1. A method of cufflessly and non-invasively measuring wrist blood pressure in association with a communication device, the method comprising: (a) detecting an electrocardiogram (ECG) using an ECG sensor, detecting infrared pulse waves using an infrared sensor, and detecting pressure pulse wave signals using a pressure sensor, the ECG, infrared pulse waves and pressure pulse waves being detected from a wrist region of a user; (b) detecting feature points from the ECG, the infrared pulse waves and the pressure pulse wave signals detected in (a) from the user; (c) extracting variables for calculating a highest blood pressure and a lowest blood pressure by applying the feature points detected in step (b) to a blood pressure calculation algorithm; and (d) calculating the highest blood pressure and the lowest blood pressure of the user by deducing a scatter diagram using the extracted variables and compensating using absolute pressure to correct a magnitude of a detected pulse after comparing the infrared pulse wave signals to each other to obtain a vector component to search for a measured position and depth of an artery; and transmitting the calculated data to a portable communication device.