Biology subjects

Concu, A.

Publications and source records attributed to Concu, A..

2 recordsLinked to original sources

bioRxiv2019

BONE FRACTURE DETECTION BY ELECTRICAL BIOIMPEDANCE: FIRST NON-INVASIVE MEASUREMENTS IN EX-VIVO MAMMALIAN FEMUR

The fracture of long bones is one of the pathologies of greater demand of systems of medical emergencies, the method used for the diagnosis, the radiology of X-rays, produces damages to the patients and to the hospitals environment. For these reasons, our group is studying the implementation of a new diagnostic technique for the detection of bone fractures by bioimpedance measurements. To simulate a limb, two phantom of bovine femurs (the one with an entire bone and the other with a sawn bone) were constructed and non-invasive Electrical Impedance Spectroscopy measurements were taken on them in order to identify differences in their respective Cole Cole diagrams. Impedance spectroscopy was performed by a frequency sweep between 1 Hz and 65 kHz at a fixed current of 1 mA. The results obtained show wide differences in the Cole Cole diagrams of both phantoms (entire and fractured bone), especially concerning the real component of the, which latter, around the bones section corresponding to that of the lesion in both femurs, was always lower in the fractured femur than the entire one. These first superficial (non-invasive) measurements correspond to the electrical impedance spectroscopy bases and these could -in turn- correspond to what occurs in mammals immediately after the fracture happens, i. e. a dramatic increase in electrical conductivity due to diffusion into the fracture site of more conductive materials such as the blood and the extravascular fluids.

bioengineering↗

bioRxiv2019

Differences in the Electrical Impedance Spectroscopy variables between right and left forearms in healthy people: a non invasive method to easy monitoring structural changes in human limbs?

The resistive component of the bioimpedance was non invasively assessed in both right and left forearms of 11 healthy female and 9 males (28.4 {+/-} 1.4 years; 63.8 {+/-} 11.8 kg; 167.4 {+/-} 7.5 cm) all of which were right-handed. A homemade electrical impedance spectroscopy device which implemented the AD 5933 electronic board from Analog Devices Inc., USA, was utilized, and the bipolar modality of bioimpedance assessment was chosen using two disposable ECG surface electrodes placed in each end of the biceps brachial muscles while subject were comfortably sitting. Forearms resistance was acquired at sweeping frequencies steps of 15, 30, 45, 60 and 75 KHz. Results showed a significantly lower man value of resistance in right versus left forearms (- 27.4 {Omega}, P<0.05), or about -4%, at the frequency of 15 KHz. Even though there was a progressive reduction, this right versus left forearm resistance difference persisted as statistically significant up to the frequency of 45 KHz. It was concluded that the risk of some mistakes do exists when lymphedema may occur in one arm and electrical impedance spectroscopy was utilized to monitoring in that arm the water volume trend in comparison with the other side arm since these results underline in the main forearm a largely low value of the resistance than in the auxiliary one, even in healthy subjects. So, care must be taken when the electrical impedance spectroscopy was adopted in these clinical assessments.

bioengineering↗