Search for: All records

BackgroundIn light of recent retrospective studies revealing evidence of disparities in access to medical technology and of bias in measurements, this narrative review assesses digital determinants of health (DDoH) in both technologies and medical formulae that demonstrate either evidence of bias or suboptimal performance, identifies potential mechanisms behind such bias, and proposes potential methods or avenues that can guide future efforts to address these disparities. ApproachMechanisms are broadly grouped intophysical and biological biases(e.g., pulse oximetry, non-contact infrared thermometry [NCIT]),interaction of human factors and cultural practices(e.g., electroencephalography [EEG]), andinterpretation bias(e.g, pulmonary function tests [PFT], optical coherence tomography [OCT], and Humphrey visual field [HVF] testing). This review scope specifically excludes technologies incorporating artificial intelligence and machine learning. For each technology, we identify both clinical and research recommendations. ConclusionsMany of the DDoH mechanisms encountered in medical technologies and formulae result in lower accuracy or lower validity when applied to patients outside the initial scope of development or validation. Our clinical recommendations caution clinical users in completely trusting result validity and suggest correlating with other measurement modalities robust to the DDoH mechanism (e.g., arterial blood gas for pulse oximetry, core temperatures for NCIT). Our research recommendations suggest not only increasing diversity in development and validation, but also awareness in the modalities of diversity required (e.g., skin pigmentation for pulse oximetry but skin pigmentation and sex/hormonal variation for NCIT). By increasing diversity that better reflects patients in all scenarios of use, we can mitigate DDoH mechanisms and increase trust and validity in clinical practice and research. 

Background: Hypertension is a major risk factor for cardiovascular disease and requires long-term health treatment and ongoing monitoring to the extent that traditional management approaches may be limited in providing. Adopting appropriate digital tools like mobile health technology (mHealth) could be an effective strategy for improving the control and management of this public health burden. This pilot studyevaluated the feasibility of the AHOMKA care model at two tertiary hospitals in Ghana. Outcome measures were changes in systolic (SBP) and diastolic (DBP) blood pressure model acceptance by patients and health care providers.Objective: This study sought to assess the overall pattern of home blood pressure self-monitoring among participants from two teaching hospitals in southern Ghana, using mHealth.Methods: Participants attending two (2) cardiology clinics were recruited for this mixed-method pilot study over a period of eight (8) weeks. Following a longitudinal single-group approach, we conducted structured interviews at the baseline and end-line and used exports of the AHOMKA mHealth application, in-depth interviews and focus group discussions with patients and healthcare providers. Repeated measuresanalysis of variance was adopted to assess differences in SBP and DBP between baseline and end line.Results: This pilot study involved 27 participants with a mean of 50.4 ± 11.0 years-approximately 1:1 male-female participation. Mean SBP decreased by 11.6 mm Hg (95% CI = 15.0 to -8.2), from an average of 138.6 mmHg at baseline to 126.2 mmHg at endline. Average DBP was also significantly reduced by 3.0 mmHg (95% CI = -5.5 to -0.5), from an average of 87.0 mmHg at baseline to 83.0 mmHg at endline. Patients and healthcare providers were satisfied and optimistic about the AHOMKA care model.Conclusion: The encouraging trend in BP outcomes and high response rate from this pilot study provides evidence for further investigation involving the assessment of the effectiveness of the AHOMKA care model while culturally adapting the model to the Ghanaian context. In the spectrum of hypertension interventions, AHOMKA has the potential to ease the burden on the public health system 

Real-time and non-invasive measurements of tissue concentrations of oxyhemoglobin (HbO2) and deoxyhemoglobin (HbR) are invaluable for research and clinical use. Frequency-domain near-infrared spectroscopy (FD-NIRS) enables non-invasive measurement of these chromophore concentrations in human tissue. We present a small form factor, dual-wavelength, miniaturized FD-NIRS instrument for absolute optical measurements, built around a custom application-specific integrated circuit and a dual-slope/self-calibrating (DS/SC) probe. The modulation frequency is 55 MHz, and the heterodyning technique was used for intensity and phase readout, with an acquisition rate of 0.7 Hz. The instrument consists of a 14 × 17 cm2 printed circuit board (PCB), a Raspberry Pi 4, an STM32G491 microcontroller, and the DS/SC probe. The DS/SC approach enables this instrument to be selective to deeper tissue and conduct absolute measurements without calibration. The instrument was initially validated using a tissue-mimicking solid phantom, and upon confirming its suitability for in vivo, a vascular occlusion experiment on a human subject was conducted. For the phantom experiments, an average of 0.08° phase noise and 0.10% standard deviation over the mean for the intensities was measured at a source–detector distance of 35 mm. The absorption and reduced scattering coefficients had average precisions (variation of measurement over time) of 0.5% and 0.9%, respectively, on a window of ten frames. Results from the in vivo experiment yielded the expected increase in HbO2 and HbR concentration for all measurement types tested, namely SC, DS intensity, and DS phase. 

Hemoglobin is one of the most important chromophores in the human body, since oxygen is carried to the tissue by binding with the hemoglobin. Therefore measuring the concentrations of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) is very important in both clinical settings and academic fields. Frequency domain near infrared spectroscopy (fdNIR spectroscopy) is a technique that can be used to measure the absolute concentrations of HbO and HbR non-invasively and locally. The fdNIR spectrometer utilizes the attenuation and the phase shift (with respect to the source) that an intensity modulated NIR light experiences in order to calculate the absorption (μ_a) and reduced scattering (μ^′s) coefficient of the tissue. In this work, a miniaturized dual-wavelength fdNIR spectrometry instrument is presented with both tissue-like phantom and in vivo occlusion measurements. Systematic tests were performed on tissue phantoms to quantify the accuracy and stability of the instrument. The absolute errors for μ_aand μ^′s were below 15% respectively. The amplitude and phase uncertainty were below 0.25% and 0.35°. In vivo measurements were also conducted to further validate the system.