Feasibility and Acceptability of a Medical Grade, Smartphone-based, Fetal Heart Rate Monitor for Outpatient Use: the HeraBEAT™ Clinical Trial
Phase: NA
Conditions: Pregnancy Related
Sponsor: Mayo Clinic

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CLD-HBT-611_v3.1 – 02/22/2021  
 
 
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Functionality and Acceptability of a Medical Grade, Smartphone based, Fetal Heart Rate 
Monitor for Self-Administration by Low Risk Pregnant Women 
 
The HeraBEAT USA™ Trial 
 
 
PRINICIPAL INVESTIGATOR 
 
Yvonne S. Butler Tobah, MD 
Consultant, Obstetrics 
Department of Obstetrics and Gynecology 
Mayo Clinic, Rochester, MN 
 
CO – INVESTIGATORS  
 
Abimbola Famuyide, M.B.B.S 
Chair, Department of Obstetrics and Gynecology 
Mayo Clinic, Rochester, MN 
 
Regan Theiler, MD, PhD 
Chair, Division of Obstetrics 
Department of Obstetrics and Gynecology 
Mayo Clinic, Rochester, MN 
 
 
CLD-HBT-611_Version 3.1 – 02/22/2021 
This is an Investigator-Sponsored study.  
Mayo Clinic, Rochester, MN is the Study Sponsor. 
 
 
1.0 Specific Aims 
 
The coronavirus disease 2019 (COVID-19) global pandemic rapidly changed the standard model 
of prenatal care in the United States. In response to this pandemic, the Society for Maternal Fetal 
Medicine (SMFM) and the American College of Obstetricians and Gynecologists (ACOG) 
recommended integrating telehealth services as appropriate, limiting face-to-face patient contact 
if clinically possible, and considering alternative methods of providing obstetric care, to decrease 
the risk of COVID-19 exposure1–3.  
 
Evidence for integrating home monitoring devices and telehealth services for the provision of 
prenatal care is limited4,5 Innovative options for home monitoring of fetal well-being, as a 
component of virtual or a hybrid prenatal care model is equally negligible. While a few studies 
have focused on home monitoring of maternal blood pressure, capillary blood glucose, and 
contraction patterns, 5few have investigated maternal home monitoring of fetal heart rate, as a 
component of virtual or hybrid prenatal care.  

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In addressing this gap, HeraMED designed and tested a medical grade, smartphone fetal heart 
rate monitor - HeraBEAT USA™ ((HeraBEATTM) - for self-administration at home, under 
clinical guidance of an obstetric provider.   
 
We propose that HeraBEAT™ self-administered at home by pregnant women, under clinical 
guidance, will result in accurate monitoring of fetal heart rate, provide peace of mind to patients 
between prenatal appointments, and enhance the overall prenatal experience of pregnant women.  
 
To evaluate the functionality and acceptability of HeraBEAT™ we plan to:  
 
1. Assess the functionality of HeraBEAT™ self-administered by pregnant women.  
a. Hypothesis: Pregnant women will demonstrate a working knowledge on use of the 
device, when observed by medical staff, will trouble-shoot appropriately and will rate the 
device instructions as easy to follow.  
b. Hypothesis: Pregnant women will appropriately self-monitor FHR successfully at home, 
transmit the data to caregivers, and use the device as prescribed. 
 
2. Assess the acceptability of HeraBEAT™ when self-administered by a pregnant women in the 
home by assessing the following 
a. Hypothesis: Pregnant women will rate the device as easy to use, easy to interpret, and 
have minimal disruption in lifestyle as measured by a standardized survey.  
b. Hypothesis: The intervention will reduce the rate of healthcare utilization without 
impacting maternal safety or the process of care standards specified by the American 
College of Obstetricians and Gynecologists (ACOG). 
 
 
2.0 Background and Significance 
 
The current traditional rhythm of prenatal care in the United States assumes dependence on brief 
face to face visits consisting of low-level physical assessments and the opportunity to 
communicate about the progress of the pregnancy6,7.  It has been proven that this method 
provides benefit to mothers and their fetuses, but the potential that greater benefit could be 
achieved using 21st century technology has not been widely explored3,8. The current COVID-19 
pandemic has shifted the method in which obstetric providers plan and provide prenatal care, as 
global practice changes encourages limited face-to-face interaction, with more reliance on 
telehealth options for the provision of care9.   
 
Alternative models for the provision of obstetric care is limited in the literature, but have recently 
gained traction in obstetric practice, given the current COVID-19 pandemic.  A recent systematic 
review of telehealth interventions to improve obstetric care reported improved schedule 
optimization for high risk pregnancies, and improved obstetric outcomes for smoking cessation 

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and breastfeeding5. Our randomized, telemedicine integrated, reduced model care – OB Nest – 
augmented with fetal Doppler and sphygmomanometer home monitoring devices resulted in 
higher patient satisfaction of care among OB Nest patients while maintaining similar maternal 
and fetal outcomes when compared to standard prenatal care10. Similarly, a study which 
decreased the frequency of prenatal care and augmented care with a mobile prenatal care App, 
found no difference in patient or provider satisfaction11,12.  
 
Despite the rapid growth in a variety of technological advances and innovations in healthcare to  
support home monitoring13–17, including home holter monitors, wireless scales for monitoring 
weight, and home sphygmomanometer for monitoring blood pressure, there has been relatively 
little research efforts focused on home monitoring devices, self-administered by pregnant 
women, under the guidance of a clinical team, especially innovative options for home monitoring 
of fetal well-being. This gap is important as leveraging innovative technological advances and 
other connected health modalities may allow future re-design of prenatal care, that enhances the 
overall experience of expectant mothers18–20 while allowing for rapid adoption during healthcare 
crises like the current global COVID-19 pandemic.  
 
Recently, the Clinical Excellence Research Center at Stanford University proposed that the costs 
of delivering prenatal care could be reduced by 2.5% to 13% by using supplemental telehealth 
innovative tools8. Despite the major impact this could potentially have on the delivery of prenatal 
care, research and investments in this concept has remained limited, and uptake slow, until the 
recent COVID-19 pandemic. 
 
Consequently, this study proposes to assess HeraBEAT,™ a novel fetal heart rate device, 
administered at home by pregnant women, under clinical guidance, to augment options for 
virtual prenatal care.  
 
 
 
3.0 Preliminary Research  
 
 
3.1 Basic Principles of FHR Monitoring  
 
Fetal heart rate monitoring is a method for examining the condition of an unborn fetus in the 
uterus by noting its heart rate.  This is typically done by a manual handheld device in an 
outpatient setting during routine prenatal care, or continuously, by electronic FHR measurement 
when pregnant women are admitted for obstetric care. Fetal ultrasound is also utilized to monitor 
FHR in clinical settings.  These methods for monitoring FHR was originally introduced in the 
1960s and 1970s, with the hope that it would assist physicians in the diagnosis of fetal hypoxia 
or abnormal fetal heart21.  
 
 
 
 

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3.2 Doppler FHR Principle 
 
The typical Doppler fetal heart rate monitor is a hand-held ultrasound transducer that uses the 
Doppler Effect to provide an audible simulation of the heart beat and displays the number of 
beats per minute. To achieve this, the device is pressed against a pregnant women’s abdomen 
and acoustic waves are then interpreted as FHR. An ultrasound probe is a key component in the 
system. The probe consists of an oscillator to generate ultrasound frequency (for these 
applications, the range is 1–3 MHz) followed by an amplifier to condition the sine wave in the 
order of volts. This waveform is applied to the transmitter transducer to send vibrations through 
the body and bounce back when the density of the medium changes. Another transducer is then 
used to receive the bounced vibrations and convert them to electrical signals21. Basic FHR 
Doppler systems are available for outpatient use under clinical guidance. However, self-
monitoring of FHR by pregnant women at home is currently not a standard approved use of FHR 
Doppler devices, although Doppler devices are routinely sold for public consumption.  
 
3.3 Investigational Device 
 
The ‘HeraBEAT USA™ (HeraBEATTM) is a wireless Smart Fetal Ultrasound Doppler 
measuring device designed to be self-administered by pregnant women. The ‘HeraBEAT™’ 
device safety and performance claims allow continuous and accurate measurement of fetal heart 
rate (FHR) and maternal heart rate (MHR) throughout the pregnancy starting at 12 weeks 
gestation. This study shall evaluate the device performance starting at 20 weeks gestation.  
 
Technologically, HeraBEATTM is similar to other FHR devices currently on the market in terms 
of device usage but differ by design in its interface. The HeraBEATTM   device uses a 
smartphone-based interface, with real time instructions for localizing FHR. The device also 
measures the maternal heart rate (MHR) and uses this in its algorithm. This is primarily in order 
to overcome common lay person usage errors such as confusion between MHR and FHR or 
difficulties locating the FHR due to lack of experience. The data obtained from the device is 
uploaded to a secure HIPAA compliant cloud-based server for medical providers to review. The 
intended use, indication for use and contraindications are similar to current medical grade 
handheld fetal Doppler devices.   
 
The specifications for the HeraBEAT™ are:  
• The device will measure fetal heart rate in range of 50-240 BPM. 
• The device will measure fetal heart rate with accuracy of ±2 BPM. 
• The device will measure fetal heart rate with resolution of 1 BPM. 
• FHR value is calculated and displayed every 1 second. 
• Device measures FHR and MHR starting at 12 week gestation. 
• The device will measure maternal heart rate in range of 45-240 BPM. 
• The device will measure maternal heart rate with accuracy of ± 2% or 1 BPM, whichever is 
greater. 
• The device will measure maternal heart rate with resolution of 1 BPM. 

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• MHR value is calculated and displayed every 1 second. 
 
3.4 Device Components 
 
The ‘HeraBEAT™’ device is a handheld device consisting of two main units:  
1. The HeraBEAT™ sensor device and  
2. The HeraBEAT™ smart phone application for iOS/Android (App).  
 
The function of the HeraBEAT™ device is to sense the fetal heart rate signals, process the data 
and transmit the information wirelessly to the HeraBEAT™ App. The HeraBEAT™ App. 
receives the digital information from the HeraBEAT™ device, displays the data to the user, 
saves it for additional use, controls the commencement and termination of the measurement 
session, and automatically sends the measurement data to a qualified HIPAA compliant cloud 
server(HeraBEAT dashboard). 
 
The HeraBEATTM device (Figure 1) is a wireless device, operating on rechargeable battery (low 
voltage) that communicates with a smartphone via standard low power bluetooth-4 Low Energy 
(BLE) data link. The HeraBEATTM device does not contain buttons or switches. Power ON/OFF 
management is executed via timers and sensing of motion by the accelerometer. The 
HeraBEATTM device is managed by an internal Microcontroller (MCU). It controls the battery 
charger and power management, Blue Tooth Low Energy (BLE) and indicator lights. 
 
 
 
Figure 1. Illustration- Left: HeraBEATTM app. Right: HeraBEATTM device. 
3.5 The HeraBEATTM Application (App) 
 
The HeraBEATTM App. (Figure 2) runs on a Smartphone (Android version 6 and above and iOS 
version 11 and above). The application communicates with the HeraBEATTM device over 
Bluetooth low energy (BLE), controls the operation of the device, and receives the FHR and MHR 
value in real time for displaying numerally and graphically to the user.  The application can also 
record these values for later review and transmission to a healthcare provider.  
 

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Figure 2. Representative HeraBEATTM app screens 
 
3.6 Device Classification 
Fetal monitoring devices, including fetal Dopplers, which acquire and display the fetal heart rate 
and/or uterine contractions, are FDA Class II medical devices. 
 
Table 1: ‘HeraBEATTM’ system specification 
Safety 
Complies with 
IEC/EN  
60601-1, 60601-1-2, 60601-1-11, 
60601-2-37  
Classification 
Anti-electric Shock Type 
Class II electrical device when AC/DC 
adapter connected. 
Otherwise Internally powered 
equipment. 
Anti-electric Shock Degree 
Type BF equipment 
Degree of Protection 
against Harmful Ingress of 
Water 
IP22  
Protection against falling drops of 
water when unit is tilted 15o. 
Physical 
Characteristics 
Device size 
88 x 37 mm, 3.5 x 1.5 inch  
(Diameter × Height, ±0.08inch 
Device weight 
Approximately 4.58 Ounce 
Operating 
Environment 
Temperature 
From 41°F up to 104°F 
Humidity 
From 5% up to 90% RH (non-
condensing) 
Storage/Transp
ort 
Environment 
Temperature 
From -4°F up to 140°F 
Humidity 
From 5% up to 95% (non-condensing) 
Light intensity 
No direct sun light 
Pregnancy Week 
12 to 42 

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FHR 
Performance 
FHR Measuring Range; 
Accuracy; Resolution 
50 to 240 BPM; ±2BPM; 1 BPM 
 
MHR Measuring Range; 
Accuracy; Resolution 
45 to 240 BPM; ±2% or 1 BPM, 
whichever is greater; 1 BPM 
Auto Acquisition stop 
5 minutes of successful measurement 
Recommended Ultrasound Transmission Gel 
Aquasonic 100 Ultrasound 
Transmission Gel, by Parker 
Laboratories. 
Power consumption 
< 2 W 
Rechargeable 
Li-ion Battery 
Nominal Capacity 
3.7VDC, 1250 mAh 
Continuous Work Time 
4 hours (with a new battery) 
Power Input  
5 V DC, >0.3A 
Charge Time 
4 hours 
Ultrasound 
(NEMA/FDA) 
Nominal Frequency 
2 MHz ±10% 
 
Ultrasonic Output Power 
(P) 
70mW 
 
Peak rarefactional pressure 
(pr) 
0.03 MPa 
 
Ultrasonic Output Intensity 
(Isata) 
≤20mW/cm2 
 
Mechanical Index (MI) 
0.02 
 
Thermal index (TIS; TIB) 
0.26; 0.7  
 
Measurement Mode 
Continuous Wave Ultrasound Doppler 
 
Effective Radiating Area of 
Transducer 
4.9±0.5 cm2 
BLE 
specification 
frequency band of 
transmission 
2.4 – 2.5 GHz  
Channels (2MHZ spacing)  
3 Advertising channels @ 2402, 2426, 
2480Mh 
36 data channels 
frequency characteristics of 
the modulation 
DSSS: GFSK (modulation index = 0.5) 
Maximum RF Input 
-10 dBm 
Typical Receive Sensitivity 
-94 dBm 

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Maximum RF Tx Output 
Power 
+4 dBm 
3.7 The HeraBEAT™ Functional Description 
 
The operation of the device starts when the application is open and the HeraBEATTM device is 
turned-on:  
1. Step 1: Achieving Bluetooth (BLE) connectivity between the HeraBEATTM device and the 
HeraBEAT App.  Pairing is obtained following a onetime PIN code entered by the user. 
The user is then directed to register and enter her last menstrual cycle (LMP). An estimated 
fetal gestational age is calculated. Once the application is open, the application 
automatically searches for and connects to the HeraBEAT™ device. 
2. Step 2: The user must apply the provided gel to the bottom of the HeraBEAT™ device.  
3. Step 3: The User presses the “START” command in the HeraBEATTM App., and is guided 
to start searching for FHR signals by a built in Guided Search. 
4. At this time, the device sends the App. the quality index of the FHR (QFHR), the QFHR 
index indicate to the application when the location and position of the device over the 
abdomen is satisfactory and FHR signal is measured.  
5. When the QFHR is appropriate, the application instructs the user to hold the position over 
the abdomen and the device sends the FHR and MHR values for display and recording 
within the mobile App.  
6. Step 4: The FHR and MHR measurements stop when either the user presses the “STOP” 
command or closes the application, or a predetermined time period has been reached.  
Complete instructions for use of the HeraBEAT™ are provided in Appendix A. 
 
HeraBEAT™ dashboard layout and specification provided in Appendix B. 
 
 
The following is a list of HeraBEAT™ safety claims:   
• HeraBEATTM works at low voltage (5V) which is supplied from an internal rechargeable 
battery (tested per IEC 60601-1). 
• HeraBEATTM device material is isolated and made of electric non-conducting material. In 
addition, the device does not operate while charging.  
• HeraBEATTM transmits ultrasonic energy, at a maximum intensity of 20mW/cm2, according 
to IEC 60601-2-37 ‘Medical electrical equipment – Part 2-37: Particular requirements for the 
safety of ultrasonic medical diagnostic and monitoring equipment’ 
• The device turns off if not connected to the mobile application for several seconds. 
• All materials are biocompatible and approved for use on skin surface. 

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• HeraBEATTM controls the temperature level inside the device to assure that the device 
temperature remains below the safe temperature limit. In addition, a built-in-test (BIT) is 
implemented to verify the correct functioning of temperature Sensor.  
The device conforms to risk management best practices according to ISO 14971:2007 – Medical 
Devices – Application of Risk Management to Medical Devices.  
 
4.0 HeraBEAT™ Research Data to Date 
 
A prospective feasibility clinical performance and usability validation study was performed 
using the ‘Compass’ (A previous brand name for the HeraBEATTM), Self-Administered Fetal 
Heart Rate Monitor in Pregnant Women in 2016, at Assaf  Harofeh Medical Center and a private 
OBGYN clinic in Rishon Letzion, Israel. HeraMED Ltd. served as the study sponsor and Michal 
Feingold, M.D. served as the principal investigator. This study was conducted in compliance 
with the Israeli Ministry of Health regulations, the ethical principles of the Declaration of 
Helsinki, and the current Good Clinical Practices (GCP) set forth in EN ISO 14155 (2011) 
standard.22 
 
The study was a prospective, non-randomized, open-label, single center, single arm study, with 
end-to-end clinical and usability validation to evaluate the performance, usability and safety of 
the Compass system in pregnant women. 
 
The objectives of this study were to validate the safety and performance of self-operation of the 
Compass by intended users in realistic use scenarios and conditions. The chosen scenarios 
represented all steps involved in performing FHR measurement, verifying user's understanding 
of labeling and instructions for use when using the device, verifying that potential users were 
able to perform self-selection prior to using the device and evaluate user’s subjective 
perspective/satisfaction. 
 
The study enrolled expectant mothers with confirmed 12 week gestation pregnancy.  Twenty five 
(25) participants were screened and 23 were enrolled, completed and analyzed. Indication for use 
included expectant mothers ≥18 years, with singleton fetus, gestational ages of 12 weeks or 
greater and familiar with Smart phone usage. Exclusion criteria included multifetal gestation, 
maternal history of defibrillation, electro-surgery, and patients with external electrical 
stimulators, cardiac pacemakers or requiring use of MRI or other high frequency medical 
equipment. 
 
Primary Endpoint for performance included an evaluation of the ability of participants to self-
measure FHR with the device. Primary Endpoints for usability included an evaluation of the 
following: success rate of the user’s ability to self-select the device in accordance with the label; 
success rate of the user in independently performing critical and essential tasks (objective 
measure) and user perspective of success (subjective measure, systematically collected) for 
critical and essential tasks. The Secondary Endpoint for safety included an evaluation by 
reporting the incidence and severity of all device related adverse events.  

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The study consisted of a single visit, conducted on one day.  Patients were self-selected during 
the screening process. Usability and performance of the device was evaluated by study 
personnel.  
 
The feasibility study results were as follows:  
• Performance success rate of Fetal Heart Rate detection was 100% (CI 85.2 – 100.00). 
• The Pass/Fail success rate for all the usability critical and essential tasks was 100% in the 
following domains: 1. Self-Selection, 2. Task Performance:  Training Material, Handling 
the Compass, Performing the Procedure, Performing the Switching Off.  
• User Perspective of Success was evaluated by a post tasks questionnaire. Each question was 
evaluated on a scale from 1 to 5 (1. Strongly disagree; 2. Disagree; 3. Neither agree nor 
disagree; 4. Agree; 5. Strongly agree).  Mean scores were calculated for each question. 
Results ranged from 4.3 to 5.0, indicating that expectant moms agreed or strongly agreed 
with the ease of use of the device.  
• There were no safety issues or adverse events reported. Post-development testing indicated 
that the Compass System (now HeraBEAT™) was successful in achieving its per protocol 
efficacy and safety endpoints, usability and performance measures.  
 
 
5.0 Study Methods 
 
5.1 Overview 
 
Primary Objective 
1) To evaluate the functionality of HeraBEAT™ when self-administered by pregnant women by 
assessing the following:  
a) Study participants’ independent use of the device assessed by study personnel 
observation, including ability of participants to read and follow HeraBEAT™ device 
instructions, and find fetal heart rate without assistance evaluated using the HeraBEAT™ 
Independent Device Assessment Form. (Appendix C).     
b) Data transmission from the device to the healthcare provider via a HIPAA compliant 
cloud-based server, assessed by evaluating the data transmitted to the healthcare provider 
from the HeraBEAT™ US device, including subject’ success in finding FHR, time to 
find FHR, frequency of use, and clinical utility of the FHR/MHR data (Appendix B). 
 
Secondary Objective 
1) To evaluate the acceptability of HeraBEAT™ when self-administered by a pregnant women 
in the home by assessing the following: 
a) Patient usability and ease of use assessment as measured by the System Usability Scale 
(SUS), Appendix D.  
b) Impact on utilization of care as measured by urgent triage and/or emergency care visits 
for concerns regarding fetal well-being. 

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5.2 Research Design and Participants 
 
We propose a single center randomized cross-over study in the outpatient obstetric setting at an 
academic institution in the mid-west, United States to test the functionality and acceptability of 
HeraBEAT™ for self-administration by pregnant women.   
 
5.3 Participant Selection 
 
This study will recruit low risk pregnant women, with singleton pregnancies, presenting for 
prenatal care at the Obstetrics and Gynecology Department at Mayo Clinic Rochester. No 
waivers or exemptions to any eligibility criteria will be permitted. Each criterion will be 
addressed and documented in the mother’s case report form for eligibility assessment. Patients 
will be recruited as a convenience sample after eligibility is assessed.  
 
5.4 Eligibility criteria 
 
Inclusion Criteria: 
1. At least 18 years of age 
2. Able to speak, read and understand English 
3. Able to provide informed consent (i.e. no impairments or barriers) 
4. Owns a suitable iOS or Android device and demonstrates average control and basic 
understanding of using a smartphone (i.e. download App, operate BT etc.) 
5. At least 12 weeks gestation, or following first OB provider visit with pregnancy confirmation  
6. Pregnancy documented as low risk  
 
Exclusion Criteria: 
1. 
Any observed cranial or cardiac anomalies on formal ultrasound 
2. 
Multifetal gestation 
3. 
Maternal history of defibrillation 
4. 
Maternal history of electro-surgery 
5. 
 Patients with external electrical stimulators, cardiac pacemakers or requiring use of MRI 
or other high frequency medical equipment 
6. 
Clinical judgment that determines that the pregnancy is at high risk for complications that 
would require outpatient or inpatient monitoring for clinical care.    
 
5.5 Study Design 
 
As part of current standard of care, pregnant women are initially evaluated by an obstetric 
physician, nurse practitioner or midwife during the first trimester. During this visit, the study 
nurse will complete the assessment for eligibility criteria for low risk pregnant women. Upon 
confirmation of eligibility, the nurse will contact the study coordinator.  The study coordinator 
will approach the patients with study information, ascertain interest in participation, and obtain 
signed informed consent from those interested. 

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Between 18 and 20 weeks gestation, all patients complete a fetal sonography assessment for fetal 
anatomy as part of routine prenatal care. An obstetric provider will review the results with the 
patient, and confirm that fetal anatomy is normal. Patients with abnormal fetal cardiac or cranial 
anomalies will be excluded from the study. If the patient interest remains, the study coordinator 
will confirm ongoing consent and randomize the patient into the study. This will be documented 
in the appropriate section of the patient’s electronic medical records. 
 
Study personnel (obstetric nurses or clinicians) will then provide patients with a study kit, 
containing the HeraBEAT™ device or a standard fetal Doppler device (based on randomization 
assignment), discuss the limitations of both devices, and instruct patients on the range of normal 
fetal heart rate.  
 
Study personnel will then observe the study subjects’ independent self-administration of the 
devices in the prenatal clinic after patients receive a brief tutorial of the devices operation. Study 
subjects will be able to refer to the device instructions for use but will not receive assistance or 
prompts during this testing session. Study personnel will note any mistakes or difficulties by the 
subjects on the HeraBEAT™ Independent Device Use Assessment Form (Appendix C). Once 
the observation period is completed, study personnel will document all observations, review and 
correct any errors made by patients during use of the device, assist patients in confirming 
accurate use, perform teach back, and provide the study subject with a device for home use. 
Patients will be instructed to call clinic or Triage with any questions or concerns regarding 
results of fetal monitoring at home. All calls and recommendations provided will be documented.  
 
5.6 Schema 
 
Patients will be instructed to monitor their fetus once weekly, using their assigned device, from 
20 weeks to 36/37 weeks gestation. Patients using the HeraBEAT™ device will have their FHR 
and MHR data displayed on their App, and uploaded to a HIPPA compliant cloud based server, 
which can be accessed by the healthcare provider for review (Appendix B). Patients using the 
standard handheld Doppler device will be given a study brochure for recording their weekly data. 
Patients using the HeraBEAT™ device will be instructed to bring their device during their 
outpatient clinical appointments, for comparison of MHR and FHR during their routine clinic 
appointments using methods documented in Appendix E.  
 
After approximately 8 weeks of monitoring, patients will complete a System Usability Survey 
(SUS Survey), Appendix D to assess ease of use of the device, then crossover to the alternate 
study product.  
 
Patients who are randomized to HeraBEAT™ from 20weeks gestation to 28 weeks gestation will 
be given the standard fetal Doppler. Patients who are randomized to the standard Fetal Doppler 
will switch to the HeraBEAT.™ At the conclusion of each patient device use (28 weeks and 36 
weeks gestation), participants will complete the System Usability Survey (Appendix D) to assess 
ease of use of each device.  
 

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Prior to registering study participants, all eligibility criteria will have been met and fully 
documented. Mothers will be randomized by the study coordinator after completion of standard 
informed consent for participation in clinical research including permission to use Protected 
Health information.   
 
Registration/randomization is available via the Study Data Management System (SDMS), a web 
application portal framework supported through Mayo Health Sciences Research.   
 
5.7 Intervention  
 
All randomized participants will be assigned to an obstetric physician, midwife or combination 
of physician/nurse practitioner care team that will supervise care during her pregnancy. All 
laboratory tests, imaging, and standardized evaluations that ensure the safety of the participant 
and her fetus will be conducted in both arms of the study as per departmental protocol.  
 
Participants will be instructed to seek care (per routine obstetric precautions) for any concerns 
regarding fetal wellbeing, irrespective of their FHR on home monitoring devices. No clinical 
decisions will be solely based on the results of home monitoring data. Data uploaded from the 
HeraBEAT™ device will be monitored by trained study personnel via the HeraBEAT dashboard 
: https://hera-med.rmdy.health/CoachConsole/Account/Login . FHR abnormalities will be 
investigated, using standard obstetric clinical protocols.   
 
All adverse events (AEs) experienced by the subjects while at home or in the clinic will be 
recorded on the HeraBEAT™ study case report form and evaluated for type of event, severity, 
whether the AE qualifies as a serious adverse event (SAE), and relationship of the AE to the 
HeraBEAT™ device use. 
 
1- Nurse assesses eligibility criteria, ascertains mother’s interest, and study coordinator will obtain consent 
and complete randomization Patients will be given home monitoring equipment after their fetal anatomy 
sonography is complete, inclusion/exclusion criteria confirmed and Patient Usability Form completed 
(Appendix C).  
2- After 8 weeks of use, participants will complete the System Usability Scale (SUS) survey (Appendix D), 
return the first study device and crossover to the second device. An independent device use assessment 
(Appendix C) will be assessed by study nursing staff and completed for the second device.  
3- At the conclusion of 8 weeks of self-monitoring with assigned device, participants will complete the System 
Usability Scale (SUS) survey to assess ease of use (Appendix D).  

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5.8 Data Collection 
 
Self-reported responses from surveys will be collected from participants after 8 weeks of use for 
each device via e-mail (REDCap Survey) or mailed paper surveys.  If a participant does not have 
access to email then the survey will be mailed for completion with a self-addressed envelope 
with pre-paid postage.  Data from the medical record will be abstracted for all participants that 
are registered in the study to capture demographics, socio-economic status, utilization, standards 
of prenatal care, delivery outcomes and safety data.  The time frame for collection will be from 
time of enrollment to the 6-8 week postpartum appointment.  
 
Table 2: Outline of data collection by weeks of pregnancy. 
Gestational Weeks 
12 wks 
18-20 
wks 
24 wks 
28 wks 
32 
wks 
36 - 37 
wks 
Subject interest  
X 
X 
 
 
 
 
Subject eligibility 
X 
X 
 
 
 
 
Informed consent 
 
X 
 
 
 
 
Fetal Anatomy Sonography 
 
X 
 
 
 
 
Independent Device Use 
Assessment  
 
X 
 
X 
 
 
Weekly device use 
 
X 
X 
X 
X 
X 
SUS Survey  
 
 
 
X 
 
X 
5.9.1 Participants Demographics  
 
Participant characteristics to be collected at time of enrollment through self-report and medical 
record review will include: age, race/ethnicity, education level, marital status, BMI, due date, 
parity, previous miscarriage, previous C-section and insurance.   
5.9.2 Participants Reported Outcomes 
 
System Usability Survey: Ease of use will be evaluated using a survey assessing comfort with 
use, troubleshooting, ease of obtaining FHR, any safety concerns, and whether or not the device 
was useful for confirming fetal well-being.  
 
Medical device usage: While mothers are using the standard home Doppler they will be asked to 
track usage information. These metrics will include date of use, user (mother/partner), estimated 
time to find FHR, and estimated FHR.  
 
5.9.3 Clinical/Practice Important Outcomes 
 
Safety and Healthcare Utilization: Data will be captured from the medical record review and 
participant’s report of any safety concerns. A medical record review will be conducted to capture 

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all in-office visits within the OB Clinic, all triage visits and any hospitalizations that were 
prompted by FHR monitoring obtained at home, and recorded on the study case report form.  
 
Patient engagement with remote monitoring devices will be measured by the number of times 
patients record FHR or both MHR and FHR data. Participant compliance with instructions 
regarding frequency of device use will be assessed by reviewing the device use statistics gained 
from information automatically uploaded to the HIPAA compliant cloud storage each time the 
device is used (Appendix B and https://hera-med.rmdy.health/CoachConsole/Account/Login).  
 
Participants who use the device more often than what is recommended will be re-instructed on 
appropriate use (once weekly).   
 
6.0 Follow-up Guidelines 
 
All participants will be followed per protocol guidelines and deviations from protocol will be 
reported to the IRB.  If a participant refuses to continue to participate and consent is withdrawn, 
they will then be considered a withdrawn participant and no further data will be collected 
through medical review or self-report.  Participants withdrawn prior to the end of the study will 
turn in their device at the time of withdrawal and continue routine prenatal care.  
 
 
7.0 Stop Guidelines 
 
All enrolled participants may choose to discontinue at any time. Since they will already be 
assigned to an obstetric provider, no interruption of care will be introduced. Participants may 
also be asked to discontinue the study if their pregnancy is subsequently diagnosed as high risk, 
or if cardiac or cranial anomalies are identified on routine fetal sonography. 
 
8.0 Data Analysis Plan 
 
The study will be analyzed according to the intention to treat principle, including all mothers 
randomized to the study in the arm to which they were randomized, regardless of whether they 
received the intervention assigned.  
 
Baseline characteristics will be reported in the study results with continuous values being 
reported as means and standard deviations or median interquartile range as appropriate. 
Categorical values will be reported as counts and proportion. Two sample t-tests or Wilcoxon-
rank sum test and chi-squared tests or Fishers exact test will be used as appropriate.  Any 
baseline imbalances (p<0.05) will be explored as a possible confounder to adjust for when the 
outcome measures are analyzed.  We will adhere to the CONSORT guidelines to transparently 

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report study results and ensure that sufficient information is included to allow for assessment of 
the study’s internal and external validity.  
 
Ease of use will be estimated from the System Usability (SUS) validated questionnaire. These 
data will be analyzed as a two sample t-test prior to cross over. After cross over we will analyze 
these data using an ANCOVA adjusting for order of medical devices or as a paired t-test as 
appropriate. 
 
Within the SUS survey, we will also examine trends within individual questions using chi-square 
tests. Clinical concerns in FHR will be indicated as a FHR less than 110 bpm or greater than 160 
bpm. These data will be analyzed as McNemar’s test on the association of the study medical 
devices with the clinical standard of care. Comparing ease of use metrics will be done using an 
ANCOVA analysis or generalized estimating equation as appropriate adjusting for gestational 
age. Additional ad-hoc analysis will be performed using standard techniques appropriate for 
randomized trials, with each outcome compared between study arms using t-tests for continuous 
outcomes and chi-square tests for dichotomous outcomes.  If there are differences in baseline 
characteristics between the two study groups, these will be accounted for using ANCOVA or 
regression models which include an indicator for study arm. 
 
Participants and study clinicians (nurses, obstetric providers) will not be blinded to the 
intervention after randomization occurs. Study statistician and data analysts will be blinded as to 
which arm participants were assigned to. Statistical analysis performed by Mayo Clinic 
Statistician and Ms. Tzippy Shochat, MSc, Statistical Consultant, Rabin Medical Center, 
Beilinson Hospital, Israel.  
 
8.1 Missing data 
We will make every effort to minimize missing data.  Trial enrollment, completeness of data 
collection, and fidelity of follow-up procedures will be reviewed and reported during study team 
meetings which will be conducted on a monthly basis.  As the majority of data collected is part 
of the standards of care that are routinely collected in the patients EMR and captured directly 
from the source, the expected missing data will likely be minimal. The study statistician will 
conduct frequency reports to assess for missing data, and the study team will trouble shoot any 
problems encountered.  We will report rates of missing data for each outcome by study arm, and 
known reasons for missing data.  For data elements that are used to adjust study comparisons we 
will use multiple imputation to account for any that are missing at random (MAR). 
8.2 Sample Size 
Difference in ease of use between our standard fetal Doppler and HeraBEAT™ device, as 
measured by the System Usability Survey (SUS) will be the primary outcome. Approximately 
1500 – 2000 expectant mothers receive prenatal care in the obstetric department annually. We 
aim to recruit 50 participants (50 per arm, with cross-over) for a 99.7% power to detect a 10-
point difference in SUS, as this accounts for a withdraw / post-randomization exclusion, 
estimated as high as 10% (assuming a proportion of expectant mothers to withdraw participation 
after being enrolled or found to not meet criteria after the fact). 

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9.0 Potential Limitations 
 
9.1 Conflict of Interest 
 
Obstetric Study Personnel, Abimbola Famuyide, MBBS and Yvonne Butler Tobah, MD are 
participating Mayo Clinic Innovators, with Know-How license agreement, and stock/equity in 
HeraMED Ltd. They will not be involved in the direct recruitment of patients for this study. 
They will participate in future manuscripts of research findings.  
 
9.2 Early Termination / Data Safety Monitoring Board 
 
This study will be monitored for early termination due to any validated safety concerns. The 
existing obstetric safety review board will be utilized. All reported patient safety concerns will 
be promptly communicated and investigated by study personnel.  
9.3 Confidentiality 
 
Protection of subject privacy: The privacy of all study participants will be protected by avoiding 
the use of names on all research data (field notes, transcribed conference call, meetings, etc).  
 
All research material will be maintained on a secure server at Mayo Clinic and locked in file 
cabinets, and all material will be destroyed seven years following completion of the study.  
The following entities will be allowed to access their study data: 
• The Study Sponsor 
• The Study Monitor 
• Representatives of the US Food and Drug Administration 
 
Subjects must give permission for the above access in order to participate in the study. 
 
9.4 Data Management   
 
All study coordinators will be required to use the current version of all documents and forms and 
adhere to the study schedule.  Any paper forms collected will be stored within the Obstetrics 
Department for 3 years under lock.  Survey data will be captured via email from study 
participants using the REDCap system, which is a HIPAA compliant secure data entry system 
that allows for validated data entry, edit checks and logs of all data changes.  Participants unable 
or unwilling to use the e-mail surveys will be provided a paper copy. The statistical team will 
develop the REDCap data capture system for the data collection as well as survey collection.  
The data can be accessed by the statistical team at any time and downloaded into a statistical 
software package.  The survey’s via e-mail will be administered and tracked for completion by 
the statistical team.  The statistical team will coordinate with the study coordinator for the 
mailing and receipt of surveys where mothers have indicated mailing only.  The study 
coordinator will be responsible for the actual mailing of the survey, where the statistical team 
will provide information to help them coordinate.  In cases where a response is not received 

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within 10 working days a second survey will be mailed or e-mailed, according to mothers’ 
wishes.   
Data generated by the HeraBEAT™ device will not contain any patient identifiers. The 
HeraBEAT™ device generates a UUID- Unique Identifier for each install. The UUID is 
available in the app at: Home Screen>Settings>About. The app attaches the UUID to saved 
measurements, which are in turn uploaded to HeraMED’s cloud anonymously. No protected 
health information (PHI) will be stored in HeraBEAT server (the FHR measurement will contain 
no identifiable data and only the UUID).  The HeraBEAT server is HIPAA compliant. The 
physical storage is in a secured, HIPAA compliant Azure server (Microsoft Azure Cloud Data 
Center - US East 2 - 101 Herbert Drive - Boydton).  The deidentified data can be accessed only 
by HeraMED CTO and project manager and RMDY CTO, IT manager and DBA.  The DB is 
encrypted using SQL Server Enterprise TDE. The server system keeps a full audit trail.  
The Mayo Clinic research team will have secured access to the measurement data via a web-
based dedicated service (HeraBEAT Dashboard): 
 https://hera-med.rmdy.health/CoachConsole/Account/Login   
All data, documents, and analysis findings will be password protected and backed up on a 
routine basis. The data will be stored within the secure system for seven years following 
completion of the study. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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