximum target, eliminating the need to choose between fixed conservative or aggressive power settings.
Solution Approach 2:
The system transitions from static fixed power limits to dynamic adaptive power control. The control circuit continuously adjusts power delivery parameters in response to thermistor feedback, allowing the system to be aggressive when safe and conservative when needed, optimizing both procedure speed and safety throughout the operational cycle.
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 reliably maintains the heating element's temperature within a safe and effective range, preventing damage to the tool and tissues, and allows for automated control, reducing the risk of human error during medical procedures.
Implementation Method 1
The first power control circuit may be configured to supply constant output power to the heating element during a first time interval to heat the heating element to a target temperature
Implementation Method 2
The second power control circuit may be configured to supply pulsed output power to the heating element during a second time interval following the first time interval to maintain a temperature of the heating element within a target temperature range
Data Source
AI summary
Provided is an endoscopic vessel harvesting system comprising a direct current (DC) power control system connected to a therapeutic tool comprising a heating element. The DC power control system may include an input connection to receive power from a power supply. A first power control circuit may supply constant output power during a first time interval to heat the heating element to a target temperature. A second power control circuit may supply pulsed output power during a second time interval to maintain a temperature of the heating element within a target temperature range. An output connection may receive the output power and may supply controlled power to the heating element by supplying the constant output power during the first time interval, the pulsed output power during the second time interval, followed by a third time interval during which no power is supplied. Methods and systems are also disclosed.