These high-frequency acoustic waves can do more.
Researchers have now 3-D printed a new kind of device that can harness high-pressure ultrasound to move, manipulate, or destroy tiny objects like particles, drops, or biological tissue at scales comparable with cells. By providing unprecedented control of photoacoustic waves – which are generated by lasers – such a device can be helpful for performing precise surgery, analyzing the properties of materials, and for scientific research in the lab, such as in the field of microfluidics.
This control is crucial. Previous devices could only produce basic kinds of acoustic waves – planar waves – which focus on a single point like the way a magnifying glass focuses light waves.
These devices, called laser-generated focused ultrasound transducers, work by converting laser pulses into vibrations. The key part of the transducer is a glass surface that acts like a lens. Laser pulses hit the glass surface, which is coated in a thin film of carbon nanotubes. The heat causes this coating to expand rapidly, which generates the vibrations needed to produce high-frequency and high-pressure acoustic waves. But because the substrate material is glass, it is limited to planar, cylindrical, or spherical shapes. More complicated shapes are difficult and expensive to make out of glass.
The new type of transducer also produces acoustic waves with high-frequency laser pulses. But instead of glass, the researchers used 3-D printers to make a lens out of clear liquid resin. By using a 3-D printer, they could create a lens of any shape, which allows them to generate acoustic waves of any shape. As a result, the researchers can focus the waves at multiple points at the same time or they can control the phase of the waves and focus the waves on different points at various times.
To make their transducer work, the researchers developed a new method to coat the clear resin by painting layers of polymer and carbon nanotubes at room temperature. Conventional methods like vapor deposition require high temperatures that would have melted the cured resin. Their proof-of-concept transducer generates a planar and focused wave at the same time, and it performs as well as a glass one. About two square centimeters in size, it costs only about two dollars to print.
By focusing waves at different points and times, the device can exert shear force and sort, isolate, and manipulate droplets, particles, or biological cells. It would be a powerful tool in microfluidics, for example, which requires strong, precise, and fast control of liquids. To that end, the researchers are now using 3-D-printed photoacoustic transducers to make actuators.
Indian Market Dynamics
The Indian ultrasound systems market in 2014-15 is estimated at 966 crore. In 2015-16, an 8–10 percent increase over 2014-15 is seen in all four segments: premium, high-end, mid-end, and entry level. Black-and-white systems continue to show a steady decline.
The major players are GE Healthcare, Philips, Siemens, and Toshiba. Other major brands aggressive in this segment are Mindray, Samsung, Carestream, Trivitron, Skanray, BPL, Hitachi, Konica Minolta, Blue Star, and Analogic Ultrasound (BK Medical). The portable segment is dominated by Sonosite, GE, Philips, Mindray and Esaote.
Some customers in 2015-16 include corporate chains as Fortis, Apollo, Medanta, Care Hospitals, Global Hospitals and YMC (Yashwantrao Mohite college of Arts, Science and Commerce) in Pune; large diagnostic centers as Amrita Institute of Medical Sciences, Kochi; and Dr Boopathy Vijayaraghavan, Coimbatore.
It seems that the high-end systems are finding greater use in applications as cardiology and OB/GYN, whereas the mid-level systems are being used more for radiology. 3D and 4D imaging is increasingly getting popular. Sound elastography, especially for whole body, is gaining traction. The use of ultrasound in other areas such as emergency medicine (EM), anesthesiology, and musculoskeletal applications has shown increasing use of this modality.
Wi-Fi connectivity, touch screen, battery backup for not just portable but also premium systems, are features increasingly being offered by most brands.
The strict implementation of the Prenatal Diagnostic Tests Act, which prevents deliberate abortion of female fetuses after determining the gender of the baby, is restraining the growth of this segment in India.
Central schemes such as Janani Suraksha Yojna and ASHA (accredited social health activist) have been launched to promote antenatal checkups and institutional deliveries for pregnant women living below poverty line in India where infant mortality is high. The central government spent Rs. 1300 crore under the scheme JSY by sponsoring 100 percent maternal expenditure of women under certain conditions. More ultrasound machines have been instrumental in ensuring good maternal health in such programs, although the utilization has been a meager 20 percent in public hospitals.
The steady influx of low-cost ultrasound machines due to reduced import duties and increased local production due to surge in demand and easily available technology has heightened competition pushing down the procurement cost in India, thus forcing major players to reduce their margins.
Innovative advances in high-resolution ultrasound now enable detailed anatomical characterization and accurate differentiation of benign from malignant disease. Ultrasound has become the core component of thyroid nodule guidelines, but it is important that the key technological aspects of the modality are understood and that challenges and limitations remain with the technique. The large evidence base for ultrasound elastography indicates that the assessment of nodule stiffness can improve the imaging evaluation of thyroid lesions and potentially avoid unnecessary FNAC/surgery for benign nodules, particularly if integrated with ultrasound classification. The potential for 3D and CEUS in thyroid nodule ultrasound has not yet been realized, but the emergence of these novel approaches is an illustration of the huge strides that have been made in the underlying ultrasound technology. Elastography shows promise for improving clinical outcomes in numerous applications. The technology has seen strong investment over the last 18 months as suppliers strived to develop a reproducible methodology. Whilst advances have been made, the technology still requires further refining for widespread use. Nevertheless, elastography has been shown to improve clinical outcomes in obstetrics and gynecology, breast imaging, and imaging of the liver.
Fusion ultrasound systems are also gaining interest. The use of ultrasound in conjunction with MRI and CT images improves diagnostic outcomes. Furthermore, growing interest in minimally invasive procedures has resulted in strong growth in the interventional ultrasound market. Advances in new software and connectivity to advanced visualization tools have streamlined fusion technology for radiologist's further driving adoption. This technology is projected to be one of the most important advances in premium ultrasound equipment over the next five years. Despite the high cost of premium ultrasound systems, the advanced features in these systems are important not only for some traditional applications such as obstetrics and gynecology, and cardiology, but perhaps also for the newer applications of breast imaging, interventional cardiology, and internal medicine. Commoditization is starting to occur in the core of the ultrasound market with many traditional specialties using midrange and high-end systems as a valuable standard in many disciplines.
Indian Market Dynamics is based on market research conducted by Medical Buyer in January 2016.