|This article, XM49 Caduceus Medical Battlfield Nanobot Dispenser, is currently under active construction.|
- "Three spikers in the arm, one in the abdomen, and burning defoliant from a flame grenade splashed across my chest. The medic pops the top, I feel this warm fuzzy feeling, and suddenly I've stopped bleeding. A pity about the numbness, but its not like I was going to do anything with that hand anyway."
- ―Anonymous Serviceman
Introduced in 2539, the XM49 Caduceus MBND is a small reusable container carried by UNSC Navy Corpsmen on the battlefield designed to store and manufacture surgical nanobots for improved combat field dressings and rudimentary surgery. Since its introduction, it has been adopted by virtually all branches of the UNSCDF, though it sees the most use among the UNSC Marine Corps.
UNSC firearms use relatively conventional ammunition, consisting of hardened metallic projectiles accelerated by the weapon. While the exact means by which these projectiles are accelerated differ, ranging from railguns to conventional ballistic firearms, the effects they have are relatively standard; penetration of the flesh and rupturing of muscles, bones and internal organs. When the Covenant began their campaign of conquest, it came as a rude awakening to discover that much of their battlefield medical treatment techniques and equipment had suddenly been rendered obsolete. Accelerated bolts of superheated plasma inflict fourth-degree burns, and while the fuel rods fired by Carbines have similar penetration performance to UNSC projectile weapons, they also produce low-level radiation, further complicating treatment. When UNSC Navy medics took to the field of battle for the first time on Harvest, they were forced to abandon much of their past training, improvising on the fly to save lives.
The Caduceus was an attempt by the Navy to provide vastly superior battlefield treatment. Nanobots have been in use by the UNSC for decades, and while most are simple automatons programmed to convert one substance into another, more advanced versions see use in military and civilian hospitals as atmospheric sterilisers. Working closely with programmers from Ulysses Software Engineering and the Office of Naval Intelligence, Bellum Aerospace Industries was asked to provide a sophisticated compact medical nanobot storage and production kit for use in the field. Initial prototypes were limited in their effectiveness - the XM11 through to XM17 were only capable of sterilising the atmosphere around a patient in a three meter radius, and while it improved conditions considerably, it still proved limited. The XM18 through to XM23 were able to treat severe plasma burns, repairing the damaged tissue to a limited degree, enabling UNSC medics to stop the bleeding in all but the most severe wounds, though the process was excruciatingly painful for the patient. The XM24 through XM39 remedied this fault by incorporating a high intensity, quick-acting anaesthetic, and models XM40 through XM49 improved the nanobot replication process, allowing quicker reuse times and increased effectiveness on the patient.