Muhammad Mhajna1, Nadav Schwartz2, Lorinne Levit-Rosen3, Steven Warsof4, Michal Lipschuetz3, Martin Jakobs5, Jack Rychik6, Christof Sohn7, Simcha Yagel3. 1. Nuvo-Group, Ltd, Tel-Aviv, Israel. Electronic address: muhammad.mhajna@nuvocares.com. 2. Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. 3. Obstetrics & Gynecology Division, Hadassah-Hebrew University Medical Center, Jerusalem, Israel. 4. Eastern Virginia Medical School, Norfolk, VA. 5. Department of Neurosurgery, University Hospital, Heidelberg, Germany. 6. The Fetal Heart Program, The Children's Hospital of Philadelphia, Philadelphia, PA. 7. Department of Obstetrics and Gynecology, University Hospital, Heidelberg, Germany.
Abstract
BACKGROUND: Access to prenatal care can be challenging due to physician shortages and rural geography. The multiple prenatal visits performed to collect basic fetal measurements lead to significant patient burden as well. The standard of care tools for fetal monitoring, external fetal heart rate monitoring with cardiotocography, as used today, must be applied by a medical professional in a healthcare setting. Novel tools to enable a remote and self-administered fetal monitoring solution would significantly alleviate some of the current barriers to care. OBJECTIVE: To compare maternal and fetal heart rate monitoring data obtained by 'Invu system' (a wireless, wearable, self-administered, fixed-location device containing passive electrical and acoustic sensors) to cardiotocography, toward a true remote fetal monitoring solution. MATERIALS AND METHODS: A prospective, open-label, multicenter study evaluated concurrent use of Invu and cardiotocography in pregnant women, aged 18 to 50 years, with singleton pregnancies ≥32+0 weeks' gestation (NCT03504189). Simultaneous recording sessions from Invu and cardiotocography lasted for ≥30 minutes. Data from the 8 electrical sensors and 4 acoustic sensors in the Invu belt were acquired, digitized, and sent wirelessly for analysis by an algorithm on cloud-based servers. The algorithm validates the data, preprocesses the data to remove noise, detects heartbeats independently from the two data sources (electrical and acoustic), and fuses the detected heartbeat arrays to calculate fetal heart rate (FHR) and maternal heart rate (MHR). The primary performance endpoint was Invu FHR limit of agreement within ± 10 beats per minute (bpm) of FHR measured with cardiotocography. RESULTS: A total of 147 women were included in the study analysis. The mean (SD) maternal age was 31.8 ±6.9 years, and the mean gestational age was 37.7 ±2.3 weeks. There was a highly significant correlation between FHR measurements from Invu and cardiotocography (r = 0.92; P<0.0001). The 95% limits of agreement for the difference, the range within which most differences between the two measurements will lie, were -8.84 bpm to 8.24 bpm. Invu measurements of MHR were also very similar to cardiotocography and were highly significantly correlated (r = 0.97; P<0.0001). No adverse events were reported during the study. CONCLUSION: Although captured by very different methods, the FHR and MHR outputs wirelessly obtained by the Invu system through passive methods were very similar to those obtained by the current standard of care. The limits of agreement for FHR measured by Invu were within a clinically acceptable ± 8 bpm of cardiotocography FHR. The Invu device uses passive technology to allow for safe, non-invasive and convenient monitoring of patients in the clinic and remotely. Further work should investigate how remote perinatal monitoring could best address some of the recent challenges seen with prenatal care and maternal and fetal outcomes. CLINICAL TRIAL INFORMATION: Registration date: April 20, 2018; First participant enrollment: February 28, 2018; ClinicalTrials.gov registration NCT03504189; https://clinicaltrials.gov/ct2/show/NCT03504189.
BACKGROUND: Access to prenatal care can be challenging due to physician shortages and rural geography. The multiple prenatal visits performed to collect basic fetal measurements lead to significant patient burden as well. The standard of care tools for fetal monitoring, external fetal heart rate monitoring with cardiotocography, as used today, must be applied by a medical professional in a healthcare setting. Novel tools to enable a remote and self-administered fetal monitoring solution would significantly alleviate some of the current barriers to care. OBJECTIVE: To compare maternal and fetal heart rate monitoring data obtained by 'Invu system' (a wireless, wearable, self-administered, fixed-location device containing passive electrical and acoustic sensors) to cardiotocography, toward a true remote fetal monitoring solution. MATERIALS AND METHODS: A prospective, open-label, multicenter study evaluated concurrent use of Invu and cardiotocography in pregnant women, aged 18 to 50 years, with singleton pregnancies ≥32+0 weeks' gestation (NCT03504189). Simultaneous recording sessions from Invu and cardiotocography lasted for ≥30 minutes. Data from the 8 electrical sensors and 4 acoustic sensors in the Invu belt were acquired, digitized, and sent wirelessly for analysis by an algorithm on cloud-based servers. The algorithm validates the data, preprocesses the data to remove noise, detects heartbeats independently from the two data sources (electrical and acoustic), and fuses the detected heartbeat arrays to calculate fetal heart rate (FHR) and maternal heart rate (MHR). The primary performance endpoint was Invu FHR limit of agreement within ± 10 beats per minute (bpm) of FHR measured with cardiotocography. RESULTS: A total of 147 women were included in the study analysis. The mean (SD) maternal age was 31.8 ±6.9 years, and the mean gestational age was 37.7 ±2.3 weeks. There was a highly significant correlation between FHR measurements from Invu and cardiotocography (r = 0.92; P<0.0001). The 95% limits of agreement for the difference, the range within which most differences between the two measurements will lie, were -8.84 bpm to 8.24 bpm. Invu measurements of MHR were also very similar to cardiotocography and were highly significantly correlated (r = 0.97; P<0.0001). No adverse events were reported during the study. CONCLUSION: Although captured by very different methods, the FHR and MHR outputs wirelessly obtained by the Invu system through passive methods were very similar to those obtained by the current standard of care. The limits of agreement for FHR measured by Invu were within a clinically acceptable ± 8 bpm of cardiotocography FHR. The Invu device uses passive technology to allow for safe, non-invasive and convenient monitoring of patients in the clinic and remotely. Further work should investigate how remote perinatal monitoring could best address some of the recent challenges seen with prenatal care and maternal and fetal outcomes. CLINICAL TRIAL INFORMATION: Registration date: April 20, 2018; First participant enrollment: February 28, 2018; ClinicalTrials.gov registration NCT03504189; https://clinicaltrials.gov/ct2/show/NCT03504189.
Authors: Dennis Ryu; Dong Hyun Kim; Joan T Price; Jong Yoon Lee; Ha Uk Chung; Emily Allen; Jessica R Walter; Hyoyoung Jeong; Jingyue Cao; Elena Kulikova; Hajar Abu-Zayed; Rachel Lee; Knute L Martell; Michael Zhang; Brianna R Kampmeier; Marc Hill; JooHee Lee; Edward Kim; Yerim Park; Hokyung Jang; Hany Arafa; Claire Liu; Maureen Chisembele; Bellington Vwalika; Ntazana Sindano; M Bridget Spelke; Amy S Paller; Ashish Premkumar; William A Grobman; Jeffrey S A Stringer; John A Rogers; Shuai Xu Journal: Proc Natl Acad Sci U S A Date: 2021-05-18 Impact factor: 11.205