Optimizing the Previs Device for Prediction of Postoperative Ileus
Phase: NA
Conditions: Ileus
Sponsor: Jennifer Hrabe

Cover Page for Study Protocol 
 
 
Sponsor-Investigator: 
Jennifer Hrabe 
NCT Number: 
NCT03505476 
Unique Protocol ID: 
201801808 
Official Title: 
Optimizing the Previs Device for 
Prediction of Postoperative Ileus 
Date of Document: 
28 September 2020 
 

 
 
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Device Name:  
 
 
 
Previs Device 
Title of Study:  
Optimizing the Previs device for Prediction of 
Postoperative Ileus (Previs Optimization) 
Study Center:  
 
 
 
University of Iowa  
Estimated number of subjects:  
475 subjects (50% male, 50% female) will be 
recruited and enrolled in this study.  
Study Period:   
 
 
 
February 2018 until completion 
Estimated date of first enrollment:  
February 2018 will be the earliest day of 
enrollment, pending approval from UI IRB. 
Estimated date of last enrollment:   
We estimate that all subjects will be enrolled by 
January 2020. 
Sponsor:   
 
 
 
     
Entac Medical, Inc. 
Version: 
 
 
 
 
4.0 
Date:  
 
 
 
 
September 28, 2020 
 
 
 
 
 
 
 
 
 
 
 

 
 
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Table of Contents 
 
I. 
Statement of Compliance: ........................................................................................ 3 
II. 
IRB Oversight: .......................................................................................................... 4 
III. 
Location of Study Procedures: ................................................................................. 5 
IV. 
Trial Design: ............................................................................................................. 6 
V. 
Study Aims: .............................................................................................................. 7 
VI. 
Main Screening Criteria: .......................................................................................... 8 
VII.  Screening/Recruitment procedures: ......................................................................... 8 
VIII. Inclusion Criteria: ..................................................................................................... 9 
IX. 
Exclusion Criteria: .................................................................................................... 9 
X. 
Study Procedures: ................................................................................................... 10 
 
Table 1.  Study Procedures: .................................................................................... 10 
XI. 
Possible Risks of the Study: ................................................................................... 11 
XII. 
Adverse Event Reporting: ...................................................................................... 12 
XIII. Data Management: .................................................................................................. 14 
XIV. Primary End points: ................................................................................................ 15 
XV. 
Payment for Participation: ...................................................................................... 16 
XVI. Subject Safety: ........................................................................................................ 17 
XVII. Statistical design plan: ............................................................................................ 18 
 
 
 
 
 
 
 
 

 
 
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I. 
Statement of Compliance: 
This study will be conducted in compliance with the protocol, Good Clinical Practice and the 
applicable Food and Drug Administration and other Department of Health and Human Services 
regulatory requirements. 
All key personnel (all individuals responsible for the design and conduct of this study) have 
completed Human Subjects Protection and Good Clinical Practice training. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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II. 
IRB Oversight: 
 
Human Subjects Office / IRB 
J. Andrew Bertolatus, MD 
Hardin Library, Office 105 
600 Newton Rd 
Iowa City, IA 52242 
FWA#: FWA00003007 
Voice: 319-335-6564 
Fax: 319-335-7310 
Email: irb@uiowa.edu 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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III. 
Location of Study Procedures: 
 
University of Iowa Hospitals and Clinics (UIHC) 
200 Hawkins Drive 
Iowa City, Iowa 52242 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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IV. 
Trial Design: 
 
This is a prospective, non-randomized, open label, single center study designed to assess 
and optimize performance of the Previs device. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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V. 
Study Aims:  
 
The aims of this study are: 
 
1) To incorporate digital signal processing algorithms and design changes from 
prior trials into a re-designed prototype, self-contained, noninvasive device that 
retains or improves the predictive accuracy. 
 
2) To continue making iterative refinements on prototype device design to one 
that reliably performs in a health care environment. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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VI. 
Main Screening Criteria: 
 
We will recruit men and non-pregnant women of any ethnic background between the age 
≥ 18 and ≤ 100 years that are scheduled to undergo an elective intestinal resection 
surgery by the colorectal surgery service at UIHC. 
VII. 
Screening/Recruitment procedures: 
 
Adult patients presenting to the Digestive Health Center at UIHC for elective intestinal 
resection surgery or to Urology Clinic at UIHC for cystectomy, that qualify, will be 
offered participation in the trial. Study team will review potential subject’s chart for 
possible inclusion/exclusion criteria. This pre-screening is done so that potential subjects 
and their families are not approached until the study team reviews and verifies that it 
would appear that the subject may qualify.   
The study team will approach the potential subject and tell them that they may qualify for 
a study and ask if they are interested in hearing about the study.  If the potential subject is 
interested, the study will be explained to them in detail.  They will be encouraged to ask 
questions and talk it over with the treating physician and family members.  
If the potential subject would like to participate, one of the members of the study team 
will go over the consent form with them, answering any questions they may have as the 
study team goes through the consent form. Once they have reviewed the entire consent 
form the study team will ask them once again if they have any questions. After all 
questions are answered, they can sign the consent form if they choose to participate. The 
patient will have the time between the discussion of the study and the day of surgery to 
decide if they would like to participate.  This time interval is typically 1 to 2 weeks.   
To avoid any coercion all subjects are offered the opportunity to talk with the treating 
physician or family prior to signing a consent form. Study participation has no influence 
on the standard of care they would otherwise receive for their disease process 
 
 
 
 
 
 
 
 
 

 
 
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VIII. 
Inclusion Criteria: 
 
• Age ≥ 18 and ≤ 100 years 
• Patient undergoing elective intestinal resection surgery by the colorectal surgery 
service at UIHC.  
• Patient undergoing cystectomy surgery by the urology service at UIHC 
IX. 
Exclusion Criteria: 
 
• Allergies to any of the device components (ie: adhesive) 
 
• Inability to have prototype device applied to their abdominal wall due to a 
condition (ie: fistulas, stomas, drains, etc). 
 
• Patients who develop documented evidence of intraperitoneal infection or urinary 
tract infection within 14 days of surgery will be excluded from analysis for 
primary outcome (but data will undergo analysis for potential detection of 
secondary ileus) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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X. 
Study Procedures: 
 
• Potential subject is approached at preoperative visit to discuss study, if interested. 
• Informed consent signed. 
• Previs device is applied either in the operating room at the completion of surgery 
or in the recovery room. 
• Time and serial number of device application will be logged into study register. 
• Study team member will administer Instrument Questionnaire daily, while 
hospitalized, for up to 10 days. 
• Study team member will remove the Previs device 10 days post-operative or at 
subject discharge from the hospital. 
• Study team will monitor the medical record and talk with subject for 14 days to 
collect any data related to a possible infection (intraperitoneal or urinary tract 
infection).  
• Study team member will contact the subject 14 days post-operative to administer 
Instrument Questionnaire. 
• Study team will review the subject’s medical record to assess for any evidence of 
hospital readmission within 30 days of discharge. 
 
 
 
 
 
Table 1 
Schedule of events 
Event 
Screening Visit 
Day of Surgery (Day 
1) 
Day 2,3,4,5,6,7,8,9,10 
14 Day Follow-Up 
Informed Consent 
X 
 
 
 
Medical History 
X 
 
 
 
Medical Record 
Review 
 
X 
X 
X 
Review of 
inclusion/exclusion 
criteria to confirm 
subject eligibility 
X 
 
 
 
Device placement 
 
X 
 
 
Device removal 
 
 
Xa 
 
Instrument 
Questionnaire 
 
X 
X 
X 

 
 
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Adverse events 
monitoring 
 
X 
X 
X 
 
a. 
At day 10 post-operative or discharge, whichever comes first. 
 
 
 
 
XI. 
Possible Risks of the Study: 
 
Risk of skin irritation where the device is placed.  To minimize the risk of skin irritation, 
subjects will not be enrolled who have allergies to any of the device components or the 
adhesives that will be used.  Study members will also monitor the device placement to 
ensure there is no irritation. 
Loss of confidentiality is also a risk. To reduce risk of a loss of confidentiality, 
precautions will be taken to ensure privacy. The PI and study team will maintain 
appropriate medical and research records for this study, in compliance with ICH E6 GCP, 
Section 4.9 and regulatory and institutional requirements for the protection of 
confidentiality of subjects. Research records generated in this study will be stored in file 
cabinets in a locked room and/or on a secure electronic database. Only authorized study 
team at the sites will have access to the data. Subjects will not be directly identified by 
name. Any identifiers that would link the subjects to the database will be stored in a 
password protected RedCap database.  All subjects will be identified by a coded ID 
number. 
 
 
 
 
 
 
 
 
 
 

 
 
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XII. 
Adverse Event Reporting: 
 
Subjects are monitored for adverse events during the study. Subjects are also educated on 
the risks of the study and contact phone numbers for the study team. Subjects are 
encouraged to contact the study personnel with any questions or concerns.  
 
The University of Iowa requires Investigators to collect and report to the University of 
Iowa IRB if any of the following occur: 
 
• An unanticipated problem involving risks to subjects or others is any event or 
problem that: 
1) was unexpected (in terms of nature, severity or frequency) given (a) 
the research procedures that are described in the protocol-related 
documents, such as the IRB- approved research protocol and informed 
consent document; and (b) the characteristics of the subject population 
being studied AND 
2) suggests that the research places subjects or others (those not directly 
involved in the research such as research staff or family members) at a 
greater risk of harm (including physical, psychological, economic, or 
social harm) than was previously known or recognized AND 
3) is related or possibly related to participation in the research (possibly 
related means there is a reasonable possibility that the incident, 
experience or outcome may have been caused by the procedures 
involved in the research). 
• Receipt of new information 
During the course of a study, researchers may become aware of new 
information that would impact a subject’s decision to participate, or 
continue participating in the research study. For example, interim analyses 
of data may identify a trend which impacts the safety of subjects, or may 
identify early efficacy (benefit) of one of the interventions under study. In 

 
 
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addition, results from other research studies or changes in standards of 
practice or care may affect conduct of a study and would need to be 
communicated to research subjects. 
 
• Noncompliance 
Noncompliance is a failure to follow the federal regulations with respect 
to protection of human subjects in research or failure to follow the 
determinations of the IRB with respect to conduct of the research as 
approved by the IRB. 
 
Once per year, the IRB is required to review and approve all non-exempt research 
projects at intervals appropriate to the degree of risk, but not less than once a year. This is 
called "continuing review.” Continuing review for non-exempt research is required to 
occur as long as the research remains active for long-term follow-up of the research 
subject, even when the research is permanently closed to the enrollment of new subjects 
and all subjects have completed all research-related interventions and to occur when the 
remaining research activities are limited to collection of private identifiable information. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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XIII. 
Data Management: 
 
The following people/agencies may have access to subject data/records: 
 
• Study team 
• Federal government regulatory agencies 
• Auditing departments of the University of Iowa 
• University of Iowa IRB 
• Sponsor and/or its representative 
To protect confidentiality, we will assign each subject a study ID. All records will be in a 
locked cabinet in a locked office or password protected computer system. Data and 
records will be managed as follows: 
• Paper/hard copy records (hard copy surveys, questionnaires, case report forms, 
pictures, etc.) - Whenever possible, subject identifying information will be 
blacked out on all paper or hard copy records and replaced with the subject's 
unique study identifier. Paper records will be stored in a locked file cabinet in the 
study team's locked office.  
• Electronic records (computer files, electronic databases, etc.) – All electronic data 
bases will only be accessed by the study team and available only with a username 
and password assigned to study team by the PI.  
• After the completion of the study, all identifiable information will be destroyed 
according to the University of Iowa’s IRB standards, as soon as possible. 
 
 
 
 

 
 
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XIV. 
Primary End points: 
 
Performance of Previs device within 18 hours after surgery for predicting subsequent 
development of gastrointestinal impairment due to ileus. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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XV. 
Payment for Participation: 
 
Subjects will not receive payment for participating in this study.  The study related device 
and study procedures will be paid for by the study. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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XVI. 
Subject Safety: 
 
• To minimize risks all subjects are carefully pre-screened and screened trying 
to identify any factors that could contribute to increased risk.  
• All study procedures are completed at University of Iowa Hospitals and 
Clinics by a very experienced and well trained staff and monitored by the 
Principal Investigator. 
• All confidential information is kept in locked offices and password protected 
computers only available to study team members.  
• The participant has contact information and study team members available 
24/7.  
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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XVII. 
Statistical design plan: 
 
The definition of post-operative ileus is "the presence of emesis, need for nasogastric intubation, 
or reversal of the diet beyond 24 hours from the completion of surgery". As the goal of the first 
phase of this trial is to optimize the device for predicting ileus, we will be maximizing the 
performance of the device through measurement of sensitivity, specificity, positive predictive 
value, negative predictive value, AUC, and accuracy of the device for each 10-20 patients 
(dependent upon the incidence of ileus in each group). The device performance will be compared 
to the surgeon prediction of ileus development, which will be assessed within the first 24 hours 
after surgery.  The threshold for use in the second phase (validation phase) will be chosen to 
maximize sensitivity while maintaining the highest possible specificity.  Ultimately, device 
performance will be considered successful if sensitivity higher than that of surgeons can be 
achieved for predicting ileus. 
The study team would like to increase our enrollment plan to 225 patients. We believe that there 
will be a significant need for pre-optimization where the algorithm is tweaked based upon results 
in smaller cohorts. Enrollment of 225 patients should allow us an adequate number of cohorts to 
iteratively pre-optimize the algorithm prior to validation in the final cohort.