Use of a wearable device to compare subjective and objective fatigue in lung cancer patients and cancer-free controls

PURPOSE

The study evaluates the use of heart rate variability (HRV), a measure of autonomic nervous system (ANS) modulation via wearable smart bands, to objectively assess cancer-related fatigue (CRF) levels. It aims to enhance understanding of fatigue by distinguishing between LF/HF ratios and LF/HF disorder ratios through HRV and photoplethysmography (PPG), identifying them as potential biomarkers.

METHODS

Seventy-one lung cancer patients and 75 non-cancer controls wore smart bands for one week. Fatigue was assessed using Brief Fatigue Inventory, alongside sleep quality and daily interference. HRV parameters were analyzed to compare groups.

RESULTS

Cancer patients showed higher fatigue and interference levels than controls (64.8% vs. 54.7%). Those with mild fatigue had elevated LF/HF disorder ratios during sleep (40% vs. 20%, P = 0.01), similar to those with moderate to severe fatigue (50% vs. 20%, P = 0.01), indicating more significant autonomic dysregulation. Notably, mild fatigue patients had higher mean LF/HF ratios than controls (1.9 ± 1.34 vs. 1.2 ± 0.6, P = 0.01), underscoring the potential of disorder ratios in signaling fatigue severity.

CONCLUSIONS

Utilizing wearable smart bands for HRV-based analysis is feasible for objectively assess CRF levels in cancer patients, especially during sleep. By distinguishing between LF/HF ratios and LF/HF disorder ratios, our findings suggest that wearable technology and detailed HRV analysis offer promising avenues for real-time fatigue monitoring. This approach has the potential to significantly improve cancer care by providing new methods for managing and intervening in CRF, particularly with a focus on autonomic dysregulation as a crucial factor.

Cancer-related fatigue classification based on heart rate variability signals from wearables

Background

Cancer-related fatigue (CRF) is the most distressing side effect in cancer patients and affects the survival rate. However, most patients do not report their fatigue level. This study is aimed to develop an objective CRF assessment method based on heart rate variability (HRV).

Methods

In this study, patients with lung cancer who received chemotherapy or target therapy were enrolled. Patients wore wearable devices with photoplethysmography that regularly recorded HRV parameters for seven consecutive days and completed the Brief Fatigue Inventory (BFI) questionnaire. The collected parameters were divided into the active and sleep phase parameters to allow tracking of fatigue variation. Statistical analysis was used to identify correlations between fatigue scores and HRV parameters.

Findings

In this study, 60 patients with lung cancer were enrolled. The HRV parameters including the low-frequency/high-frequency (LF/HF) ratio and the LF/HF disorder ratio in the active phase and the sleep phase were extracted. A linear classifier with HRV-based cutoff points achieved correct classification rates of 73 and 88% for mild and moderate fatigue levels, respectively.

Conclusion

Fatigue was effectively identified, and the data were effectively classified using a 24-h HRV device. This objective fatigue monitoring method may enable clinicians to effectively handle fatigue problems.

Comparison between subjective and objective fatigue in patients with lung cancer and cancer-free participants: Evaluation of diagnostic criteria for cancer-related fatigue

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Background: Cancer-related fatigue is one of the most distressing symptoms of cancer patients. Finding a patient's fatigue often requires the use of a subjective assessment scale, such as the Brief Fatigue Inventory (BFI). There are few objective ways to measure fatigue. The aim of this study was to evaluate whether objective cancer-related fatigue (CRF) diagnostic criteria can differentiate cancer from cancer-free participants and to explore the relationship between subjective and objective fatigue. Methods: In this study, we used a photoplethysmography (PPG) smartband device to collect the PPG information from the patients. During PPG measurements, the heart rate variability (HRV) signal was included in the data collection process for subsequent calculation of the LF/HF ratio. Participants completed a self-report measure to assess demographics, fatigue levels, and brief sleep diaries for the next 7 days. At the same time, the participants wore a wristband to collect HRV signals, which triggered HRV every hour over a 24-hour period for 7 consecutive days. Results: Cancer patients (n = 71) and cancer-free controls (n = 75) were studied. Study participants completed CRF questionnaires and heart rate variability (HRV) records. The smartband can be worn continuously for 120 hours as an objective measure of activity phase, sleep phase and HRV. Compared with controls, cancer patients were more fatigued and were more likely to be disturbed by fatigue (t = -3.73, p < 0.001), especially general activity (t = -2.93, p < 0.001), walking ability (t = -3.6, p < 0.001) and normal work (t = -2.18, p = 0.03). Wearing the bracelet can get the LF/HF value of HRV in the time domain. The LF to HF and LF/HF disorder ratios were further divided into active and sleep phases. During sleep phase, the LF/HF disorder ratio was higher in the cancer group than in the control group regardless of whether fatigue was mild or moderate (t = -2.5, p = 0.01; t = -2.8, p = 0.01, respectively). The LF/HF disorder ratios was higher in cancer patients with mild fatigue than in cancer-free participants during sleep phase (40% vs 20%, respectively). Cancer patients with moderate fatigue had higher incidence of LF/HF disorder ratios than cancer-free participants (50% vs 20%, respectively). Conclusions: It can be concluded that the diagnostic criteria of subjective and objective CRF can distinguish cancer and cancer-free cases. Using this objective fatigue device could provide an indicator for further clinical monitoring. Clinical trial information: NCT04300842.

Measurement of Cancer-Related Fatigue Based on Heart Rate Variability: Observational Study

BACKGROUND

Cancer-related fatigue is a serious side effect of cancer, and its treatment can disrupt the quality of life of patients. Clinically, the standard method for assessing cancer-related fatigue relies on subjective experience retrieved from patient self-reports, such as the Brief Fatigue Inventory (BFI). However, most patients do not self-report their fatigue levels.

OBJECTIVE

In this study, we aim to develop an objective cancer-related fatigue assessment method to track and monitor fatigue in patients with cancer.

METHODS

In total, 12 patients with lung cancer who were undergoing chemotherapy or targeted therapy were enrolled. We developed frequency-domain parameters of heart rate variability (HRV) and BFI based on a wearable-based HRV measurement system. All patients completed the BFI-Taiwan version questionnaire and wore the device for 7 consecutive days to record HRV parameters such as low frequency (LF), high frequency (HF), and LF-HF ratio (LF-HF). Statistical analysis was used to map the correlation between subjective fatigue and objective data.

RESULTS

A moderate positive correlation was observed between the average LF-HF ratio and BFI in the sleep phase (ρ=0.86). The mapped BFI score derived by the BFI mapping method could approximate the BFI from the patient self-report. The mean absolute error rate between the subjective and objective BFI scores was 3%.

CONCLUSIONS

LF-HF is highly correlated with the cancer-related fatigue experienced by patients with lung cancer undergoing chemotherapy or targeted therapy. Beyond revealing fatigue levels objectively, continuous HRV recordings through the photoplethysmography watch device and the defined parameters (LF-HF) can define the active phase and sleep phase in patients with lung cancer who undergo chemotherapy or targeted chemotherapy, allowing a deduction of their sleep patterns.

Isovalent Ca and Ba substitutions in thermoelectric layer-structured oxyselenide Sr2CoO2Cu2Se2

Multilayered compounds typically present exotic functionalities, and some of them have been suggested as potential materials for thermoelectric conversion owing to their unique capability to decouple electronic and heat transport. Here we report new [CoO2] and [Cu2Se2] layered A2CoO2Cu2Se2 compounds in which Sr at the intervening alkaline-earth A site is partially replaced with Ca or Ba. The parent Sr2CoO2Cu2Se2 phase is a direct gap p-type semiconductor, and density functional theory (DFT) calculations indicate its topmost valence band consists of Cu 3d-Se 4p states. Upon the isovalent cation substitution the lattice modification in the ab plane is constrained by the stiff [CoO2] layer such that the lattice shrinkage/expansion mainly happens along the c axis. Substitution of Sr with the heavier and larger Ba significantly enhances the thermopower but more hole states would be required to optimize the thermoelectric performance. Thermal stability is related to the inter-oxide-selenide-layer interaction, and our thermogravimetric measurement data reveal that the A2CoO2Cu2Se2 materials could operate in the intermediate temperature region.

The processing of coreference for reduced expressions in discourse integration

Three reading-time experiments in Chinese are reported that test contrasting views of how pronominal coreference is achieved. On the one hand, studies of reading time and eye tracking suggest that reduced expressions, such as the pronoun he, serve as critical links to integrate separate utterances into a coherent model of discourse. On the other hand, probe-word recognition studies indicate that full anaphoric expressions, such as a repeated name, are more readily interpreted than reduced expressions due to their rich lexical information, which provides effective cues to match the representation of the appropriate referent in memory. The results indicate that the ease of integrating the critical referent into a model of discourse is a function of the congruence of lexical, semantic, and discourse features conveyed by a syntactically prominent reduced expression within linguistic input. This pattern supports the view that a reduced expression is interpreted on-line and indeed plays a critical role in promoting discourse coherence by facilitating the semantic integration of separate utterances.

Encoding operation and transcoding as the major loci of the frequency effect

The present study used a lexical naming task as well as a regular naming task and a lexical decision task for locating the frequency effects in lexical decision and naming. The naming of Chinese characters in the lexical naming task (pseudocharacters also presented as in the lexical decision task) involves decision processes, while they are absent in the regular naming task. Since naming a Chinese character necessarily involves lexical access, a decision component of the frequency effect in lexical decision can be isolated. This procedure will not work for alphabetic orthographies, because sublexical processes underestimate the frequency effect in the regular naming task. As a consequence, not only can a prelexical component of the frequency effect in lexical decision be estimated, but a postlexical component of the frequency effect in naming can be estimated.

Variation of geosmin content in Anabaena cells and its relation to nitrogen utilization

The addition of the proper amount of ammonium to the culture medium containing nitrate as nitrogen source enhanced the growth rate of Anabaena viguieri. The amount of geosmin produced by these cells varied with the concentrations of ammonium added. A negative correlation between the amount of geosmin produced and of the growth rate of cells was revealed. This was also found in cells grown on various forms of nitrogen sources. Without supply of any nitrogen compound, this organism is capable of fixing gaseous nitrogen, and under these conditions the cells grew relatively slowly. However, they produced more geosmin (per unit protein mass) than cells grown in the presence of combined nitrogen. The isolation of heterocysts, in which nitrogen was fixed, showed that these cells produced higher amounts of geosmin than vegetative cells. The possible relation of nitrogen assimilation to the production of geosmin in the cells was discussed.