# Compensation of Measurement Uncertainty in a Remote Fetal Monitor
## 3 Uncertainty Estimation Approach
### Experimental Clinical Studies  
During experimental tests, several fetal monitoring instruments, in remote sites, were connected to patients and sent data signals to the OMC based at the Central Hospital. The patients were informed about their data usage and consented to publish their data for research purposes.  
Data collected at OMC were primary signals without processing, that is, directly from the analog-digital converter of the instrument. For each test, a set of data with fetal heart rate and signs of uterine activity was stored. Table 1 shows the clinic studies in detail, to validate the proposed approach.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Patient Name** & **Age (Year)** & **Studies Number** & **Place** & **Distance from OMC** \\ \hline Subject 1 & 37 & 42 & Toliman & 81.7 Km \\ Subject 2 & 41 & 45 & Jalpan de Serra & 187 Km \\ Subject 3 & 35 & 40 & Queretaro & 9.1 Km \\ Subject 4 & 26 & 43 & Amelaco de Bonfil & 71.1 Km \\ Subject 5 & 43 & 32 & Queretaro & 9.4 Km \\ Subject 6 & 18 & 34 & San Luis Potosi & 215 Km \\ Subject 7 & 28 & 36 & Queretaro & 10.7 km \\ Subject 8 & 31 & 38 & Queretaro & 18.3 Km \\ Subject 9 & 19 & 43 & Colima & 576 Km \\ Subject 10 & 21 & 47 & Queretaro & 13.5 Km \\ Subject 11 & 39 & 51 & Queretaro & 30.4 Km \\ Subject 12 & 42 & 53 & Queretaro & 13.1 Km \\ Subject 13 & 29 & 54 & El Marques & 7.1 Km \\ Subject 14 & 33 & 57 & El Marques & 6.8 Km \\ Subject 15 & 36 & 58 & Salamanca & 89.7 Km \\ Subject 16 & 25 & 58 & Puebla & 329 Km \\ Subject 17 & 42 & 58 & Guadalajara & 378 Km \\ Subject 18 & 45 & 61 & Queretaro & 2.1 Km \\ Subject 19 & 38 & 75 & Queretaro & 17.4 Km \\ \hline \hline \end{tabular}
\end{table}
Table 1: Clinical Studies for approach validation.  
Figure 6: Scheme of the fetal monitor used for testing.  
Experimental tests were conducted in the State of Queretaro. In the first stage, health care professionals of a Women and Child hospital in the city of Queretaro assessed patients. Patients were trained to handle the equipment at home, to step by step visualize data on the fetal monitor screen, and even to place two sensors on the abdominal region of the patient. One sensor measures the fetal heart rate, and the other measures the uterine activity of the patient. In the second stage, experimental tests for the fetal monitor were conducted with patients from remote sites. Data generated by each patient were sent to an OMC in the city of Queretaro. The locations of patients transmitting their records were in many different areas of the State of Queretaro, or in places nearby the State.  
Distances from these sites to the OMC were 180 Km on average. Nineteen patients were evaluated, with around 40 studies for each patient. The number of measurements for each clinical study was 900, on average, to prove the approach proposed in this work, providing measurement reliability for fetal heart rate and uterine activity. Figure 7 shows some images of the sites where tests were conducted.  
Samples for each medical device were received and stored at OMC. The objective at this stage was to generate a database of unprocessed signals, containing bioelectrical perturbations, to implement and to validate the proposed methodology. Only fetal heart rate signals were processed.