View
219
Download
1
Category
Tags:
Preview:
Citation preview
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
• Conformational change• Gas pressure driven• Rotational of 15 degrees
Low O2 environment
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
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
Recommended