On July 1, 1980, U.S. Patent No. 4,210,141 issued to Raymond Brockman and William Nadeau on Hiccough Treatment Appliance:

The appliance for treating hiccoughs includes a container portion adapted to hold a quantity of liquid, a dispensing portion for dispensing the liquid, and a tongue-depressor portion adjacent the dispensing portion for projecting into the mouth of a person drinking liquid from the appliance to depress the person’s tongue while the liquid is being swallowed.

Twenty-one years later, on October 16, 2021, Italian Giancarlo Ciolfi received U.S. Patent No. 6,302,112 on a Device for Inducing a Prompt Recovery from Hiccoughs:

For most hiccoughs are a minor annoyance, but for some they can be much more than that. Take for instance Charles Osborne, who since an accident on June 13, 1922, hiccoughed nonstop for 68 years until they suddenly stopped in 1990 – a year before his death in May 1991.

Only about 76 US patents mention hiccoughs, while 2138 US patents mention hiccups, and 33 US mention both spellings.