© 1999 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999

7.4.6.6 Artificial Symptoms

The triggering of artificial symptoms in the human body offers at best a primitive, noisy, misinterpretable, and low bit rate outmessaging channel. Outmessaging protocols may allow a population of in vivo nanorobots to communicate systemwide status (e.g., "low serum oxygen," "low serum glucose," "immune system under attack,") or specific conditions (e.g., "cancer tumor detected in breast," "breach of intestinal wall detected") directly with the patient by inducing recognizable physiological cues (e.g., fever, nausea, shivering, tingling, gasping, tinnitus, hypothalamic "reward" center stimulation). But message noise level is high because these signals are readily confused with natural symptoms that may normally communicate the presence of entirely unrelated conditions.

One suggestion to improve the signal/noise ratio is to insert artificial genes that code for enzymes producing a harmless but chromatic signaling compound that colors the urine when excreted, or which adds an unusual color to hair or fingernails as a diagnostic telltale.²⁹⁹¹ Nanodevices also could "manually" trigger such a gene, or manufacture the colorant themselves. Alternatively, coordinated nanorobot-induced neural firings might produce externally-measurable changes in the cranial radiative electric field.³⁴⁷² All these sorts of information transfer are very energy inefficient and are about as informative as "Indian smoke signals."⁷³¹ Artificial symptoms have only limited utility as a primitive channel for nanodevice outmessaging.

Last updated on 19 February 2003