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

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

7.4.7 Outmessaging to External Receivers

Much of the extensive self-diagnostic data that could theoretically be made available to the patient via dermal displays (Figs. 7.7A and 7.7B) is probably beyond the comprehension of the typical user and thus will require professional interpretation. All such information may be rapidly downloaded to instruments under the physician's control via a wide variety of outmessaging transducers including cable connections through transdermal output ports (Section 7.4.2.7), magnetic induction, infrared or acoustic links with internal communications organs (Section 7.3.4), or dermal displays configured for optimal high-capacity optical external data transfers. Physicians might also receive information from in vivo nanorobots which generate subtle physiological patterns (e.g., an artificial electrical or mechanical signal superimposed on the normal cardiac or respiratory "carrier wave") requiring sensitive clinical diagnostic equipment to detect, though of course great care must be taken to ensure that such imposed patterns are non-nosogenic. Nanorobots could operate an implanted radio transmitter.

Artificial data secretion glands or other distributed data secretion sources may write huge quantities of data onto nonmetabolizable messenger molecules which are then excreted by the patient, recovered from the urine by laboratory nanodevices, then passed through a reading device, thus making the information available to the physician. A minimum urine flow of ~120 cm³/day containing D_message ~ 26 bits/nm³ messenger molecules (Section 7.2.1.1) at an innocuous concentration of only 100 parts per million by volume allows a data stream of ~4 x 10¹⁵ bits/sec to flow from patient to physician -- subject to unavoidable time delays for excretion, materials processing and message extraction. The total power requirement to originally encode this information in vivo is 1-1000 zJ/bit (Section 7.2.6) or 4-4000 microwatts for the entire stream, well within safe whole-body thermogenic limits. This technique may be especially valuable in long-term whole-body monitoring, neural recording and archiving (Chapter 25), and related data-intensive applications that require acquisition of information streams from millions or billions of scattered individual in vivo data-gathering sources.

Many of the inmessaging techniques summarized in Section 7.4.1 may also be operated in reverse to achieve outmessaging to the physician from in vivo nanodevices.

Last updated on 19 February 2003