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About Us

We are Health Professionals who are part of a group of professions known as Health and Social Care Professionals. We mainly work in the area of diagnostics, carrying out tests directly on patients and very often providing reports on these tests.  We also work in the therapeutic area, following up on initiated therapies to ensure compliance and effectiveness.

General information is given below regarding the various tests carried out by the five disciplines; Cardiac, Neurophysiology, Gastro-Intestinal, Respiratory and Vascular.



Cardiac Physiologists are an important part of a multi-disciplinary team. This team includes medical, nursing and other healthcare professionals who work together in the investigation, diagnosis and treatment of patients with heart disease.
Cardiac Physiologist duties can be divided into invasive and non-invasive. Most invasive test are carried out in a sterile theatre like environment, where catheters and contrast are used to look at patients coronary arteries or insertion of a pacemaker .The range of services vary depending on each hospital and practice type.

Electrocardiogram (ECG)

Non-invasive recording of the electrical activity occurring in the heart each time it contracts. The recording is taken via electrodes positioned at specific sites on the limbs and chest.  The heart rate is measured and the ECG pattern and rhythm interpreted. It is a useful means of diagnosing disorders of the heart, many of which produce deviations from normal electrical patterns such as coronary disease, pericarditis, cardiomyopathy, myocarditis and arrhythmias. 

Exercise Stress Test

Non-invasive procedure that provides diagnostic and prognostic information and evaluates an individual’s capacity for dynamic exercise. The object of the test is to increase myocardial oxygen consumption and the demand for coronary blood flow by a standardised form of exercise. Where blood flow is impaired by coronary artery disease, myocardial ischaemia results. The subsequent electrocardiogram (ECG), haemodynamic and clinical response can help the clinician form a broader diagnostic impression in patients with or without symptoms.  Moreover, in those with known coronary artery disease, Exercise Stress Tests can be used to assess the severity of disease and monitor the response to medical and surgical intervention.

24hour Holter Monitor

This test is performed in the evaluation of cardiac arrhythmias, some of which may occur intermittently. The Physiologist fits a portable ECG monitor called a Holter Monitor on to the patient for 24/48 hours up to 7 days and records the patient’s heart rate and rhythm whilst they go about their daily activities. This aids in the diagnosis and choice of treatment for the patient.  The monitors are fitted by the physiologist and upon their return they are analyzed by the physiologist with a report generated demonstrating ECG strips of importance with an interpretative report. 

Event Recorders

This is a small portable monitor that is connected by a Cardiac Physiologist to the patient for a week or more in order to record infrequent, intermittent cardiac arrhythmias that may be occurring and are symptomatic. This aids in the diagnosis and treatment of this for the patient.  Again a report, including interpretation is generated by the physiologist

24hour Blood Pressure Monitor

The physiologist fits a portable BP monitor on the patient for 24 hrs. This records the patient’s systolic and diastolic blood pressure readings as they carry out their normal daily activities and so aids in the diagnosis and treatment of hypertension.  A report is generated by the physiologist


Uses ultrasound to create two- and three-dimensional images of the heart structures. It can also produce accurate assessment of the blood flowing through the heart, using Doppler ultrasound. This allows assessment of both normal and abnormal blood flow through the heart.
Echocardiography is a vital tool in the detection, diagnosis, evaluation and treatment of patients with chest pain, ischaemic heart disease, valvular heart disease, cardiomyopathy, pericardial disease, cardiac masses and tumours, disease of the great vessels, pulmonary disease, systematic hypertension, arrhythmias and palpitations, congenital heart disease both in the newborn and adults, cardio embolic disease and trauma patients.
Echocardiography has become routinely used in the diagnosis, management, and follow-up of patients with any suspected or known heart diseases. It is a vital tool in the assessment of patients pre-operatively and can often decide the need for further therapies such as Internal Cardiac Defibrillator.
Echocardiography is not just a Cardiology test, it is a routine test as part of most chemotherapy regimens, as part of a stroke patient’s work-up, pre-operative assessment to mention just three.

  • Transthoracic Echocardiogram is a non invasive procedure. The echocardiography transducer (or probe) is placed on the chest wall of the patient, and images are obtained. The Cardiac Physiologist acquires the images and using the analysis package makes the appropriate measurements. At the end of the scan all the images and measurements are transferred to a digital imaging storage system and the physiologist creates a clinical, interpretative report with diagnostic details – for example Left Ventricular Ejection Fraction, grading of valvular disease
  • Transoesophageal Echocardiogram is performed by passing a transducer on the end of a probe into the oesophagus of the patient. Clear images of the heart structures can be obtained without the interference of the lungs and chest. As this is an invasive procedure the probe is manipulated by a Cardiac Physician. While the Cardiac Physician manipulates and positions the probe the Cardiac Physiologist acquires the images and using the analysis package makes the appropriate measurements.  Conscious sedation may be used in order to make the patient more comfortable during the procedure and the physiologist may be responsible for monitoring the patient.
  • Contrast Echocardiography is the addition of ultrasound contrast medium, or imaging agent, to traditional echocardiography. The ultrasound contrast is made up of tiny micro bubbles filled with a gas core and protein shell. This allows the micro bubbles to circulate through the cardiovascular improve the image quality.
  • Stress Echocardiogram is an echocardiogram that is performed while the person exercises on a treadmill or stationary bicycle. This test can be used to visualize the motion of the heart walls and pumping action when the heart is stressed. It may reveal a lack of blood flow that isn't always apparent on other cardiac tests. The echocardiogram is performed prior to and just after the exercise.
  • Dobutamine Stress Echocardiogram This is another form of stress echocardiogram with ultrasound imaging to evaluate underlying coronary artery disease. However, instead of exercising to stress the heart, the patient undergoes a pharmacological stress test. The stress is obtained by giving a drug that stimulates the heart and makes it "think" it is exercising. The echocardiogram is performed while the drug is administered in an IV form.
  • Stress Echocardiography is used as non0invasive test of coronary artery disease which has a higher specificity than traditional stress testing.  It is also useful for assessing valvular heart disease and also assessing the likelihood that a patient will benefit from revascularisation
  • Three-Dimensional Echocardiography now possible, using a matrix array ultrasound probe and an appropriate processing system. This enables detailed anatomical assessment of cardiac pathology, particularly valvular defects, and cardiomyopathies. The ability to slice the virtual heart in infinite planes in an anatomically appropriate manner and to reconstruct three-dimensional images of anatomic structures makes 3D echocardiography unique for the understanding of the congenitally malformed heart. Real Time 3-Dimensional echocardiography can be used to guide the location of bioptomes during right ventricular endomyocardial biopsies, placement of catheter delivered valvular devices, and in many other intraoperative assessments. This area is a rapidly expanding and continually evolving field


Pacing and AICD Analysis

This procedure involves the complex reprogramming of Pacemakers and implantable devices that deliver an internal shock to deliver life-saving therapy. The Cardiac Physiologist plays a key role during Pacemaker insertion; this is usually carried out in the Cathlab by a Cardiologist.
The Physiologist is responsible for making all of the electrical measurements on the pacing lead(s) after insertion transvenously into the patients’ right heart to ensure optimal pacing/sensing and pacemaker longevity.
All further follow up, over the life of these pacemakers is performed by the Physiologist at outpatient pacing clinics.
Other more advanced interventional procedures performed in specialist centers include the implant of Automatic Implantable Cardioverter Defibrillators (AICD) and Biventricular Pacemakers with or without AICD capability. 
Many of these devices are now followed up in a remote fashion, using internet based technologies, improving long term surveillance, patient quality of life and improving efficiencies.  All device follow-up clinics and reprogramming decisions are physiologist led

Electrophysiological Studies

This is an invasive electrophysiological procedure which involves introducing multipolar catheter electrodes into the venous and/or arterial system at various positions to record electrical activity from portions of the atria or ventricles or the region of the His bundle and also allows stimulation of these areas electrically. These studies are performed diagnostically, to provide information on the type of rhythm disturbance and insight into its electrophysiological mechanism and is used therapeutically to terminate a tachycardia by electrical stimulation as well as to evaluate effects of therapy by determining whether a particular intervention prevents electrical induction of a tachycardia. These studies help predict the future clinical efficacy of pharmacologic and nonpharmacologic (such as Ablation techniques) modes of antiarrhythmic therapy.  The Physiologist is responsible for setting up all equipment relevant to the case including patient monitoring.  They are also responsible for recording and documenting procedure information on the EP recording system, operation of Radiofrequency Ablator, Cardiac Stimulator and 3D mapping system.  The Physiologist also performs intracardiac EGM measurements and highlights changes in rhythm, EGM morphology and any other issues that arise.

Cardiac Catheterization

Cardiac Catheterization is an invasive procedure performed by Cardiologists and enables the pressure within the heart chambers to be measured and recorded, blood samples to be taken at various sites within the heart to measure the oxygen content and samples of tissue from the heart lining to be removed for analysis.
The physiologist is responsible for the monitoring and recording of the patient’s vital signs and in the documentation of all equipment and drugs used during diagnostic procedures such as Coronary Angiography, Right & Left Heart Studies, interventional procedures such as Percutaneous Coronary Intervention and stent insertion.  The physiologist is responsible for defibrillation and the use of emergency equipment such as temporary pacing and intra-aortic balloon pumps.
Many new techniques have been introduced into our Cardiac Catheterization Laboratories and Cardiac Physiologists have led the way in helping to embed these new techniques and becoming competent in the use of these new pieces of equipment.  They include Intravascular Ultrasound (IVUS), Optical Coherence Tomography (OCT), two new imaging techniques, Rotablation, a technique for opening calcified vessels and Renal Denervation, a Catheter based treatment for Resistant Hypertension. 
Emergency Percutaneous Coronary Intervention is now the standard 24/7, 365 days a year treatment for ST elevation MI, as rolled out by the HSE National Acute Coronary Syndrome Program.


Gastrointestinal function investigations have become an important tool in the diagnosis of digestive diseases. Over the past 25 yrs many techniques have been developed to assist surgeons and physicians in the diagnosis and treatment of patients. Oesophageal disorders are extremely common with most patients presenting with symptoms of gastro-oesophageal reflux such as heartburn, epigastric and retrosternal discomfort, bloating and nausea. Many patients also present with dysphagia (difficulty swallowing), which may be indicative of a mechanical disorder of the lower oesophageal sphincter or a disorder of oesophageal peristalsis. In some cases dysphagia may be indicative of something more sinister such as oesophageal carcinoma. Patients with angina-like chest pain, respiratory symptoms such a wheezing and cough, laryngeal and voice disorders and patients with unexplained dental erosion are also commonly referred for GI physiology investigations to help ascertain whether the primary cause of their symptoms is gastro – oesophageal reflux disease. The GI physiology unit also carries out lower GI investigations to help colorectal surgeons and physicians in the diagnosis of Ano rectal disorders.

At present there are 7 full time Clinical Measurement Scientists working in Ireland, with approx 8 research nurses/ doctors providing a limited service. Most of the Units are Dublin based, with the exception of Cork, Wexford and Galway. There is no paediatric service in Ireland.

All procedures carried out by a GI Physiologist, requires the Physiologist to invasively pass an investigative catheter into an un-sedated patient, without medical supervision. Upper GI investigations require the GI Physiologist to pass a catheter trans nasally; Lower GI Investigations require investigative catheters to be passed rectally. Recently, GI Physiologist has undergone training to allow administration of local aesthetic spray directly to the patient, to allow for better tolerance of the investigations. The GI Physiologist is responsible to document a detailed medical history of the each patient and to assess suitability for the procedure. The physiologist is responsible for the documentation of all equipment and drugs used during diagnostic procedures.

Tests carried out in a GI Physiology Unit:

  • Oesophageal Manometry
  • High Resolution Manometry
  • 24-hr pH monitoring
  • 24-hr Impedance pH monitoring
  • 24-hr Bile Monitoring
  • Electrogastrography
  • Capsule Endoscopy
  • Breath testing which include:
  • Lactose intolerance
  • Intestinal bacterial overgrowth
  • Intestinal transit time
  • Diagnosis of H.Pylori
  • Malabsortion of sugars
  • Pancreatic Function
  • Liver Function
  • Anorectal manometry


Upper GI Manometry

The oesophagus is a muscular tube that is responsible for the transit of food from mouth to stomach. Oesophageal manometry tests the muscle function of the oesophagus and its sphincters. Patients complaining of difficulty with swallowing, unexplained chest pain or regurgitation of food should undergo oesophageal manometry.   It is also used in the assessment of patients with Oesophageal Cancer both pre and post treatment, and Barrett’s Oesophagus. There are 3 main investigations to document motility function of the upper GI Tract. Again a report, including interpretation is generated by the Physiologist


Lower Oesophageal Sphincter Manometry (LOS);

This procedure gives the doctor information about the function of the oesophago-gastric junction. The study measures the location of the sphincter and also its relaxation.  It is most useful in the diagnosis of certain medical conditions, such as Achalasia, and can also indicate the suitability of patients for anti-reflux surgery. Post surgery it is necessary to ensure that the valve hasn’t been tightened too much, thus causing problems swallowing.
The GI Physiologist will interpret the data and provide an accurate report on the investigation.  

Stationary Oesophageal Body Manometry;

This study measures propagation and amplitude of swallows within the oesophageal body. It can determine whether patients have primary motility disorders or disturbances. Patients referred for anti-reflux surgery must have manometry performed to out-rule any underlying motility problem which maybe a contra-indication for surgery. It can be used to diagnose patients with Nutcracker Oesophageal, Spasm or Scleroderma.
The GI Physiologist will interpret the data and provide an accurate report on the investigation.  

Stationery Upper Oesophageal Sphincter (UOS);

This study involves locating the UOS and measures’ its function. Patients who attend the ENT or Respiratory clinics can benefit from this procedure. It can be used to help diagnose problems with initiation of swallow and can help ENT Clinician or Speech Therapist   in their treatment of the patient. The GI Physiologist will interpret the data and provide an accurate report on the investigation.  
Lower GI Manometry

Ano-Rectal Manometry;

Anorectal Manometry is used for the assessment of internal and external anal sphincter function, sphincter length and recto-anal inhibitory reflex and sensation. Patient with the following problems may benefit from this study, such as Faecal incontinence ,Constipation, In the diagnosis of Hirsprung’s disease, Mechanical injury i.e. obstetric injury, spinal injuries effecting S2-S4 , Neurological  damage i.e. pudendal nerve damage , Rectal prolapse  or suspected Systemic disease – Diabetes, scleroderma, MS . Failure of the anal sphincters to function correctly, can lead to either faecal incontinence or constipation. These studies are also of value where reversal of a colostomy pouch may be considered. Depending on the result, the patient may be referred for surgery or for Physiotherapy. This procedure involves the investigation of the ano-rectal canal to document resting pressures, Valsalva manoeuvres, as well as the function of the internal and external anal sphincters.

Recto-Anal Inhibitory Reflex;

A pressure probe is passed into the rectum with an inflatable balloon attached. This balloon is then inflated to measure patient response to different volumes of air, and the relaxation of the anal sphincters. Nerve damaged caused by Childbirth or Surgery can be identified using this technique.
The GI Physiologist will interpret the data and provide an accurate report on the
Vector Volume;
This procedure maps out the resting and squeeze pressure of the anal sphincters, from this, a 3D profile is produced identifying the exact location of damaged muscle. This information can then used for Bio Feedback. The GI Physiologist will interpret the data and provide an accurate report on the investigation.

Bio- feedback;

This study involves the insertion of a transducer into the ano-rectal canal, and monitors the patients’ response to pelvic floor exercises. Again a report, including interpretation is generated by the physiologist.

High Resolution Manometry/ High Resolution Impedance Manometry
Traditional Manometry normally used 4 pressure sensors, 5 cms apart. High-resolution manometry (HRM) with up to 36 pressure sensors , 2 cms apart. This allows pressure data to be presented in real time as a compact, visually intuitive “spatiotemporal plot” of oesophageal pressure activity. HRM recordings reveal the complex functional anatomy of the oesophagus and its sphincters. Spatiotemporal plots provide objective measurements of the forces that move food and fluid from the pharynx to the stomach and determine the risk of reflux events. The probe is placed transnasally in the unsedated patients, and moniters Oeosphageal Motility Function by giving the patient water to drink and records activity. The GI Physiologist will interpret the data and provide an accurate report on the investigation.  In some units, the physiologist has a role as part of the Multi-disciplinary team when discussing complex medical cases e.g. .using the Chicago Classification for Achalasia patients  and predicting which treatment pathways will likely yield the best response using the HRM tracings as a guide).

24 hour pH Study ( Acid Tests)

24 hr pH monitoring is recognised as the ‘gold-standard’ method for the measurement of oesophageal acid exposure. It has high sensitivity and specificity in the diagnosis of gastro-oesophageal reflux disease (GORD). The 24 hr pH test records the frequency and duration of acid reflux into the oesophagus during eating, sleeping and daily routines Patients referred for this procedure usually suffer from heartburn / indigestion. The procedure is usually performed off anti-reflux medication - to assess how bad the heartburn is, or on medication to make sure the acid in the stomach is controlled adequately. This procedure is also performed to assess a patient post Anti-reflux surgery and also post Oesophagectomy (type of surgery for Oesophageal Cancer) for leakage of acid into the oesophagus.  There are a number of different protocols depending on Clinical preference. A pH probe is placed 5cms above the oesophago-gastric junction for routine procedures, and the patient returns to following day for disconnection and removal of the probe/ monitor. Other variations require extra sensors to be placed either proximally in the oesophagus or in the stomach. The physiologist is responsible for the correct placement of the sensors and to report and interpret the result.

24hr Oesophageal pH profile;

Single channel monitoring is the most routine procedure performed on patients suffering from heartburn or indigestion.

24hr Gastric pH profile;

This study measures the pH of the gastric contents 5cm below the distal border of the LOS, and is usually performed in patients on anti-reflux medication, or in the assessment of patients with Gall bladder disease.


Bile Studies

Though acid is the most commonly assessed refluxate, duodeno-gastro oesophageal reflux may also occur which can be injurious to the oesophageal lining. Bile in the oesophageal body is measured by the use of a fibre optic probe, which is passed trans nasally into the oesophagus .Like the 24 hr pH monitor, the Bilitec system is ambulatory, with the patient leaving the hospital with the monitor and returning the following day.
This procedure is mainly performed in patients where bile juices are suspected to be leaking back into the oesophagus. It may be performed simultaneously with 24h pH monitoring, where the patient is intubated with two probes placed transnasally and two monitors around their waists.  It is based on a spectrophotometer analysis of bilibrubin pigment.

Electrogastrography (EGG)

EGG is a non-invasive recording of the electrical activity occurring in the stomach, which is stimulated by a test meal. The recording is taken via electrodes placed on the surface of the abdominal wall.   The signal is recorded and gastric pattern and rhythm interpreted both pre and post-prandially over a three hour period.  Patients who complain of nausea, bloating after meals or unexplained vomiting are referred for this study. A large number of patients with Diabetes also suffer from a condition known as gastroparesis and EGG is routinely used to monitor this condition. Post oesophagectomy patients also benefit greatly from this test, as their stomachs have been reshaped and replaced by the oesophagus. The EGG can evaluate whether the stomach is still functioning post surgery.  Following an overnight fast, the patient is positioned on a couch in a semi-reclined position, and connected to the computer via surface electrode over the stomach. After a fasting period of 30 minutes the patient is given a calorie controlled meal and then the effect of the meal on the myoelectrical activity of the stomach is recorded over an hour post prandially.

Breath Testing

Carbon- 13 Testing for Helicobacter Pylori
Carbon-13 breath tests have been used for several years as safe, simple and non-invasive method of monitoring organ function and nutritional status. It has been employed in the study of gastric emptying, liver function, fat absorption, bacterial overgrowth and oro-caecal transit time. Following an overnight fast, breath samples are taken prior and 10 mins post ingestion of a radio-labelled test drink.  The breath sample is measured by isotope ratio mass spectrometry or infrared isotope analysis.  While many nurses take breath samples, the GI physiologist is responsible for the analysis and calibration of the infra-red isotope analyser.

Hydrogen Breath tests

The patient is referred from the Gastroenterology clinic with symptoms of IBS or chronic diarrhoea. The tests are relatively cheap, and are a quick way to diagnose bacterial overgrowth or carbohydrate malabsorbtion in the Colon. Following a 12h fast, with a restricted diet for previous 24hours, the patient ingests a test solution. It is a very labour intensive test requiring breath samples to be taken every 10 mins over a period of 3 hours, on 5 different occasions. Once diagnosed the patient can be treated with Antibiotics or by diet.  This allows the patient to return back to the care of the GP, reducing unnecessary Hospital attendances. Some Units also perform a combined Hydrogen/ Methane breath test, which can be more sensitive in the case of patients that do not produce Hydrogen.
1.    Glucose Hydrogen Breath test to identify Small Bowel Bacterial Overgrowth
2.    Lactulose Hydrogen Breath test to identify Small Bowel Bacterial Overgrowth
3.    Lactose Malabsorption Breath Test
4.    Sucrose Malabsorption Breath Test.
5.    Fructose Malabsorption Breath Test
6.    Intestinal Transit Studies

Capsule Endoscopy (CE)

During this technique a small camera, approximately the size of a standard tablet, is swallowed by the patient and allowing excellent visualisation of the entire small bowel. This allows us to diagnose sources of bleeding and other pathologies that hitherto may only have been diagnosed at surgery. Indications for CE include Obscure GI Bleeding, - Evaluation of Crohn's disease, Suspected Small Bowel Tumour, Surveillance of inherited polyposis syndromes and Evaluation of drug-induced small bowel injury.
This technique is performed on an Out-Patient basis.  Role of the GI Physiologist includes data entry prior to procedure, explaining the procedure risks & benefits with the patient, attaching the abdominal sensors to the patient & hooking them up to the recorder. The study generally lasts for 7.5 hours and the Physiologist disconnects the patient after the study, downloads the study & analyses the recording.

Impedance pH monitoring

Combined multichannel intraluminal impedance-pH (MII-pH) monitoring detects gastro-oesophageal reflux and identifies acid and non-acid reflux events. It can be used in patients with persistent symptoms on medication. Combining impedance and pH, distinguishes between patients with acid reflux association, non-acid reflux association and symptoms with no reflux association. The procedure involves intubating the patient with a 24h impedance pH probe. The patient leaves the Unit and returns the following day. The monitor is disconnected, off loaded into computer software and analysed.  The physiologist interprets the report for the referring Consultant.



Neurodiagnostics analyzes and monitors nervous system function to promote the effective treatment of neurological diseases and conditions. CM Scientists also work extensively in the research field. The following gives an overview of the clinical scope of practice in neurophysiology. 

Neurophysiology scientists record electrical activity arising from the brain, spinal cord, and peripheral nerves using a variety of techniques and instruments. This involves preparing patients for procedures, obtaining medical histories, recording electrical potentials, calculating results, writing technical reports, and maintaining equipment. Scientists may work with specific treatments. They develop a good rapport with patients and comfort them during the recording procedure, which can last from 20 minutes (for a single nerve conduction study) to 8 hours (for an overnight sleep study), 10 hours for Monitoring during spinal surgery or up to 3 weeks for EEG Video Long term monitoring is specialist Epilepsy Monitoring Units to assess patients suitability for neurosurgery to treat their epilepsy.

Neurophysiology scientists are trained to understand neurophysiology and recognize normal and abnormal electrical activity in the central and peripheral nervous systems. They are the frontline professionals with responsibility for accurately recording and analysing neurophysiological data working closely with consultants who perform interpretation and clinical correlation of results. Considerable individual initiative, reasoning skill, and sound judgment are all expected of the neurophysiology scientist.

The most common procedures that Clinical Measurement Scientist in Neurophysiology (CMSN) performs are the electroencephalogram, long term monitoring, intra-operative neuromonitoring, the polysomnogram (Sleep study), evoked potential studies, and nerve conduction studies. The electroencephalogram [EEG] is the most frequently performed procedure.

Electroencephalogram (EEG)

The Electroencephalogram [EEG] is a recording of the on-going electrical activity of the brain. An EEG is used to assist in the diagnosis of epilepsy and a variety of neurological symptoms. EEGs also are used to evaluate the effects of head trauma or the consequences of severe infectious disease. EEG information can help doctors determine medical and surgical treatment of epilepsy. Patients having surgery on arteries in the neck or around the heart often have EEG monitoring performed during the procedure, providing the surgeon with additional information about brain function and assuring surgeons that the brain receives enough oxygen. In conducting an EEG, highly sensitive monitoring equipment records the activity through electrodes that are placed at measured intervals on a patient’s scalp. The test is not painful. The test itself usually takes about 90 minutes and the principal role of the patient is simply to remain still, relaxed and comfortable.

The simultaneous recording of EEG and videotaped behaviour over extended periods of time is referred to as long-term monitoring (LTM). It is the gold standard in diagnosing patients with intermittent or infrequent disturbances as well as in the diagnosis of seizures and other neurological disorders, such as unexplained coma.

Intraoperative Neuromonitoring

Intraoperative Neuromonitoring [IONM] is the use of neurophysiological monitoring techniques during surgery to provide information to the surgeon about nervous system integrity. The use of IONM guards against neurological complications during surgery and helps reduce the risk of negative surgical outcomes such as paralysis or stroke. IONM is used to monitor neurosurgical procedures and orthopaedic procedures, including spinal surgery for scoliosis, tumours, and aneurysms; vascular surgeries; acoustic neuroma surgery; and carotid endarterectomy. Otolaryngologists use intra-operative neuromonitoring to monitor cranial nerve function during ear, nose, and throat (ENT) surgeries.

Polysomnogram [PSG]

The Polysomnogram [PSG] is a recording during sleep that uses EEG and other physiologic monitors to evaluate sleep and sleep disorders, such as loud snoring, difficulty staying awake during the day, falling asleep at inappropriate times, insomnia, and uncontrollable urge to move one’s legs. Physicians use polysomnograms to identify dysfunction in sleep/wake cycles, to diagnose breathing disorders during sleep, and to evaluate treatment of these disorders.

Evoked Potentials [EP]

Evoked Potentials [EP] are recordings of electrical activity from the brain, spinal nerves, or sensory receptors in response to specific external stimulation. Evoked potentials are helpful in evaluating a number of different neurological problems, including spinal cord injuries, hearing loss, blurred vision and blind spots, acoustic neuroma, and optic neuritis. This test is commonly performed by the scientist during surgery on the spine to help the surgeon make sure nerves are not damaged during the operation. Evoked potentials also are performed in a clinical neurodiagnostic laboratory, using either earphones to stimulate the hearing pathway, a checkerboard pattern on a television screen to stimulate the visual pathway, or a small electrical current to stimulate a nerve in the arm or leg. A common indicator for evoked potential testing is a workup for diagnosis multiple sclerosis.

Nerve Conduction Studies [NCS]

Nerve Conduction Studies [NCS] evaluate electrical potentials from peripheral nerves. CM Scientists stimulate the nerve with an electrical current and then record how long it takes the nerve impulse to reach the muscle. Patients referred for NCS tests suffer from nerve conditions which produce numbness, tingling, muscle pain, muscle weakness, muscle cramping, abnormal movements, pain or loss of sensation, or neurological diseases affecting primarily the feet, legs, hands, arms, back, and neck.  Patients with a potential diagnosis of Carpal Tunnel Syndrome are commonly referred for this test.

The need in Ireland for skilled CM scientists in the field of Neurophysiology is great and plans for expansion of Neurodiagnostics are underway nationwide holding promise of significant employment opportunities in clinical and surgical areas. The growth of Sleep Disorder medicine will also bring further opportunities for employment in years to come.


Respiratory scientists are part of a large multidisciplinary team. Their role is to investigate respiratory and sleep disorders through various diagnostic tools and methodologies. A wide range of conditions fall under a number of categories of investigation.

Respiratory Investigations

Diagnostic – investigation to ascertain cause of presenting symptom. The most common reason is the investigation of unexplained shortness of breath. Tests will commonly include measurement of airway function, transfer characteristics of the lungs and pulmonary circulation, assessment of the mechanical properties of the lungs and thorax and integrated functional assessment of the cardiopulmonary system at rest and during exercise.

Monitoring of Disease State and Progression – investigations relevant to a particular condition are undertaken and repeated over an extended timeframe to assess the patient’s condition. Many respiratory diseases are progressive and require monitoring of progression to determine optimal therapeutic interventions and flag the need for changes in therapy to optimise outcomes.

Therapy Assessment – respiratory and non-respiratory conditions may have a positive response to treatment and pulmonary function testing is used to assess potential benefits. Many treatments, particularly in rheumatology and oncology have serious adverse effects on the respiratory system, and in these cases pulmonary function testing is used to assess side effects and guide future treatment.

Screening – assessment of patients at risk of developing diseases, or for specific assessments such as preoperative assessment or prior to commencement of an exercise programme.

Disability Evaluation - pulmonary function testing is commonly used to assess disability or functional impairment as part of rehabilitation, legal or insurance assessments.

Public Health – used in epidemiological surveys, in the derivation of reference equations, and in clinical research protocols.


Respiratory & Sleep Diagnostic Tests

Respiratory Scientists provide a wide range of diagnostic testing to patients with suspected and/or confirmed respiratory disease and/or sleep related breathing problems.  The performed test or tests will depend on the clinical question being asked upon referral.  Additional testing may be required depending on the information found. The respiratory scientist follows a series of steps prior to delivering test results.  A clinical director provides the differential diagnosis.


Work flow of a respiratory Scientist

The following Respiratory Investigations are available for the screening and evaluation of Respiratory Disease.

 Spirometry
 Static Lung Volumes
 Single breath carbon monoxide diffusing capacity (DLCO)
 Respiratory Muscle Pressures
 Body Plethysmography
 Hypoxic Challenge Testing (Fitness to fly)
 Skin Allergy Testing
 Cardiopulmonary Exercise Testing (CPET)
 IOS-Impulse Oscillometry
 Exhaled Nitric Oxide

 Bronchial Challenge Testing
- Exercise Induced Bronchospasm
- Histamine Provocation Testing
- Methylcholine Challenge Testing
- Mannitol Challenge Testing


Spirometry is invaluable as a screening test of general respiratory health in the same way that blood pressure provides important information about general cardiovascular health. It is a physiological test that measures how an individual inhales or exhales volumes of air as a function of time. The primary signals measured in spirometry are volume and flow.

Static Lung Volumes – Gas Methods

This test measures lung volumes, functional residual capacity (FRC), residual volume (RV) and total lung capacity (TLC)  which are used to classify restrictive impairments, confirm small airway obstruction and to quantify the degree of air-trapping in overt airway obstruction. In contrast to the relative simplicity of spirometric volumes, a variety of techniques have been developed for the measurement of absolute lung volumes. These include the following: gas dilution techniques (nitrogen (N2) or helium dilution (He)) and body plethysmography

Single Breath Carbon Monoxide Diffusing Capacity (DLCO)

This test provides information about the transfer of oxygen between the alveoli and the pulmonary-capillary blood. Respiratory conditions such as pulmonary fibrosis, sarcoidosis, restrictive lung disease or pulmonary emboli etc that affect the interstitial areas of the lungs require assessment of gas exchange to support the diagnosis and monitor these conditions over time.

Respiratory Muscle Strength

The measurement of maximal inspiratory pressure (MIP) via the mouth, or sniff nasal inspiratory pressure (SNIP) via the nose, are important tests used to determine inspiratory muscle strength. The primary usefulness of these measurements is in the diagnosis of patients with neuromuscular disease or injuries involving the inspiratory muscles. They are also useful for evaluating patients whose strength of inspiration is reduced secondary to hyperinflation, severe chest wall deformities, or drugs.

Hypoxic Challenge Test (Fitness to Fly Assessment)

Air travel is a common mode of travel for millions of people worldwide and for the vast majority it is safe, however for patients with compromised lung function due to a variety of respiratory diseases it may not be so. Cabin altitudes of up to 8,000 feet, result in progressive falls in cabin oxygen levels to approximately 15% that may induce hypoxia in patients with lung disease, which could lead to respiratory arrest in severe cases. A fitness to fly test is therefore a valuable tool for the physician issuing recommendations to patients with lung disease wishing to undertake air travel, particularly long haul flights.

Skin Allergy Tests

This test performed on the surface skin of the forearm, producing immediate reactions can detect causative factors in atopic allergy. Atopic diseases include hay fever, perennial rhinitis, eczema and asthma. Allergens commonly tested for include house dust mite, selections of pollens, animal hairs, moulds & fungi.

Cardio Pulmonary Exercise Test (CPET)

CPET provides a global assessment of the integrative exercise responses involving the pulmonary, cardiovascular, hematopoietic, neurophyscological and skeletal muscle systems. It is therefore a valuable tool in stressing the organs involved and determining what abnormalities exist. This relatively non-invasive, dynamic physiological overview permits the evaluation of both sub-maximal and peak exercise responses, providing the physician with relevant information for clinical decision making. CPET is increasingly being used for the evaluation of undiagnosed exercise intolerance or unexplained breathlessness and exercise related symptoms and for the determination of functional capacity and impairment as part of the pre assessment for heart/lung transplant and before major thoracic surgery.

IOS- Impulse Oscillometry

Impulse oscillometry is used to measure total respiratory resistance.  Test impulses are generated (multiple frequencies 4-32Hz) and superimposed on the patients tidal breathing for up to 90 seconds.  This is mainly an effort/cooperation independent measure of Respiratory impedance and is well tolerated by children of a young age and adults of any age.

Exhaled Nitric Oxide (eNo)

Nitric oxide is present in exhaled breath of patients and is a useful marker of airway inflammation.  A nitric oxide analyser is a high sensitivity detector for measuring nitric oxide and is based on gas-phase chemiluminescent reaction between nitric oxide and ozone. The exhaled NO measurements are in parts per billion.  Increased levels of exhaled NO indicate airway inflammation.

Bronchial Challenge Testing

Bronchial challenge testing is used to identify and characterise airway hyper responsiveness by provoking airway changes in susceptible patients. Bronchial challenge tests are also sometimes used to screen individuals who may be at risk from environmental or occupational exposure to toxins. This challenge test uses a stimulant to provoke airway changes in susceptible patients. A number of stimuli can be used, such as exercise, occupational exposures and chemical aerosolized substances Methacholine/Histamine or a dry powder formula, Mannitol.

Sleep Investigations

Diagnostic – investigation of sleep disturbances associated with a range of conditions. Studies range in complexity from assessment of overnight respiratory parameters to polysomnographic studies investigating respiratory and neurological sleep disturbances.

Therapeutic – overnight studies used to determine optimal treatment of sleep disorders, in particular obstructive sleep apnoea syndrome, and to monitor efficacy of treatment.

Sleep Investigations and screening carried out in the Sleep Laboratory include.

 Cardio-Respiratory Sleep Study (Limited)
 Full ploysomnography testing (PSG)
 Multiple sleep latency testing (MSLT)
 Continuous Positive Airway Therapy (CPAP)
 CPAP/APAP compliance monitoring

Cardio-respiratory Sleep Study (Limited)

This sleep study records respiratory events only, the sleep/wake stages are not assessed. Ventilation (airflow) is usually measured by two different flow sensors (thermister and nasal pressure). Respiratory effort is assessed by respiratory inductance belts (RIP) and oxygen saturation is measured non invasively by pulse oximetry. Body position, snore events, bilateral leg EMG as well as heart rate via a 3 lead ECG are often also recorded depending on the equipment available. The computerised automated analysis is manually edited according to national and international standardised guidelines, by trained and experienced Respiratory Scientists after the study has been completed, to ensure accurate and reliable results are available for clinical interpretation.

Polysomnography (PSG):

This type of sleep test assesses both sleep and respiration on a multi-channel recorder. The PSG is considered the gold standard test, but it is very time consuming and is reserved for patients without obvious clinical signs of OSAS (i.e. query narcolepsy, period leg movement disorder etc) or in patients where a limited study did not provide a definitive diagnosis. Along with the respiratory sensors listed under the limited sleep study, other physiological signals are measured such as electroencelography (EEG) for brain activity, electrooculography (EOG) to detect eye movement and on the chin to detect electromyography (EMG) activity. This multichannel recording is then manually scored by highly trained Clinial Measurement Scientists.

Continuous Positive Airway Pressure (CPAP) Therapy

A CPAP machine is an electrical device, small enough and quiet enough to sit on a nightstand. It takes in air from the room, lightly pressurises it and delivers it through a flexible tube to a special mask attached to the patient’s nose or nose and mouth (called a full face mask). This air is positive pressure and acts as a splint to keep the airway open, thus eliminating obstructive apnoeas. This treatment gives immediate relief to OSAS sufferers by providing uninterrupted breathing and sleep patterns.

An APAP device automatically adjusts the pressure on a breath by breath basis between 4-20 cm H2O to keep the airway open thus avoiding apnoeas as the patient sleeps. The sum of all the APAP pressures required by the patient during the night is then calculated by the system software in the morning to provide a 95th centile pressure value between 4-20cm H2O, which is usually the fixed pressure required to eliminate most of the events during sleep and is often the pressure prescribed for long term CPAP treatment.

CPAP/APAP Compliance Monitoring

Patients are requested to bring their CPAP/APAP devices and mask system with them each time they attend the Sleep clinic for review. A micro chip in these therapy devices records various details including the amount of time the patient had been wearing the mask and how many nights the patient is on treatment etc as the treatment is only effective whilst the patients use the device during sleep on a continuous basis. The Respiratory Scientist downloads the compliance data from the CPAP unit usually via a PC and the relevant information is then recorded in the patient healthcare record for review by the medical team.


Respiratory and sleep diagnostics require the use of a wide range of instrumentation. Technological advances over the last decade in particular have increased the range and accuracy of diagnostics in the field. Despite these advances, respiratory investigations remain fully manual and require meticulous real time quality control and a complex interaction with the patient to obtain accurate and clinically useful results.

The respiratory scientist provides diagnostics to a wide range of services. Apart from the respiratory service itself, most will test patients referred from cardiology, rheumatology, oncology, medicine for the elderly, general practice and occupational health. Depending on location, the referrals may also originate from cardio thoracic surgery, anaesthetics, A/E, neurology, infectious diseases, transplant medicine, general surgery, ENT, orthopaedics, paediatrics, and endocrinology.


Education and Qualifications:

The primary qualification to work in this field in Ireland is the B Sc (Hons) in Clinical Measurement Science offered by the Dublin Institute of Technology.
Respiratory Scientists may apply for membership of the Irish Association of Respiratory Scientists (IARS) and the Association of Respiratory Technologists & Physiologists (ARTP, UK).
Graduates may undertake the Irish Association of Respiratory Scientists, National Assessment in Lung Function when they have been working full time for 1 year.



The role of a vascular physiologist is to provide a non-invasive vascular diagnostic service for a wide range of vascular disorders.
All vascular diagnostic ultrasound tests are non-invasive and virtually painless and involve gel and an ultrasound machine:

1. Carotid and Vertebral Examination

This diagnostic study uses ultrasound to examine the main arteries in the neck that supply the brain. During this test the physiologist checks for narrowing or blockage of the vessels and give accurate information about the degree of stenosis (narrowing) of the vessel and the type of material within any narrowing or blockage. Generally a narrowing of less than 50% is asymptomatic whereas narrowing of greater than 70% would indicate the need for carotid surgery. In the case of an intervention the physiologist can mark the area to be operated on and assess the success of the procedure in theatre or post-operatively.

2. Trans-cranial doppler examination

A transcranial Doppler (TCD) ultrasound examination is a noninvasive technique that assesses blood flow within the circle of Willis and the vertebrobasilar system. Older systems are non-imaging and use spectral doppler analysis of waveforms obtained with a continuous wave doppler probe. The more modern transcranial colour coded doppler sonography (TCCS) uses waveforms and the colour duplex imaging combined.

3. Arterial Assessment

Lower limb and upper limb arterial assessment are carried out to assess arterial blood flow to the limbs. Pressure cuffs are placed on the arms and ankles/toes/fingers to assess the arterial flow to the extremities. Further studies may be carried out depending on the results of this preliminary test. A normal test is a good indication of the absence of peripheral arterial disease. In the case of the lower limbs  depending on the results of the pressure measurement an exercise stress test may also be carried out.

If a significant blockage is found then a further ultrasound examination called an arterial duplex of the limb may take place in order to ascertain the area or areas of disease within the vessels.

4. Venous Assessment

Varicose Vein Assessment: A varicose veins assessment is carried out to examine for the presence, location and origin of varicose veins in the leg. In general this procedure is carried out with the subject standing as this allows more thorough assessment of all the veins present. A partial deep venous examination is also carried out to assess patency and competency of the major deep leg veins. This assessment can be time consuming and can be ergonomically difficult for the practitioner so should only be carried out if the intention is to carry out some form of intervention by the surgical team.
Deep Vein Thrombosis: This study is carried out to determine if there is a clot in any of the deep veins in the leg. The veins are assessed by compression in B-mode and then imaged in colour to rule out any thrombus. Pulse wave doppler can also be used to look for any haemodynamic changes.As the appearance of thrombus changes on ultrasound over time after the acute phase, ultrasound examination can be a good tool to observe a DVT as it organises and recanalises on treatment.




5. Abdominal examination:


Examination of the arteries and/or veins within the abdomen, most commonly to assess for the presence of an abdominal aortic aneurysm (AAA) but may also be used to assess the abdominal branches of the aorta for abnormalities. Fasting may be required for assessment of the abdominal vessels.

In the case of a AAA the most common type of repair carried out is an endovascular repair using a graft that is inserted within the vessel to seal off the area of abnormal dilatation. Regular follow-up scans of the graft can be carried out to ensure continued patency and that there are no leaks around the synthetic graft.

6. Arteriovenous Fistula (AVF)

Patients on haemodialysis for renal failure can require the formation of an AVF for vascular access. An artery and vein are joined surgically, usually in the arm. This results in the dilation of the vein with high velocity blood flow within. The AVF can then be used as the site for dialysis much more easily than native vein.

Using ultrasound scanning the most suitable artery and vein for AVF formation is determined before surgery. After formation of an AVF it may require scanning to assess patency and how it is functioning. Often a venous valve can remain and cause an area of narrowing that can then easily by removed using a catheter to improve flow through the fistula.

7. Bypass Graft

When an artery in the leg is blocked, one of the options is a bypass graft around this area of blockage. The area of blockage is marked on the leg in the vascular laboratory as well as a suitable vein to use as a conduit if possible. If vein is not an option then a synthetic graft is used. After the procedure the graft is regularly examined by ultrasound by the vascular physiologist to check for any narrowings that could lead to it becoming blocked.

8. Pseudoaneurysm

A pseudoaneurysm can occur when a punctured artery does not heal allowing a ‘bulge’ to form from one wall of the artery. This most commonly occurs after femoral access for a coronary artery angiogram or stenting. Often following these procedures there may be significant swelling, bruising and tenderness over the groin and it is necessary to perform and ultrasound examination of the area to ensure that a pseudoaneurysm is not present. It is also possible to treat a smaller pseudoaneurysm by compressing it and ultrasound observation of this can be useful in the appropriate setting.