COMPUTATIONAL TASKS IN MEDICAL NANOROBOTICS - Bio-Inspired and Nanoscale Integrated Computing - page 411

semiautonomous nanorobot activities and includes a specific 26-step sequential
process for performing whole-genome chromosome exchange nanosurgery on a
living cell using the chromallocytes [7]. Each step must be verified as complete
before the next step can be initiated. Failure to reliably and provably complete any
given step should trigger a safe mission abort protocol in which the nanorobot
must appropriately reverse any steps already completed, thus restoring the cell to
its original condition, then withdraw safely from the cell and subsequently from
the patient's body, while reporting all details of this failure to the attending
physician. Autonomous control of a 26-step chromosome exchange operation will
include numerous sensor-driven checkpoints. Motions and speeds of sensored
mobile components must also be restrained to within safe operating envelopes.
Other possible operating protocols of this highly sophisticated medical nanorobot
are outlined in Section 15.4.
Specialized protocols required for chromallocytes could be particularly
complex. Significantly modified procedures will be required for numerous unusual
cases including (1) proliferating, pathological, multinucleate, and karyolobate
cells, (2) cells in locations where access is difficult such as brain, bone, or mobile
cells, (3) cells expressing genetic mosaicism, and (4) alternative missions such as
mitochondrial DNA replacement [7].

15.3. COMMON FUNCTIONS REQUIRING ONBOARD COMPUTATION

Functions which may be common to many different classes of medical nanorobots
and must be controlled by the onboard nanocomputer include those listed below.

1. Pumping. Single-molecule recognition, sorting, and pumping via mole-
cular sorting rotors [1f] to allow molecule-by-molecule exchanges with the
environment. The typical 10 4 -10 5

sorting rotors requiring individual control, though many can probably be
operated in banks or clusters of 10-100 rotors. Molecular pumps would
be a primary system in nanorobots such as pharmacytes [10] which are
intended solely to dispense drugs or other reagents.
2. Sensing. Chemical sensors [1j], pressure [1k] and temperature [1i] sensors,
ullage sensors (include onboard pressure tank management) [1o], elec-
trical, magnetic and optical sensors [1av], position/orientation sensors
[1aw], gravity sensors [1ax], and molecular recognition sites [1ay, 1az];
and coordination and interpretation of macrosensing data providing
onboard information from external acoustic [1ba], proprioceptive [1aw],
electric/magnetic [1bb], or optical [1bc] sources, or direct neural traffic
eavesdropping [1bd]. The typical

1 micron nanorobot might have

B B

B 1 micron nanorobot might employ

10 4 -10 5 sensors of various kinds requiring individual control.
3. Configuration. Control of device shape [1be]; gas-driven extensible
bumpers to maintain physical contact among adjacent devices during

B