RESUMO
Objective To acquire high spatial resolution two-dimension pulse pressure distribution for objectifying research of pulse diagnosis in traditional Chinese medicine.Methods A sensor array with flexible packing was designed and implemented.The array was formed on a circle substrate with 37 silicon piezoresistive pressure sensors,which were distributed as equilateral triangles with 1.95 mm pitch.The diameter of the substrate was 15 mm.By using flexible packing,the array had the hardness similar to that of human finger,which made this method closer to the traditional Chinese diagnosis.After differential amplifying,37-way pulse pressure signals were digitalized and reconstructed to obtain the pulse pressure distribution.Results With the application of the sensor array,the pulse pressure signals were measured and transformed into pulse pressure distribution.Conclusions The experimental result contains the relevant characteristics of traditional Chinese pulse diagnosis' description,providing a new way for objective study of traditional Chinese pulse diagnosis and further study.
RESUMO
Objective To develop and test a high precision medical device which allows measurement of bioimpedance in regions below skin surface,and to enable the assessment of strained muscle's situation and instruct patient's rehabilitation exercise.Methods The system was based on the four-electrode impedance measurement mode and designed by using impedance converter network analyzer AD5933 and monolithic operational amplifier AD844.The hardware consisted of an excitation current source,a response signal adjustment circuit,a digital demodulation circuit and a shield driving circuit.This hardware circuit was combined with a LCD screen and a keyboard,which turned it into a portable precision bioimpedance testing device.Results Using an model of three components as test target,a comparison between the device and the Agilent 4294A precision impedance analyzer was presented.In the range of 1 kHz to 100 kHz,the device showed the similar relative error of the complex impedance's modulus and 1 degree absolute error of the complex impedance's phase.The strained muscle's bioelectrical impedance changes in a clinical case during the convalescent were presented and discussed with the results proven to be clinical meaningful.Conclusions The device is accurate,simple and convenient,which is proved qualified on helping doctors to assess the injury states of the strained muscle and to instruct patient's rehabilitation exercise.