Sympathetic Skin Response Measurement Using Needle Electrode Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sympathetic skin response measurement techniques face challenges in accurately measuring the time period from stimulation to response, especially in aged individuals, and distinguishing C fiber stimulation from external noises, which affects the evaluation of sympathetic nerve normality/abnormality.
Innovation Solution
A sympathetic skin response measuring apparatus with a stimulation electrode configuration that includes a needle electrode and a contact electrode, connected to a stimulation power supplying section that selectively stimulates C fibers by changing electrical polarity, allowing for precise measurement of sympathetic skin response and conduction velocity through resistance changes and pulse signal delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electric stimulation is applied to measure sympathetic skin response, then the measurement can be performed, but when the stimulation intensity is lowered, discrimination from external noises becomes difficult
Solution Approach 1:
The stimulation electrode is divided into a needle electrode and a contact electrode that are separated from each other. The needle electrode selectively stimulates C fibers while the contact electrode serves as a reference, enabling discrimination of C fiber-specific responses from external noises even at low stimulation intensities.
Solution Approach 2:
The needle electrode acts as an intermediary that selectively interacts with C fibers through insertion into the skin, while the contact electrode provides a reference signal. This intermediary structure enables the system to distinguish C fiber stimulation responses from external electromagnetic noises.
2Object-affected harmful factors
If strong electric stimulation is applied to ensure discrimination from external noises, then noise discrimination improves, but selective stimulation of C fibers becomes difficult
Solution Approach 1:
The needle electrode is inserted locally into the skin to create a focused stimulation field that selectively activates C fibers in the immediate vicinity. This localized approach allows use of low stimulation intensity while maintaining C fiber selectivity and enabling noise discrimination.
Solution Approach 2:
The stimulation parameters are optimized by using a needle electrode configuration that changes the electrical field distribution. This parameter change enables selective C fiber stimulation at low intensities by concentrating the electrical field locally around the needle tip where C fibers are accessed.
3Measurement precision
If button-pressing method is used for quantitative sensory testing, then patient perception can be measured, but in aged persons a considerable time period is required from perception until button is pressed
Solution Approach 1:
The mechanical button-pressing system is replaced with an electrical measurement system using electrodes. The needle electrode delivers stimulation and the measurement electrode detects the sympathetic skin response automatically, eliminating the need for patient motor response and reducing measurement time significantly.
Solution Approach 2:
The measurement system automatically detects the sympathetic skin response through electrical signals from the electrodes without requiring patient action. The system serves itself by automatically recording the time from stimulation to response detection, eliminating delays associated with patient motor response.
4Ease of operation
If electrodes are disposed on palm or finger tips for SSR measurement, then non-invasive measurement is achieved, but accurate measurement of time period from stimulation to sensing timing becomes impossible
Solution Approach 1:
The needle electrode is inserted into the skin before stimulation to establish a direct electrical pathway to the nerve endings. This preliminary action enables accurate timing measurement because the electrical stimulation and response detection occur through the same inserted electrode, providing precise temporal reference.
Solution Approach 2:
The inserted needle electrode serves as an intermediary that provides both stimulation delivery and response detection functions at the same location. This intermediary structure enables simultaneous and accurate measurement of stimulation timing and response timing, overcoming the limitation of surface electrode methods.
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 objective and accurate evaluation of sympathetic nerve function by selectively stimulating C fibers, improving measurement accuracy and distinguishing responses from external noise, particularly in aged individuals.
Implementation Method 1
a pulse signal in which electrical polarity of the first electrode is set to a positive pole and electrical polarity of the second electrode is set to a negative pole is supplied
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A sympathetic skin response measuring apparatus includes : a stimulation power supplying section configured to supply a power for stimulating only C fibers in a living body, to a stimulation electrode adapted to be applied to the living body; a measuring section configured to measure information of a sympathetic skin response based on a signal obtained from a measurement electrode adapted to be applied to the living body; and an outputting section configured to output the information measured by the measuring section.