Development and Evaluation of Non- Invasive Blood Pressure Monitor for Laboratory Rats

Abstract

Accurate blood pressure measurement in small laboratory animals is crucial for cardiovascular and pharmacological research. However, blood pressure monitors for laboratory rats are expensive and not locally fabricated. This study was conducted to develop and evaluate a low-cost, locally fabricated tail-cuff blood pressure monitoring system for laboratory rats. The device was developed using a high-sensitivity MPXHZ6400AC6T1 pressure sensor, an Arduino Uno microcontroller, a relay-controlled air pump, a solenoid valve, and an LCD unit for real-time visualization of systolic and diastolic readings. Pilot testing was performed on five adult Wistar rats under standardized laboratory conditions to determine the workability of the device. The developed tail-cuff system recorded a mean systolic blood pressure (SBP) of 135.4 ± 3.86 mmHg and a mean diastolic blood pressure (DBP) of 100.7 ± 3.42 mmHg, with consistent and reproducible results across trials. When compared with results obtained from a reference tail-cuff device and invasive methods reported in the literature, the developed system showed close alignment with invasive benchmarks. The minimal 5–7% deviation between the developed tail cuff and invasive methods indicates that the system provides valid readings while overcoming the overestimation tendencies observed in conventional tail-cuff systems. Overall, the findings confirm that the developed automated tail-cuff blood pressure monitoring system provides a stable, accurate, and reproducible non-invasive measurement technique for small animals. By integrating automated pressure control, precise sensing, wireless data handling, and digital signal optimization, the system successfully bridges the gap between invasive accuracy and non-invasive practicality