Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Prof Hugh McCann


Contact details

School of Electrical & Electronic Engineering
University of Manchester
PO Box 88
Sackville Street
M60 1QD
United Kingdom
+44 (0)161 306 4791

Additional identifiers

EudraCT number number

Protocol/serial number

077724; NRES:07/H1003/H145/CMFT:9644

Study information

Scientific title

Real-time functional brain imaging using Electrical Impedance Tomography of Evoked Responses: two stage volunteer safety and patient randomised crossover trial



Study hypothesis

Functional brain imaging using positron emission tomography has shown that general anaesthesia reduces brain function in a dose-related manner. It is hypothesised that fEITER will derive similar images of human brain function arising from the normal changes in synaptic impedance that occur during cerebral processing of sensory information, but much faster than existing scanning methods and with a suitcase-sized device. We expect fEITER to visualise the reduction in cerebral sensory processing during anaesthesia, and this study will allow the preparation of a dose-response curve indicating the level of anaesthesia with fEITER. Deep surgical anaesthesia has a maximal effect on reducing brain metabolism, so such measurement will permit calibration of the 100% level for sensitivity of fEITER. The null hypothesis is that fEITER will visualise no effect of anaesthesia on brain function.

As of 05/10/2010 the initial end date of this trial has been extended by the funders, the Wellcome Trust. The initial end date at time of registration was 30/09/2010. Stage 1 healthy volunteers is completed (n = 20) and stage 2 patients is recruiting with n = 4 to date.

Ethics approval

South Manchester Research Ethics Committee approved on the 30th January 2008 (ref: 07/H1003/H145). Confirmation of continued favourable opinion was given on 11th August 2009.

Study design

Two stages:
1. Volunteer safety trial
2. Patient randomised blinded crossover trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Brain function during anaesthesia


For both stages 1 and 2, 32 electroencephalogram (EEG) electrodes will be affixed to the scalp at the beginning of the trial (10 minutes). For stage 1 (healthy volunteers), a one-hour trial of fEITER will proceed, comprising sequential one-minute presentations of auditory (click and tone) and visual (flash) sensory stimuli presented in a random sequence during fEITER tomograpic measurements of brain function in response to the sensory stimuli. For stage 2 (anaesthetised patients), an awake tolerance test of two, one-minute presentations of visual and auditory stimuli will be tested with fEITER (control) and then repeated, sequential one-minute tests of fEITER will be conducted during anaesthesia and surgery. The randomisation and crossover will be in the depth of anaesthesia used (concentration of anaesthetic agent) within normal clinical ranges. Depth of anaesthesia will be assessed before and after each one-minute fEITER test using a commercial depth of anaesthesia monitor (Bispectral Index). The total duration for stage 2 will be the length of surgery, which is variable.

Please note that as of 26/05/10 the end date of this trial has been extended from 30/06/10 to 30/09/10

Intervention type



Not Applicable

Drug names

Primary outcome measure

Production of functional brain images that discriminate between different depths of anaesthesia and awake subjects, assessed continuously during the fEITER trial using 1-minute epochs of cerebral conductance data obtained every 10 ms, and determined by off-line analysis, including 3D functional brain image reconstruction, after the trial.

Secondary outcome measures

No secondary outcome measures

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Stage 1:
1. Healthy volunteers
2. Aged 18 to 80 years, gender: female, trans or male

Stage 2:
1. American Society of Anaesthesiologists (ASA) grade I - II
2. Adult patients aged 18 to 80 years, gender: female, trans or male
3. Scheduled for elective surgery under routine general anaesthesia

Participant type

Healthy volunteer

Age group




Target number of participants

20 healthy volunteers; 20 patients

Participant exclusion criteria

Stages 1 and 2:
History of epilepsy or neurological impairment

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

School of Electrical & Electronic Engineering
M60 1QD
United Kingdom

Sponsor information


University of Manchester (UK)

Sponsor details

Oxford Road
M13 9WL
United Kingdom
+44 (0)161 276 8582

Sponsor type




Funder type


Funder name

Wellcome Trust (UK) - University Translation Award (grant ref: 077724)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2011 results:

Publication citations

Additional files

Editorial Notes

27/04/2016: Publication reference added