Fig 1.
Wireless fetal monitoring prototype technology.
Components illustrated include (from left to right): 1. Data gateway device (Android tablet) with fetal cardiotocograph output demonstrated on monitor. 2. Doppler monitor for assessing fetal heart beat attached with elastic strap to a model of a pregnant woman.
Fig 2.
Components of the wireless fetal monitoring prototype technology [7] (from left to right):
1. Wireless Sensing Hardware represents the prototype technology as created by West Health Institute. This is capable of sensing fetal heartbeat and uterine contractions, digitizing the single, and transmitting this signal via Bluetooth technology. 2. The Gateway represents a smartphone or tablet device with operating system 4.2.1 or greater and capable of running a customized software application. The application on the device allows visualization of the fetal cardiotocograph in real-time, and submission of this data via the Internet to a web portal and user interface.
Table 1.
Characteristics of Study Participants.
Fig 3.
Illustration of steps required for submission of a completed monitoring session.
In panel A, step 1 involves hitting the save button. In panel B, step 2 requires the user to confirm completion of the session. In panel C, the user must then hit “Submit “to complete step 3. In panel D, the screen with “Uploading Data” confirms submission is complete. In our experience step 3 was the most often missed step, as there is no prompt to hit the “Submit” button at this stage. This miss-step was correctable with further training and practice with the application.
Fig 4.
Examples of cardiotocographs obtained with the prototype technology.
Panels A and B show (from top to bottom) fetal heart rate, maternal heart rate, uterine tone and contractions. The fetal cardiotocograph in panel A received a mean score of 5 on readability. The fetal heart rate depicted is continuous with no breaks and loss of contact allowing easy interpretation of the baseline heart rate and to assess for increases and decreases in heart rate. Panel B shows a fetal cardiotocograph that received a mean score of 1.7. Here lack of a continuous heart rate tracing prevents interpretation of the fetal heart rate at all times. For example it is hard to distinguish if gaps in the tracing represent decreases, increases or no change in the baseline fetal heart rate.
Table 2.
Acceptability of the wireless fetal monitor.