To successfully integrate into our lives, the product or technology should effectively solve a problem – work when it’s needed – and remain almost invisible when not.
The perennial demand for smaller, quieter, less intrusive products requires ever more advanced technology and manufacturing processes. Compact components enable the creation of wearable technology, for instance, and the size reduction of fixed equipment, so that it is less obtrusive. Minimizing noise remains a primary focus, particularly for devices that are used frequently.
For the many products that use pumps, meeting these challenges is difficult. Conventional pump technologies (e.g. rotary vane, diaphragm) generate audible noise and vibration during use, as can be seen in the video to the right.
Therefore, historically, compromise has been unavoidable. Additional components were needed to minimize the noise and vibration, such as damping materials. This complicates assembly, adds cost and limits size.
Disc pumps, however, are silent.
The disc pump’s piezoelectric actuator sits at the core of the device; this is the equivalent of the motor in a conventional pump. Two specially-designed acoustic cavities sit either side of the actuator, in which a resonant standing wave is established.
The graph to the right shows the typical emission spectrum when running the disc pump at it’s maximal continuous power. As you can see, the fundamental operating frequency of 21kHz is above the limit of human hearing, making it an ideal choice for applications where discreet operation is important.
“One of the first questions I get asked when demonstrating the disc pump is: ‘Is it on yet?'” explains our Business Development Manager, John Watson. “Before joining The Lee Company, I was selling motor driven, piston & rotary vane pumps and a common complaint was the noise and vibration – with the disc pump, neither of these are an issue”.
Ambulatory Blood Pressure Monitoring Cuffs
During a 24 hr observation with a current ABPM, blood pressure is measured at regular intervals during the day and night as patients go about their business. This can provide a clear picture of how blood pressure changes throughout the day – outside of a clinical setting.
However, the noise and vibration of current ABPM cuffs can be unsettling for the patient, disturbing everyday activities including sleep. This disruption can also trigger the ‘white-coat hypertension’ effect at home, reducing the effectiveness of the monitoring cuff.
With the disc pump… in an ABPM cuff there is no noise or vibration on inflation/deflation, so the cuff can function with minimal disruption to the patient, collecting more accurate data.
Air Quality Monitoring
Tightening legislation and the growing global focus on air quality, worker safety, and environmental emissions is driving the requirement for a new generation of measurement and monitoring systems, from gas samplers and detectors, to laboratory analyzers and particle counters.
However, current monitoring systems can generate noise levels that are disruptive – particularly where these systems are used continuously in an internal setting (e.g. office space). Increased noise levels may also mask other systems issues.
With the disc pump… the operational noise of a pump is taken out of the equation, with no need to include dampening hardware, enabling the design of smaller, more sensitive and discreet monitoring systems.