Non-invasive detection of hypoglycaemia using a novel, fully biocompatible and patient friendly alarm system

Dogs can discriminate between human baseline and psychological stress condition odours

Previous research suggests that dogs can detect when humans are experiencing stress. This study tested whether baseline and stress odours were distinguishable to dogs, using a double-blind, two-phase, three-alternative forced-choice procedure. Combined breath and sweat samples were obtained from participants at baseline, and after a stress-inducing (mental arithmetic) task. Participants’ stress was validated with self-report and physiological measures recorded via a Biopac MP150 system. Thirty-six participants’ samples were presented to four dogs across 36 sessions (16, 11, 7 and 2 sessions, respectively). Each session consisted of 10 Phase One training trials and 20 Phase Two discrimination trials. In Phase One, the dog was presented with a participant’s stress sample (taken immediately post-task) alongside two blanks (the sample materials without breath or sweat), and was required to identify the stress sample with an alert behaviour. In Phase Two, the dog was presented with the stress sample, the same participant’s baseline sample (taken pre-task), and a blank. Which sample (blank, baseline, or stress) the dog performed their alert behaviour on was measured. If dogs can correctly alert on the stress sample in Phase Two (when the baseline sample was present), it suggests that baseline and stress odours are distinguishable. Performance ranged from 90.00% to 96.88% accuracy with a combined accuracy of 93.75% (N trials = 720). A binomial test (where probability of success on a single trial was 0.33, and alpha was 0.05) showed that the proportion of correct trials was greater than that expected by chance (p < 0.001). Results indicate that the physiological processes associated with an acute psychological stress response produce changes in the volatile organic compounds emanating from breath and/or sweat that are detectable to dogs. These results add to our understanding of human-dog relationships and could have applications to Emotional Support and Post Traumatic Stress Disorder (PTSD) service dogs.

Enhancing the Selection and Performance of Working Dogs

Dogs perform a variety of integral roles in our society, engaging in work ranging from assistance (e.g., service dogs, guide dogs) and therapy to detection (e.g., search-and-rescue dogs, explosive detection dogs) and protection (e.g., military and law enforcement dogs). However, success in these roles, which requires dogs to meet challenging behavioral criteria and to undergo extensive training, is far from guaranteed. Therefore, enhancing the selection process is critical for the effectiveness and efficiency of working dog programs and has the potential to optimize how resources are invested in these programs, increase the number of available working dogs, and improve working dog welfare. In this paper, we review two main approaches for achieving this goal: (1) developing selection tests and criteria that can efficiently and effectively identify ideal candidates from the overall pool of candidate dogs, and (2) developing approaches to enhance performance, both at the individual and population level, via improvements in rearing, training, and breeding. We summarize key findings from the empirical literature regarding best practices for assessing, selecting, and improving working dogs, and conclude with future steps and recommendations for working dog organizations, breeders, trainers, and researchers.

Detection of Impending Aggressive Outbursts in Patients with Psychiatric Disorders: Violence Clues from Dogs

Aggression in psychiatric wards is a continuing matter of concern for both patients and medical staff. Here we have tested the hypothesis that the frequency of such incidents can be reduced with a new strategy of using trained alert dogs that warn of impending violent outbursts. Dogs were positioned among patients in psychiatric wards. Analyses show that the dogs warned of impending aggressive outbursts, responding to signals from a specific patient out of a group of unfamiliar psychotic patients. Their alerts were not a response to stress as canine cortisol levels were not significantly changed. Visual glance was the preferred method used by young dogs to respond to patient. Until a similar electronic technology is developed, trained alert dogs can help caregivers to protect both the patient and those around them from injuries that may otherwise result from aggressive outbursts in psychiatric patients.

An Idiographic Investigation of Diabetic Alert Dogs' Ability to Learn From a Small Sample of Breath Samples From People With Type 1 Diabetes

OBJECTIVE

There is a growing market for diabetes-alert dogs but little has been published regarding their ability to reliably detect hypoglycemia. We aimed to determine whether 2 dogs could detect hypoglycemic breath samples from people with type 1 diabetes (T1D) and then transfer detection to novel hypoglycemic breath samples.

METHODS

Breath samples were collected from individuals with T1D during times of normo-, hypo- and hyperglycemia. Two dogs, previously trained (3 alternative forced choice) with breath samples from 3 different individuals with T1D, were presented with 3 breath samples from the same individual: 1 hypoglycemic, 1 normoglycemic and 1 hyperglycemic, and trained to identify the hypoglycemic sample using a "yes/no" procedure. The dogs' ability to transfer detection was then tested by presenting them with a novel sample set from the same individual. Then we tested whether 1 dog could transfer detection of the odour of hypoglycemia by presenting new samples from a different individual.

RESULTS

One dog was able to transfer detection of the odour of hypoglycemia to samples from the same individual (specificity 89%, sensitivity 62%), but a second dog was not. Results were inconclusive regarding the ability of 1 dog to transfer detection of the odour of hypoglycemia across 2 individuals.

CONCLUSIONS

The results suggest that some dogs can be trained to detect hypoglycemic breath of an individual with T1D, but detection may not transfer to novel samples from other individuals. Results should be interpreted with caution, as the dogs were trained with only a small number of breath samples before testing.

An Owner-Independent Investigation of Diabetes Alert Dog Performance

Objective: To quantify Diabetes Alert Dog (DAD) performance by using owner-independent measures.

Research Design and Methods: Eight owners of accredited DADs used a FreeStyle Libre Flash Glucose Monitoring System (FGMS). Concurrent Closed Circuit Television (CCTV) footage was collected for between 5 and 14 days in each owner's home or workplace. The footage was blind-coded for dogs' alerting behaviors. The sensitivity, False Positive Rate and Positive Predictive Values (PPV) of dogs' alerts to out-of-range (OOR) episodes were calculated. Ratings for 11 attributes describing participant's lifestyle and compliance (taken from each dog's instructor) and the percentage of DAD alerts responded to by the owner as per training protocol (taken from CCTV footage) were assessed for association with dog performance.

Results: Dogs alerted more often when their owners' glucose levels were outside vs. inside target range (hypoglycaemic 2.80-fold, p = 0.001; hyperglycaemic 2.29-fold, p = 0.005). Sensitivity to hypoglycaemic episodes ranged from 33.3 to 91.7%, the mean was 55.9%. Mean PPV for OOR episodes was 69.7%. Sensitivity and PPV were associated with aspects of the dog and owner's behavior, and the owner's adherence to training protocol.

Conclusions: Owner-independent methods support that some dogs alert to hypo- and hyperglycaemic events accurately, but performance varies between dogs. We find that DAD performance is affected by traits and behaviors of both the dog and owner. Combined with existing research showing the perceived psychosocial value and reduced critical health care needs of DAD users, this study supports the value of a DAD as part of a diabetes care plan. It also highlights the importance of ongoing training and continued monitoring to ensure optimal performance.

Communication in Dogs

Simple Summary

Communication takes place between members of the same species, as well as between heterospecific individuals, such as the long co-habitation process and inter-dependent relationship present in domestic dogs and humans. Dogs engage in visual communication by modifying different parts of their body; in tactile communication; and also in auditory and olfactory communication, with vocalizations and body odours, respectively. The aim of this review is to provide an overview of the recent literature about dog communication, describing the different nature of the signals used in conspecific and heterospecific interactions and their communicative meaning. Lateralized dog brain patterns underlying basic neural mechanisms are also discussed, for both conspecific and heterospecific social communication.

Abstract

Dogs have a vast and flexible repertoire of visual, acoustic, and olfactory signals that allow an expressive and fine tuned conspecific and dog–human communication. Dogs use this behavioural repertoire when communicating with humans, employing the same signals used during conspecific interactions, some of which can acquire and carry a different meaning when directed toward humans. The aim of this review is to provide an overview of the latest progress made in the study of dog communication, describing the different nature of the signals used in conspecific (dog–dog) and heterospecific (dog–human) interactions and their communicative meaning. Finally, behavioural asymmetries that reflect lateralized neural patterns involved in both dog–dog and dog–human social communication are discussed.

Do dogs sense hypoglycaemia?

AIMS

To summarize the current knowledge on the phenomenon of dogs, both trained and untrained, sensing hypoglycaemia and alerting their owners to it.

METHODS

Electronic databases were searched for all types of articles reporting on untrained or trained 'diabetes alert' dogs. Articles published up until December 2014 in the English or German language were included.

RESULTS

Several case reports and observational studies provide evidence that animals can perform at a level above that attributable to chance, and may reliably detect low diurnal as well as nocturnal hypoglycaemic episodes. Behavioural changes in untrained dogs were reported during 38-100% of hypoglycaemic events experienced by their owners. The sensitivity and specificity of the performance of trained diabetes alert dogs sensing hypoglycaemia ranged from 22 to 100% and 71 to 90%, respectively. Additionally, 75-81% of patients with diabetes who owned a trained dog reported a subsequent improvement in their quality of life. Nevertheless, the available data are limited and heterogeneous because they rely on low patient numbers and survey-based studies prone to recall bias.

CONCLUSION

Further research is needed to confirm the preliminary data on the reliability and mechanism underlying the dogs' abilities to detect hypoglycaemia, and its impact on patient outcomes.

Dogs Can Be Successfully Trained to Alert to Hypoglycemia Samples from Patients with Type 1 Diabetes

INTRODUCTION

Hypoglycemia (Hypo) is the most common side effect of insulin therapy in people with type 1 diabetes (T1D). Over time, patients with T1D become unaware of signs and symptoms of Hypo. Hypo unawareness leads to morbidity and mortality. Diabetes alert dogs (DADs) represent a unique way to help patients with Hypo unawareness. Our group has previously presented data in abstract form which demonstrates the sensitivity and specificity of DADS. The purpose of our current study is to expand evaluation of DAD sensitivity and specificity using a method that reduces the possibility of trainer bias.

METHODS

We evaluated 6 dogs aging 1-10 years old who had received an average of 6 months of training for Hypo alert using positive training methods. Perspiration samples were collected from patients during Hypo (BG 46-65 mg/dL) and normoglycemia (BG 85-136 mg/dl) and were used in training. These samples were placed in glass vials which were then placed into 7 steel cans (1 Hypo, 2 normal, 4 blank) randomly placed by roll of a dice. The dogs alerted by either sitting in front of, or pushing, the can containing the Hypo sample. Dogs were rewarded for appropriate recognition of the Hypo samples using a food treat via a remote control dispenser. The results were videotaped and statistically evaluated for sensitivity (proportion of lows correctly alerted, "true positive rate") and specificity (proportion of blanks + normal samples not alerted, "true negative rate") calculated after pooling data across all trials for all dogs.

RESULTS

All DADs displayed statistically significant (p value <0.05) greater sensitivity (min 50.0%-max 87.5%) to detect the Hypo sample than the expected random correct alert of 14%. Specificity ranged from a min of 89.6% to a max of 97.9% (expected rate is not defined in this scenario).

CONCLUSIONS

Our results suggest that properly trained DADs can successfully recognize and alert to Hypo in an in vitro setting using smell alone.

Perceptions about professionally and non-professionally trained hypoglycemia detection dogs

AIMS

Patients with diabetes increasingly have questions about diabetes alert dogs. This study evaluated perceptions about dogs trained professionally or otherwise to detect glucose levels.

METHODS

A link to a survey about glucose detecting dogs was announced on diabetes websites.

RESULTS

135 persons responded, with 63 answering about their child with diabetes. Most respondents obtained their dog from a professional trainer (n = 54) or trained it themselves (n = 51). Owners of self- and professionally-trained dogs were very positive about dogs' abilities to alert them to low and high glucose levels, while owners of dogs that learned entirely on their own (n = 15) reported lower frequencies of alerts and more missed hypoglycemic episodes, p<.01. Regardless of how dogs learned, perceptions about managing diabetes were improved during periods of dog ownership relative to times without, p<.001. Self-reported rates of diabetes-related hospitalizations, assistance from others for treating hypoglycemia, and accidents or near accidents while driving reduced during periods of dog ownership compared to periods without dogs, ps<.01.

CONCLUSIONS

These data suggest potential effectiveness of and high satisfaction with glucose-detecting dogs. Clinicians can use these results to address pros and cons of dog ownership with patients who inquire about them.

Hypo- and Hyperglycemic Alarms: Devices and Algorithms

Soon after the discovery that insulin regulates blood glucose by Banting and Best in 1922, the symptoms and risks associated with hypoglycemia became widely recognized. This article reviews devices to warn individuals of impending hypo- and hyperglycemia; biosignals used by these devices include electroencephalography, electrocardiography, skin galvanic resistance, diabetes alert dogs, and continuous glucose monitors (CGMs). While systems based on other technology are increasing in performance and decreasing in size, CGM technology remains the best method for both reactive and predictive alarming of hypo- or hyperglycemia.

Onco-epidemiology of domestic animals and targeted therapeutic attempts: perspectives on human oncology

The spontaneous tumor biology has been investigated with the support of animalists using animals as a preclinical model allowing translation of results in clinical practice. This review provides an insight into the field of comparative oncology. Evidence shows that companion animal health care is impressively growing in terms of development of new therapies and diagnostic tools, nutrition and disease prevention. However, even if most animal tumors might be a reliable model to study human carcinomas, many open questions, related to the opportunities to select and recruit new models in oncology, along with their legal and ethical implications, remain unanswered.

Investigation into the value of trained glycaemia alert dogs to clients with type I diabetes

Previous studies have suggested that some pet dogs respond to their owners' hypoglycaemic state. Here, we show that trained glycaemia alert dogs placed with clients living with diabetes afford significant improvements to owner well-being. We investigated whether trained dogs reliably respond to their owners' hypoglycaemic state, and whether owners experience facilitated tightened glycaemic control, and wider psychosocial benefits. Since obtaining their dog, all seventeen clients studied reported positive effects including reduced paramedic call outs, decreased unconscious episodes and improved independence. Owner-recorded data showed that dogs alerted their owners, with significant, though variable, accuracy at times of low and high blood sugar. Eight out of the ten dogs (for which owners provided adequate records) responded consistently more often when their owner's blood sugars were reported to be outside, than within, target range. Comparison of nine clients' routine records showed significant overall change after obtaining their dogs, with seven clients recording a significantly higher proportion of routine tests within target range after obtaining a dog. HbA1C showed a small, non significant reduction after dog allocation. Based on owner-reported data we have shown, for the first time, that trained detection dogs perform above chance level. This study points to the potential value of alert dogs, for increasing glycaemic control, client independence and consequent quality of life and even reducing the costs of long-term health care.

Domestic dogs and human health: an overview

PURPOSE

The domestic dog is one of the most commonly owned, and widely utilized, animals in today's society. This paper provides an overview of research that has explored the relationship between the domestic dog and human well-being.

METHODS

The article initially concentrates on the value of dogs for physical health in humans, exploring the evidence that this species can prevent us from becoming ill, facilitate our recovery from ill-health, and even serve as an early warning system for certain types of underlying ailment including cancer, oncoming seizures and hypoglycaemia. The paper then examines the relationship between dogs and psychological health in humans, exploring the ability of this species to aid the disabled and serve as a therapist to those in institutional settings such as hospitals, residential homes and prisons. Weaknesses in the existing research in this area are highlighted throughout the article.

CONCLUSIONS

Taken together, the studies reviewed suggest that dogs can have prophylactic and therapeutic value for people.

Volatile metabolic monitoring of glycemic status in diabetes using electronic olfaction

The increased incidence of Type I and Type II diabetes among adults and adolescents is a growing public health concern worldwide. The primary objective of diabetes mellitus management involves keeping glycemia levels within the euglycemic range to prevent a variety of serious health complications. Unfortunately, daily self-monitoring is both a requirement and a problem for many patients with diabetes, particularly children and adolescents. Studies have shown that as many as 43% of adolescents and 30% of children (<14 years old) regularly forget to use glycemic tests and are significantly poorer at recognizing and reporting symptoms and signs of hypoglycemia/hyperglycemia. For this reason, methods for noninvasive, continuous monitoring that can signal glycemic status to a parent, teacher, or other caregiver would improve the care and management of symptoms of diabetes among these individuals. The goal of this review is to describe and evaluate electronic olfaction technology ("electronic nose") for monitoring the presence and levels of volatile chemicals from human body and breath that can be used to evaluate status of diabetes. The review is organized in four sections. The first section reviews the chemistry of the volatile signals that are produced by the body that are indicative of metabolic status. The second section provides an overview of novel sensor technology, e.g., "electronic olfaction," that mimics the biological olfactory system and can be used to monitor and identify complex plumes of volatiles that are signatures of metabolic states. The third section reviews studies that have employed electronic "nose" technology for diagnosis and monitoring of diabetes via urine and breath, and the final section discusses needed future directions for the development of olfactory-based metabolic monitoring, particularly among noncompliant populations.

The impact of severe hypoglycemia and impaired awareness of hypoglycemia on relatives of patients with type 1 diabetes

OBJECTIVE

Severe hypoglycemia is a major problem for patients with type 1 diabetes and their relatives. The aim of this study was to compare patients' and relatives' assessments of rates of severe hypoglycemia and state of awareness and to explore the influence on involvement and concern of relatives.

RESEARCH DESIGN AND METHODS

A cross-sectional paired questionnaire survey on hypoglycemia and the state of awareness was used in our study comprising 284 unselected adult patients with type 1 diabetes and their closest cohabitant. The cohabitant questionnaires also addressed involvement and concern.

RESULTS

The agreement between assessments of rates of severe hypoglycemia and state of awareness made by patients and cohabitants was weak (kappa 0.404 and 0.442, respectively; P < 0.001). Cohabitants recalled more episodes of severe hypoglycemia than patients (2.7 vs. 1.6 episodes/patient-year; P < 0.001). Degree of involvement was positively related to the rate of severe hypoglycemia (P = 0.002) and negatively related to the state of awareness (P = 0.007) but not to level of HbA(1c), duration of diabetes, or presence of late complications, except for peripheral neuropathy (P = 0.01).

CONCLUSIONS

Cohabitants of patients with type 1 diabetes recall significantly more episodes of severe hypoglycemia than the patients. The rate of severe hypoglycemia and state of hypoglycemic awareness are the principal determinants of degree of cohabitants' involvement in their partners' disease.