Medical Serial Pulse Protocol for Surgical Instrument Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ultrasonic surgical instruments face challenges in effectively sealing blood vessels and providing visual feedback to surgeons during procedures, leading to potential damage from excessive heat generation and inefficiencies in tissue cutting and coagulation.
Innovation Solution
The development of an ultrasonic surgical system that includes a tissue impedance module and a generator capable of monitoring tissue impedance, using frequency step functions to separate tissue layers and provide feedback through visual, audible, and tactile indicators, ensuring precise cutting and coagulation without relying solely on clamp force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultrasonic energy is applied to seal blood vessels, then vessel sealing is achieved, but the inner muscle layer must be separated from the adventitia layer which requires increased clamp force
Solution Approach 1:
The system applies a frequency step function to separate the inner muscle layer from the adventitia layer before applying standard ultrasonic energy for sealing. This preliminary separation action prepares the tissue structure in advance, allowing standard clamp forces to achieve effective vessel sealing without requiring excessive force.
Solution Approach 2:
The system changes the ultrasonic frequency parameter by applying a frequency step function that temporarily shifts the operating frequency to separate tissue layers, then returns to the standard resonant frequency for sealing. This parameter change enables effective vessel sealing at lower clamp forces by optimizing the tissue structure prior to sealing.
2Reliability
If the surgeon continues to activate the harmonic instrument without visual feedback of cut completion, then possible damage to the harmonic instrument and surrounding tissue occurs due to heat generation
Solution Approach 1:
The system introduces acoustic feedback by detecting changes in acoustic impedance during the cutting process. When the cut is complete, the acoustic impedance changes characteristically, providing audible feedback to the surgeon that the cut is complete. This feedback loop prevents over-activation and potential damage to the instrument and surrounding tissue.
Solution Approach 2:
The system replaces visual feedback with acoustic feedback by using acoustic impedance detection. The acoustic feedback mechanism provides real-time information about cut completion through sound, substituting for the unavailable visual feedback and enabling the surgeon to know when to stop activation without direct visualization.
3Reliability
If a tuning inductor is used to maintain generator output at the ultrasonic transducer's resonant frequency, then frequency stability is improved, but a different tuning inductor is required for each transducer with different static capacitance
Solution Approach 1:
The system uses a digital signal processor to dynamically adjust and maintain the generator output frequency at the ultrasonic transducer's resonant frequency. Instead of using a fixed tuning inductor, the DSP continuously monitors and adjusts the frequency, eliminating the need for manual inductor matching while maintaining frequency stability.
Solution Approach 2:
The system replaces the mechanical/electrical tuning inductor with a digital signal processing approach. The DSP calculates and applies the appropriate frequency adjustments electronically, substituting the physical inductor matching process with a flexible software-based solution that adapts to different transducer capacitances without requiring hardware changes.
4Manufacturing precision
If ultrasonic energy is applied for tissue cutting and coagulation, then precise cutting and coagulation are achieved, but heat is generated that can cause damage if activation continues after cut completion
Solution Approach 1:
The system uses acoustic impedance feedback to detect when the cut is complete and provides audible feedback to the surgeon. This feedback mechanism enables the surgeon to stop activation at the appropriate time, preventing excessive heat generation and damage to surrounding tissue while maintaining precise cutting and coagulation during the active phase.
Solution Approach 2:
The system employs periodic monitoring of acoustic impedance during the cutting process to detect completion. By continuously monitoring and detecting characteristic impedance changes, the system provides real-time feedback that enables precise control of activation duration, preventing overheating while maintaining cutting precision.
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
This system enhances vessel sealing efficiency, reduces heat-related damage, and provides reliable feedback to surgeons, improving procedural precision and safety.
Implementation Method 1
Vibrating at high frequencies (e.g., 55,500 times per second), the ultrasonic blade denatures protein in the tissue to form a sticky coagulum
Implementation Method 2
A tissue impedance module may be coupled to the blade and configured to monitor changes in tissue state by monitoring changes in tissue impedance
Implementation Method 3
The generator is programmed to apply a frequency step function to the ultrasonic transducer to mechanically displace the blade in multiple modes in an effort to separate the inner muscle layer of the vessel from the adventitia layer
Implementation Method 4
A tissue impedance module may be coupled to the blade and configured to monitor changes in tissue state by monitoring changes in tissue impedance
Data Source
AI summary
An apparatus is disclosed. The apparatus includes a circuit configured to transmit a signal as a serial protocol over a pair of electrical conductors. The serial protocol is defined as a series of pulses distributed over at least one transmission frame. At least one pulse in the transmission frame is simultaneously encoded by modulating an amplitude of the pulse to represent one of two first logic states and modulating a width of the pulse to represent one of two second logic states. An instrument and a generator also are disclosed.