Non-invasive volumetric analysis of asymptomatic hands using a 3-D scanner

Utilization of 3-dimensional scanner technology to measure circumference and volume of limbs in patients bitten by venomous snakes

INTRODUCTION

The objective of this study was to compare limb circumference measurements between a three-dimensional scanner and a measuring tape.

METHODS

Patients older than 18 years, who were bitten by a green pit viper and visited the emergency department between 1 October and 20 December, 2019 were included. Two physicians measured the circumference of a bitten limb and a contralateral unaffected limb twice using both a measuring tape and a three-dimensional scanner. Each patient was measured at the first emergency department visit and again at 24 h, 48 h, and 72 h post-snakebite. There were three points of measurement on both limbs.

RESULTS

There were 408 anatomical locations from 17 patients for measurement. The three-dimensional scanner and the measuring tape demonstrated a very high correlation (r-squared >0.940, P value <0.001) in measuring limb circumferences. Bland Altman plots also demonstrated the two methods measured limb circumferences with similar results with mean differences <1 cm. Intraclass correlation coefficient between the two methods was greater than 0.8 in every site for the lower limbs, but for the upper limbs, most sites had a poor agreement (ranges: 0.073-0.633). For limb volume measurement, the three-dimensional scanner provided excellent and moderate inter and intrarater reliabilities for the lower and upper limbs, respectively.

DISCUSSION

The three-dimensional scanner could be reliably used to assess limb circumference with a strong correlation and with a relatively small error compared with the conventional method. Pictures from the scan can also be constructed to calculate limb volume that could have potential for other clinical purposes such as in evaluating antivenom response for limb swelling.

CONCLUSIONS

Circumferences from the three-dimensional scanner were comparable to those from the measuring tape, especially for the lower limbs, and the three-dimensional scanner demonstrated an added value for calculating limb volume.

Effect of laparoscopic handle size on surgical performance: A randomized crossover trial

Laparoscopic instrument handles design and dimensions are crucial to determine the configuration of surgeons' hand grip and, therefore, can have a deleterious effect on overall surgical efficiency and surgeons' comfort. The aim of this study is to investigate the impact of laparoscopic handle size and hand surface area on surgical task performance. A single-blind, randomized crossover trial was carried out with 29 novice medical students. Participants performed three simulated tasks in "black box" simulators using two scissor-type handles of different sizes. Surgical performance was assessed by the number of errors and time required to complete each task. Hand anthropometric data were measured using a 3D scanner. Execution time was significantly higher when cutting and suturing tasks were performed with the smaller handle. In addition, hand surface area was positively correlated with peg transfer task time when performed with the standard handle and was correlated with cutting task time in small and standard handle groups. We also found positive correlations between execution time and the number of errors executed by larger-handed participants. Our findings indicate that laparoscopic handle size and hand area influence surgical performance, highlighting the importance of considering hand anthropometry variances in surgical instrument design.

A Pilot Study of Determining the Reliability of a New Three-Dimensional Scanning System for Measuring Truncal Thickness After Breast Cancer Surgery

Background: Lymphedema often affects the trunk after breast cancer surgery. Measuring volume baseline can help detect lymphedema-related changes early, thereby allowing for early intervention efforts. However, there is no quantitative method for detecting truncal lymphedema. As a preliminary investigation into the development of a new method for measuring truncal lymphedema, this study aimed to investigate the reliability and define the minimal detectable change (MDC) in posterior truncal thickness using a three-dimensional (3D) scanning system. Methods and Results: This observational study included 21 women who had undergone a mastectomy for breast cancer. The 3D images of every subject's trunk were captured by a handheld 3D scanner at two time points. The acquired 3D images were used to calculate the differences in thickness between the affected and unaffected sides at eight points on the trunk. The reliability was determined by checking for agreement between the trials (intraclass correlation coefficient) and by investigating the presence of systematic bias between the measurement error and true value (Bland-Altman analysis). Then, the MDC was calculated. For 14 of the 21 participants, 3D images without missing data at both time points were obtained. Analysis indicated that there was no systematic bias regarding the mean value at the seven body points. Fair-to-excellent reliability was shown at the five points in the middle of the trunk (MDC: 4.14-9.79 mm). The other three points (at the top and bottom of the trunk) had limited reliability. Conclusions: The 3D scanning system effectively measured the differences in thickness between the affected and unaffected sides of participants' posterior trunks, with fair-to-excellent reliability in the middle of the trunk.

Reliability and Validity of Physical Tools and Measurement Methods to Quantify Hand Swelling: A Systematic Review

OBJECTIVE

Hand swelling may result from injury or trauma. Various physical assessment tools and measurement methods can be used to quantify the volume or size of the hand or fingers; however, the reliability and validity of each tool and measurement method have not been evaluated. The purpose of this study was to evaluate the reliability and validity of physical assessment tools and methods used to quantify hand and finger volume orsize.

METHODS

MEDLINE, CINAHL, EMBASE, Web of Science, and Scopus were searched using key terms related to swelling, edema, volume, size, hand, measures, reliability, and validity. Cross-sectional or longitudinal studies that assessed reliability and/or validity of physical assessment tools or measurement methods to quantify hand swelling were included. Two examiners independently extracted data from the included articles and appraised the articles' quality using the Consensus-Based Standards for the Selection of Health Measurement Instruments methodology. Data extracted from studies analyzing reliability and validity were grouped by type of assessment tool and measurement method.

RESULTS

Five physical assessment tools used for quantification of hand swelling were evaluated, including tape measure, water volumeter, bioimpedance spectroscopy, ring gauge, 3-dimensional techniques. All assessment tools had good to excellent reliability (ICC = 0.74 - 0.99), and moderate to high validity (Pearson coefficient = 0.58 - 0.99), for quantification of the volume or size of the hand or fingers.

CONCLUSION

All measurement methods with these tools had good to excellent reliability and moderate to high validity. The evidence underpinning the figure-of-eight technique, which uses a tape measure, was the highest. Because these physical assessment tools and measurement methods assess different aspects and regions of the hand, which one is selected depends on the region of interest for assessment and the availability of tools.

IMPACT

Reliable tools and measurement methods are available to measure the size or volume of the hand and fingers, either together or separately. The best tool will depend on the aim of assessment and tool availability.

LAY SUMMARY

Hand swelling can occur with injuries, burns, or lymphedema. This review shows that tools are available to accurately measure swelling in any part of thehand.