An individual's cardiovascular health is important. The measurement of blood pressure (BP) can be performed nonintrusively during normal daily activities. A study was designed to estimate systolic BP by measuring pulse arrival time (PAT) nonintrusively. PAT was obtained nonintrusively to estimate each individual's BP while he or she worked at a computer. Electrocardiogram (ECG) was measured with a capacitive-coupled electrocardiogram (CC-ECG) system and photoplethysmogram (PPG) was measured using specially installed circuits in a computer mouse. PAT was calculated from CC-ECG and PPG, and compared to PAT measured by the standard method. Three individuals participated in this study. Results correlated well. An equation to estimate BP from the measured PAT was derived for each of three individuals during a training period. Estimated BP was compared with measured BP in a series of experiments under varied BP conditions. For each individual, the estimated BP followed the measured BP within a tolerable error range. This method was also used for long-term BP monitoring. Results showed that this method could be useful for monitoring BP for telemedicine and e-health.