Respirocytes A Mechanical Artificial Red Cell: Exploratory Design in Medical Nanotechnology -Robert...
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Transcript of Respirocytes A Mechanical Artificial Red Cell: Exploratory Design in Medical Nanotechnology -Robert...
RespirocytesA Mechanical Artificial Red Cell: Exploratory Design in Medical Nanotechnology
-Robert A. Freitas Jr.
Presented byUmaMaheswari Ethirajan
Overview Introduction Preliminary Design Issues Nanotechnological design of Respiratory
Gas carriers Baseline design Therapeutics Safety and Bio-compatibility Applications Summary and Conclusion
Introduction Molecular manufacturing processes applications. Medical implications – precise interventions at
cellular and molecular levels. Medical nanorobots – research, diagnoses and
cure. Preliminary design for artificial mechanical
erythrocyte or Red Blood Cell (RBC) – Respirocyte.
Preliminary Design Issues
Biochemistry of respiratory gas transport – oxygen and carbon-dioxide.
Existing Artificial Respiratory Gas carriers Hemoglobin Formulations
50% more O2 than natural RBCs. Dissociates to dimers, Binds to O2 more tightly, Hemoglobin
oxidized. Fluorocarbon Emulsions
Physical solubilization – emulsions of droplets Shortcomings of Current technologies
Too short life time Not designed for CO2 transport vasoconstriction
Design of Respiratory Gas carriers Pressure Vessel
Spherical, Flawless diamond or sapphire 1000atm – optimal gas molecule packing
density Discharge time very less - <2 minutes
Recharging with O2 from lungs
Respiratory gas equilibrium – more CO2
Provide additional tankage for CO2
Means for gas loading and unloading
Molecular Sorting Rotors
Binding site pockets – rims – 12 arms
Selective binding Eject – cam action Fully reversible – load
and unload 7nm x 14nm x 14nm 2 x 10-21 kg Sorts molecules of 20
or fewer atoms 106 molecules/ sec
Molecular Sorting Rotors (cont’d) Power saving – generator subsystem 90% occupancy of rotor binding sites Multi-stage cascade – virtually pure gases
Sorting Rotors binding sites O2, CO2, Water, Glucose
Device Scaling On-board computer – 58nm diameter sphere 37.28% of tank surface – sorting rotors Reasonable range – 0.2 to 2 microns Present study assumes – approx. 1 micron
Buoyancy control Loading and unloading water ballast Very useful – exfusion from blood Example – specialized centrifugation apparatus
Nanotechnological Design of Respiratory Gas carriers (cont’d)
Baseline Design - Power
glucose & oxygen – Mechanical Energy Glucose – blood & Oxygen – onboard storage Glucose Engine – 42nm x 42nm x 175nm Output is water – approx. glucose absorbed Fuel tank – glucose storage – 42nm x 42nm x
115nm Mechanical or hydraulic power distribution
Rods & gears Pipes & valves
Control – onboard computer
Baseline Design - Communications Physician – broadcast signals Modulated compressive pressure pulses Mechanical transducers – surface of
respirocytes Transducers – pressure driven actuators Internal Communication
Hydraulic - Low pressure acoustic spikes Mechanical - Mechanical rods and couplings
Baseline Design - Sensors
Sorting rotors – quantitative molecular concentration sensors
Internal pressure sensors – gas tank loading, ballast and glucose fuel tanks, internal/external temperature sensors.
Baseline Design – Onboard Computation
104 bit/sec computer 105 bits of internal memory
Gas loading and unloading Rotor field and ballast tank management Glucose engine throttling Power distribution Interpretation of sensor data Self-diagnoses and control of protocols
Baseline Design – Tank Chamber Design
Diamondoid honeycomb or geodesic grid skeletal framework
Perforated compartment walls Present design – CO2 and O2 separate Proposed – same chamber Disadvs
Respiration control – CO2 level
Reverse CO2 overloading Reduction of maximum outgassing rate
Therapeutics Minimum Therapeutic dose
Human blood O2 capacity – 8.1 x 1021 molecules Each respirocyte – 1.51 x 109 O2 molecules Full duplication – 5.36 x 1012 devices Hypodermal injection or transfusion
Maximum Augmentation Dose Fully O2 charged dose – 9.54 x 1014 respirocytes 12 minutes and peak exertion 3.8 hours at rest
Control Protocols Precise external control by physician Programmable for sophisticated behaviors
Safety and Bio-compatibility Mechanical failure modes
Device overheating Non-combustive device explosion Radiation damage
Coagulation Inflammation Phagocytes
Applications Transfusions Treatment of Anemia Fetal and Child-related disorders Respiratory Diseases Cardiovascular and Neurovascular applications Tumor therapy and Diagnostics Asphyxia Underwater breathing Endurance oriented sport events Anaerobic and aerobic infections Veterinary medicine
Summary and Conclusion Artificial erythrocyte Avoiding carbonic acidity – mechanical transport
of CO2 236 times more O2 per unit volume than natural
RBCs Tough diamondoid material Numerous sensors On-board nano-computer Remotely programmable Lifespan of 4 months Future advances in molecular machine system
engineering – actual construction.
References Drexler KE. Nanosystems
: Molecular Machinery, Manufacturing, and Computation. New York: John Wiley & Sons, 1992.
www.foresight.org