Introduction
• An average adult has 5 L of blood
• Blood
– Red blood cells
– White blood cells
– Platelets
– Plasma
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Erythrocytes
• Red blood cells
• Disc-like bi-concave
shape
• O2 and CO2 delivery
• Hemoglobin
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Hemoglobin
• Quaternary protein
structure containing
heme groups
• 1 RBC = 270 million
Hb molecules
• 1 Hb molecule = 4
heme groups
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Heme Group
• Relaxed state
– Fe ion becomes accessible
to O2 as it is on the same
plane
• Tensed state
– Fe ion becomes less
accessible to O2 as it is
pulled out of the plane
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
T vs. R state
Low O2 environment
• Conformational change
• Gas pressure driven
• Rotational of 15 degrees
High O2 environment
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Perceived Clinical Problem
• Shortage of blood supply
• Blood types are a barrier to blood transfusion
• 4.9 million patients/year needs blood
transfusion in the US
• Demand for blood > blood donations
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Respirocytes
• 1st nanomedical device-design
technical paper: 1996 by
Freitas
• Resembles RBCs
• Spherical w/ various diameter
• Aid medical treatments:
–
–
–
–
Anemia
Carbon monoxide poisoning
Respiratory diseases
Blood transfusion
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Respirocytes – Current Design
• Powered by glucose
engines
• Gas exchange is
selective -- via
sorting rotors
• Made of sapphire
or diamond
(insulators)
• Various diameters
from 0.2 to 100
microns
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Respirocytes – Design Issues
•
•
•
•
•
•
•
Over-heating
Radiation damage
Interference with other blood components
Biocompatibility
Introduces unnecessary cell aggregation
Over-pressure of gases
Unpredictable robot life time
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Respirocytes – Alternative Design
• Utilize blood glucose as energy source
• Flat disc, mimics RBCs
– Diameter: 5 μm
– Thickness: 1 μm
•
•
•
•
•
Central CPU
Gas selective membrane (diffusion entrance)
Sensor controlled valves
Open/close valves for diffusion
Selective rotors for releasing gas molecules
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Respirocytes – Alternative Design
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Respirocytes – Alternative Design
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Alternative Design – Flow Chart
Sensor
pCO2 > pO2
Release O2
Open CO2
membrane valve
pO2 > pCO2
Release CO2
Open O2
membrane valve
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Ethical Issues
• Misuse of respirocytes for athletic purposes
• Alters the natural body state by introducing
foreign objects
• Can create miniature bombs to kill bacteria –
Can create weapons of mass destruction
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
Conclusion and Future Work
• Goal: universal blood source
• Purpose: To improve the quality of life of
patients suffering from anemia, lung cancer,
blood transfusions, and diseases that cause
excess blood loss
• Problems associated w/cell aggregation &
biocompatibility requires further investigation
Introduction
Respirocytes
Ethical Issues
Erythrocytes
Proposed Design
Conclusion & Future Work
References
• [1] Lin, S., “Medical Nanorobot: Constructing Biological
Motor Powered Nanomechanical Devices,” Science in
NanoMedicine & NanoMechanics.
• [2] “Nanotechnology, nanomedicine and nanosurgery,”
International Journal of Surgery, 2005.
• [3] Breault, K. et al., “Nanomedicine,” California Engineer,
vol. 82, pp. 9-14, spring 2004.
• [4] http://dev.nsta.org/evwebs/10955/page2.html
• [5] El-Sayed, S. et al., “Nanobiotechnology and its
applications.”
• [6]
http://www.nda.ox.ac.uk/wfsa/html/u10/u1003_01.htm