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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Atmo Gas capsule localisation study in healthy volunteers
Scientific title
Validation of Atmo Gas capsule localising technique via intestinal ultrasound in healthy volunteers
Secondary ID [1] 299849 0
Universal Trial Number (UTN)
Trial acronym
Linked study record
This record is a follow-up study for ACTRN12619001219178

Health condition
Health condition(s) or problem(s) studied:
Gastrointestinal dysmotility
316880 0
Condition category
Condition code
Oral and Gastrointestinal 313550 313550 0 0
Normal oral and gastrointestinal development and function

Study type
Description of intervention(s) / exposure
The study will involve ingestion of a wireless, gas-sensing (Atmo) capsule with simultaneous gastrointestinal ultrasound (GIUS) imaging to validate the localisation of the Atmo capsule. This study will occur once.

Following an overnight fast, the subjects will arrive at the Department of Gastroenterology, Alfred Hospital for the study. A baseline gastrointestinal ultrasound (GIUS) will be performed by an experienced GIUS-trained gastroenterologist to assess the participant's basic abdominal anatomy (the participant will be consenting and fully awake and be able to see the scan in real-time). The images from this scan are not recorded.

Following ingestion of the Atmo capsule, dynamic scanning using GIUS will commence following the transit of the capsule through the stomach and small intestine. Ultrasound images of the capsule passing through the pylorus (stomach) and ileocaecal junction will be taken. Images of these landmarks will record time and proof of capsule transit. Data will be collected in a coded manner. Ultrasound imaging will cease once arrival of the capsule in the large intestine has been confirmed.

Additionally, once the ultrasound imaging has been completed, participants will be allowed to leave the facility. Instructions on confirming passage of capsule during a bowel movement will be provided. It is anticipated that the Atmo capsule will take approximately 24-48 h to pass through the gastorintestinal system. Participants will also be instructed to keep the Atmo receiver close to their body (within 1.5 m) at all times.
Intervention code [1] 316106 0
Treatment: Devices
Comparator / control treatment
Gastrointestinal ultrasound (GIUS)

Gastrointestinal ultrasound is an attractive technique that is easily accessible and is not associated with radiation risk to participants. This method can recognise and distinguish anatomical structures according wall characteristics, size, contents and motility patterns. Thus, stomach, small bowel and colon have different appearances. The gas capsule is readily recognised sonographically. Visualisation of the gas capsule within the gastrointestinal tract has previously been performed in one healthy volunteer with good success. Additionally, with the improved image resolution of latest generation of GIUS machines and the clear visibility of the capsule sonographically. GIUS is able to accurately identify the ileo-caecal junction and, therefore, distinguish small and large intestine.

As outlined above, dynamic ultrasound scanning will be performed immediately from ingestion of Atmo capsule following the transit of the gas capsule throughout the gastrointestinal tract for the next 6 - 8 h. Continuous scanning will occur if gastric emptying or passage to the ileocaecal junction is anticipated.
Control group

Primary outcome [1] 323181 0
(a) confirmation of gastric emptying landmark using a composite of
(i) the time at which the first gradient inflection for the motility marker was recorded in the stomach (verified visually via graphs generated by the Atmo data receiver) AND
(ii) the times that direct visualisation of the capsule disappeared from the stomach/entered the duodenum on sonographic imaging.
Timepoint [1] 323181 0
Estimated within 4 h after ingestion of the Atmo capsule
Primary outcome [2] 323182 0
(b) confirmation of ileal-caecal junction using a composite of
(i) the time at which a second gradient inflection for the O2-equivalent motility marker was recorded after gastric emptying and no further temperature drop associated with water ingestion have occurred
(b) the time via sonographic imaging that direct visualisation of the capsule entered the caecum.
Timepoint [2] 323182 0
Estimated within 6-8 h post-Atmo capsule ingestion
Secondary outcome [1] 381096 0
Gastric emptying time assessed by the Atmo capsule, defined as the duration between capsule ingestion and gastric emptying landmark and verified by sonographic images as the appearance of the capsule in the duodenum
Timepoint [1] 381096 0
Within 4 h post capsule ingestion
Secondary outcome [2] 381667 0
Whole gut transit time assessed by the Atmo capsule, defined as the duration between capsule ingestion and expulsion.
Timepoint [2] 381667 0
Within 24-48 h post-capsule ingestion
Secondary outcome [3] 381672 0
Small bowel transit times defined by duration between gastric emptying and proposed ileal-caecal junction as assessed using data from the Atmo capsule and verified by sonographic images.
Timepoint [3] 381672 0
Within 6-8 h
Secondary outcome [4] 381673 0
large bowel transit time defined as duration between ileal-caecal junction and passage of capsule as denoted by temperature drop or loss of signal coinciding with a bowel movement
Timepoint [4] 381673 0
Within 24-36 h

Key inclusion criteria
Healthy controls without known gastrointestinal disease/disorder
Minimum age
18 Years
Maximum age
55 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
history of gastrointestinal, endocrine or neurological disorders known to influence gastrointestinal motility, dysphagia, presence of suspected strictures, radiation enteritis or gastric bezoar; pregnancy; individuals with a body mass index >30 kg/m2, those with previous abdominal surgery (except appendicectomy) or implantable devices such as a pacemaker; antibiotic, prebiotic or probiotic use in the last 4 weeks; intake of proton pump inhibitors, H2 receptor antagonists, antacids in the last 7 days or prokinetics in the last 2 days; those who are currently receiving diathermy or have planned MRI or diathermy in the next 2 months.

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Single group
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Descriptive data will be used to report the outcomes of the study. Comparison will be made between (a) the times of exit from the stomach and the first O2-equivalent gradient inflection; and (b) the times of the passage of the capsule into the caecum and the occurrence of anaerobic conditions. Equivalence will be defined as an agreement of less than or equal to 25% between the two devices (or less than or equal to 30% as previously defined by Rao et al. 2009). A second approach to demonstrating equivalence will also be explored via linear regression and by assessing degrees of agreement between the paired time points using the Bland-Altman plots. Agreement is considered strong if 95% values lie within ±2 SD of mean differences. The results, conduct and reporting of the study will conform with the STARD 2015 guidelines (

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 16099 0
The Alfred - Melbourne
Recruitment postcode(s) [1] 29613 0
3004 - Melbourne

Funding & Sponsors
Funding source category [1] 304306 0
Commercial sector/Industry
Name [1] 304306 0
Atmo Biosciences
Address [1] 304306 0
436 Elgar Rd
Box Hill VIC 3128
Country [1] 304306 0
Primary sponsor type
Monash University
Level 6 The Alfred Centre
99 Commercial Rd
Melbourne VIC 3004
Secondary sponsor category [1] 304551 0
Name [1] 304551 0
Address [1] 304551 0
Country [1] 304551 0

Ethics approval
Ethics application status
Ethics committee name [1] 304759 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 304759 0
Room 111, Chancellery Building D,
26 Sports Walk, Clayton Campus
Research Office
Monash University VIC 3800
Ethics committee country [1] 304759 0
Date submitted for ethics approval [1] 304759 0
Approval date [1] 304759 0
Ethics approval number [1] 304759 0

Brief summary
The invention of an ingestible gas-sensing capsule promises a world of possibilities in research understanding of the activities of the gut bacteria in response to food. This technology, named the ATMO capsule, is capable of detecting changes in multiple gas concentrations (oxygen, carbon dioxide, hydrogen and methane) as a result of bacterial breakdown of food components (e.g. fibre) as it travels through different parts of the digestive tract. The completion of Phase 1 clinical studies in 23 healthy controls have proven its safety and functionality. Further studies are now needed to explore the utility of this technology in a clinical setting, such as in the assessment of regional transit times. If these studies are successful, this will mean the availability of a technology that is low cost, non-invasive and potentially usable as a point-of-care testing for individuals with gut conditions.

A particularly attractive feature of the ATMO capsule is its ability to distinguish the small (aerobic region) vs large intestine (anaerobic region) via changes in oxygen concentrations. A step-wise decrease in oxygen levels have also been proposed as landmarks for distinguishing movement from the stomach to the small intestine. However, these anatomical landmarks remain theoretical and require further validation. A study utilising a similar ingestible capsule (the SmartPill capsule) is already underway to achieve this goal but preliminary results from this study require validation via an non-invasive imaging technique - gastrointestinal ultrasound. We have previously had good success in locating the ATMO capsule in one healthy volunteer but further data are needed to visualise the ATMO capsule within two key proposed anatomical positions (stomach to duodenum; ileum to caecum) in order to provide a way of validating gas profile landmarks.

We hypothesised that changes in oxygen-equivalent and hydrogen concentrations as measured by the gas capsule provide identification of key anatomical landmarks within the gastrointestinal tract.

The aim of the study was to develop and validate markers of anatomical landmarks of the ATMO gas capsule using gastrointestinal ultrasound in healthy controls.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 98114 0
Prof Peter Gibson
Address 98114 0
Level 6 The Alfred Centre
99 Commercial Rd
Melbourne VIC 3004
Country 98114 0
Phone 98114 0
Fax 98114 0
Email 98114 0
Contact person for public queries
Name 98115 0
Dr CK Yao
Address 98115 0
Level 6 The Alfred Centre
99 Commercial Rd
Melbourne VIC 3004
Country 98115 0
Phone 98115 0
Fax 98115 0
Email 98115 0
Contact person for scientific queries
Name 98116 0
Dr CK Yao
Address 98116 0
Level 6 The Alfred Centre
99 Commercial Rd
Melbourne VIC 3004
Country 98116 0
Phone 98116 0
Fax 98116 0
Email 98116 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
As this is a industry-funded project, data will by only be available via manuscript for publication in an international peer reviewed journal.
What supporting documents are/will be available?
Ethical approval
How or where can supporting documents be obtained?
Type [1] 7296 0
Ethical approval
Citation [1] 7296 0
Link [1] 7296 0
Email [1] 7296 0
Other [1] 7296 0
Summary results
No Results