Retinal Rake Impedance Detection for Tissue Differentiation
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Solution Overview
Problem
During vitreoretinal surgery, surgeons face challenges in differentiating between healthy and diseased tissues due to the lack of feedback during the procedure, which can lead to damage to surrounding tissues.
Innovation Solution
A retinal rake equipped with two electrodes that detect electrical impedance differences between various tissues, providing visual, auditory, or tactile signals to indicate the type of tissue in contact, allowing for more precise tissue identification and manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual observation through slit lamp is used to identify tissue types, then the surgeon can view the interior of the eye, but the surgeon cannot reliably distinguish between healthy and diseased tissues
Solution Approach 1:
The patent applies feedback by providing real-time electrical impedance measurements to the surgeon during surgery. The device continuously monitors impedance values and provides immediate feedback through visual or audible signals, enabling the surgeon to distinguish between healthy and diseased tissues based on their different electrical properties rather than relying solely on visual observation.
Solution Approach 2:
The patent uses electrical impedance as an intermediary parameter to indirectly identify tissue types. Instead of directly observing tissue characteristics through the slit lamp, the device measures electrical impedance between two points and uses this intermediate measurement to infer tissue type, providing information that cannot be obtained through visual observation alone.
2Productivity
If manual tissue removal based on visual observation is performed, then the surgeon can remove epiretinal membranes, but surrounding healthy tissues may be damaged
Solution Approach 1:
The device provides real-time feedback during tissue removal by continuously monitoring electrical impedance. When the impedance values indicate contact with healthy tissue (within normal ranges), the system alerts the surgeon, allowing immediate adjustment of the removal process to avoid damaging healthy tissues while maintaining efficient removal of diseased tissue.
Solution Approach 2:
The patent replaces reliance on mechanical visual inspection with an electrical measurement system. Instead of using the slit lamp and surgeon's visual judgment to identify tissue boundaries, the system uses electrical impedance measurements to detect tissue type, providing more reliable discrimination between healthy and diseased tissues during the mechanical removal process.
3Measurement precision
If electrical impedance measurement is added to the retinal rake, then tissue differentiation capability is improved, but device complexity increases
Solution Approach 1:
The patent makes the retinal rake multi-functional by integrating both mechanical tissue removal capability and electrical impedance measurement functionality into a single device. The same retinal rake that mechanically removes epiretinal membranes also serves as an electrode for electrical measurements, eliminating the need for separate diagnostic equipment and reducing overall system complexity.
Solution Approach 2:
The device merges the mechanical rake structure with electrical measurement components by incorporating electrodes directly into the rake. This combination allows simultaneous mechanical manipulation and electrical sensing functions, reducing the number of separate components and simplifying the overall device architecture while providing enhanced tissue differentiation capability.
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 solution enables surgeons to accurately distinguish between healthy and diseased tissues, minimizing damage to surrounding tissues and improving the precision of tissue removal during surgery.
Implementation Method 1
Various in vivo healthy and diseased tissues or fluids within a body have different, detectable electrical conductivities. In a specific example, epiretinal membranes (ERMs) have a relatively high electrical impedance, which causes them to be relatively electrically inactive. However, retinal tissue has a lower electrical impedance, which causes it to be relatively electrically active.
Data Source
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AI summary
The subject invention utilizes the characteristics of in vivo tissue impedances to provide an embodiment of a medical instrument capable of providing a visible and/or preferably an audible signal to a surgeon that more clearly indicates which type of tissue(s) is in contact with the instrument. A preferred embodiment comprises a handheld, battery operated retinal rake having two electrodes, wherein at least one electrode is the modified retinal rake. Upon contact with different optical tissues, e.g., epiretinal membranes, retinal tissue, vitreous humor, etc., the electrodes detect varying impedances which are translated by onboard circuitry into various signals that indicate what type of tissue, fluid, structure, etc. is in contact with the retinal rake.