Ultrasonic Transducer 15mc: Radar Trainer
date: label: date made
content: c.1940s
label: date made
content: about 1949
name: label: Associated Name
content: Wild, John J.
label: Associated Name
content: Reid, John M.
label: Associated Name
content: Neal, Donald
label: Associated Name
content: University of Minnesota
label: Associated Name
content: National Cancer Institute
label: Associated Name
content: National Institutes of Health
label: maker
content: Paul Rosenberg Associates
notes: label: Description
content: This is a piezoelectric quartz crystal used as a transducer by Dr. John J. Wild during his experiments using ultrasound technology to image living human tissue. The term piezoelectricity means "pressure-electricity." When pressure is directed towards this type of crystal, the crystal in turn produces an electric signal. Conversely, when the crystal receives an electric signal, it produces pressure in the form of sound waves. The crystal can "send" and "receive" sound waves in this way. This makes the quartz crystal a transducer, or a device that converts mechanical signals into electrical signals. In the 1940s and 1950s many doctors, scientists, and engineers were looking for ways to record and translate these electrical signals into usable data for various medical procedures. This was the early development of ultrasound imaging. The earliest "images" were one-dimensional waves that measured time and amplitude. By the early 1950s scientists ued two-dimensional images that measured time and amplitude, and recorded location. John Wild and John Reid used this crystal and many others like it to develop multiple hand-held ultrasound imaging machines for their use in diagnostics.
label: Description
content: This particular crystal likely came from the Wold-Chamberlin Naval Air Station in Minnesota where Wild was working with Donald Neal in 1949 to investigate how radar technology could be used on human tissue. Wild claims these crystals came from the "junk" pile at the air base. The crystal emits a 15 megacycle frequency and was used while submerged in water to transmit the energy, which was necessary because the 15mc frequency does not transmit well through air. Water is an excellent transmitter for sound. The estimated value of this crystal in 1949 was about one hundred dollars. The device is very delicate.
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, New York
label: Associated Place
content: United States: Minnesota, Minneapolis, Wold-Chamberlain Air Base/Station
label: Associated Place
content: United States: Minnesota, Minneapolis
topic: label: Subject
content: Radar
label: Subject
content: Ultrasound
label: Subject
content: Medicine
label: Subject
content: Imaging
label: Subject
content: Diagnostic Equipment
label: Subject
content: Cancer
setName: label: See more items in
content: Medicine and Science: Medicine
creditLine: label: Credit Line
content: Gift of Ellen L. C. Wild and Valerie C. Wild
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2015.0300.02
label: model number
content: PRA23G
label: accession number
content: 2015.0300
label: catalog number
content: 2015.0300.02
objectType: label: Object Name
content: piezoelectric crystal
physicalDescription: label: Physical Description
content: metal (overall material)
label: Physical Description
content: quartz (overall material)
label: Measurements
content: crystal: 5/8 in x 5/8 in; 1.5875 cm x 1.5875 cm
label: Measurements
content: overall: 4 cm x 5.3 cm; 1 9/16 in x 2 3/32 in