None listed
Conditions
Brief summary
Negative sensitivity is one of the most significant source of error in regards to the tetrapolar method used most commonly in bio-impedance (Grimnes & Martinsem 2006). The tetrapolar method consists of a pair of current carrying electrodes which sends tiny electrical current into a localised area. This current is then detected via another pair of electrodes, which help map out the resistance levels in the area. Numerous studies have been conducted making use of this method to help understand the underlying material composition of the area, without the need for time consuming imagery and surgeries (Oh & Sadleir 2005 and Moretti et al. 2011). Unfortunately a common error which occurs in this method, is the occurrence of negative sensitivity, which acts an opposing force and distorts measurements made with the tetrapolar method. In particular, impedance measurements made around the fingers and wrist area, which has the highest concentration of resistivity in the body (Foster & Lukaski 1996 and Gislason et al. 2010). Moreover, the use of FEM modelling and experimental data to help examine impedance readings have been well documented as a feasible method with good results for understanding the effects of errors in the execution of the tetrapolar method (Jafarppor et. al. 2011). While there are many causes where this error has affected measurements, there has yet to be any definitive research into negative sensitivity itself. Thus we hope to fill in the gaps left in the literature and conduct a pilot study into the origins and circumstances of negative sensitivity, rather than leaving it as an excuse for future error.
Interventions
Bio impedance devices measure the opposition (impedance) of body tissues to a small applied alternating electrical current. Using a typical tetrapolar electrode arrangement, intended to reduce impedance contributions from the electrodes themselves, the current is delivered through one pair of surface electrodes and voltages measured across available voltage electrodes. Typically the voltage electrodes are placed several centimetres distant from the current electrodes. The two components of i
Bio impedance devices measure the opposition (impedance) of body tissues to a small applied alternating electrical current. Using a typical tetrapolar electrode arrangement, intended to reduce impedance contributions from the electrodes themselves, the current is delivered through one pair of surface electrodes and voltages measured across available voltage electrodes. Typically the voltage electrodes are placed several centimetres distant from the current electrodes. The two components of impedance, namely, resistance (opposition to the current passes through the tissue) and reactance (opposition due to capacitance of the membranes, tissue interfaces and non-ionic tissues) provide information about (1) the tissue fluid distribution and electrolyte composition and (2) cell membrane mass and status. Bioimpedance testing applied involving six electrodes placed on hand with a voltage applied for 2 seconds which is not felt by the participant. 5 readings will be taken with ascending negative sensitivity applied to each bioimpedance measurement by switching the electrodes. One testing session of approximately 10 minutes with no further follow-up.
Sponsors
University of Sydney
Eligibility
Sex/Gender
All
Age
18 Years to 25 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy.
Exclusion criteria
For safety reasons those who have: Implanted devices such as pacemakers Pregnant women Known medical conditions (heart disease) Skin disease Broken skin on hands, Will be excluded
Outcome results
None listed