Lunar Astra

The Lunar Astra is a bone densitometer that measures bone mineral density and body composition (lean and fat tissue mass) using dual-energy X-ray absorptiometry (DXA). It is intended for use by medical professionals to assess bone health, fracture risk, and body composition in pediatric, adult, and elderly patients across multiple anatomical sites including spine, femur, forearm, hand, and total body.

The Lunar Astra uses a 76 kV/3.5 mA X-ray tube with cerium K-edge filter (vs. 100 kV/2.5 mA with samarium filter in the primary predicate), resulting in lower skin entrance doses (72 μGy for spine vs. 146 μGy). It employs a CdTe detector with 1.2×1.2 mm pitch, omits a mechanical shutter, includes an internal QA block, supports 525 lb patient weight, and offers e-Delivery of software. Basic acquisition, scan modes, and analysis algorithms remain functionally equivalent to predicates.

Not stated in this summary.

The Lunar Astra is substantially equivalent to the Lunar iDXA (K052581) and enCORE version 18 (K191112) predicates because it retains the same fundamental DXA technology and core algorithms for computing BMD, BMC, and body composition. Hardware modifications (lower kV tube, adjusted detector pitch, internal QA block) are compensatory design changes that maintain the same precision and accuracy specifications. All indications for use are identical or expanded from the secondary predicate, and verification and validation testing confirmed equivalent safety and effectiveness.