Mapping the differential impact of spontaneous and conversational laughter on brain and mind: an fMRI study in autism.

Spontaneous and conversational laughter are important socio-emotional communicative signals. Neuroimaging findings suggest that non-autistic people engage in mentalizing to understand the meaning behind conversational laughter. Autistic people may thus face specific challenges in processing conversational laughter, due to their mentalizing difficulties. Using fMRI, we explored neural differences during implicit processing of these two types of laughter. Autistic and non-autistic adults passively listened to funny words, followed by spontaneous laughter, conversational laughter, or noise-vocoded vocalizations. Behaviourally, words plus spontaneous laughter were rated as funnier than words plus conversational laughter, and the groups did not differ. However, neuroimaging results showed that non-autistic adults exhibited greater medial prefrontal cortex activation while listening to words plus conversational laughter, than words plus genuine laughter, while autistic adults showed no difference in medial prefrontal cortex activity between these two laughter types. Our findings suggest a crucial role for the medial prefrontal cortex in understanding socio-emotionally ambiguous laughter via mentalizing. Our study also highlights the possibility that autistic people may face challenges in understanding the essence of the laughter we frequently encounter in everyday life, especially in processing conversational laughter that carries complex meaning and social ambiguity, potentially leading to social vulnerability. Therefore, we advocate for clearer communication with autistic people.

"Sorry for Holding You Up": Surgeons' Apologies for Lateness in Clinic Settings.

Doctors running late may convey a lack of respect which can impair the therapeutic relationship. This study examines how surgeons address lateness in consultations with patients. We analyzed 52 consultation recordings from a range of surgical specialties in an Australian metropolitan setting. Conversation analysis was used to analyze interactional sequences where lateness was addressed. Six sequences were identified within four recordings. The two consultations with two apologies include a surgeon and registrar apologizing in a neurosurgical consultation and a surgeon apologizing twice within a colorectal consultation. Apologies were either accepted or responded to with an account for not accepting the apology. When these accounts were made, consultations could only progress when patients accepted an explanation for lateness or the degree of complainability about lateness was reduced. The infrequent occurrence of apologies for lateness, and the way in which these sequences unfolded when they did occur, suggest that there is greater acceptability of lateness for surgeons than in ordinary social situations.

Assessing the reliability and cross-sectional and longitudinal validity of fifteen bioelectrical impedance analysis devices.

The purpose of this investigation was to expand upon the limited existing research examining the test-retest reliability, cross-sectional validity and longitudinal validity of a sample of bioelectrical impedance analysis (BIA) devices as compared with a laboratory four-compartment (4C) model. Seventy-three healthy participants aged 19-50 years were assessed by each of fifteen BIA devices, with resulting body fat percentage estimates compared with a 4C model utilising air displacement plethysmography, dual-energy X-ray absorptiometry and bioimpedance spectroscopy. A subset of thirty-seven participants returned for a second visit 12-16 weeks later and were included in an analysis of longitudinal validity. The sample of devices included fourteen consumer-grade and one research-grade model in a variety of configurations: hand-to-hand, foot-to-foot and bilateral hand-to-foot (octapolar). BIA devices demonstrated high reliability, with precision error ranging from 0·0 to 0·49 %. Cross-sectional validity varied, with constant error relative to the 4C model ranging from -3·5 (sd 4·1) % to 11·7 (sd 4·7) %, standard error of the estimate values of 3·1-7·5 % and Lin's concordance correlation coefficients (CCC) of 0·48-0·94. For longitudinal validity, constant error ranged from -0·4 (sd 2·1) % to 1·3 (sd 2·7) %, with standard error of the estimate values of 1·7-2·6 % and Lin's CCC of 0·37-0·78. While performance varied widely across the sample investigated, select models of BIA devices (particularly octapolar and select foot-to-foot devices) may hold potential utility for the tracking of body composition over time, particularly in contexts in which the purchase or use of a research-grade device is infeasible.

Embedding telehealth for sustainable health services linking Oceania.

The expansion of telehealth during the COVID-19 pandemic can be further adapted and extended to align with principles of climate justice. We argue that high-emission countries with well-developed medical systems, like Australia, should support communities disproportionately impacted by climate change who request assistance, like in small island states of Oceania. Linking health services in small island states with neighbouring countries' medical systems can support sustainability, if such reconfigurations are appropriately resourced and accessibility is prioritized. Investments in telehealth, particularly reconfiguring services through community-led linkages with larger medical systems, supports the sustainable development goal of universal access to healthcare.

Patient Responses to Diagnosis in Surgeon-Patient Consultations.

How diagnosis fits within the overall activity structure of surgical consultations remains under-researched. We set out to contribute to this developing area of research with a particular focus on responses to diagnosis as an achievement of patient agency. We identified 26 diagnostic sequences in a collection of 35 video recorded surgical consultations and examined these in detail using conversation analysis. The activity of diagnosis and the transition to treatment recommendation appear to be structured somewhat differently in surgeon-patient consultations than has been reported for primary care settings. In particular, patient responses to diagnosis are more frequent and more likely to be extended. The analysis provides evidence that both parties orient to surgeons' accountability for their own diagnostic reasoning, and also the medical authority of the referring doctor and the subjective experience of the patient. In delivering the diagnosis, the surgeon must be cognizant of the opinions of both the patient and the referring doctor, which may align to a greater or lesser extent with their own diagnosis.

Comparison of Indirect Calorimetry and Common Prediction Equations for Evaluating Changes in Resting Metabolic Rate Induced by Resistance Training and a Hypercaloric Diet.

ABSTRACT: Rodriguez, C, Harty, PS, Stratton, MT, Siedler, MR, Smith, RW, Johnson, BA, Dellinger, JR, Williams, AD, White, SJ, Benavides, ML, and Tinsley, GM. Comparison of indirect calorimetry and common prediction equations for evaluating changes in resting metabolic rate induced by resistance training and a hypercaloric diet. J Strength Cond Res 36(11): 3093-3104, 2022-The ability to accurately identify resting metabolic rate (RMR) changes over time allows practitioners to prescribe appropriate adjustments to nutritional intake. However, there is a lack of data concerning the longitudinal utility of commonly used RMR prediction equations. The purpose of this study was to evaluate the validity of several commonly used prediction equations to track RMR changes during a hypercaloric nutritional intervention and supervised resistance exercise training program. Twenty resistance-trained men completed the study. The protocol lasted 6 weeks, and subjects underwent RMR assessments by indirect calorimetry (IC) preintervention and postintervention to obtain reference values. Existing RMR prediction equations based on body mass (BM) or dual-energy X-ray absorptiometry fat-free mass (FFM) were also evaluated. Equivalence testing was used to evaluate whether each prediction equation demonstrated equivalence with IC. Null hypothesis significance testing was also performed, and Bland-Altman analysis was used alongside linear regression to assess the degree of proportional bias. Body mass and FFM increased by 3.6 ± 1.7 kg and 2.4 ± 1.6 kg, respectively. Indirect calorimetry RMR increased by 165 ± 97 kcal·d -1 , and RMR:FFM increased by 5.6 ± 5.2%. All prediction equations underestimated mean RMR changes relative to IC, with magnitudes ranging from 75 to 155 kcal·d -1 , while also displaying unacceptable levels of negative proportional bias. In addition, no equation demonstrated equivalence with IC. Common RMR prediction equations based on BM or FFM did not fully detect the increase in RMR observed with resistance training plus a hypercaloric diet. Overall, the evaluated prediction equations are unsuitable for estimating RMR changes in the context of this study.

Autistic traits and mental health in women with the fragile-X premutation: maternal status versus genetic risk.

BACKGROUND: Research on women with the fragile-X premutation (FX-p) has been underrepresented within the field of behavioural phenotypes. AIMS: To understand whether the FX-p confers risk for autistic traits, depression and anxiety, independent of maternal status. METHOD: In study 1, mothers of children with fragile-X syndrome (M-FXp; n = 51, mean age 43 years (s.d. = 5.80)) were compared with mothers of autistic children (M-ASD; n = 59, mean age 42 (s.d. = 5.80)), mothers of children with Smith-Magenis syndrome (M-SMS; n = 27, mean age 39 (s.d. = 7.20)) and mothers of typically developing children (M-TD; n = 44, mean age 40 (s.d. = 4.90)). In study 2, the M-FXp group were compared with non-mothers with the FX-p (NM-FXp; n = 17, mean age 32 (s.d. = 9.20)), typically developed non-mothers (NM-TD; n = 28, mean age 31 (s.d. = 6.80)) and the M-TD group. All participants completed an online survey, including measures of IQ, autistic traits, anxiety, depression and positive affect. RESULTS: In study 1: the M-FXp group reported more autistic traits than the M-TD group (P < 0.05, η2 = 0.046). Anxiety and parental stress were elevated in the M-FXp, M-SMS and M-ASD groups relative to the M-TD group (all P ≤ 0.003, η2 = 0.079-0.322). In study 2: a main effect of premutation status indicated that women with the FX-p report elevated autistic traits and anxiety (P ≤ 0.007, η2 = 0.055-0.060); this did not interact with maternal status. CONCLUSIONS: The findings indicate that women with the FX-p show an increased risk for autistic traits and anxiety. This risk is specific to the presence of the FX-p and is not fully accounted for by maternal status or the stress of caring for children with neurodevelopmental disorders.

Preliminary Evidence That Real World Sleep Timing and Duration are Associated With Laboratory-Assessed Alcohol Response.

BACKGROUND: Sleep timing and evening chronotype have been implicated in alcohol use problems but research has yet to study them in relation to theory-driven laboratory-based measures of alcohol use disorder risk. The current study examined (i) whether chronotype, sleep timing, and/or sleep duration are associated with alcohol response (subjective stimulation, sedation, and behavioral disinhibition) and (ii) if sex and race moderate these associations. METHODS: Adult drinkers (N = 144; 46 female participants) completed 2 counterbalanced beverage administration sessions (alcohol and nonalcohol) during which they rated stimulation/sedation and completed a cued go/no-go task. They reported bed and waketimes over 10 days. RESULTS: Later sleep timing was associated with greater increases in alcohol stimulation, but among male and White participants only. Later sleep timing (among male participants) and greater eveningness (examined among White male participants only) were associated with greater overall stimulation on average in the alcohol session relative to the nonalcohol session, irrespective of alcohol consumption. More variable sleep duration was associated with greater increases in sedation. CONCLUSIONS: These findings offer preliminary, but novel evidence that sleep characteristics may relate to the relative stimulating and sedating effects of alcohol, thereby influencing the risk for alcohol problems.

Larger extrastriate population receptive fields in autism spectrum disorders.

Previous behavioral research suggests enhanced local visual processing in individuals with autism spectrum disorders (ASDs). Here we used functional MRI and population receptive field (pRF) analysis to test whether the response selectivity of human visual cortex is atypical in individuals with high-functioning ASDs compared with neurotypical, demographically matched controls. For each voxel, we fitted a pRF model to fMRI signals measured while participants viewed flickering bar stimuli traversing the visual field. In most extrastriate regions, perifoveal pRFs were larger in the ASD group than in controls. We observed no differences in V1 or V3A. Differences in the hemodynamic response function, eye movements, or increased measurement noise could not account for these results; individuals with ASDs showed stronger, more reliable responses to visual stimulation. Interestingly, pRF sizes also correlated with individual differences in autistic traits but there were no correlations with behavioral measures of visual processing. Our findings thus suggest that visual cortex in ASDs is not characterized by sharper spatial selectivity. Instead, we speculate that visual cortical function in ASDs may be characterized by extrastriate cortical hyperexcitability or differential attentional deployment.

Treatment with a monoclonal antibody against methamphetamine and amphetamine reduces maternal and fetal rat brain concentrations in late pregnancy.

We hypothesized that treatment of pregnant rat dams with a dual reactive monoclonal antibody (mAb4G9) against (+)-methamphetamine [METH; equilibrium dissociation rate constant (KD) = 16 nM] and (+)-amphetamine (AMP; KD = 102 nM) could confer maternal and fetal protection from brain accumulation of both drugs of abuse. To test this hypothesis, pregnant Sprague-Dawley rats (on gestational day 21) received a 1 mg/kg i.v. METH dose, followed 30 minutes later by vehicle or mAb4G9 treatment. The mAb4G9 dose was 0.56 mole-equivalent in binding sites to the METH body burden. Pharmacokinetic analysis showed baseline METH and AMP elimination half-lives were congruent in dams and fetuses, but the METH volume of distribution in dams was nearly double the fetal values. The METH and AMP area under the serum concentration-versus-time curves from 40 minutes to 5 hours after mAb4G9 treatment increased >7000% and 2000%, respectively, in dams. Fetal METH serum did not change, but AMP decreased 23%. The increased METH and AMP concentrations in maternal serum resulted from significant increases in mAb4G9 binding. Protein binding changed from ∼15% to > 90% for METH and AMP. Fetal serum protein binding appeared to gradually increase, but the absolute fraction bound was trivial compared with the dams. mAb4G9 treatment significantly reduced METH and AMP brain values by 66% and 45% in dams and 44% and 46% in fetuses (P < 0.05), respectively. These results show anti-METH/AMP mAb4G9 therapy in dams can offer maternal and fetal brain protection from the potentially harmful effects of METH and AMP.

Vitamin D deficiency in patients with intellectual disabilities: prevalence, risk factors and management strategies.

BACKGROUND: People with intellectual disabilities have a high risk of osteoporosis and fractures, which could partly be as a result of vitamin D deficiency. AIMS: To compare the serum vitamin D (25(OH)D) levels of 155 patients with intellectual disabilities under psychiatric care and 192 controls, investigate potential risk factors for vitamin D deficiency in people with intellectual disabilities and assess available treatments. METHOD: Cross-sectional observational study followed by treatment evaluation. Results Almost twice as many patients with intellectual disabilities had vitamin D deficiency (25(OH)D <50 nmol/l) compared with controls (77.3% v. 39.6%, P<0.0001). In the intellectual disabilities group, winter season (P<0.0001), dark skin pigmentation (P<0.0001), impaired mobility (P = 0.002) and obesity (P = 0.001) were independently associated with lower serum 25(OH)D. In most patients, 800 IU colecalciferol daily normalised 25(OH)D levels. CONCLUSIONS: Vitamin D deficiency is highly prevalent in people with intellectual disabilities, partly because of insufficient exposure to sunlight. Screening and treatment strategies, aiming to reduce these patients' high fracture risk, should be introduced. Similar strategies may be required in other psychiatric populations at risk for fractures and with a tendency to spend excessive time indoors.

Isoleucine 309 acts as a C4 catalytic switch that increases ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) carboxylation rate in Flaveria.

Improving global yields of important agricultural crops is a complex challenge. Enhancing yield and resource use by engineering improvements to photosynthetic carbon assimilation is one potential solution. During the last 40 million years C(4) photosynthesis has evolved multiple times, enabling plants to evade the catalytic inadequacies of the CO(2)-fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). Compared with their C(3) ancestors, C(4) plants combine a faster rubisco with a biochemical CO(2)-concentrating mechanism, enabling more efficient use of water and nitrogen and enhanced yield. Here we show the versatility of plastome manipulation in tobacco for identifying sequences in C(4)-rubisco that can be transplanted into C(3)-rubisco to improve carboxylation rate (V(C)). Using transplastomic tobacco lines expressing native and mutated rubisco large subunits (L-subunits) from Flaveria pringlei (C(3)), Flaveria floridana (C(3)-C(4)), and Flaveria bidentis (C(4)), we reveal that Met-309-Ile substitutions in the L-subunit act as a catalytic switch between C(4) ((309)Ile; faster V(C), lower CO(2) affinity) and C(3) ((309)Met; slower V(C), higher CO(2) affinity) catalysis. Application of this transplastomic system permits further identification of other structural solutions selected by nature that can increase rubisco V(C) in C(3) crops. Coengineering a catalytically faster C(3) rubisco and a CO(2)-concentrating mechanism within C(3) crop species could enhance their efficiency in resource use and yield.

Framing the consultation: the role of the referral in surgeon-patient consultations.

This study describes and analyzes the impact of the referral process on communication at the beginning of surgeon-patient consultations. We used conversation analysis to analyze the opening interactional activities of surgeon-patient consultations in New Zealand. This study focuses on 20 video-recorded consultations recorded between 2004 and 2006. Participants in surgeon-patient consultations began referred consultations by discussing the referral letter in what we have termed "referral recognition sequences." These sequences are coconstructed activities that can be implicit or explicit and address the minimized epistemic distance between surgeons and patients that is caused by the referral process. These sequences can be simple or complex, and this complexity may be determined by the quality of the referral letter received. Acknowledgment of the referral letter assists in achieving alignment between surgeon, patient, and referring doctor regarding the presenting problem. If this alignment is not achieved, progressivity of the consultation is affected, as there is disagreement as to why the patient is seeing the surgeon. This research shows that to assist in the progressivity of surgeon-patient consultations, referral letters should be clear and patients made aware of the reason for referral. Surgeons should also overtly address the minimized epistemic distance caused by the referral letter to ensure patients present their problems in full.

Can group membership modulate the social abilities of autistic people? An intergroup bias in smile perception.

Autistic adults struggle to reliably differentiate genuine and posed smiles. Intergroup bias is a promising factor that may modulate smile discrimination performance, which has been shown in neurotypical adults, and which could highlight ways to make social interactions easier. However, it is not clear whether this bias also exists in autistic people. Thus, the current study aimed to investigate this in autism using a minimal group paradigm. Seventy-five autistic and sixty-one non-autistic adults viewed videos of people making genuine or posed smiles and were informed (falsely) that some of the actors were from an in-group and others were from an out-group. The ability to identify smile authenticity of in-group and out-group members and group identification were assessed. Our results revealed that both groups seemed equally susceptible to ingroup favouritism, rating ingroup members as more genuine, but autistic adults also generally rated smiles as less genuine and were less likely to identify with ingroup members. Autistic adults showed reduced sensitivity to the different smile types but the absence of an intergroup bias in smile discrimination in both groups seems to indicate that membership can only modulate social judgements but not social abilities. These findings suggest a reconsideration of past findings that might have misrepresented the social judgements of autistic people through introducing an outgroup disadvantage, but also a need for tailored support for autistic social differences that emphasizes similarity and inclusion between diverse people.

Autistic adults perceive and experience laughter differently to non-autistic adults.

Human interaction is immersed in laughter; though genuine and posed laughter are acoustically distinct, they are both crucial socio-emotional signals. In this novel study, autistic and non-autistic adults explicitly rated the affective properties of genuine and posed laughter. Additionally, we explored whether their self-reported everyday experiences with laughter differ. Both groups could differentiate between these two types of laughter. However, autistic adults rated posed laughter as more authentic and emotionally arousing than non-autistic adults, perceiving it to be similar to genuine laughter. Autistic adults reported laughing less, deriving less enjoyment from laughter, and experiencing difficulty in understanding the social meaning of other people's laughter compared to non-autistic people. Despite these differences, autistic adults reported using laughter socially as often as non-autistic adults, leveraging it to mediate social contexts. Our findings suggest that autistic adults show subtle differences in their perception of laughter, which may be associated with their struggles in comprehending the social meaning of laughter, as well as their diminished frequency and enjoyment of laughter in everyday scenarios. By combining experimental evidence with first-person experiences, this study suggests that autistic adults likely employ different strategies to understand laughter in everyday contexts, potentially leaving them socially vulnerable in communication.

Tailoring communication practices to support effective delivery of telehealth in general practice.

BACKGROUND: The unprecedented increase in telehealth use due to COVID-19 has changed general practitioners' (GP) and patients' engagement in healthcare. There is limited specific advice for effective communication when using telehealth. Examining telehealth use in practice in conjunction with perspectives on telehealth as they relate to communication allows opportunities to produce evidence-based guidance for optimal use of telehealth, while also offering practitioners the opportunity to reflect on elements of their communicative practice common to both styles of consultation. The objective of this research was to develop evidence-based resources to support effective, person-centred communication when GPs and patients use telehealth. This included examination of interactional practices of recorded telehealth consultations, exploration of GP and patient perspectives relating to telehealth, and identifying priorities for guidance informed by these analyses as well as participant co-design. METHODS: This study involved recording telehealth consultations (n = 42), conducting patient surveys (n = 153), and interviewing patients (n = 9) and GPs (n = 15). These were examined using interaction analytic methods, quantitative analysis, and thematic analyses, to create a robust, integrated picture of telehealth practice and perspectives. The process of research translation involved a co-design approach, engaging with providers, patients, and policy makers to facilitate development of evidence-based principles that focus on supporting effective communication when using telehealth. RESULTS: Three key themes relating to communication in telehealth were identified across the different analyses. These were relationship building, conversational flow, and safety netting. The draft best practice principles drawn from these themes were modified based on co-design feedback into five Best Practice Principles for Communication between GPs and Patients using Telehealth. CONCLUSIONS: Effective communication is supported through relationship building and attention to conversational flow in telehealth consultations, which in turn allows for safety netting to occur. In telehealth, GPs and patients recognise that not being co-present changes the consultation and use both intuitive and strategic interactional adjustments to support their exchange. The mixed-method examination of experiences through both a detailed analysis of telehealth consultations in practice and comparative exploration of GP and patient perspectives enabled the identification of principles that can support effective communication when using telehealth. Co-design helped ensure these principles are ready for implementation into practice.

Evaluative contexts facilitate implicit mentalizing: relation to the broader autism phenotype and mental health.

One promising account for autism is implicit mentalizing difficulties. However, this account and even the existence of implicit mentalizing have been challenged because the replication results are mixed. Those unsuccessful replications may be due to the task contexts not being sufficiently evaluative. Therefore, the current study developed a more evaluative paradigm by implementing a prompt question. This was assessed in 60 non-autistic adults and compared with a non-prompt version. Additionally, parents of autistic children are thought to show a genetic liability to autistic traits and cognition and often report mental health problems, but the broader autism phenotype (BAP) is an under-researched area. Thus, we also aimed to compare 33 BAP and 26 non-BAP mothers on mentalizing abilities, autistic traits, compensation and mental health. Our results revealed that more evaluative contexts can facilitate implicit mentalizing in BAP and non-BAP populations, and thus improve task reliability and replicability. Surprisingly, BAP mothers showed better implicit mentalizing but worse mental health than non-BAP mothers, which indicates the heterogeneity in the broader autism phenotype and the need to promote BAP mothers' psychological resilience. The findings underscore the importance of contexts for implicit mentalizing and the need to profile mentalizing and mental health in BAP parents.

Factors Associated with Increased Knowledge about Breast Density in South Australian Women Undergoing Breast Cancer Screening.

Background: There is growing awareness of breast density in women attending breast cancer screening; however, it is unclear whether this awareness is associated with increased knowledge. This study aims to evaluate breast density knowledge among Australian women attending breast cancer screening. Method: This cross-sectional study was conducted on women undergoing breast cancer screening at The Queen Elizabeth Hospital Breast/Endocrine outpatient department. Participants were provided with a questionnaire to assess knowledge, awareness, and desire to know their own breast density. Result: Of the 350 women who participated, 61% were familiar with 'breast density' and 57% had 'some knowledge'. Prior breast density notification (OR = 4.99, 95% CI = 2.76, 9.03; p = 0.004), awareness (OR = 4.05, 95% CI = 2.57, 6.39; p = 0.004), younger age (OR = 0.97, 95% CI = 0.96, 0.99; p = 0.02), and English as the language spoken at home (OR = 3.29, 95% CI = 1.23, 8.77; p = 0.02) were independent predictors of 'some knowledge' of breast density. A significant proportion of participants (82%) expressed desire to ascertain their individual breast density. Conclusions: While knowledge of breast density in this Australian cohort is generally quite low, we have identified factors associated with increased knowledge. Further research is required to determine optimal interventions to increase breast density knowledge.

Exploring patient ideas, concerns, and expectations in surgeon-patient consultations.

OBJECTIVES: This study explores patient perspectives (ideas, concerns, and expectations) in surgeon-patient consultations. METHODS: We examined 54 video-recorded consultations using applied conversation analysis. Consultations took place from 2012 to 2017 in an Australian metropolitan hospital clinic centre and involved seven surgeons across six specialties. RESULTS: Patient perspectives emerged in less than one third of consultations. We describe the initiation of and response to potential perspectives sequences, demonstrating how patients and surgeons co-construct these sequences when they do occur. CONCLUSIONS: Findings suggest a need for greater attention to supporting patient agency through explicit pursuit of patient perspectives. The implications extend to the Calgary-Cambridge Guide, suggesting that it may benefit from a focus on active pursuit and appropriate responsiveness to patient perspectives. PRACTICE IMPLICATIONS: This study highlights the need for surgeons to actively engage with the patient perspective offered in consultations, emphasising the importance of respect for the patient's knowledge and expectations to improve patient satisfaction and healthcare outcomes.

Mobile phone applications for 3-dimensional scanning and digital anthropometry: a precision comparison with traditional scanners.

BACKGROUND: The precision of digital anthropometry through 3-dimensional (3D) scanning has been established for relatively large, expensive, non-portable systems. The comparative performance of modern mobile applications is unclear. SUBJECTS/METHODS: Forty-six adults (age: 23.3 ± 5.3 y; BMI: 24.4 ± 4.1 kg/m2) were assessed in duplicate using: (1) a mobile phone application capturing two individual 2D images, (2) a mobile phone application capturing serial images collected during a subject's complete rotation, (3) a traditional scanner with a time of flight infrared sensor collecting visual data from a subject being rotated on a mechanical turntable, and (4) a commercial measuring booth with structured light technology using 20 infrared depth sensors positioned in the booth. The absolute and relative technical error of measurement (TEM) and intraclass correlation coefficient (ICC) for each method were established. RESULTS: Averaged across circumferences, the absolute TEM, relative TEM, and ICC were (1) 0.9 cm, 1.5%, and 0.975; (2) 0.5 cm, 0.9%, and 0.986; (3) 0.8 cm, 1.5%, and 0.974; and (4) 0.6 cm, 1.1%, and 0.985. For total body volume, these values were (1) 2.2 L, 3.0%, and 0.978; (2) 0.8 L, 1.1%, and 0.997; (3) 0.7 L, 0.9%, and 0.998; and (4) 0.8 L, 1.1%, and 0.996, with segmental volumes demonstrating higher relative errors. CONCLUSION: A 3D scanning mobile phone application involving full rotation of subjects in front of a smartphone camera exhibited similar reliability to larger, less portable, more expensive 3D scanners. In contrast, larger errors were observed for a mobile scanning application utilizing two 2D images, although the technical errors were acceptable for some applications.