AcuSim: a Synthetic Dataset for Cervicocranial acupuncture Points Localisation

Sun et al. · Scientific Data · 2025

🔬Synthetic Dataset with CNN📊n=63,936 synthetic imagesHigh Impact - Methodological Innovation

Evidence Level

STRONG
85/ 100
Quality
4/5
Sample
5/5
Replication
4/5
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OBJECTIVE

Create a synthetic dataset for automatic localization of acupuncture points in the cervicocranial region using artificial intelligence

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WHO

504 synthetic anatomical models with variations in gender, weight, and physical features

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DURATION

Dataset development and validation with 3,480 training epochs

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POINTS

174 volumetric acupuncture points in the cervicocranial region with 5 mm precision

🔬 Study Design

63936participants
randomization

Training Images

n=57600

90% of the dataset to train CNN neural network

Validation Images

n=6336

10% of the dataset to validate model accuracy

⏱️ Duration: Dataset development and AI model training

📊 Results in numbers

0%

Point localization accuracy

0%

Points within the 5 mm margin

0.12-0.17 pixels

Final mean localization error

11,126,952

Total point annotations

Percentage highlights

99.73%
Point localization accuracy
92.86%
Points within the 5 mm margin

📊 Outcome Comparison

Point localization accuracy

Trained CNN Model
99.73
Expert Annotation
92.86
💬 What does this mean for you?

This study created an artificial intelligence system capable of identifying acupuncture points on the head and neck with high accuracy using synthetic images. The system can locate points with precision equivalent to that of human experts, representing a significant advance in making acupuncture treatment more accurate and accessible.

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Article summary

Plain-language narrative summary

This innovative study presents the development of AcuSim, a revolutionary synthetic dataset to automate the localization of acupuncture points in the cervicocranial region (head and neck). The research addresses a critical limitation in traditional Chinese medicine: dependence on experts to accurately locate acupuncture points, a process that is expensive, time-consuming, and subject to individual variation. The researchers created 504 photorealistic synthetic anatomical models, representing different body types, genders, hairstyles, and facial features. Using advanced computer graphics techniques in software such as Blender and DAZ Studio, they generated 63,936 high-resolution RGB-D images (1024×1024 pixels), each with precise annotations of 174 volumetric acupuncture points.

The methodology used domain randomization to capture human anatomical diversity, including variations in height, weight, and body fat proportions. The automatic annotation system used the traditional finger-cun method based on World Health Organization guidelines, positioning three-dimensional points as volumetric spheres rather than simple 2D points. For validation, they developed a convolutional neural network based on the VGG19 architecture with fully connected layers for multitask prediction of point coordinates and names. The model was trained for 3,480 epochs, converging after approximately 800 epochs for the training set and 1,250 epochs for validation.

The results demonstrated exceptional accuracy of 99.73% in point localization, with mean error of only 0.12-0.17 pixels in the final phases of training. When compared with annotations by traditional Chinese medicine experts, 92.86% of predictions were within the clinically acceptable error margin of 5 mm. The system incorporated automatic occlusion filters to remove points not visible due to hair or other obstructions, ensuring superior data quality. Two-way ANOVA statistical analysis confirmed that variations between anatomical models did not significantly affect accuracy, while different point locations showed expected variations due to anatomical complexity.

The dataset substantially surpasses previous work in scale and accuracy, offering more than 11 million annotations compared with the maximum of 28,000 in earlier studies. The clinical implications are significant: the system can facilitate acupuncturist training, reduce educational costs, and improve treatment standardization. Automation of point localization can make acupuncture more accessible and reliable, especially in regions with a shortage of specialists. Limitations include the need for additional validation with real images and expansion to other anatomical regions.

Future developments plan to incorporate transfer learning and domain adaptation techniques to improve generalization to real-world scenarios. This work represents a milestone in the digitalization of traditional Chinese medicine, demonstrating how artificial intelligence can preserve and modernize ancient practices, maintaining their therapeutic efficacy while improving accuracy and accessibility.

Strengths

  • 1Extensive synthetic dataset with more than 63,000 high-quality images
  • 2Accuracy above 99% validated against human experts
  • 3Innovative automatic annotation methodology with occlusion filters
  • 4Comprehensive anatomical diversity with 504 different models
  • 5Precise 3D-2D coordinate system with clinically relevant error margin
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Limitations

  • 1Validation limited to synthetic models, requiring testing with real images
  • 2Restricted focus on the cervicocranial region, not covering the whole body
  • 3Reliance on a single CNN architecture (VGG19) for validation
  • 4Need for domain adaptation to generalize to real clinical scenarios
Prof. Dr. Hong Jin Pai

Expert Commentary

Prof. Dr. Hong Jin Pai

PhD in Sciences, University of São Paulo

Clinical Relevance

Standardization of acupuncture point localization is a real challenge in daily practice and, above all, in medical education. AcuSim represents a concrete contribution to addressing this problem: a synthetic dataset with more than 63,000 images and 11 million annotations of cervicocranial points, capable of training computer vision systems with 99.73% accuracy. For the acupuncturist physician working in pain centers or neurology outpatient clinics, where headache, neck pain, and painful shoulder syndrome account for much of the demand, the prospect of AI-assisted tools to guide anatomical localization is clinically relevant. Populations with significant morphological variations — patients with obesity, pediatric patients, elderly patients with postural changes — would benefit from a system that incorporates anatomical diversity with 504 distinct models, something not feasible to cover adequately with physical mannequins or static atlases alone.

Notable Findings

The most striking finding of the study is that 92.86% of the model's predictions fell within the 5 mm margin relative to human expert annotations — a threshold that, in clinical practice, corresponds to the interobserver variation typically accepted between experienced physicians. The final mean error of 0.12-0.17 pixels in advanced training phases evidences robust convergence. The scale of the database is also striking: more than 11 million annotations, against a maximum of 28,000 in previous studies — a difference of two orders of magnitude. The approach of representing points as three-dimensional volumetric spheres rather than flat 2D coordinates is methodologically superior and better reflects clinical reality, where the acupuncture point has associated tissue depth and volume, not just a superficial position.

From My Experience

At the HC-FMUSP Pain Center, we teach point localization with atlases, mannequins, and direct preceptor supervision — a labor-intensive process with a long learning curve, especially in the cervicocranial region, where point density and anatomical variability require accumulated experience. I have observed over recent decades that the most frequent resident errors occur precisely in this topography: confusion between gallbladder and stomach meridian points in the temporal region, or imprecision in small intestine meridian points at the occipitocervical transition. An AI system with accuracy comparable to experts could considerably accelerate this learning curve. Clinically, I combine cervicocranial points with myofascial trigger-point techniques and, frequently, with cervical physical therapy — and standardization of localization is a prerequisite for comparing outcomes across sessions. AcuSim points to a near future in which digital tools will assist the physician in confirming localization before puncture, reducing variability and strengthening the reproducibility of our clinical protocols.

Specialist physician in Medical Acupuncture. Adjunct Professor at the Institute of Orthopedics, HC-FMUSP. Coordinator of the Acupuncture Group at the HC-FMUSP Pain Center.

Full original article

Read the full scientific study

Scientific Data · 2025

DOI: 10.1038/s41597-025-04934-9

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Scientific Review

Marcus Yu Bin Pai, MD, PhD

Marcus Yu Bin Pai, MD, PhD

CRM-SP: 158074 | RQE: 65523 · 65524 · 655241

PhD in Health Sciences, University of São Paulo. Board-certified in Pain Medicine, Physical Medicine and Rehabilitation, and Medical Acupuncture. Scientific review and curation of every entry in this library.

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Medical disclaimer: This content is for educational purposes only and does not replace consultation, diagnosis, or treatment by a qualified professional. Some information may be assisted by artificial intelligence and is subject to inaccuracies. Always consult a physician.

Content reviewed by the medical team at CEIMEC — Integrated Centre for Chinese Medicine Studies, a reference in Medical Acupuncture for over 30 years.