Domain: Engineering — Biomedical Engineering
Target concept: Biological Effects of Light Wavelengths

Video generation prompt: Set up an experimental device for low-intensity laser irradiation of biological tissues. Place porcine skin tissue samples under the laser system, adjust the laser wavelength from 630 nm (red light) to 808 nm (near-infrared light), keep the power constant, and use an infrared thermal camera to capture the light penetration depth of the skin tissue from the side. The penetrated region is marked in blue.

Evaluation guide:
(i) Target concept: Wavelength-dependent optical penetration depth in biological tissue.
Minimum mechanism: Light must be absorbed/scattered differentially by tissue chromophores; longer NIR wavelengths experience less attenuation, enabling deeper photon migration and detectable thermal signal at greater depth, visualized as deeper blue zone in side-view thermal imaging.
(ii)Storyline: [Start] Static side-view shot of mounted porcine skin tissue; laser device aimed at tissue surface. → [Laser ON @ 630 nm] Blue zone appears inside tissue, limited vertical extent. → [Wavelength switch] Visible interface update (630 → 808 nm) occurs while laser remains active. → [Laser @ 808 nm] Same blue zone deepens vertically without lateral expansion or surface leakage. → [End] Blue zone remains stable until laser deactivation; no reversal or decay during irradiation. Perspective: Fixed side-view camera, no occlusion, full tissue cross-section visible throughout.

Manual:
Experimental Procedure
1. Mount porcine skin tissue sample vertically on stage.
2. Position low-intensity laser to irradiate tissue surface perpendicularly.
3. Set laser wavelength to 630 nm; activate laser.
4. Capture side-view thermal image with infrared camera.
5. Change laser wavelength to 808 nm; capture second side-view thermal image.
Observation of Experimental Phenomena
A blue-colored region appears inside the tissue, extending vertically downward from laser entry point; the blue region is shorter at 630 nm and longer at 808 nm.
Summary of Experimental Principles
Longer near-infrared wavelengths (e.g., 808 nm) penetrate biological tissue more deeply than shorter visible wavelengths (e.g., 630 nm) due to reduced scattering and absorption by melanin and hemoglobin.

Prompt Grounding rubric:
level_1: No laser device, no porcine skin tissue sample, no infrared thermal camera visible; none of the three core objects present.
level_2: Exactly one of the three core objects present (laser device OR porcine skin tissue sample OR infrared thermal camera), and no evidence of wavelength adjustment or side-view imaging setup.
level_3: All three core objects present (laser device, porcine skin tissue sample, infrared thermal camera), and laser is visibly directed toward the tissue; side-view camera orientation is implied by framing, but no visible blue marking or wavelength label.
level_4: All three core objects present, laser is visibly incident on porcine skin tissue, infrared thermal camera is positioned to capture side profile of tissue, and at least one visible wavelength label (630 nm or 808 nm) appears on laser interface or display; no blue marking yet.
level_5: All three core objects present, laser incident on porcine skin tissue in side-view configuration, infrared thermal camera clearly capturing tissue cross-section, wavelength label changes from 630 nm to 808 nm within video, and blue-colored penetrated region appears exclusively in the tissue interior, not on surface or background, with spatial continuity between laser entry point and blue zone.

Scientific and Causal Correctness rubric:
level_1: Blue marking appears on laser device, camera housing, background, or air; or appears simultaneously across full tissue thickness regardless of wavelength; or appears before laser activation.
level_2: Blue marking appears only on tissue surface (epidermis), or extends uniformly through entire tissue without depth variation, or appears identically for both wavelengths without differentiation.
level_3: Blue marking appears inside tissue (not surface), and is present during laser irradiation; but no visible distinction between 630 nm and 808 nm penetration depth, i.e., same extent or shape for both wavelengths.
level_4: Blue marking appears inside tissue (not surface), and shows a clear difference in vertical extent: blue region is shallower under 630 nm and deeper under 808 nm; all other causal links hold (laser on → blue appears; laser off → blue vanishes or fades completely).
level_5: Blue marking appears exclusively inside tissue (never on surface), begins precisely at laser entry point and extends downward as a contiguous vertical zone; under 630 nm, blue zone terminates higher in tissue; under 808 nm, blue zone extends further downward, with no discontinuity, overlap, or reversal, and disappears entirely when laser is off or wavelength is unselected.

Spatiotemporal Consistency rubric:
level_1: The porcine skin tissue jumps position, rotates, or disappears mid-video; the laser beam turns on and off erratically; the camera view cuts, jumps, or repositions abruptly; the blue marking appears or vanishes instantly with no visible motion.
level_2: The tissue stays in place, but the laser spot visibly drifts sideways across the tissue surface; the blue marking pops in and out between frames instead of fading or growing smoothly; the thermal-camera viewpoint wobbles or tilts partway through the sequence.
level_3: The tissue stays fixed in place; the laser spot stays at the same location on the tissue; the blue marking grows straight downward from its entry point without spreading sideways or breaking into fragments; the camera keeps the same static side-view throughout.
level_4: The tissue stays fixed; the laser spot stays centered and visually steady; the blue marking grows continuously and vertically with a smooth-looking intensity gradient rather than hard-edged jumps between frames; the camera keeps a fixed side-view with consistent framing and lighting, with no shadow flicker or sudden exposure change.
level_5: The tissue stays rigidly fixed with no visible tremor; the laser spot remains visually fixed at the same tissue location with no discernible drift; the blue marking grows smoothly and exclusively downward with no lateral wandering, no pulsing, and no visible flicker in opacity; the camera's side-view framing shows no perceptible parallax shift, no refocusing, and no lighting change from the first frame to the last of the sequence.