1 - Neonatology Unit, Hospital Dona Estefânia and Maternidade Dr. Alfredo da Costa, Unidade de Saúde Local São José, Centro Clínico Académico de Lisboa, Lisbon, Portugal
2 - Medicine of Woman, Childhood and Adolescence Academic Area, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
3 - CHRC - Comprehensive Health Research Centre, Nutrition Group, NOVA Medical School, Faculdade de Ciências Médicas, Lisbon, Portugal
4 - Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
5 - Research Unit, Unidade de Saúde Local São José, Centro Clínico Académico de Lisboa, Lisbon, Portugal
6 - Centre of Statistics and Its Applications, University of Lisbon, Lisbon, Portugal
7 - Population Health Statistical Area. NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
- Children (Basel). 2024;11(12):1544. doi: 10.3390/children11121544.
- Patente: Modelo de Utilidade Nacional (família de patentes) N° 10967, do Instituto Nacional de Propriedade Industrial em Portugal (https://inpi.justica.gov.pt/
Introduction: Opening the incubator side wall to insert a non-sterile length measuring device carries the risk of microbial contamination and ther-mal instability for preterm infants. To reduce this inconvenience, a laser-based length measuring board is proposed to measure body length from outside the incubator.
Methods: This device has two laser line shaped cursors which can be pointed to opposite ends of a segment to be measured. It is attached to the outer side of one of the incubator’s side walls in such manner to ensure that its axis is parallel to the longitudinal axis of the segment. To validate the measurements made with this model, a calibrated caliper consisting of a conventional rigid length measuring board with a resolution of 0.05 mm was constructed to serve as a reference. Crown-heel length was measured in a sample of 45 infants, including 32 preterm and 13 term infants at corrected gestational age at the time of measurement.
Results: Good intra-observer variability was obtained. Near perfect statistical agreement was found between measurements with both devices, with concordance correlation coefficients of 0.994 (95% CI: 0.990; 0.996) in preterm infants and 0.994 (95% CI: 0.988, 0.998) in infants at term. The clinical relevance of the agreement between measurements was assessed by the Bland-Altman plot, and the difference may reach clinical relevance (up to 1 cm) but without evidence of proportional bias.
Conclusion: The proposed validated laser-based length measuring board offers a suitable alternative to conventional length measuring boards for contactless measurement of infant body length.
Palavras Chave: caliper; contactless measurement; incubator; laser; length measuring board; preterm infant