PMUTs (Piezoelectric micromachined ultrasound transducers) represent a promising technology to transform medical diagnosing beyond point-of-care. The ultrasonic diagnostics market is estimated to double in the coming decade. We will see a transformation from general instrumentation with bulk piezoelectric ceramic transducers into specialized ultrasonic medical devices. These smart devices provide more focused information in tailored form. PMUT-technology enables low-power, miniature devices which help to distribute medical diagnostics and monitoring into homes, away from the hospital setting but also enabling novel miniaturized professional use precision instruments. Expansion of the medical grade monitoring beyond the point-of-care benefits the patients and health care providers.
PMUT technology introduction
PMUT operation is based on the piezoelectric effect, where mechanical stress on thin-film membrane generates an electrical charge and vise-versa. VTT designs state-of-the-art pMUT transducers and develops MEMS-processes based on sputtered AlN or ScAlN piezoelectric thin films in cavity Silicon-On-Insulator or surface micromachined structures. PMUT optimized process flow is CMOS compatible (AlN) and can be transferred to 3rd party foundries.
PMUTs combine several key advantages: low power, low voltage, wide frequency range (50 kHz to 50 MHZ), small size and extreme ease of array assembly. With this combination of properties, the whole transducer system can be integrated into a wide range of miniature formfactors suitable for specialized medical devices.
Medical applications for miniature ultrasound transducers
Devices with tiny size and low power consumption can be manufactured into patches, wearables, implantable devices, or probes, like a catheter, that monitor specific conditions. Continuous monitoring enables quick intervention as physicians have access to real-time and trustworthy data provided by these ubiquitous devices.
The human body is an exceptionally good conductor for 1 MHz to 50 MHz ultrasound signals. PMUTs excel in this frequency range where propagating signals are minimally invasive and provide valuable information about tissue movement, permeability, and structure.
Actively scanning PMUT provides quick response times allowing applications in gastronomic and cardiovascular monitoring fields. Low-power PMUT monitoring devices can record long-term data on tissue changes i.e., inflammation, edema, body composition or wound healing. Health parameters like flow, permeability, blood pressure and clot detection are a possibility. A lower frequency PMUTs interfaced with air can measure the air flow or the patient's movement.
Transformation to ubiquitous health care
The upcoming transformation will improve life and health care for everyone through emerging applications. Devices will measure different types of conditions like real-time blood pressure, wound healing and body composition. Ubiquitous monitoring with ultrasound will provide a way to observe chronic conditions and predict treatment outcomes. Long-time monitoring with smart devices enables early interventions. Early treatments reduce the financial and emotional burden caused by untreated progressing conditions.
In summary, medical devices with PMUTs help to revolutionize the way we treat chronic conditions. By making medical diagnostics easily available, in-time health care can be accessible for billions of people.
