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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12615000960550
Ethics application status
Approved
Date submitted
24/08/2015
Date registered
14/09/2015
Date last updated
22/08/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
Negative sensitivity effects associated with the fingers and wrist on bioimpedance measurements in healthy participants.
Scientific title
Pilot study: In the general population does negative sensitivity have a detrimental effect, or not, on bioimpedance measurements of the fingers and wrist?
Secondary ID [1] 287385 0
none
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
negative sensitivity in bioimpedance testing of the fingers and wrist. 295971 0
Condition category
Condition code
Other 296252 296252 0 0
Research that is not of generic health relevance and not applicable to specific health categories listed above

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
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.
Intervention code [1] 292651 0
Not applicable
Comparator / control treatment
N/A
Control group
Uncontrolled

Outcomes
Primary outcome [1] 295909 0
Negative sensitivity effect size as assessed against finite element modelling.
Timepoint [1] 295909 0
At each bioimpedance measurement taken during a single session.
Secondary outcome [1] 316910 0
Impedance change related to finite element modelling.
Timepoint [1] 316910 0
Following each measurement taken during a single session.

Eligibility
Key inclusion criteria
Healthy.
Minimum age
18 Years
Maximum age
25 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key 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

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Convenience sample
Timing
Prospective
Statistical methods / analysis
Participant characteristics: about 10-15 males and 10-15 females of the ages of 18-25 years old. This is to ensure that a small but reliable sample size is obtained in participants of similar characteristics. Using other similar research done as a reference, this sample size should be enough to provide enough information to reach conclusive results.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW

Funding & Sponsors
Funding source category [1] 291893 0
Self funded/Unfunded
Name [1] 291893 0
Address [1] 291893 0
Country [1] 291893 0
Primary sponsor type
University
Name
University of Sydney
Address
NSW 2006
Country
Australia
Secondary sponsor category [1] 290560 0
Commercial sector/Industry
Name [1] 290560 0
Ti2 Medical Pty Ltd
Address [1] 290560 0
11 Averill St,
Rhodes, NSW 2138
Country [1] 290560 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 293402 0
The University of Sydney
Ethics committee address [1] 293402 0
NSW 2006
Ethics committee country [1] 293402 0
Australia
Date submitted for ethics approval [1] 293402 0
Approval date [1] 293402 0
09/07/2015
Ethics approval number [1] 293402 0
2014/1005

Summary
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.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 59746 0
Dr Alistair McEwan
Address 59746 0
The University of Sydney
NSW 2006
Country 59746 0
Australia
Phone 59746 0
+61293517256
Fax 59746 0
Email 59746 0
alistair.mcewan@sydney.edu.au
Contact person for public queries
Name 59747 0
Dr Alistair McEwan
Address 59747 0
The University of Sydney
NSW 2006
Country 59747 0
Australia
Phone 59747 0
+61293517256
Fax 59747 0
Email 59747 0
alistair.mcewan@sydney.edu.au
Contact person for scientific queries
Name 59748 0
Dr Alistair McEwan
Address 59748 0
The University of Sydney
NSW 2006
Country 59748 0
Australia
Phone 59748 0
+61293517256
Fax 59748 0
Email 59748 0
alistair.mcewan@sydney.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary