We describe a Noninvasive test apparatus for determining the concentration of a substance in the blood of a patient, such as Sugar, alcohol, cholesterol, etc.The apparatus and Method include the implementation of an RF Output Signal (102) to the skin of a patient, via an Antenna (20) and the Measurement of the amplitude and phase of a Signal responseThat is a function of the RF Output Signal (102) modified by the interaction with the patient's Blood.The Invention takes Measurements at different frequencies (310) and RF output Graphic Response (300) as a function of frequency (310).The Invention is essentially characterised by deriving various derived Parameters (552, 554, 556, 550, 408, 410) the shape of the resulting graphs, namelyOne or more of the following: a shift of resonance frequency, Q factor of Resonance； group delay； Phase Change； a variation of amplitude of the grÁfi； Form FactorCo； and a gradient of the graph at different frequencies.The Invention uses models of the derived parameters as a function of the concentration of the target substance in the Blood, for their determination.Also describes a novel Circuit (1000) to obtain the measurements of amplitude and phaseA Calibration device (1929) and various improvements on the test apparatus and a portable non-invasive (3000, 4000).<；p>；SE DESCRIBE UN APARATO DE PRUEBA NO INVASIVO PARA DETERMINAR LA CONCENTRACIÓ；N DE UNA SUSTANCIA OBJETIVO EN LA SANGRE DE UN PACIENTE, TAL COMO AZÚ；CAR, ALCOHOL, COLESTEROL, ETC. EL APARATO Y EL MÉ；TODO COMPRENDEN LA APLICACIÓ；N DE UNA SEÑ；AL RF DE SALIDA (102) A LA PIEL DE UN PACIENTE, A TRAVÉ；S DE UNA ANTENA (20) Y LA MEDICIÓ；N DE LA AMPLITUD Y LA FASE DE UNA SEÑ；AL DE RESPUESTA, QUE ES UNA FUNCIÓ；N DE LA SEÑ；AL RF DE SALIDA (102) MODIFICADA POR LA INTERACCIÓ；N CON LA SANGRE DEL PACIENTE. LA INVENCIÓ；N TOMA MEDICIONES A DIFERENTES FRECUENCIAS RF DE SALIDA (310) Y GRAFICA LA RESPUESTA (300) EN FUNCI
