Non‑contact Video Marker Tracking Quantification Platform

Description

Research Hypothesis Manual acupuncture twirling-rotating manipulation relies on precise thumb-index finger coordination that has remained insufficiently quantified due to lack of scalable, high-resolution measurement tools. We hypothesized that: (1) a low-cost video-based marker tracking platform could resolve fine-scale spatiotemporal kinematics of finger joints during needle manipulation; (2) nonlinear dynamic analyses would identify specific joints governing rhythmic stability and amplitude control; and (3) multi-modal coupling analyses would reveal modular, directionally asymmetric coordination patterns between thumb and index finger modules. Furthermore, we hypothesized that individual operators exhibit distinct motor fingerprints reflecting preferred thumb-dominant versus index-dominant strategies, detectable only with sufficient measurement sensitivity and temporal stability. Data Collection Hand kinematics were captured at 4K resolution (3840 × 2160 pixels) and 60 frames s⁻¹ using a stabilized optical setup oriented perpendicular to the thumb-index manipulation plane. Eight high-contrast black markers (3M™, model 55230) were positioned on predefined anatomical landmarks: ID1 (distal index finger), ID2 (distal interphalangeal joint of index finger), ID3 (proximal interphalangeal joint of index finger), ID4 (metacarpophalangeal joint of index finger), ID5 (distal thumb), ID6 (interphalangeal joint of thumb), ID7 (metacarpophalangeal joint of thumb), and ID8 (midpoint between first and second metacarpals). A stationary reference marker enabled spatial normalization and drift correction.

Steps to reproduce

Methods and Protocols for Data Collection Experimental Setup All experiments were conducted at the Innovation Research Institute of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine. The imaging system consisted of a consumer-grade camera (capable of 4K 60 FPS recording) mounted on a stabilized tripod with the optical axis oriented perpendicular to the thumb-index finger manipulation plane. A standardized workstation with uniform LED lighting (5600K, ~800 lux) was used to eliminate shadows and ensure consistent marker contrast across sessions. Marker Placement Protocol Operators wore nitrile gloves for biosafety compliance during animal experiments; bare-hand validation was performed for clinical application assessment. Eight high-contrast black circular markers (3M™ 55230, 5 mm diameter) were positioned on predefined anatomical landmarks using the following protocol: Clean skin/glove surface with alcohol wipe Apply marker with tweezers to ensure precise positioning Verify marker adhesion and visibility in test frame Record marker identity and anatomical correspondence (ID1–ID8) Place stationary reference marker on immobile surface adjacent to hand Landmark definitions: ID1 = distal tip of index finger; ID2 = distal interphalangeal joint of index finger; ID3 = proximal interphalangeal joint of index finger; ID4 = metacarpophalangeal joint of index finger; ID5 = distal tip of thumb; ID6 = interphalangeal joint of thumb; ID7 = metacarpophalangeal joint of thumb; ID8 = midpoint between first and second metacarpals. Manipulation Protocol Operators were seated at the standardized workstation with the needle manipulation plane parallel to the camera sensor. A digital metronome (Portable Metronome v2.3.4) delivered continuous auditory cues at target frequencies. Five techniques were performed in randomized order: 90° rotation at 2 Hz; 180° rotation at 0.5 Hz, 1 Hz, and 2 Hz; 360° rotation at 2 Hz. Each trial lasted 30 s with 60 s rest between techniques. Operators were instructed to maintain natural, habitual twirling style without artificial modification. Video Acquisition Protocol Record 5 s pre-trial static frame for reference marker calibration Synchronize metronome onset with video start Capture 30 s manipulation at 4K 60 FPS Record 5 s post-trial static frame for drift assessment Export original .mp4 without compression for offline analysis Pressure Sensor Validation Protocol FlexiForce A201 sensors (Tekscan, USA; 9.53 mm sensing area, 0.203 mm thickness) were activated by applying 110% full-scale load (27.5 lb) for 3 s, repeated 4–5 times. Calibration was performed using standard weights at multiple load points with measured voltage outputs recorded via microcontroller (feedback resistor 20 kΩ, supply voltage 5 V, sampling rate 100 Hz). The optimal calibration curve was selected based on highest R² among linear, polynomial, and exponential fits.

Institutions

• Shandong University of Traditional Chinese Medicine

  Shandong, Jinan

Categories

Funders

• Shandong Provincial Natural Science Foundation Innovation

  Grant ID: ZR2022LZY023
• Taishan Scholar Foundation of Shandong Province

  Grant ID: tstp20221125

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