Case Studies

Ultrasonic sensors reduce patient recovery time

Morgan Electro Ceramics has been working with Deltex Medical in the development of its Oesophageal Doppler Probes, which are used in conjunction with the CardioQ haemodynamic status monitor. A disposable ultrasound probe is used to determine the amount of blood being pumped around the body (circulating blood volume) of patients during operations. Deltex Medical is the market leader in Oesophageal Doppler technology and numerous clinical studies have proven this technology to significantly reduce the length of hospital stay by 25-40% across a range of surgical specialities. 

West Sussex-based Deltex Medical has manufactured critical care devices for over 20 years and was looking for a partner who could design and manufacture the piezoceramic sensor that incorporates a transmitter and receiver for the CardioQ ultrasonic probe. The company became aware of Morgan Electro Ceramics because of its work in the development of innovative medical devices such as foetal heart monitors and the two have worked together to establish which material would be best suited to the application. 

“We worked closely with Morgan Electro Ceramics throughout the development of the product,” says Andy Mears, Operations Director, Deltex Medical. “The company’s extensive knowledge of ceramics was a great benefit to us.”

Morgan Electro Ceramics recommended its PZT5H piezo ceramic material for its mechanical and electrical properties, specifically its high dielectric constant and sensitivity. “The sensor uses time of flight measurement of the travelling ultrasound wave to measure the blood flow,” explains Tony Beswick, General Manager, Morgan Electro Ceramic.

The ceramic is fixed on the end of the probe, which has a diameter of approx 5mm, and is sleeved in a non-toxic, latex-free silicone rubber. It is inserted into the patients oesophagus either orally or via the nasal route and once in position the transmitted signal rebounds off blood flowing in the descending aorta. The signal is received by another piezoelectric ceramic, which converts the ultrasonic pulses back into an electrical signal. In order to produce a minimally invasive device the transmitter/receiver combination is made from a single piece of piezoceramic with wrap-around electrodes. The received signal is then digitised and displayed into a real time waveform on the CardioQ display.

“Virtually every patient undergoing surgery suffers from hypovolaemia (akin to severe dehydration),” explains Mr. Mears. “This is because of the combined effects of pre-operative starvation, the impact of the anaesthetic agents and trauma from the surgery itself. This leads to insufficient amounts of oxygen being delivered to the vital organs which can cause medical complications including peripheral and major organ failure.” Using fluids and drugs, guided by the CardioQ, to optimise the amount of circulating blood volume reduces post operative complications allowing patients to make a faster more complete recovery and return home earlier. 

“Morgan Electro Ceramics manufactures the PZT ceramic and assembles the probe components themselves on site,” says Mr Mears. “This has enabled a more efficient manufacturing process and allowed us to optimise the supply chain. 

Other applications of ceramic in medical devices include ultrasonic imaging and high power transmitters of high frequency waves that assist with surgical cutting procedures such as cataract removal. 

About Morgan Electro Ceramics
Morgan Electro Ceramics (MEC) has a comprehensive range of Piezoelectric and Dielectric materials from which many products are manufactured, including Transducers, Sensors, Actuators and High Voltage & RF capacitors. MEC has established an enviable reputation for providing value-added solutions through world-class research and development, innovative design and, perhaps most important of all, application engineering. 

As a subsidiary of The Morgan Crucible Company, MEC forms part of the Morgan Technical Ceramics Group. The Group includes Morgan Advanced Ceramics and from manufacturing locations in North America, Europe and Asia, it supplies an extensive range of products, including ceramic components, braze alloys, ceramic/metal assemblies and engineered coatings. 

For more information on Morgan Electro Ceramics contact us.