An embolic protection device includes a first filter configured to be disposed in a first vessel and a second filter configured to be disposed in a second vessel. At least certain areas of at least two successive images of the image signal are compared to each other after the transmission, and if a difference is found between the noise patterns contained in the images, it is concluded that the images have been transmitted successfully even if the image content of the images is identical. , each m may be same or different and is 0 or 1, n is an integer of 1 to 3, q1 is an integer of 1 to 2n4, q2 is an integer of 0 to 2n3, and the sum of q1 and q2 is 2n4 or a salt thereof. The membrane is suspended in the body of water by a float. The methods and systems may include sending a code that is provided by during the transaction and verifying that the code provided matches with the code sent by the remote server.