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Written by Sarah Bond
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Tuesday, 29 December 2009 15:01 |
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SleepSense was the first to implement a small bump into the design of the Piezo Snore Sensor that is placed on the skin during sleep diagnostic studies. This design feature ensures that even if the sensor's attachment on the skin loosens during the night, and much of the sensor's body doesn't touch the sink, the bump will continue to make contact with the skin and send snoring vibrations and sounds straight to the central of the crystal disk, which is the most sensitive part of the crystal.
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Written by Sarah Bond
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Tuesday, 29 December 2009 14:58 |
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Plastic films with Piezo-electric properties were first produced over 15 years ago, and are used in many types of sensors. As with Piezo Crystal Sensors, it is important that Piezo Film is isolated fromt he environment as much as possible, however Piezo Film can not be enclosed in a rigid box.
The SleepSense Piezo Film Sensor is totally flat under low tension, which results ina more accurate output, even when the belt is not tight around the body.
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Written by Sarah Bond
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Tuesday, 29 December 2009 14:54 |
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The most important design aspect of a truly effective Piezo Effort Sensor is to protect the Piezo active element from any interference that might degrade the signal and produce artifacts.
SleepSense designed the first Piezo Crystal Effort Sensor that literally suspends the Piezo Crystal element within a durable black box so that it is 'floating' without touching any walls of the box. SleepSense Piezo Effort Sensors are so well iolated within the small black box that a person can literally walk ont he sensor, re-install it, and it will work with no problems at all.
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Written by Sarah Bond
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Tuesday, 29 December 2009 14:46 |
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A properly designed sensor aims at achieving the best possible SNR (signal to noise ratio) by carefully designing out as many noise sources as possible, while maintaining good response to as many components of the desired signal as possible.
SleepSense sensors are designed to eliminate as much noise as possible by accounting for movement artifacts, noise from static charges generated by friction against bed linen, cable movement noise, and many other artifacts providing a clean, reliable signal reading throughout the night.
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Written by Sarah Bond
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Tuesday, 29 December 2009 14:42 |
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Why are inductive bands more accurate than piezo effort bands?
Inductive bands can be more accurate than Piezo bands because inductive bands produce an output that is proportional only to changes int he area enclosed by the wire loop. Piezo sensors on the other hand, produce an output proportional to the tension in an elastic band strapped around the body. The tension depends on many factors, such as the placement of the band, initial tension, slipping of the band, locking of parts of the elastic band under the weight of a patient, and many more - all of which produce errors and artifacts.
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Section Blog
