Piezo Ultrasound Transducers for Blood Flow Monitoring

During surgery, it is critical that the surgeon has real time evaluation of blood vessels in order to make assessments related to the flow of blood. Piezo transducers are at the core of modern blood flow monitors.

The piezo effect (generation of electric charge under pressure, or mechanical deformation when an electric field is applied) is found in some natural materials, such as quartz, but much better performance is achieved with special Piezo ceramic materials such as PZT (Plumbum Zirconate Titanate).

Modern piezo transducers can emit and detect high frequency sound (often in the range of 5 to 10 MHZ), when used with special electronic amplifiers. Ultrasound pulses from the probe placed near the vessel, bounce off the blood and, with the help of the Doppler Effect, can give an accurate measure for the flow velocity of the blood or just an audio signal equivalent to the flow.

PI Ceramic provides different Piezo formulations for specific applications.

PIC255 material is recommended for use in Doppler applications for these reasons:

  • High permittivity
  • High coupling factors
  • High charge constant
  • Low mechanical quality factor

More information on piezoelectric materials

 

The Doppler Effect

The Doppler Effect can be used to measure the flow rates or flow velocities of liquids, suspended particles or air bubbles. After the transducer emits an ultrasonic pulse, the ultrasonic waves (f0) are scattered or reflected by liquid particles. The resulting frequency shift of Δf between the transmitted and reflected wavefront (one transducer can be operated as transmitter/receiver) is proportional to the flow velocity vS of the particles. The angle θ between the direction of the emitted ultrasonic pulse and the measuring path must be taken into account:

The flow direction is also determined by the frequency change – higher frequency means particles approaching the receiver, lower frequency means the particles move away from the sensor. This effect is well known from a train sounding its whistle while approaching or leaving a crossing.

Medical Applications – Why Working with an Experienced Piezo Materials Manufacturer Is a Benefit

Since devices for critical medical application are FDA approved, long-term reliability and consistent performance of all components are essential for production. PI Ceramic can provide consistent batch to batch performance in small form factors such as plates or discs with specialty electrode configurations for easy probe integration, and value-added assemblies.

Consistency is based on our complete control of the piezoceramic manufacturing process from raw materials to final quality assurance, including strategic stocking of all critical materials. With 350 employees dedicated solely to manufacturing the highest quality PZT components on the market, we set the tone for your acoustic flow monitoring application.


Product Overview


More Reading

Nanopositioning Systems for Medical Technologies

Flexible Piezo Transducers find Applications in Structural Health Monitoring, Contouring, and Sound Cancellation

Ultrasound Generation: What is the difference between Multilayer Piezo Transducers and Conventional Piezo Transducers

Piezo Transducers, Actuators, and Motor Drive Solutions for Medical Engineering

PI Ceramic - Cardiovascular Surgery

Ultrasonic Ablation Using Piezo Catheters

Minimally invasive catheter solutions are used for treating cardiovascular diseases such as arteriosclerosis or atrial fibrillation: Ultrasound generated with piezo elements can be used without contact in the smallest space for a gentle treatment.

Sensor Devices

Sensor Devices

Sensor technology in industrial production is becoming especially important in conjunction with digitalization and Industry 4.0. Since ultrasound is a versatile instrument in measuring and monitoring various processes and procedures, such sensors are very sought after in the industry.

Generating Ultrasound with Piezo Components

Generating Ultrasound

Piezo components use the piezoelectric effect to generate and detect ultrasonic waves, e.g. by means of runtime measuring or the principle of the Doppler effect.

Ultrasound for Industrial Automation

PI piezo expert and Field & Technical Sales Engineer Alexander Conrad explains why piezo-based ultrasound transducers are perfekt for industrial applications. Object recognition, structural monitoring, distance and acceleration measurement all benefit from the advantages of piezo technology.

Piezo Transducers: Sensing, Ultrasound

Therapeutic Ultra Sound Piezo Transducers

Subscribe to Tech Blog

Sign up to receive an email of new blog posts.

Please read the following and confirm your consent to the processing of your data.

By submitting this form, you consent to the PI Group contacting you through the communication channels you specify. Additionally, you acknowledge that the PI Group may store, process, and analyze the necessary data.

For further information, see our >> Privacy Policy.

Each email includes an unsubscribe link that allows you to withdraw your consent.

Privacy Policy*