Fingertip Pulse Oximeter Research Articles

Assessment of Prehospital Monitor/Defibrillators for Clostridioides difficile Contamination.

The purpose of this study was to determine if Clostridioides difficile (C. diff) was present on the electrocardiogram (ECG) right arm leads, blood pressure cuffs, and fingertip pulse oximetry sensors of monitor/defibrillators used in the prehospital setting. On March 22, 2019, a total of 20 prehospital monitor/defibrillators located at an Emergency Medical Service (EMS) station in Alabama (USA) were assessed for C. diff. The inside area of the fingertip pulse oximetry sensor, patient contact side of the blood pressure cuff, and right arm ECG lead of monitor/defibrillators (n = 60) were swabbed using a sterile cotton-tipped applicator saturated in a 0.85% Sodium Chloride solution. These cotton-tipped applicators were then inserted, scored, and released into Banana Broth vials. The vials were then sealed tightly and immediately transported to the laboratory, where they were incubated at 36°C for 72 hours. Colorimetric change from red to yellow was considered a positive indication for the presence of C. diff. Of 20 blood pressure cuffs, 15 had C. diff contamination (75%); C. diff was also present on 19 of 20 fingertip pulse oximeter sensors (95%) and 20 of 20 ECG right arm monitor leads (100%). Prehospital monitor/defibrillators may represent a significant reservoir of C. diff and other pathogenic bacteria. Improved disinfection protocols for reusable monitoring equipment and transition to disposable monitoring equipment used in the prehospital setting may reduce the risk of patient and EMS provider infection.

Clinical and Laboratory Factors Associated with Severe Disease Course in Turkish Patients with SARS-COV-2 Infection

Background: Coronavirus disease 2019 (COVID-19) can demonstrate different clinical spectra. Objectives: The current study aimed to analyze the clinical and laboratory risk factors of the severe course of disease in patients with COVID-19. Materials and Methods: Consecutive patients with a diagnosis of COVID-19 pneumonia were included in the present study. The demographic characteristics, comorbid diseases, symptoms, chest computed tomography (CT) findings, laboratory data, oxygen saturation (SpO2), and body temperature of the patients were recorded. The coexistence of pulmonary infiltration in CT and SpO2 of ≤ %93 on fingertip pulse oximeter was defined as the severe course of the disease. Results: A total of 475 patients were included in the current study. The mean age of the patients was 52.02±15.9 years, and 259 (54.5%) participants were male. The disease was mild and severe in 80% (n=380) and 20% (n=95) of the patients. The age of > 50 years, coexistence of hypertension (HT) and diabetes mellitus (DM), neutrophil/lymphocyte ratio (NLR) of > 4, high lactate dehydrogenase (LDH) of > 240 U/L, C-reactive protein (CRP) of > 8 mg/dL, and D-dimer of ≥ 1000 ng/mL were determined to be the risk factors for the severe course of the disease. Conclusion: Age, NLR, CRP, LDH, D-dimer, comorbidity, and coexistence of DM and HT were the independent risk factors for the severe course of the disease. The aforementioned factors should be taken into account during risk stratification and management of patients with COVID-19.

Comparative evaluation of efficacy of external vibrating device and counterstimulation on child's dental anxiety and pain perception during local anesthetic administration: a clinical trial.

BackgroundThis study aimed to evaluate the efficacy of external vibrating devices and counterstimulation on a child's dental anxiety, apprehension, and pain perception during local anesthetic administration.MethodsThis was a prospective, randomized, parallel-arm, single-blinded interventional, clinical trial. One hundred children aged 4–11 years, requiring pulp therapy or extraction under local anesthesia (LA), were recruited and allocated equally into two groups (1:1) based on the interventions used: Group BD (n = 50) received vibration using a Buzzy® device {MMJ Labs, Atlanta, GE, USA} as a behavior guidance technique; Group CS (n = 50) received counterstimulation for the same technique. Anxiety levels [Venham's Clinical Anxiety Rating Scale (VCARS), Venham Picture Test (VPT), Pulse oximeter {Gibson, Fingertip Pulse Oximeter}, Beijing, China)] were assessed before, during, and after LA administration, while pain perception [Wong-Baker Faces Pain Rating Scale (WBFPS), Visual Analogue Scale (VAS)] was evaluated immediately after injection. Statistical analysis was performed using the Student's t-test to assess the mean difference between the two groups and the repeated measures ANOVA for testing the mean difference in the pulse rates. Statistical significance was set at P < 0.05.ResultsSignificant differences in mean pulse rate values were observed in both groups. In contrast, the children in the BD group had higher diminution (P < 0.05), whereas the mean VCARS and VPT scores were conspicuous (P < 0.05). Based on the mean WBFPS and VAS scores, delayed pain perception after LA injection was more prominent in the BD group than in the CS group.ConclusionExternal vibration using a Buzzy® device is comparatively better than counterstimulation in alleviating needle-associated anxiety in children requiring extraction and pulpectomy.

Study of changes in certain cardiorespiratory parameters in response to breath holding in swimmers

Background: Swimming subjects the human body to frequent short intervals of breath hold (BH) and resistive forces of water, increased respiratory effort and thermal stress due to immersion in water. This activity demands higher energy expenditure for movement in a viscous medium. To cope with these, certain adaptations occur in cardiovascular and respiratory systems. Aims and Objectives: Our study compared some cardiovascular and respiratory parameters in male swimmers and sedentary controls at rest and at breakpoint of BH. This helped to know whether respiratory system and cardiovascular system are susceptible to adaptation induced by swimming. Materials and Methods: Thirty regular swimmers and 30 sedentary healthy controls were considered for investigations. A portable electrocardiograph (ECG), finger-tip pulse oximeter, spirometer, and sphygmomanometer were used to record ECG (PR interval, QRS interval, QTc interval, and QRS axis), SpO2, heart rate (HR), tidal volume (TV), and blood pressure. Results: In controls, at breakpoint of BH, oxygen desaturation was extremely significant (“P” < 0.0001), TV was extremely significantly increased (“P” = 0.0006), and only within controls group, HR showed significant increase (“P” = 0.04). No statistically significant change in blood pressure was observed between the groups at breakpoint. A significant increase in TV at breakpoint of BH over that of resting value was observed in controls compared to swimmers (“P” = 0.0134). ECG changes in swimmers and controls were not significantly different. Conclusion: Regular swimming causes oxygen conserving effect, an efficient rise in TV in response to BH.

Development of a Wearable Reflection-Type Pulse Oximeter System to Acquire Clean PPG Signals and Measure Pulse Rate and SpO2 with and without Finger Motion

Clinical devices play a vital role in diagnosing and monitoring people’s health. A pulse oximeter (PO) is one of the most common clinical devices for critical medical care. In this paper, we explain how we developed a wearable PO. We propose a new electronic circuit based on an analog filter that can separate red and green photoplethysmography (PPG) signals, acquire clean PPG signals, and estimate the pulse rate (PR) and peripheral capillary oxygen saturation (SpO2). We propose a PR and SpO2 measurement algorithm with and without the motion artifact. We consider three types of motion artifacts with our acquired clean PPG signal from our proposed electronic circuit. To evaluate our proposed algorithm, we measured the accuracy of our estimated SpO2 and PR. To evaluate the quality of our estimated PR (bpm) and SpO2 (%) with and without the finger motion artifact, we used the quality evaluation metrics: mean absolute percentage error (MAPE), mean absolute error (MAE), and reference closeness factor (RCF). Without the finger motion condition, we found that our proposed wearable PO device achieved an average 2.81% MAPE, 2.08 bpm MAE, 0.97 RCF, and 98.96% SpO2 accuracy. With a finger motion, the proposed wearable PO device achieved an average 4.5% MAPE, 3.66 bpm MAE, 0.96 RCF, and 96.88% SpO2 accuracy. We also show a comparison of our proposed PO device with a commercial Fingertip PO (FPO) device. We have found that our proposed PO device performs better than the commercial FPO device under finger motion conditions. To demonstrate the implementation of our wearable PO, we developed a smartphone app to allow the PO device to share PPG signals, PR, and SpO2 through Bluetooth communication. We also show the possible applications of our proposed PO as a wearable, hand-held PO device, and a PPG signal acquisition system.

Oxygen Deficit Is a Sensitive Measure of Mild Gas Exchange Impairment at Inspired O2 between 12.5%–21%

The oxygen deficit (OD) is the difference between the end‐tidal alveolar PO2 and the estimated PO2 of arterial blood derived from the SpO2 that has the potential to be used clinically as a proxy for the alveolar‐arterial PO2 difference. Previous work has shown that a recently developed technology, the Alveolar Gas Meter, is accurate in measuring the efficiency of pulmonary gas exchange, via the OD, in patients with a history of lung disease as well as in normal subjects breathing a hypoxic mixture of 12.5% O2. This study sought to determine how the OD varied as the percent of inspired O2 changed from 21% to 12.5% in 36 healthy subjects split by age (young 22–31, n=23; old 42–90, n=13) to assess the possibility of use in a clinical setting. The PO2 and PCO2 were continually measured as the subject breathed through a mouthpiece using rapidly responding electrochemical cells, and the end‐tidal PO2 and PCO2 were calculated and averaged over 5 steady‐state breaths, while a fingertip pulse oximeter measured the SpO2. After correcting for any change in P50 resulting from the PCO2 differing from 40 mmHg, the arterial PO2 was calculated from the SpO2 by inverting the Hill‐equation. Subjects breathed 12.5, 15, 17.5 and 21% oxygen mixtures (balanced order) and their OD was measured in triplicate. Across all inspired O2 levels, the OD was higher in the older cohort than the young (p &lt;0.0001, repeated measures ANOVA, Table 1). The older cohort had a larger OD at all four oxygen levels (all p&lt;0.0001), with that difference and its variance being greater at higher inspired O2 values (age × O2 interaction p=0.002). The OD at an inspired O2 of 12.5% was significantly less than at 21% for both age cohorts. This is consistent with the known increase in ventilation‐perfusion mismatching that occurs in healthy aging. The decrease in OD magnitude as the inspired oxygen was reduced in both cohorts is consistent with the increased accuracy of the estimated arterial PO2 when based on saturation values on the steep part of the O2‐Hb dissociation curve. Further, as arterial saturation decreases there is an expected decrease in the alveolar‐arterial PO2 difference. The persisting higher OD seen in older subjects, irrespective of inspired O2, suggests that the measurement of oxygen deficit remains sensitive to mild gas exchange impairment, even when breathing air (21% O2).Support or Funding InformationFinancial support from UCSD Measured Oxygen Deficit by Age Young Old p‐value All Inspired O2 (mean±SE) −0.4±0.6 10.6±1.0 &lt;0.0001 Inspired O2 by Age Interaction 0.002 12.5% −1.4±0.7 5.7±0.6 ‐ 15% −2.7±1.0 5.2±1.8 15% vs 12.5%: NS 17.5% −2.7±1.0 9.4±1.8 17.5% vs 12.5%: NS 21% 5.1±1.3 21.9±2.1 21% vs 12.5%: &lt;0.0001

Comparative efficacy of three topical anesthetics on 7-11-year-old children: a randomized clinical study.

BackgroundThis study evaluated the efficacy of three intraoral topical anesthetics in reducing the injection needle prick pain from local anesthetic among children aged 7–11 years old.MethodsIt is a prospective, Interventional, parallel design, single-blind, randomized clinical trial in which subjects (n=90) aged 7–11 years were included in the study based on an inclusion criteria. Subjects were divided into three groups based on computer-generated randomization with an allocation ratio of 1:1:1. Groups A, B, and C received benzocaine 20% jelly (Mucopain gel, ICPA health products Ltd, Ankleshwar, India), cetacaine anesthetic liquid (Cetylite Industries, Inc, Pennsauken, NJ), and EMLA cream (2% AstraZeneca UK Ltd, Luton, UK), respectively, according to manufacturer's instructions, for 1 minute prior to local anesthetic injection. After application of topical anesthetic agent, for all the groups, baseline pre-operative (prior to topical anesthetic administration) and post-operative scores (after local anesthetic administration) of pulse rate was recorded using Pulse oximeter (Gibson, Fingertip Pulse Oximeter, MD300C29, Beijing Choice Electronic). Peri-operative (i.e., during the administration of local anesthesia) scores were recorded using Face, Legs, Activity, Cry, Consolability (FLACC) Scale, Modified Children hospital of Eastern Ontario Pain Scale (CPS) behavior rating scale, and Faces Pain Scale (FPS-R) – Revised (For self-reported pain). Direct self-reported and physiological measures were ascertained using FPS-R – Revised and Pulse oximeter, respectively, whereas CPS and FLACC scales assessed behavioral measures. To test the mean difference between the three groups, a one way ANOVA with post hoc tests was used. For statistical significance, a two-tailed probability value of P < 0.05 was considered as significant.ResultsThe Cetacaine group had significantly lower pain scores for self-report (P < 0.001), behavioral, and physiological measures (P < 0.001) than the other two groups. However, there was no significant difference between the Benzocaine group and EMLA group during palatal injection prick.ConclusionCetacaine can be considered as an effective topical anesthetic agent compared to benzocaine 20% jelly (Mucopain gel) and EMLA cream.

Total and differential leukocyte count and oxygen saturation of hemoglobin changes in healthy smokers and non-smokers

Background: Inflammatory markers are altered in smokers and smoking has been proved as one of the main causative factors for cardiovascular diseases (CVDs), inflammatory diseases, and oxidative stress stimulation. An alteration in hematological parameters and oxygen saturation of hemoglobin is expected with smoking tobacco. Aim and Objective: This study has been planned with the aim to evaluate the changes associated with the extent of adverse effects of tobacco smoking in total and differential leukocyte count (DLC) and oxygen saturation of hemoglobin in healthy smokers and non-smokers. Materials and Methods: A total of 150 healthy adults were participated in this cross-sectional study. Anthropometric measurements such as height, weight, and body mass index were taken, and information of smoking habits were obtained by a questionnaire. Blood samples were taken for the estimation of total and DLC using MS-9 automated hematology cell counter. Oxygen saturation of hemoglobin was done using fingertip pulse oximeter Nidek Medical 5300. Results: Our results showed a statistically significant rise in the total leukocyte count (TLC) (P < 0.001), lymphocyte count (P < 0.001), granulocyte count (P < 0.01), and monocyte count (P < 0.02) and showed a statistically significant decrease in SpO2 (P < 0.04) in smokers as compared to non-smokers. Conclusion: The study has shown that altered values of TLC and DLC and oxygen saturation of hemoglobin in smokers should be considered during diagnosis, interpretation of result, and treatment of patients. A high TLC and DLCs exhibited in this research may be responsible for chronic inflammation and subsequent high risk of CVD in smokers. Therefore, quitting smoking should be encouraged for better health.

Comparison of Various Methods of Detection of Hypoxemia and Correlation of Hypoxemia with Clinical Features among Pediatric Patients 3 Months to 5 Years Old with Community-Acquired Pneumonia at a Tertiary Hospital Emergency Room

Introduction: Pulse oximetry is frequently utilized as a rapid, non-invasive, point-of-care alternative to arterial blood gas analysis in measuring oxygen saturation of children with pneumonia. Objectives: To compare portable fingertip pulse oximetry saturation (SpO2PF), handheld pulse oximetry saturation (SpO2H) and arterial oxygen saturation (SaO2) in detection of hypoxemia, and correlate hypoxemia with clinical features in children with pneumonia. Methodology: This was a prospective, observational, cross-sectional study involving patients 3 months to 5 years old with pneumonia. Oxygen saturation was measured using a portable fingertip pulse oximeter, a handheld pulse oximeter, and arterial blood gas analysis. Results: Eighty-six children were included. SpO2 PF underestimated oxygen levels by 0.126% (95% CI -0.240 to 0.491), while SpO2H underestimated it by 0.323% (95% CI -0.075 to 0.721). Between portable and handheld readings, the mean difference was 0.198% (95% CI -0.089 to 0.484). Across the three methods, limits of agreement ranged from -3.388 to +4.035%. There was no statistically significant difference in variance among the three measurements. Children with tachypnea (cOR 2.623, 95% CI 1.06 – 6.48, p = 0.037), difficulty breathing (cOR 6.316, 95% CI 1.96 – 20.34, p = 0.002), and subcostal retractions (cOR 2.842, 95% CI 1.05 to 7.69, p = 0.040) were more likely to have hypoxemia. Conclusion: Pulse oximetry closely correlates with arterial blood gas analysis within acceptable limits of agreement and with no significant differences in variance among measurements. Difficulty breathing, tachypnea and subcostal retractions were significantly more likely to be observed in hypoxemic children.

Wrist-Sensor Pulse Oximeter Enables Prolonged Patient Monitoring in Chronic Lung Diseases.

Pulse oximetry is an important diagnostic tool in monitoring and treating both in-patients and ambulatory patients. Modern pulse oximeters exploit different body sites (eg fingertip, forehead or earlobe). All those are bulky and uncomfortable, resulting in low patient compliance. Therefore, we evaluated the accuracy and precision of a wrist-sensor pulse oximeter (Oxitone-1000, Oxitone Medical) vs. the traditional fingertip device. Fifteen healthy volunteers and 23 patients were recruited. The patient group included chronic obstructive pulmonary disease (COPD) (N = 8), asthma (N = 6), sarcoidosis (N = 5) and others. Basic demographic data, skin tone type, smoking status and medical history were recorded. Blood oxygen level (SpO2) and pulse-rate values were determined by a non-invasive pulse oximeter (Reference, a conventional FDA-cleared fingertip pulse oximeter) and by Oxitone-1000. All tests were performed in singleton and in a blinded fashion. The measurements were done in sitting and standing positions, as well as after a 6-min walk test. The mean age was 60.4 ± 9.83years, 55% were male. No significant differences were observed between the wrist-sensor and the traditional fingertip pulse oximeters in all tested parameters. Mean SpO2 was 96.45% vs. 97.18% and the mean pulse was 74.64 vs. 74.6bpm (Oxitone-1000 vs. Reference, respectively, p < 0.0001). Precision rate was 2.28472% and the accuracy was met (Arms -Root mean-square-error < 3%). The Oxitone-1000 is both accurate and precise for SpO2 and pulse measurements during daily activities of pulmonary patients, and is not inferior to standard devices for spot checking or short period examinations. Its wrist-sensor design is comfortable and provides the advantage of extended use.

CEREBRAL LATERALITY, EMOTION, AND CARDIOPULMONARY FUNCTIONS: AN INVESTIGATION OF LEFT AND RIGHT CVA PATIENTS

Background: It has been evidenced that the outcome of a CVA patient differs as a function of the cerebral hemisphere that is damaged by the stroke, especially in terms of emotional changes. In contrast, the Bi-Hemispheric Model of Emotion posits that each hemisphere has its own emotional specialization. The current experiment tested the competing predictions of the two theoretical perspectives in a mixed sample of left cerebrovascular accident (LCVA) patients and right cerebrovascular accident (RCVA) patients using a Dichotic Listening task and the Affective Auditory Verbal Learning Test (AAVLT). Heart Rate (HR) and Pulse Oxygen Saturation (SpO2) were recorded as sympathetic measures. It was expected that the predictions of the Bi-Hemispheric Model would be supported. A series of mixed design ANOVAs were used to analyze the data. Material/Methods: Participants consisted of 21 patients grouped into either post-acute status left cerebrovascular accident (LCVA) or right cerebrovascular accident (RCVA). Tests included the The Dichotic Listening test, The Affective Auditory Verbal Learning Test (AAVLT), HR and Sp02 measurement using a Fingertip Pulse Oximeter and the Mood Assessment Scale for depression. Results: Results revealed that both groups exhibited decreased auditory detection abilities in the ear contralateral to CVA location. Additionally, CVA patients recalled significantly more positive words than negative or neutral words and exhibited a significant learning curve. LCVA patients exhibited a recency effect, while RCVA patients exhibited a heigh tened primacy effect. Findings from the HR and Sp02 measures suggested a parasympathetic response to emotionally neutral information as well as an impaired sympathetic response to emotionally negative information in RCVA patients. Conclusions: The results lend partial support to the hypothesis drawn from the Bi-Hemispheric Model of Emotion, as evidenced by the diametrically opposite effects in these groups, which reflects opposing cerebral processes.

Validity Of The DiagnostixTM 2100 And Fitbit Charge HRTM In Assessing Heart Rate

The importance of exercise intensity is an important factor when maximizing the health benefits that result from exercise. New innovations in consumer based activity trackers and electronic healthcare monitoring devices have been able to quantify the level of exercise intensity based on heart rate (HR) values. However, there is limited research assessing the validity of these devices. PURPOSE: To assess the validity of the Fitbit Charge HR (FB) and ACSC Diagnostix 2100 Fingertip Pulse Oximeter (PO) in assessing heart rate during exercise in comparison to the heart rate from an electrocardiogram (EKG). METHODS: Healthy college students (n=30, 18 females) performed 1 min of standing rest, 10 min of the standard Bruce Protocol test on a treadmill, and a 2 min cool-down walk. Each participant simultaneously wore the FB on the right wrist, the PO on the right index finger, and had 10 electrodes placed on their chest for the 12-lead EKG. HR was recorded from each device every minute. Absolute differences between the 3 HR monitors were compared using repeated measures ANOVA. Pearson r correlation coefficients and Standard Error of Estimate (SEE) were calculated to determine the relationships between each HR monitor vs. EKG. RESULTS: Repeated measures ANOVA indicated a significant difference in HR between the 3 monitors, F(2,58)=16.876, p<0.001. Post hoc tests indicated a significant difference between EKG and FB (132.1 ± 13 vs. 120.5 ± 13.7 bpm, p<0.001), and EKG and PO (132.1 ± 13 vs. 121.9 ± 15.5 bpm, p<0.001). The correlation between the EKG and FB was r=0.64, p<0.001, SEE 10.2 bpm, whereas the correlation between EKG and PO was r=0.63, p<0.001, SEE 10.27 bpm. CONCLUSIONS: Large absolute differences and modest correlation values do not indicate a strong agreement between the FB or PO vs. EKG. Therefore, the extent of each device’s validity to monitor HR is questionable when compared to the gold standard EKG.

Childhood pneumonia diagnostics: community health workers’ and national stakeholders’ differing perspectives of new and existing aids

ABSTRACT Background: Pneumonia heavily contributes to global under-five mortality. Many countries use community case management to detect and treat childhood pneumonia. Community health workers (CHWs) have limited tools to help them assess signs of pneumonia. New respiratory rate (RR) counting devices and pulse oximeters are being considered for this purpose. Objective: To explore perspectives of CHWs and national stakeholders regarding the potential usability and scalability of seven devices to aid community assessment of pneumonia signs. Design: Pile sorting was conducted to rate the usability and scalability of 7 different RR counting aids and pulse oximeters amongst 16 groups of participants. Following each pile-sorting session, a focus group discussion (FGD) explored participants’ sorting rationale. Purposive sampling was used to select CHWs and national stakeholders with experience in childhood pneumonia and integrated community case management (iCCM) in Cambodia, Ethiopia, Uganda and South Sudan. Pile-sorting data were aggregated for countries and participant groups. FGDs were audio recorded and transcribed verbatim. Translated FGDs transcripts were coded in NVivo 10 and analysed using thematic content analysis. Comparative analysis was performed between countries and groups to identify thematic patterns. Results: CHWs and national stakeholders across the four countries perceived the acute respiratory infection (ARI) timer and fingertip pulse oximeter as highly scalable and easy for CHWs to use. National stakeholders were less receptive to new technologies. CHWs placed greater priority on device acceptability to caregivers and children. Both groups felt that heavy reliance on electricity reduced potential scalability and usability in rural areas. Device simplicity, affordability and sustainability were universally valued. Conclusions: CHWs and national stakeholders prioritise different device characteristics according to their specific focus of work. The views of all relevant stakeholders, including health workers, policy makers, children and parents, should be considered in future policy decisions, research and development regarding suitable pneumonia diagnostic aids for community use.

Continuous non-invasive monitoring of blood pressure in the operating room: a cuffless optical technology at the fingertip

Abstract Routine monitoring of blood pressure during general anaesthesia relies on intermittent measurements with a non-invasive brachial cuff every five minutes. This manuscript provides first experimental evidence that a physiology-based pulse wave analysis algorithm applied to optical data (as provided by a standard fingertip pulse oximeter) is capable of accurately estimating blood pressure changes in-between cuff readings. Combined with the routine use of oscillometric cuffs, the presented novel approach is a candidate technology to increase patient safety by providing beat-to-beat hemodynamic measurements without the need of invasive monitoring procedures.

Concurrent Validity of Resting Pulse-Rate Measurements: A Comparison of 2 Smartphone Applications, the Polar H7 Belt Monitor, and a Pulse Oximeter With Bluetooth

Pulse rate is commonly measured manually or with commercial wrist or belt monitors. More recently, pulse-rate monitoring has become convenient with the use of mobile technology that allows monitoring through a smartphone camera. This optical technology offers many benefits, although the clinimetric properties have not been extensively studied. Observational study of reliability Setting: University kinesiology laboratory. 30 healthy, recreationally active adults. Concurrent measurement of pulse rate using 2 smartphone applications (fingertip, face-scan,) with the Polar H7 belt and pulse oximeter. Average resting pulse rate for 5 min in 3 positions (supine, sitting, and prone). Concurrent validity in supine and standing was good between the 2 applications and the Polar H7 (intraclass correlation coefficient [ICC] .80-.98) and pulse oximeter (ICC .82-.98). For sitting, the validity was good between the fingertip application, Polar H7 (ICC .97), and pulse oximeter (ICC .97). The face-scan application had moderate validity with the Polar H7 (ICC .74) and pulse oximeter (ICC .69). The minimal detectable change (MDC90) between the fingertip application and Polar H7 ranged from 1.38 to 4.36 beats/min (BPM) and from 0.69 to 2.97 BPM for the pulse oximeter with both positions. The MDC90 between the face-scan application and Polar H7 ranged from 11.88 to 12.83 BPM and from 0.59 to 17.72 BPM for the pulse oximeter. The 95% limits of agreement suggest that the fingertip application may vary between 2.40 and 3.59 BPM with the Polar H7 and between 3.40 and 3.42 BPM with the pulse oximeter. The face-scan application may vary between 3.46 and 3.52 BPM with the Polar H7 and between 2.54 and 3.46 BPM with the pulse oximeter. Pulse-rate measurements may be effective using a fingertip application, belt monitor, and pulse oximeter. The fingertip scanner showed superior results compared with the face scanner, which only demonstrated modest validity compared with the Polar H7 and pulse oximeter.

A bilateral rehabilitation system for the lower limbs

Purpose: Bilateral and unilateral training equipment for the upper limbs facilitates rehabilitation after stroke. In this work, we tested the first device designed for bilateral training of the lower limbs. Method: Characteristics and usage of the novel MedExercise® ST device were evaluated by four healthy volunteers. A pedometer and temperature sensor were attached to the device and used to measure cadence and intensity of training, respectively. The heart rates of participants were recorded with a fingertip pulse oximeter. Thirty elderly patients assessed usability of the device and completed the survey. Results: It was shown that the device could be operated in sitting and recumbent positions. The resistance levels and range of joint motion were individually adjustable for each leg, allowing both bilateral and unilateral training. When pedals were linked together, one leg could help moving the other leg. Recording of training intensities allowed leg fitness testing, personalized exercise prescription and analysis of self-controlled training. A usability survey demonstrated positive perception of elderly patients towards the device. Conclusions: This training system has a range of useful features, which can facilitate rehabilitation of the lower limbs via early leg mobilization and self-controlled training.Implications for RehabilitationBilateral and unilateral training devices are widely used to improve the effectiveness of upper limb rehabilitation, but there is no analogous equipment available for the lower limbs.Here, we show that the MedExercise® ST training system allows independent exercise of each leg in bilateral and unilateral modes, and objective recording of training activities.Elderly patients attending the exercise rehabilitation clinic demonstrated a positive perception towards usability of this equipment.The results of this study suggest suitability of the system for optimization of lower limb rehabilitation, including early leg mobilisation and self-controlled training.

Evaluation of accuracy of portable fingertip pulse oximeter, as compared to that of a hospital oximeter with digital sensor

The pulse oximeter is a device that noninvasively provides continuous information about the peripheral oxygen saturation (SpO2) rate. This device is utilized in the detection of hypoxemia, due to its able to sense changes in hemoglobin oxygen saturation. The objective of this study was to verify the accuracy of the Choice® Medical MD300C3 Fingertip Pulse Oximeter, as compared to that of a hospital oximeter coupled with a Drager® Infinity Delta monitor, with the purpose of using this first methodology in dental procedures to monitor the peripheral oxygen saturation (SpO2) of patients submitted to dental treatments. Fifty-five adult patients, both genders, were selected in the Santa Casa Hospital of Maringa, Brazil. The volunteers did not present cardiac problems, prosthetic cardiac valves, pacemakers, or pulmonary diseases, and were not pregnant or children. Each patient received a portable fingertip pulse oximeter (PPO) on the middle finger of the left hand and the hospital oximeter (control device) on the forefinger of the same hand. A total of six measurements were developed. The Pearson correlation coefficient and the Bland and Altman method was used to calculate the statistical analysis. No statistically significant difference was found between the measurements taken by the utilized devices. The average of comparative analysis presented by the devices was 0.2337 ± 0.4355 (mean ± SD), suggesting a strong correlation between the obtained results. According to the methodology of the research, the PPO has similar accuracy to the conventional hospital oximeter with digital sensor. The PPO can be used in dental treatments.

Utilidad de la pulsioximetría en el cribado de enfermedad arterial periférica en pacientes ingresados en servicios de medicina interna

IntroductionAnkle-brachial index measured by a continuous wave Doppler device remains as the reference method for office diagnosis of peripheral arterial disease. This method is time consuming, requires an appropriate device and training of the examiner. We evaluated the usefulness of pulse oximetry as an easier method to screen for peripheral arterial disease. MethodsA total of 110 subjects were selected by opportunistic sampling among patients admitted to a general medicine service. Entry criteria were age older than 50years and having an additional cardiovascular risk factor. Patients with known cardiovascular disease were excluded. We measured oxygen saturation (SaO2) by means of a pocket finger tip pulse oximeter at 4limbs. SaO2 was measured at right and left index fingers and great toes with patient lying and after elevating the foot 30cm above the bed. We considered as abnormal a difference in SaO2 greater than 2% between fingers and toes. Brachial index was estimated by means of a handheld Doppler device. ResultsThe prevalence of peripheral arterial disease was 10% (95% confidence interval [CI], 6%-14%). Pulse oximetry has sensitivity 12% (95%CI, 4%-37%), specificity 67% (95%CI, 60%-74%), positive likelihood ratio 0.43 (95%CI, 0.11-1.19), negative likelihood ratio 1.27 (95%CI, 0.91-1.45) and area under the receiving operating characteristics curve 0.75 (95%CI, 0.67-0.82). ConclusionsPulse oximetry showed low accuracy as screening method for peripheral arterial disease. Simpler and more accurate devices than ankle-brachial index measured by Doppler are necessary to ease the screening of peripheral arterial disease.

LETTER TO THE EDITOR Patients with Hemoglobinopathies Require Continuous Flow Supplemental Oxygen During Commercial Airline Flights

Patients with hemoglobinopathies are known to experience complications e.g. bone pain [1], splenic infarction [2] and osteonecrosis (avascular necrosis) of the hip (anecdotal report) subsequent to commercial airline flights. These complications are due to prolonged decrease in oxygen delivery at high altitudes. There is no study in the literature that has measured the oxygen saturation in these patients on commercial airline flights where planes ascend to altitudes of 30,000 feet or greater. At these altitudes, there is a low partial pressure of oxygen which is about a quarter of that at sea level. Humans would not be able to breathe without a pressurized environment and modern commercial jets are pressurized to an altitude of 5000-8000 feet. Ideally an airplane would be pressurized to ground level pressure (760 Torr). However this is not practical as the fuselage of a plane would have to be incredibly strong (and hence very heavy and expensive to fly) to withstand the outward force caused by 760 Torr while cruising at altitudes of 30,000 feet or greater [3]. At ground level, the partial pressure of oxygen is about 150 Torr or mm of mercury (20% of atmospheric pressure at 760 Torr). Inside a plane at cruising altitude oxygen partial pressure is reduced to about 125 Torr, In most people, this is a negligible change and their blood will remain fully saturated with oxygen at this pressure. This is not the case in patients with hemoglobinopathies in which tissue oxygen delivery is already compromised. We set out to determine the changes in oxygen saturation in seven patients with and without supplemental oxygen (continuous flow and pulse dose) provided during commercial airline travel. These patients with a mix of Hgb SS and SC were stable and without any underlying conditions. We provided them with a Sequal SmartPulseTM fingertip pulse oximeter to monitor oxygen saturation as well as with a SequalTM Eclipse 3 oxygen concentrator (Sequal Technologies, San Diego, California. Phone 858 202-3100). This oxygen concentrator is one of a few that are approved by the Federal Aviation Administration (FAA) for supplemental oxygen delivery on commercial

Cardiac gating with a pulse oximeter for dual-energy imaging

The development and evaluation of a prototype cardiac gating system for double-shot dual-energy (DE) imaging is described. By acquiring both low- and high-kVp images during the resting phase of the cardiac cycle (diastole), heart misalignment between images can be reduced, thereby decreasing the magnitude of cardiac motion artifacts. For this initial implementation, a fingertip pulse oximeter was employed to measure the peripheral pulse waveform (‘plethysmogram’), offering potential logistic, cost and workflow advantages compared to an electrocardiogram. A gating method was developed that accommodates temporal delays due to physiological pulse propagation, oximeter waveform processing and the imaging system (software, filter-wheel, anti-scatter Bucky-grid and flat-panel detector). Modeling the diastolic period allowed the calculation of an implemented delay, timp, required to trigger correctly during diastole at any patient heart rate (HR). The model suggests a triggering scheme characterized by two HR regimes, separated by a threshold, HRthresh. For rates at or below HRthresh, sufficient time exists to expose on the same heartbeat as the plethysmogram pulse [timp(HR) = 0]. Above HRthresh, a characteristic timp(HR) delays exposure to the subsequent heartbeat, accounting for all fixed and variable system delays. Performance was evaluated in terms of accuracy and precision of diastole-trigger coincidence and quantitative evaluation of artifact severity in gated and ungated DE images. Initial implementation indicated 85% accuracy in diastole-trigger coincidence. Through the identification of an improved HR estimation method (modified temporal smoothing of the oximeter waveform), trigger accuracy of 100% could be achieved with improved precision. To quantify the effect of the gating system on DE image quality, human observer tests were conducted to measure the magnitude of cardiac artifact under conditions of successful and unsuccessful diastolic gating. Six observers independently measured the artifact in 111 patient DE images. The data indicate that successful diastolic gating results in a statistically significant reduction (p < 0.001) in the magnitude of cardiac motion artifact, with residual artifact attributed primarily to gross patient motion.