Real-time Respiration Rate Research Articles

In-House monitoring and measurement of respiration rateusing Disposable Paper Sensor

This present work provides an easily disposable paper-based interdigitated sensor embedded inside the mask for the detection of respiration rate continuously without direct contact with the human body. In present COVID scenario, everyone needs to wear mask for preventing the unwanted spreading of the said virus. But in tropical countries like India, People always complain about a suffocating situation while wearing mask. In order to address this, we have designed a non-invasive paper sensor that can be placed inside the mask (beneath nostril) for measuring breathing rate regularly to find out a cost-effective device capable of monitoring breathing rate. In general, we prefer use and throw type mask, thus the proposed paper-based sensor gives a cost-effective solution compared to the Current appliances of breathing sensing as most of them are burdensome, bulky, inconvenient as well as exorbitant than a paper-based respiration sensor. Essentially, these current approaches undergo through a practical limitation of frequency and time span i.e. static measurement. It is known that the humidity level of a paper changes according to the moisture content. Thus, it can easily detect the inhalation and exhalation through this changing. Moreover, variation of moisture level that happens due to breathing cycle changes the ionic conductivity of the sensor. The interdigitated design is the most suited for achieving higher sensitivity and easy to fabricate. First, we have designed it in Finite Element Method (FEM) based platform and finally this design is implemented with graphite-based electrodes on cellulose paper. Microcontroller based electronic circuitry is used in order to monitor and record the real-time respiration rate. It has been observed that the breathing rate as well as pattern gives a significant variation along with physical conditions and obstructive pulmonary diseases.

A respiratory transducer array to exploit the ultra-sensitive temperature dependence of an acrylate-based composite for real-time respiration rate monitoring

This work proposes a miniaturized respiratory transducer array that utilizes the sharp temperature dependence of the resistivity characteristic of acrylate-based composites with a positive temperature coefficient. The proposed device employs an array configuration consisting of three sensing elements with the composites of different glass transition temperatures to achieve a wide operational temperature range. The temperature transient responses caused by different breathing conditions were clearly resolved by the device, and the corresponding respiration rates were easily extracted. The transducer array was characterized in a room temperature range from 23 °C to 29 °C. In addition, the device effectively detected the respiration rate up to a distance of 30 cm. It was also demonstrated that the device is capable of quantifying the breathing rate over a practical range of frequencies (from 0.1 Hz to 2 Hz). The respiration rates measured by the proposed device were also in good agreement with the results measured simultaneously by using a commercially available nasal pressure transducer. Comparison of the results demonstrated an excellent linear correlation (r=0.953 and P < 0.001). The measured results suggest the feasibility of using this miniaturized device to monitor patients' respiration rates in clinical institutes and in other point-of-care applications.

Response of pomegranate arils (cv. Wonderful) to low oxygen stress under active modified atmosphere condition.

Successful characterization of the relationship between respiration rate (RR) and low oxygen (O2 ) limit is critical for optimizing the modified atmosphere condition. It is well documented that a low O2 atmosphere reduces the RR of fresh produce, but could also lead to abiotic stress due to the accumulation of glycolysis end products. Therefore, this study investigated the response of pomegranate arils exposed to low O2 atmosphere (composed of 2 kPa O2 , 18 kPa carbon dioxide, and 80 kPa nitrogen) and identified the low O2 limit at 5 °C and 10 °C. The study aim was achieved by using real-time RR and respiration quotient (RQ) data, microbial growth, identifying changes in the fermentative volatile organic compounds profile, and the consumption of respiratory metabolites (organic acids and individual sugars). The gas concentrations changed significantly respective to the storage temperature and resulted in a significant change in the parameters studied. The response of pomegranate arils to low O2 stress involves making alterations to the metabolic composition, especially those involved in anaerobiosis, such as the accumulation of ethanol, and an immediate increase on RQ. Pomegranate arils (cv. Wonderful) can tolerate down to 1.9 kPa O2 and 2.3 kPa O2 concentrations at 5 °C and 10 °C respectively. © 2018 Society of Chemical Industry.

Pomegranate arils (‘Wonderful’) tolerance to low O2stress during active modified atmosphere storage: based on real time respiration rate

Pomegranate arils (‘Wonderful’) tolerance to low O₂stress during active modified atmosphere storage: based on real time respiration rate

Discrete ex situ and continuous in situ real-time respiration rate measurements of fresh produce using a novel automated dynamic approach

Discrete ex situ and continuous in situ real-time respiration rate measurements of fresh produce using a novel automated dynamic approach

Effect of UV-C on the physiology and biochemical profile of fresh Piper nigrum berries

Application of UV-C has been shown to enhance the biochemical profile of various plant materials. This could be used to increase biochemical load, reducing the amount of material required but still impart equivalent flavour. As spices, such as black pepper (Piper nigrum L.), are typically dried to low moisture content to create a stable product for transportation and storage, little work has explored the use of modern postharvest treatments to enhance flavour. In this work, fresh P. nigrum berries were exposed to four UV-C doses (0, 1, 5 and 15kJm−2) and subsequently stored at 5°C for ca. 4 weeks. Two separate experiments (early and late season) were conducted across one season. Replicate P. nigrum berry clusters were stored separately within continuously ventilated 13L boxes. Real-time respiration rate (ex situ), ethylene production, fruit colour and water potential were measured at regular intervals during storage. In addition, piperine and essential oils were assessed using a simple newly developed method which enabled both compound groups to be simultaneously extracted and subsequently quantified. UV-C was found to cause significant changes in colour (from green to brown) whilst also altering the biochemical composition (piperine and essential oils), which was influenced by UV-C dose and berry maturity. Low to medium UV-C doses could potentially enhance flavour compounds in black pepper enabling processors to create products with higher biochemical load.

Impact of controlled atmosphere scheduling on strawberry and imported avocado fruit

British grown strawberry cv. Sonata and Chilean avocado cv. Hass were exposed to controlled atmospheres (CA) of 15kPa CO2+5kPa O2 (5°C) and 10kPa CO2+5kPa O2 (5 or 20°C), respectively, at early, middle or late stages during postharvest storage of avocados and at early and middle stages for strawberries. Real-time respiration rate (RR) was measured during CA storage and regular fruit sampling carried out to assess disease severity, objective colour, ethylene production and firmness. The automated in situ set-up used allowed continuous recordings of real-time respiration measurements without disruption to the CA environment. Cold stored strawberry fruit treated for 2.5 d with CA midway through the storage period were firmer and maintained a more vibrant colour despite bursts of increased RR. Furthermore, just 2.5 d of CA was sufficient to extend the shelf-life of strawberries (based on disease incidence) by a further 3 d, as compared to control. Irrespective of timing, RR of avocado stored at 20°C was reduced while under CA environment; and early CA exposure maintained firmness yet increased the incidence of internal discolouration 7 d after removal from CA. At 5°C, avocado skin colour and internal discolouration were positively affected by the mid CA treatment. These results are discussed in the context of the targeted use of CA, compared to control, for extending shelf-life, and reducing waste of these two different fruit produces. Furthermore, reducing the length of time required for CA application, which has not previously been explored in avocado or strawberries, would potentially be more energy efficient/cost effective.

Real-time respiration rate measurement from thoracoabdominal movement with a consumer grade camera.

In this paper, we propose a novel computer vision technique to measure respiration rate by counting the periodic thoracoabdominal motion in real-time using an inexpensive consumer grade camera. We compute the component of optical flow parallel to the image gradient at each pixel, which is a computationally inexpensive operation. Then, we find a principal flow field by gathering information over many frames. Subsequently, in each frame, we compute the component of flow along this principal flow field to capture the thoracoabdominal motion. Our method is very simple, easy to implement and needs no specialized hardware. This method is computationally very efficient and can be easily implemented in mobile devices. We demonstrate the efficacy of our method on real world datasets and compare the results with those obtained using impedance pneumography.

Development of a small and flexible sensor-based respirometer for real-time determination of respiration rate, respiratory quotient and low O2 limit of fresh produce

Information on the respiration rate and the low O2 limit (LOL) is important for optimization of packaging and storage systems for fresh fruit and vegetables. In this study, a small and flexible sensor-based respirometer was developed for real-time determination of the respiration rate, respiratory quotient (RQ), and LOL of fresh produce. The respirometer consisted of a wide mouth 1-L glass jar with a screw-type metal lid and an electrochemical and an infra-red sensor mounted directly on the lid of the glass jar to take continuous and non-invasive measurements of the O2 and CO2 contents. Data from the respirometer was compared with data obtained from two fluorescence-based spot sensors (OpTech and PreSens) and a headspace gas analyzer (CheckMate). A test with strawberry showed that similar respiration rates (14.1–16.2mLO2kg−1h−1 and 13.4–16.4mLCO2kg−1h−1 at 10°C) were obtained with all instruments. Further on, a Savitzky–Golay smoothing filter was implemented on the data from the respirometer to estimate the real-time respiration rate. The result showed that the respiration rate could be acquired in 2–3h after filling of the respirometer or even after 1h if the produce was equilibrated to the target storage temperature before the measurements. Detailed information on the respiration rate of wild rocket, strawberry, and carrot showed that the respiration rate decreased with time as the O2 content decreased; however, the RQ remained almost constant throughout storage until the LOL was reached. Information on the RQ and the LOL value is rare in the literature; however, the RQ and the LOL could easily be determined by the use of the respirometer. The RQ was 1.0, 1.0–1.5, and 0.5 for wild rocket, strawberry, and carrot, respectively, during storage under an O2 content above >2.0kPa. As the O2 content dropped to 0.5, 1.0 and 2.0kPa O2, for wild rocket, strawberry, and carrot, respectively, the RQ values increased sharply. The described respirometer made it easy to analyze the impact of a dynamic temperature and O2 content on the respiration rate, the RQ, and the LOL as handling was limited and real-time data could be obtained. With such detailed information, a knowledge-intensive design of packaging and storage systems for fresh horticultural produce is enabled.