Model 1020 Pulse Plethysmograph

The UFI model 1020 is a compact, flexible Pulse Plythsmograph (PPG) transducer. A matched infrared emitter and sensor allows the 1020 to detect small changes in the reflectivity and light conduction of the subject's skin and the tissue directly beneath it. These small changes are due largely to the inflow and outflow of blood associated with the beating of the heart. The Model 1020 can be used to record such pulsatile blood flow from fingers, toes, ears, the forehead, and other suitable body locations. The 1020 uses infrared excitation to reduce sensitivity to changes in ambient lighting.

Note that the use of an infrared light source means all 1020 models require an excitation voltage (approximately 5-9 Volts) for proper operation.

The three Model 1020 configurations

The standard 1020 transducer has a flat face and a permanently attached hook-and-loop strap. This transducer can be placed on a finger or other extremity and secured with the strap. The standard Model 1020 can also be attached to flat surfaces on the subject using surgical tape.

The 1020FC transducer is built into a comfortable finger clip fixture. A spring maintains light pressure to hold the finger inside the clip and the transducer against the finger. The black aluminum clip cover further reduces ambient light intrusion.

The 1020EC transducer uses a (blue) shell similar to the 1020-FC, but uses slightly tighter springs to permit easy attachment to a subject's ear lobe. The Model 1020EC may also be attached to other thin, loose portions of the skin. (Note that an older 1020EC design is shown in the top image.)

The sample data above was recorded from the finger of an adult male using our standard Model 1020. The UFI Model SRS2004/d performed the signal conditioning and data recording.

Model 1020 general specifications

• Signal source: infrared LED and photosensor with buffer
• Excitation: 6 to 9 volts DC at 20 milliamps nominal current
• Signal output: 10 to 50 millivolts (typical, finger application)
• Typical attachment: hook-and-loop strap (standard 1020)
• Standard lead length: 6 feet (180cm)
• Size: 0.6" x 0.6" x 0.25" (15mm x 15mm x 6.4mm) for standard Model 1020
• Weight: approximately 1 ounce (28g)

Interfacing your equipment with the Model 1020 is usually fairly simple, as this technical note describes. You may also want to read over these general guidelines for interfacing transducers with signal conditioners, especially if the topic is new to you.

Review a representative Model 1020 user manual

Published references to the UFI Model 1020