Smart needle to diagnose metastatic lymph node using electrical impedance spectroscopy

Abstract

ObjectivesThe cause of cervical lymphadenopathy varies from inflammation to malignancy. Accurate and prompt diagnosis is crucial as delayed detection of malignant lymph node can lead to a worse prognosis. To improve the diagnostic accuracy of metastatic lymph node, electrical spectroscopy was employed to study human normal and metastatic lymph nodes using a hypodermic needle with fine interdigitated electrodes on its tip (EoN). Subjects and MethodsThe electrical impedance of samples collected from 8 patients were analyzed in the sweeping frequency range from 1 Hz to 1 MHz. To align the impedance level data of the patients, normalized impedance was employed. ResultsThe optimal frequency exhibiting the best discrimination results between the normal and cancerous tissues was introduced based on a discrimination index. A high sensitivity (86.2%) and specificity (88.9%) were obtained, which implied that the EoN holds the potential to improve the in vivo diagnostic accuracy of metastatic lymph node during biopsy and surgery. ConclusionEoN has a promising potential to be utilized in real-time in actual clinical trials without a need for any pre/post-treatment during FNA or surgery. We believe that the EoN could reduce unnecessary operations with its associated morbidity.