High inter- and intra-observer agreement for measuring tissue oxygenation of the plantar surface of the foot in healthy participants with the Hyperview®: A pilot study

Abstract

Objectives The Hyperview® is a novel camera that applies hyperspectral imaging to project local concentrations of oxyhaemoglobin (OXY), deoxyhaemoglobin (DEOXY) and O2-saturation (O2-SAT) in a map. In this pilot validation study, we assessed inter - and intra-observer agreement for measuring OXY, DEOXY and O2-SAT in healthy participants. Methods The plantar region of the right foot was assessed with the Hyperview® in 50 healthy participants. Two consecutive pictures were taken by the same observer, followed by two images by a second observer. Measurements were performed without and with standardization (a static device for both the foot and the Hyperview camera). Inter- and intra-observer agreements were expressed as Intraclass Correlation coefficients (ICC) with their 95% confidence interval (CI). A score <0.40 indicates poor agreement, 0.40–0.59 fair, 0.60–0.74 good and 0.75–1.00 excellent agreement. Bland and Altman plots were also generated. Results Without standardization, the ICC values between the observers for OXY, DEOXY and O2-SAT ranged from 0.70 to 0.83. The intra-observer agreement of both observers ranged from 0.36 to 0.83. With standardization, the ICC values between the observers ranged from 0.80 to 0.82 and intra-observer agreement varied from 0.75 to 0.92. Four Bland and Altman plots were generated of the measurements of OXY by observers 1 and 2. Conclusions When standardization is used, the Hyperview® camera is a reliable device with excellent intra- and inter-observer agreements for the assessment of OXY, DEOXY and O2-SAT. In future research, the inter- and intra-observer agreements of the camera should be investigated in patients with diabetes and/or peripheral arterial disease.

Assessment of microcirculatory changes in local tissue oxygenation after revascularization for peripheral arterial disease with the Hyperview®, a portable hyperspectral imaging device

“…Published studies reporting on average values of Hyperview ® measurements in healthy participants show a wide variation. 8,16 Kleiss et al 8 found an average for OXY of 85.2 arbitrary units (SD 24.9) whereas van Schilt et al 10 reported an average of 69.6 (SD 21.8). Therefore, we advice to perform pre-intervention measurements to compare the patient with his or her own measurements to observe changes.…”

“…13 Within the same session a Hyperview ® measurement was performed according to a standardized protocol, which has been validated in healthy participants in a previous study. 10 In this protocol, the room temperature was set at an ambient temperature of 20-23°of Celsius. The patients were placed in a supine position on an examination table with the head of the table elevated to 45°.…”

“…An earlier study of this research group with the Hyperview ® showed that the use of the Hyperview ® is less time consuming than the existing gold standard and has high reproducibility, especially when applying a standardized protocol. 8,10 In this study, we applied this standardized protocol and showed that the instrument is sensitive to detect changes in the microcirculation.…”

“…Moreover, the measurements are painless, take up to only an average of 7 min, and are easy to learn and perform. 8,[10][11][12] The aim of this study is to assess whether the Hyperview ® is able to detect microcirculatory changes after revascularization.…”

“…Moreover, the measurements are painless, take up to only an average of 7 min, and are easy to learn and perform. 8,10-12

Figure 1.Hyperview® camera.

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