Biophysics & Medical Physics
7 terms
Magnetic Resonance Imaging (MRI)
Biophysics & Medical Physics
Tesla B₀ (~1.5–3.0 T) & MHz
A non-invasive medical imaging modality utilizing powerful magnetic fields, radiofrequency (RF) pulses, and nuclear magnetic resonance (NMR) of hydrogen protons to image soft tissue.
Larmor Frequency ν₀ = (γ / 2π) B₀ (γ_proton ≈ 42.58 MHz/T)
Magnetoencephalography (MEG)
Biophysics & Medical Physics
fT (Femtoteslas = 10⁻¹⁵ T)
A non-invasive functional neuroimaging technique mapping brain activity by measuring weak magnetic fields produced by neuronal electric currents using SQUID sensors.
Magnetic Field B ~ 10–100 fT (10⁻¹⁵ Tesla)
Medical Lasers
Biophysics & Medical Physics
W or J/cm² (Fluence)
Laser devices engineered for surgical cutting, tissue coagulation, and photomedical treatments exploiting specific light-tissue absorption interactions.
Selective Photothermolysis: Laser Pulse Duration ≤ Thermal Relaxation Time τ_r
Medical Linear Accelerator (LINAC)
Biophysics & Medical Physics
MV (Megavoltage Photon Beams 6–18 MV)
A high-energy medical accelerator generating megavoltage X-ray photon or electron beams for external beam radiation cancer therapy.
RF Cavity Electron Acceleration to 6–18 MeV → Bremsstrahlung X-Rays
Medical Ultrasound
Biophysics & Medical Physics
MHz (Frequency 2–15 MHz) & MRayl (Acoustic Impedance)
A non-invasive diagnostic imaging modality using high-frequency acoustic waves (2–15 MHz) to image soft tissue reflection interfaces.
R = ((Z₂ - Z₁) / (Z₂ + Z₁))², Z = ρ c (Acoustic Impedance)
Membrane Potential
Biophysics & Medical Physics
mV (Millivolts)
The electrical potential difference across a biological cell membrane produced by asymmetric ion concentration gradients.
V_m = V_in - V_out (Resting Potential ≈ -70 mV)
Molecular Motors
Biophysics & Medical Physics
pN (Piconewtons) & nm (Step Length)
Protein-based molecular machines that convert chemical energy from ATP hydrolysis into mechanical work and linear movement.
F_step ≈ 6 pN, Step Size d ≈ 8 nm (Kinesin on Microtubule)