Net Time Delay (NTD) Technology
UltraScan™ 650 relies on CyberLogic’s patented NTD technology, which is based on measuring transit times of ultrasound signals propagating through the forearm, and allows direct measurement of the amount of bone. The NTD has been validated with computer simulations, in vitro studies, and clinical data, and represents a completely distinct approach to processing of ultrasound data.
Bone mineral density (BMD) is the most important factor in determining the risk of osteoporotic fracture. The UltraScan™ 650 provides a direct evaluation of BMD. A clinical study conducted at Columbia University shows that its output, BMDUS, is highly correlated (r = 0.931) with x-ray based (DXA) measures of BMD. BMDDXA has‒‒until now that is‒‒been the “gold standard” for bone assessment.
In contrast, other bone sonometer products on the market utilize conventional measurement parameters such as the speed of sound (SOS) and broadband ultrasound attenuation (BUA). These parameters are only weakly correlated with BMD and thus these products perform very poorly in identifying individuals with osteoporosis. A summary of the relevant studies are provided here. The figure below compellingly demonstrates that the NTD technology employed by the UltraScan™ 650 not only possesses a high level of accuracy comparable to that of DXA, but its accuracy is also significantly superior to that of traditional BUA and SOS measurement methods.
A number of papers and patents related to the NTD technology can be found in the References. Specifically, a summary of the key clinical data can be found in: (A comprehensive paper summarizing the performance of the UltraScan 650 in a clinical trial can be found in our publication by Stein et al. in Ultrasound in Medicine & Biology.) The simulation and in vitro data can be found, respectfully, at: "Ultrasound Simulation in Bone" and "Ultrasonic Assessment of the Radius in vitro".
1/3 RADIUS
The UltraScan 650 utilizes the 1/3 radius for determination of BMD. The 1/3 radius has been used for over 5 decades by x-ray methods (SPA, DPA, SXA, DXA) and is well-established as a useful anatomical site for bone assessment and osteoporotic fracture risk determination. It is also an extremely convenient site, and generally requires nothing more than rolling up one’s sleeve. The figure shows the two bones of the forearm (radius and ulna) as well as the cross section of the radius. Note that the UltraScan 650 is the only through-transmission ultrasound device approved in the U.S. for measurement at the 1/3 radius, and the only one approved by the FDA for measurement of BMD.
FOREARM POSITIONING TECHNOLGY
The UltraScan 650 incorporates patented positioning technology, which makes for both reproducible and accurate measurement of BMD at the 1/3 radius. Whereas conventional ultrasound measurements of the heel lead to great variations in results because of the difficulty in re-positioning, the UltraScan 650 can be respositioned extremely accurately. In addition, standard DXA requires significant technician interaction in terms of processing the data; in contrast, the UltraScan 650 does not require nor does it permit any user interactions with data processing.
UltraScan 650 BMDUS™ Technology
Device Description:
The UltraScan 650 is an ultrasound device that is designed to non-invasively and quantitatively assess the amount of bone at the 1/3 location of the radius in the forearm of an individual. The UltraScan 650, with a user-supplied laptop, is designed for the measurement of bone mineral density (BMD in g/cm2) of the radius at the 1/3 location. The UltraScan 650 outputs BMDUS which is a measurement of the BMD that would be measured by dual-energy X-ray absorptiometry (DXA) at the same anatomical location, that is, a measurement of BMDDXA, at the 1/3 radius. The UltraScan 650 also outputs the T-score in standard deviations (SD) and z-score in SD as well. The precision of the measurement is 2.1%, when expressed as a coefficient of variation.
FDA-approved Indications for Use:
UltraScan 650 can be used to determine BMDUS Index in adult men and women. The BMDUS is a clinical measure based on ultrasound variables of the forearm which is highly correlated with the value of BMD of the 1/3 radius as provided by DXA, with a standard error of the measurement of 0.041 grams/cm2.
BMDUS is expressed in grams/cm2 and as a T- and z-score, derived from comparison to a normative x-ray absorptiometry reference database.
BMDUS has a precision comparable to that of x-ray absorptiometry, which makes it suitable for monitoring bone changes in postmenopausal women.
The UltraScan™ 650 is a through-transmission system and is designed to measure the radius at the 1/3rd location (shown as the radius and ulna and the cross-section of the radius in the pictures above), a site that has been measured for decades with x-ray densitometers.
Innovation Summary
By combining patented NTD technology, a well-established measurement site, and robust positioning, UltraScan 650 enables DXA-equivalent bone assessment in a compact, radiation-free system. Its portability and ease of use support deployment in primary care and other frontline settings, helping to reduce under-diagnosis of osteoporosis and enabling earlier intervention to prevent fractures.