Abstract: [Problem] To provide means for detecting heart failure more simply and highly accurately. [Solution Means] A method of detecting heart failure from a sample collected from an organism, the method comprising the step of: performing sandwich immunoassay of NT-proANP or a fragment thereof contained in the sample using a first antibody for capturing for which an epitope lies on any site among positions 31 to 67 of an amino acid sequence of NT-proANP and a second antibody for labeling for which an epitope lies on any site among positions 31 to 67 of the amino acid sequence of NT-proANP, and the like. The epitopes of the two types of antibodies: one for capturing and the other for labeling, both of which lie among positions 31 to 67 of the amino acid sequence of NT-proANP.

Abstract: Provided herein is a method for filling a functional liquid droplet ejection head with functional liquid. The method includes: initially filling functional liquid channels and intrahead channels included in the functional liquid droplet ejection head with a functional liquid by introducing functional liquid from a functional liquid tank through the functional liquid channels to the functional liquid droplet ejection head used in an inkjet mode; and passing cleaning liquid into the functional liquid channels and the intrahead channel included in the functional liquid droplet ejection head prior to the initially filling.