Opthalmic Ultrasound Probes Controlled Through Magnetic Fields

Opthalmic Ultrasound Probes Controlled Through Magnetic Fields

 A new 50-MHz, high-frequency ultrasound biomicroscope (UBM) ophthalmic probe now includes an advanced magnetic transducer.

The scanning motion in the ultrasound is controlled through magnetic fields instead of mechanical movements as in earlier versions.

This new technology offers a faster scanning process, which has increased the image resolution by one-third. Further advantages include a lighter-weight design and less vibration when performing an ultrasound, decreasing user fatigue. The probe’s durability and effectiveness is also improved by eliminating mechanical components.

Quantel Medical (Clermont-Ferrand, France; www.quantel-medical.com) has introduced two new diagnostic ultrasound probes to their flagship ultrasound platform, Aviso, at the American Society of Cataract and Refractive Surgery annual meeting, held April 2013 in San Francisco (CA, USA). The new probes provide enhanced diagnosis capability for posterior and anterior segment ophthalmic conditions.

The new 10 MHz B-scan probe offers similar benefits for posterior pole diagnosis. This B-scan probe provides superior image quality for viewing and assessment of the detailed structures in the vitreous and the orbital wall.

Increased image acquisition rate allows for high-definition characterization of ocular structures and their movements. The dynamic gain functionality of the 10 MHz allows users to adjust settings to find the optimal tissue differentiation in the image, allowing for more visual clarity and better determination of the condition of the eye.

“These two product introductions reflect Quantel’s commitment to developing the most robust and advanced ultrasound technology available to ophthalmologists,” stated Mr. Jean-Marc Gendre, CEO of Quantel Medical. “Image quality and ease of acquisition are two critical features that we strive to improve and provide to our customers.”

The Aviso ultrasound platform is configurable to include the new 50-MHz and 10-MHz probes, as well as biometry and Standardized echography modules. Quantel Medical’s range of posterior and anterior segment ultrasound diagnostic systems provide eye-care physicians of all specialties with a critical tool for determining pathology and obtaining accurate measurements.

Testing Tiles Designed for Ultrasound Treatment of Soft Tissue Injuries

Testing Tiles Designed for Ultrasound Treatment of Soft Tissue Injuries

A new application could help improve the quality of ultrasound treatment for soft tissue injuries such as ligament damage and muscle strains.

Ultrasound is commonly used in physiotherapy to hasten healing of tissue injuries. Ideally, the sound waves should be applied uniformly tothe treatment site, but it is well known that this does not occur typically in practice. This can affect quality of treatment and even  cause damage.

The UK National Physical Laboratory (NPL; Teddington, UK; www.npl.co.uk) has developed a way to quickly map the distribution and intensity of ultrasound, allowing treatment heads to be used to administer the treatment more effectively. The application will signal physiotherapists to sharp “hot-spots,” allowing them to move the head to smooth the intensity or discard it where it could cause more harm than good. It also has potential for manufacturers, who could rapidly evaluate the effect that design alterations have on the intensity distribution.

Piezoelectric-based treatment heads, during treatment, transform electrical energy to mechanical energy, creating the vibrations needed to produce the ultrasound waves. These are transmitted into the target tissue with the aid of a thin layer of coupling gel. The treatment heads actually vibrate in a complex pattern, partly because of the fact that they are extremely resonant devices. This leads to variations in acoustic pressure and acoustic intensity over the treated region, resulting in “hot-spots,” which can cause over-heating and even damage to the tissue. Without carrying out the complicated and time-consuming process of mapping the acoustic field, it is very difficult to know precisely where the acoustic energy is going.

NPL scientists have devised an answer to this hurdle by developing a simple tool to help visualize the distribution and intensity of the acoustic energy. The approach works by using crystals that are thermochromic (in that they lose their color when heated up above a specific trigger temperature). Importantly, the effect is reversible; the crystals regain their original color on cooling.

The tool consists of two-layers; the bottom layer comprises of the thermochromic crystals encapsulated in a polyurethane rubber matrix, which absorbs sound. The top layer is colorless and is employed to capture the heat within the tile. The tile heat generated by the acoustic energy is quickly and evenly trapped, and the crystals turn white as they reach the trigger temperature. This then produces a pattern on the tile, which represents the temperature distribution generated by the treatment head, which in turn relates to the spatial distribution of the acoustic intensity. The pattern can be clearly visible after only 10 seconds of exposure to the ultrasound.

Bajram Zeqiri, an NPL science fellow who led the project, described how you would test an ultrasound treatment head with the tiles. “In clinical practice the new ‘imager’ tiles would be used in much the same way you would treat a patient: by applying coupling gel to the treatment head, coupling it to the tile, switching on for typically 10 seconds, and then removing and observing the resulting image.”

The tiles can be used to quickly monitor for treatment head damage, asymmetric beam-patterns (hot-spots), and more simply to validate whether the devices are actually working at all. The capability to gain comparatively complicated data from a simple and cost-effective device, in such a short period of time, should help improve the quality of physiotherapy ultrasound treatments.