Novel drug delivery systems have been the subject of research for decades. This is because of a host of limitations with oral administration, the most widely-used route for administering medicine and challenges with several available alternatives. One of the most exciting new areas consist of pulmonary drug delivery systems, by which medication is delivered through the lungs. The harnessing of processes used in microelectronics and nanotechnology holds forth promise of a revolution in therapeutic medication.

The oral route: difficulties across generations, affects compliance
In spite of assumptions about convenience, oral dosage forms are not universally accepted. A recent study called ‘A Hard Truth to Swallow’ showed that over 55% of people, regardless of age or gender, faced “swallowing difficulties when taking tablets or capsules.” The study, by Spiegel Institut in Mannheim, surveyed 2,000 people in Germany and the US.
Surprisingly, although 44% of participants older than 65 years were affected, 70% of respondents in the 16–34 age group also reported problems – for example, with regard to swallowing, taste or odour, and irritation to digestive tract. This, in turn, clearly impacts on compliance.

The challenge of hepatic first pass metabolism
Broadly speaking, oral drug delivery faces challenges of low bioavailability and limits in the duration of therapeutic action.
A key problem consists of what is known as hepatic first pass metabolism (or pre-systemic metabolism). This is a phenomenon, by virtue of which the concentration of a medicinal product is reduced (in some cases, very sharply) before it reaches systemic circulation. Such a process involves the liver, to where a drug is borne from the gut wall via the portal vein, before reaching the rest of the body. The liver is biochemically selective and metabolizes drugs, in some cases to a massive extent, transferring only a part of the active ingredients to the circulatory system. As a result, there are marked differences in the effectiveness of oral drugs, due to variations in the degree of first pass metabolism.

IV administration
Bioavailability (BA) is defined as the proportion of an administered dose which reaches systemic circulation, and is considered one of the principal pharmacokinetic properties of drugs.
Given this, intravenous (IV) administration of a medicine means 100% bioavailability, which is why some consider IV administration to be a form of gold standard. The effects of IV medication are dependable. The entire administered dose immediately reaches systemic circulation. In turn, this allows for precise titration against a patient’s response.
However, IV administration has several limitations. It requires a functioning cannula, typically in a hospital, clinic or a patient’s bedsite – both due to procedural requirements as well as the need to avoid infections. Together, the latter entail that IV requires more staff and money. Finally, the process of cannulation can be distressing, especially in small children or those with needle phobias.
Indeed, even in a hospital setting, most IV patients are switched as soon as possible to oral therapy; the only exceptions are those critically ill or unable to absorb oral medications.

Injections, suppositories and topicals
Oral medications have sought to address some of their own inherent and long-evident limitations. These included slow- or extended-release formulations. However, as far as the issue of hepatic first pass metabolism is concerned, there is little reason to celebrate.
Instead, research has been focused on alternative routes of administration which, like IV, avoid first-pass effects, but do not necessarily require a clinical setting. Traditional alternatives include topical medications, intramuscular/subcutaneous injection and rectal administration via suppository drugs. Each of them continues to be investigated. All have pros and cons.

Topical administration is non-invasive and straightforward. It is also associated with significant patient satisfaction. However, most drugs have a high molecular weight and are poorly lipid soluble, and cannot be absorbed via skin or mucous membranes. Even when they are, the process is slow.

Injections have far better absorption profiles, and are preferred for drugs with low oral BA levels or those requiring a long duration of action, such as some psychotropic medications. Its onset is also more rapid than oral, or the topical route.  However, absorption via injection can be unpredictable, when a patient is poorly perfused. Like IV, injections can also frighten children and needle phobics.
On their part, rectal suppositories also have good absorption since hemorrhoidal veins drain directly into the inferior vena cava, and thus bypass the hepatic metabolism challenge. However, although onset of action is fast, the duration of action is short. In addition the absorptive ability of the rectum mucosa is lower than that of the small intestine.  Finally, rectal administration can provoke inherent feelings of resistance or revulsion, especially in adults.

Pulmonary delivery: the promise
In the light of all these, pulmonary drug delivery systems (PDDS) may offer a promising new alternative.
PDDS offers extremely fast absorption and onset of therapeutic action, due to the large surface area of the respiratory endothelium and its thinness. The plasma profiles after PDDS closely duplicate that of IV. As a result, it serves to reduce dose size and dosing intervals. This also helps to diminish side effects.
Aerosols and intra-tracheal inhalations
PDDS administers drugs to the lungs via the nasal or oral route, using two techniques: aerosol and intra-tracheal inhalation.
Aerosols provide more uniform distribution and greater penetration into the peripheral (alveolar) region of the lung. However, aerosol delivery is expensive. It also faces difficulty in measuring precise dose, when inside the lungs
Intra-tracheal inhalation (or instillation) is a much simpler and cheaper process than aerosols. It uses a syringe to deliver a medicated solution into the lungs. This addresses one of the major problems with aerosol delivery – to quantify the amount of drug delivered into the lungs.
Particle aerosol inhalers, in particular, are now increasingly commonplace for treating respiratory disease. Nebulizers, dry powder inhalers (DPI) and pressurized metered dose inhalers (pMDI) allow for local delivery of high concentrations of therapeutics in the lung, in many cases avoiding toxicities associated with oral or even injectable therapies.
Together, pMDIs and dry powder inhalers (DPIs) are estimated to deliver more than 90% of inhaled medications.

New PDDS applications
PDDS has also established its utility in emergency situations, given its absorption advantage.
One of the highest opportunities in PDDS is seen for macromolecules such as peptides and proteins, which usually need to be administered via injections (e.g. insulin). However, more experience with PDDS is required, especially about potential side effects after routine use.

Challenges for PDDS
PDDS, however, still faces limitations.
The first is that the particles which are to be inhaled need somewhat precise and reproducible aerodynamic factors related to diameter and density, as well as velocity, in order to successfully transit the nose and mouth and their filtration systems – which are designed to keep such matter out. As a result, there is always a certain degree of deposition of drugs in the nasal and oral passage.
Secondly, once in the lungs, the particles must overcome the pulmonary phagocytic barrier to release drugs at the required rate in order to achieve the intended therapeutic effect. For successful PDDS, designers must take careful account of properties such as pH value, ionic strength etc. which can affect the release of the drug, and thus its therapeutic effects.
Finally, PDDS is always accompanied by wastage of the drug. Due to material limitations of physics, a significant part of the drug is retained in the container.

As a result, pulmonary drug delivery remains inefficient, sometimes strikingly so. In spite of the growth in their availability, dose delivery efficiencies for dry powder asthma inhalers is estimated at just 3-15% for children and 10-30% for adults. The most advanced pMDIs deliver just 60% of inhaled material to bronchial airways. These were some of the findings in a review entitled ‘Targeted drug-aerosol delivery in the human respiratory system’, published in a 2008 issue of the  ‘Annual Review of Biomedical Engineering’.

Lessons from microelectronics manufacturing
In recent years, researchers have sought to address some of the key challenges of PDDS.
These, as we have noted, concern aerodynamic factors such as diameter and density of the particles.
Conventionally, pharmaceutical aerosols for DPIs are manufactured by milling (micronization) or spray drying techniques. These lead to wide particle size distributions and limited control over particle shape. Additional challenges include the need for non-agglomerating powders with the active ingredients, especially when they concern products such as proteins and monoclonal antibodies.
Recently, some manufacturers have sought to learn from the microelectronics industry by seeking to generate high-precision aerosol particle-based respiratory drug delivery systems. Such particle engineering techniques have shown special promise for targeted pulmonary delivery, when combined with inhalable nanoparticles, especially in solid-state dry powders.

PRINT and nano-particles
One leading example is called PRINT (Particle Replication in Non-Wetting Templates) which co-opts the precision and nanoscale spatial resolution in lithographic techniques used by the microelectronics industry, to provide  unprecedented control over particle size and shape.
A 2013 edition of ‘Angewandte Chemie International Edition’ describes PRINT as “a continuous, roll-to-roll, high-resolution molding technology which allows the design and synthesis of precisely defined micro- and nanoparticles.”
PRINT’s micromolding enables the formulation of particle systems of small molecules, biologics and oligonucleotides – all of which hold special promise for next-generation therapeutic PDDS applications.  In itself, the technique is highly versatile and is also being researched for application to oral and topical dosage forms.
The PRINT manufacturing process has begun to be tested for clinical applications. In the US, Liquidia Technologies and Accelovalence have completed Phase I and II studies to use PRINT to produce GMP-compliant bioabsorbable particles that improve the immune response and efficacy of seasonal influenza vaccines, at a scale relevant to clinical development.

Other approaches: iSPERSE
Other research efforts focus on chemistry. For example, another US firm, Pulmatrix, has recently been awarded a patent in Europe for iSPERSE, a PDDS systems based on proprietary cationic salt formulations which can accommodate high drug loads and large drug molecules in highly dispersible particles, in a manner claimed to be both robust and flexible enough to accommodate multi-drug formulations. The advantage of iSPERSE is that it has shown superior delivery capabilities compared with conventional dry powder technologies which use lactose blending or low-density particles.

Emerging markets: major new opportunities
Such efforts are likely to be rewarded given the large number of blockbuster respiratory products going off-patent – with growing demand in the developing world. In Latin America, for example, COPD deaths have risen by 65% in the last decade, while figures indicate 12 million people affected by the disease in India. In China, in China, chronic respiratory diseases have become the second leading cause of death.
We have seen that the generic capsule-based dry powder inhaler (DPI) segment in developing markets shows a lot of promise and demand is rising. However, when it comes to these products, patients in developing markets have not been best served by strategies employed by major pharmaceutical companies in the US and Europe, which have developed DPIs customized exclusively for one specific active pharmaceutical ingredient (API).

In June 2017, the European Commission adopted an Action Plan to tackle Antimicrobial Resistance (AMR) which is responsible for an estimated 25,000 deaths in the EU every year.  Worldwide, the death toll from AMR is reported to be as high as 700,000. The World Bank warns that by 2050, the economic impact of drug-resistant infections due to AMR would be on par with the financial crisis in 2008.

Contamination and resistance
Overall, healthcare-associated infections (HAIs) affect up to 15% of hospitalized patients. The main causes are persistent microbial contamination of hospital surfaces, along with a growth of drug-resistant pathogens. Although antimicrobial misuse is believed to be largely responsible for AMR, hospital hygiene has come sharply into focus as traditional cleaning methods begin to encounter limits in their capacity to control infection.

WHO guidelines on hand hygiene
According to the World Health Organization (WHO), good hand hygiene practices could halve the infection level in hospitals.  The WHO guidelines are also known as the ‘Five Moments for Hand Hygiene.’ They involve the occasion before a patient is touched, before clean/aseptic procedures, after body fluid exposure/risk, after touching a patient, and after touching the patient’s surroundings. However, much more needs to be done to validate training or control the implementation of the WHO guidelines.

Challenges of compliance
One of the biggest challenges is the time required for the most effective form of hand hygiene, namely alcohol-based hand rubs (ABHR). WHO recommends applying ABHRs for 20 to 30 seconds, while the US Centers for Disease Control and Prevention (CDC) recommends doing so until the hands feel dry, which it states ought to take about 20 seconds. Such time-spans are considered far too long for busy, practising clinicians.
However, it seems that such requirements may be unnecessarily arduous. In Dec 2017 / Jan 2018, a clinical observational study in Germany found that reducing the recommended application time for hand rubs improved compliance rates with no significant difference in efficacy. The researchers at the Institute for Hygiene and Environmental Medicine of the University Hospital of Greifswald focused on nurses who applied ABHRs for either 15 or 30 seconds. The study found ABHRs were “equal or even more effective” within 15 seconds versus 30 seconds for a variety of micro-organisms. The only caveat was that the ABHR needed to have a proven efficacy after 15 seconds. This did not extend to all ABHRs available on the market, and particularly not to gel formulations.

Other researchers are approaching the problem differently. In October 2013, an article in the journal ‘Clinical Infectious Diseases’ published results of a meta-study on hand hygiene, which it called “the critical intervention underlying modern infection prevention efforts.” The authors concluded that, in spite of limited research and evidence, “bundles including education, feedback, reminders, access to ABHR and administrative support” would be the most effective at improving hand hygiene compliance.

Three years before this, the ‘American Journal of Infection Control’ reported results from a project at one hospital, where compliance with hand hygiene was improved and sustained through use of a multi-faceted bundle approach. One aspect of the latter was a violation notice letter sent to non-compliant staff and enforced by managers. This appears to have been the key factor in dramatically raising hand hygiene compliance from a rate of 34% to more than 90% in the space of just two years.

Recent developments in hand hygiene
Recent developments related to hand hygiene include new test methods for evaluating hand hygiene products, improvements in ABHR, novel antisepsis techniques and new strategies for monitoring hand hygiene practices among healthcare personnel.  A host of new methodologies is also being explored to implement hand hygiene at hospitals. These range from new digital tools to robotics, artificial intelligence and genetics.

Gesture recognition algorithms
In late 2017, global hand hygiene company GOJO reported results from a ‘smart hospital’ project with two medical technology companies from Ireland, SureWash and MEG Support Tools. The three joined forces with an infection control team at Manchester’s Christie Hospital, to create a live data dashboard using an interactive training kiosk from SureWash, an audit app from MEG and GOJO’s Smartlink dispenser. Analytics were run in real time on the data to provide actionable feedback when hand hygiene standards slipped.

Patients and infection control
During the study, hand hygiene education and compliance were also targeted at patients by means of gesture recognition and camera-based algorithm technology.
Indeed, patients have recently begun to be harnessed as key actors in infection prevention. So far, there were few resources available for such a task, in spite of a growing body of evidence to suggest that patients’ flora too were a primary source of several infections, and that these could be prevented by correct hand hygiene. Most previous work involving patients had simply included them as monitors of hand hygiene practices by healthcare workers.

Clean bots
Germ-killing robots provide a new weapon in the arsenal against health care-associated infections.
One study funded by the CDC in the US showed that germ-killing robots (also being described as Clean Bots) could reduce common healthcare-associated infections by 30 percent.
At the end of 2017, Vanderbilt University Medical Center in Nashville, Tennessee, began deploying robots to protect hospitalized patients from two of the toughest strains of resistant bacteria: methicillin-resistant staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The first area of application is the burns ward, which hosts some of the most vulnerable patient groups. Rooms are cleaned with traditional liquid disinfectants. After this, hallway doors and curtains are closed, while  cabinets and drawers are left open. This is followed by the despatch of a remote-controlled robot, which floods the room with ultraviolet radiation to kill any residual germs. The robot shuts itself down after its sensors detect adequate reflected UV from the room surfaces, which typically takes about 25 minutes. However, longer settings can be used in rooms likely to host hospital-acquired infections.
Nevertheless, authorities at the Vanderbilt Medical Center reiterate that Clean Bots are not a replacement for good hand hygiene.
Vanderbilt now plans to monitor the effects of the robots on infection rates and on workflow, and is developing protocols to optimize use of the robots without delaying patients arriving from the emergency department or the recovery room.

Artificial intelligence
Artificial intelligence (AI) is also being utilized to enhance hygiene. The magazine ‘New Scientist’ recently reported efforts by a Stanford University research team, which sought to harness AI to spot behaviour that might contribute to the spread of infection. Towards this, the researchers used video cameras at a hospital in a range of hotspots such as patient rooms, hallways and adjacent to hand sanitizing dispensers. The cameras made recordings over the course of one high activity hour. 80 percent of the video was used to train tracking algorithms, while the rest was used to test the algorithms.
During the hour when the recording was made, 170 people entered patient rooms. However, only 30 followed appropriate protocols for hand hygiene. The researchers found that computer vision algorithms were more accurate in making such a judgement than people in the hospital covertly recording hand sanitation practices.
The researchers are now planning to outfit three hospitals for a year to see how the technology and the observations it reports impact infection rates. One of the researchers, Alexandre Alahi, told ‘New Scientist’ that though it may not be affordable to have a doctor in a room round-the-clock, an AI doctor could well be economically viable, freeing up humans to do other jobs.

Video analytics
Video analytics has also been used for a study by the Division of Infectious Diseases and Hospital Epidemiology at University Hospital Zurich to make in-depth follow-up of hand hygiene practices, in order to systematically document hand-to-surface exposures (HSE) and delineate true hand transmission pathways. The authors of the study, published in the October 30, 2017 issue of ‘Antimicrobial Resistance & Infection Control’ concluded that the “abundance of HSE underscores the central role of hands in the spread of potential pathogens while hand hygiene occurred rarely at potential colonization and infection events.” They aim to propagate their hand trajectory monitoring approach to design more efficient prevention schemes.

The trajectories of infection
One of the newest tools in the fight against infection seeks to provide a first-person view of pathogen transmission. It involves the documentation of hand-to-surface exposures (HSE) by healthcare workers and tracking their trajectories.
The process, which was developed by researchers at Zurich University Hospital in Switzerland, uses a head-mounted camera and commercial coding software to code HSE type and duration based on a hierarchical scheme. It identifies HSE sequences with particular relevance to infectious risks, based on the WHO’s ‘Five Moments for Hand Hygiene.’
The Swiss researchers recorded and studied hand movements of 8 nurses and two physicians and confirmed the central role of hands in the spread of potential pathogens. During the study period of almost five hours, a total of 4,222 HSEs were identified, corresponding to one HSE every 4.2 seconds. Of this, 291 HSE transitions were ‘colonization events’, occurring from outside to inside the patient zone. Hand hygiene occurred rarely at potential colonization and infection events.
According to the researchers, an in-depth analysis of hand trajectories during active patient care may help to design more efficient prevention schemes.

Colour coding bedsheets
While tools such as video analytics and robotics offers new approaches to the challenge of hygiene, others are turning to imaginative, lower tech solutions. In India, health officials in West Bengal’s Raiganj district hospital recently announced that bedsheets of varying colours would be used on different days a week to check cross infection and ensure that the beds and the wards were cleaned every day.
There authorities were responding to complaints that bedsheets were not regularly changed, in some cases even after a patient had been discharged. Using bedsheets of different colours gives an immediate solution to such a problem. The hospital has put up a chart mentioning days of the week and the corresponding colour of the bedsheets, allowing family members of patients to confirm that their beds had been cleaned.

Smartphones are turning out to be an exciting weapon against the scourge of cardiovascular disease, which is considered by the World Health Organization (WHO) to be the most common cause of death worldwide.
Reasons for such a development are varied. Smartphones bristle with sensors like cameras and accelerometers which can be used for making, storing and transmitting diagnostic measurements. Smartphones are also small, mobile and capable of being paired with wearable devices such as  wristbands, watches, skin patches etc.

Real-time and continuous measurement
The concept of always-on continuity, enabled by smartphones, makes sense in several cardiovascular health-related contexts. To date, most authoritative studies in this field are based on questionnaires, and focused on variables like diet, exercise, sleep etc. They have also relied almost wholly on participant recall.
By contrast, the sensors in mobile smartphones allow for real-time and continuous measurement of a range of factors. This can make a major difference.
For instance, high blood pressure (hypertension) is known to be a leading cause of strokes and heart attacks. However, blood pressure is very difficult to measure precisely. It can vary widely over just one day, and increase if one simply dangles one’s feet off a table, or for that matter becomes stressed by the exam itself. In this case, a wearable which monitors blood pressure through the day and night, and provides an average over time to compare with those from previous days or weeks, has clear advantages over the spot metric offered by blood pressure measurement at a physician’s clinic.

Applications in atrial fibrillation
Elsewhere, smartphone apps are now targeting the diagnosis of irregular heart rhythms, which can indicate atrial fibrillation (AF), another major cardiovascular risk. Such irregularities need not be symptomatic, but can be all the more dangerous because of that.
In 2014, the US Food and Drug Administration (FDA) approved the AliveCor Heart Monitor, which consists of a smartphone app plus a phone case fitted on its back with special sensors. Touching the sensors allows visualization of cardiac electrical activity on the phone screen.  
Currently, a host of other smartphone apps alert users about potential AF without requiring any special sensor-equipped case. Though yet to be cleared by the FDA, reports suggest they might be similar in accuracy to AliveCor.
Migration from fitness to the medical
Another approach to arrhythmia has been taken by the Media Lab at the Massachusetts Institute of Technology (MIT). The latter’s Cardiio spin-off also illustrates the potential for migrating smartphone apps from fitness monitoring to the medical. In 2012, Cardiio launched an eponymous fitness app to measure heart rate based on facial light reflection, given that a beating heart pumps and increases blood volume in the vessels. On its part, blood hemoglobin absorbs light, and this decreases the amount of light reflected by the skin. Though such tiny changes in reflection are invisible to the human eye, they can be sensed by smartphone cameras and interpreted by apps.
Cardiio recently deployed its light-reflection system in another app, which detects the irregular heartbeat patterns of atrial fibrillation.
An electrocardiogram (ECG), which involves the attachment of electrodes to the chest to measure electrical impulses in a heartbeat and detect irregularities, remains the standard for AF-detection. However, as in the case of the blood pressure variations mentioned above, clinicians are aware that an ECG might not pick up an AF, should the heart rhythm irregularity be sporadic. Indeed, in some cases, irregularities are discovered only after patients suffer a stroke. One of the most common of these is known as paroxysmal AF, which causes spontaneous irregular heartbeats that are not straightforward to diagnose.

Supplementing traditions, new frontiers
In general, no one believes that smartphones will replace diagnosis by traditional medical devices. However, they have begun to supplement the latter, and are expected to continue doing so. Such a process is taking smartphones into ever-newer frontiers.
For example, engineers at the California Institute of Technology (Caltech) have demonstrated a smartphone app which measures ‘left ventricular ejection fraction’ (LVEF). LVEF is the volume of blood pumped by the heart per beat as the arteries expand and contract, and is one of the principal measures of heart health. It is typically assessed by ultrasound, which can take hours and be performed only by technicians.
The Caltech app requires patients to hold a smartphone camera against the carotid artery in their neck. This feeds directly into the heart and provides especially accurate information. The procedure, which lasts under two minutes, involves the camera measuring the expansion and contraction of the carotid artery’s walls. An algorithm in the app uses this data to calculate blood flow from the heart. According to some reports, the app provides LVEF data which is as accurate as an ultrasound.
Many industry experts foresee that next generation wearables will have ECG and pulse oximetry capabilities, with some going as far as predicting that wearables, supported by sensors embedded discretely in clothing, could be used for continuous blood glucose and blood pressure monitoring.

Part of wider mHealth drive
As smartphones begin to be seen as a strategy to fight cardiovascular disease,  many manufacturers and app developers have sought to commercially capitalize on the wider mobile personal health (mHealth) movement. Indeed, it is now becoming accepted that mobile devices and apps can provide data to make meaningful and informed clinical decisions.
For some cardiovascular conditions, mHealth is also seen as enhancing the ability for pre-emptive intervention by giving patients more accessible diagnostic tools and information. 
Indeed, CVD prevention represents an ideal zone for propagating and popularizing mHealth. Cost‐efficient and scalable approaches can yield large scale insights into behaviours shaping/adversely impacting on cardiovascular health. Such solutions, in turn, can provide the raison d’etre for interventions which seek to change risky behaviour.
To make this work in the long term, however, providers, payers and professional societies concerned with cardiovascular health need to closely partner with mHealth developers. So too should regulators, especially given the emergence of a growing body of evidence about the benefits of smartphone-driven mHealth – not least in areas such as cardiovascular health.

Universities join industry in research
Until now, the gap in conclusive evidence has largely been on the clinical side, and there have been calls for more research to see how viable – and valuable – such solutions really are.
In January 2017, the authoritative ‘Journal of the American Medical Association’ published the results of a smartphone-centric cardiovascular study in the US, with physical activity patterns tracked and identified through cluster analysis and correlated with self-reported disease. The study found that a pattern of lower overall activity with more frequent transitions between active and inactive states was associated with the prevalence of equivalent self-reported cardiovascular disease as a function of higher overall activity with fewer transitions.
The JAMA study also drew several other conclusions. The first was confirmation of the existence of a sufficiently large smartphone-using population, who could be engaged to demonstrate cardiovascular health status using smartphones. Secondly, it showed that large-scale, real-time data could be gathered from mobile devices, stored, transferred and shared securely. The authors also noted that more data than any previous collected about the standard six-minute walk test could be generated in weeks.
Industry is enthusiastically upporting these efforts. The Apple Watch app Cardiogram, for example, has presented results saying that it could diagnose atrial fibrillation with 97 percent accuracy. Cardiogram had collaborated with the University of California San Francisco as part of Heart eHealth, the largest study to date on mHealth and heart disease. Apple recently announced it would be partnering with Stanford University researchers to run a study targeted at investigating AF.

Europe launches apps aimed at patients and professionals
In Europe, the European Society of Cardiology (ESC) has funded the creation of two AF apps targeted at patients, and at healthcare professionals.
The patient app provides education on AF, including sections on pathology, symptoms, prognosis, associated co-morbidities, management strategies and practical self-care tips. It is also designed to present information on individual stroke risk and provide a personal health record and symptom diary. On their part, patients fill in sections about their relevant health histories, which can facilitate consultation when shared with their healthcare professionals.
The professional app is designed as an interactive management tool incorporating new ESC Practice Guidelines on AF, and allows both conventional viewing of guideline text and recommendations, as well as interactive treatment algorithms. It is also aimed at improving consultation efficiency, via the provision of a patient register, pre-filled with data supplied by the patient app mentioned above.

Need for caution remains
In spite of all the buzz around smartphones and cardiovascular health, several experts have also been urging caution.
Major issues include a lack of representativeness. The bulk of smartphone users, not least those willing to experiment with new apps, are young, while cardiovascular disease risks rise in older age groups. In the US, for example, only 12% of adults aged over 65 years are estimated to own a smartphone.
Some studies in Europe have found such trends to be reversing. For example, a survey by consultants Deloitte in the UK last year indicates that 71% of 55-to-75 year olds now own an app-capable handset, and this age group has seen a faster adoption rate than any other over the past five years. However, members of the demographic tended to use their smartphones less than younger people.
Finally, younger users can also be fickle, with a steep drop-off in engagement over time. One survey found that only 80% of consumers continued to use their wearables regularly after three months.  Such factors can produce major risks for data integrity in a study.

The limits of mass consumer technology
Another problem is technology. In spite of dramatic progress in recent years, an Apple Watch is easy to cheat.
Accuracy is another drawback. One smartphone app to measure blood pressure required users to place a smartphone against their chest and a finger over the camera. However, it was discovered to have missed high blood pressure in as many as eight of 10 patients. This was also the problem with a phone case which sought to measure blood pressure at the fingertip, but studies were inconclusive about whether the case was good enough for use in a home environment. 
Healthcare professionals point to some more serious limitations. Devices checking heart rates infer rhythms from the pulse, and it is possible to have a normal pulse with an abnormal heart rhythm.