Monitoring (medicine)

A medical monitor as used in anesthesia.

In medicine, monitoring is the evaluation of a disease or condition over time.

It can be performed by continuously measuring certain parameters (for example, by continuously measuring vital signs by a bedside monitor), and/or by repeatedly performing medical tests (such as blood glucose monitoring in people with diabetes mellitus).

Transmitting data from a monitor to a distant monitoring station is known as telemetry or biotelemetry.

Classification by target parameter

Monitoring can be classified by the target of interest, including:

• Cardiac monitoring, which generally refers to continuous electrocardiography with assessment of the patients condition relative to their cardiac rhythm. A small monitor worn by an ambulatory patient for this purpose is known as a Holter monitor.
• Hemodynamic monitoring, which monitors the pressure and flow of blood within the circulatory system.
• Respiratory monitoring
• Neurological monitoring, such as of intracranial pressure. Also, there are special patient monitors which incorporate the monitoring of brain waves (electroencephalography, gas anesthetic concentrations, bispectral index (BIS), etc. They are usually incorporated into anesthesia machines. In neurosurgery intensive care units, brain EEG monitors have a larger multichannel capability and can monitor other physiological events, as well.
• Blood glucose monitoring

Monitoring of vital parameters can include several of the ones mentioned above. In critical care units of hospitals, bedside units allow continuous monitoring of a patient, with medical staff being continuously informed of the changes in general condition of a patient. Some monitors can even warn of pending fatal cardiac conditions before visible signs are noticeable to clinical staff, such as atrial fibrillation or premature ventricular contraction (PVC).

Instruments

Main article: Medical monitor

An instrument used for monitoring can be called a medical monitor, and may have an integrated display that shows the data of interest directly, and/or have the ability to transmit the data to a network or other means of processing, storing or displaying it.

Interpretation of monitored parameters

Monitoring of clinical parameters is primarily intended to detect changes (or absence of changes) in the clinical status of an individual. For example, the parameter of oxygen saturation is usually monitored to detect changes in respiratory capability of an individual.

Change in status versus test variability

When monitoring a clinical parameters, differences between test results (or values of a continuously monitored parameter after a time interval) can reflect either (or both) an actual change in the status of the condition or a test-retest variability of the test method.

In practice, the possibility that a difference is due to test-retest variability can almost certainly be excluded if the difference is larger than a predefined "critical difference". This "critical difference" (CD) is calculated as:^[1]

$CD = K \times \sqrt{CV_a^2 + CV_i^2}$

, where:^[1]

• K, is a factor dependent on the preferred probability level. Usually, it is set at 2.77, which reflects a 95% prediction interval, in which case there is less than 5% probability that a test result would become higher or lower than the critical difference by test-retest variability in the absence of other factors.
• CV_a is the anaytical variation
• CV_i is the intra-individual variability

For example, if a patient has a hemoglobin level of 100 g/L, the anaytical variation (CV_a) is 1.8% and the intra-individual variability CV_i is 2.2%, then the critical difference is 8.1 g/L. Thus, for changes of less than 8 g/L since a previous test, the possibility that the change is completely caused by test-retest variability may need to be considered in addition to considering effects of, for example, diseases or treatments.

Critical differences for some blood tests^[1]

Sodium	3%
Potassium	14%
Chloride	4%
Urea	30%
Creatinine	14%
Calcium	5%
Albumin	8%
Fasting glucose	15%
Amylase	30%
Carcinoembryonic antigen	69%
Glycosylated hemoglobin	21%
Hemoglobin	8%
Erythrocytes	10%
Leukocytes	32%
Platelets	25%

Critical differences for other tests include early morning urinary albumin concentration, with a critical difference of 40%.^[1]

Techniques in development

The development of new techniques for monitoring is an advanced and developing field in smart medicine, biomedical-aided integrative medicine, alternative medicine, self-tailored preventive medicine and predictive medicine that emphasizes monitoring of comprehensive medical data of patients, people at risk and healthy people using advanced, smart, minimally invasive biomedical devices, biosensors, lab-on-a-chip (in the future nanomedicine^[2][3] devices like nanorobots) and advanced computerized medical diagnosis and early warning tools over a short clinical interview and drug prescription.

As biomedical research, nanotechnology and nutrigenomics advances, realizing the human body's self-healing capabilities and the growing awareness of the limitations of medical intervention by chemical drugs-only approach of old school medical treatment, new researches that shows the enormous damage medications can cause^[4][5], researchers are working to fulfill the need for a comprehensive further study and personal continuous clinical monitoring of health conditions while keeping legacy medical intervention as a last resort.

In many medical problems, drugs offer temporary relief of symptoms while the root of a medical problem remains unknown without enough data of all our biological systems^[6] . Our body is equipped with sub-systems for the purpose of maintaining balance and self healing functions. Intervention without sufficient data might damage those healing sub systems.^[6] Monitoring medicine fills the gap to prevent diagnosis errors and can assist in future medical research by analyzing all data of many patients.

Given Imaging Capsule endoscopy

Examples and applications

The development cycle in medicine is extremely long, up to 20 years, because of the need for U.S. Food and Drug Administration (FDA) approvals, therefore many of monitoring medicine solutions are not available today in conventional medicine.

Glaucoma

A monitor for detection of increased intraocular pressure.

In glaucoma patients, high intraocular pressure (IOP) can slowly damage the optic nerve and lead to blindness. An advanced IOP continuous monitoring device can help the patients to learn which daily activity is best for low IOP values.^[7]

Blood glucose monitoring

In vivo blood glucose monitoring devices can transmit data to a computer that can assist with daily life suggestions for lifestyle or nutrition and with the physician can make suggestions for further study in people who are at risk and help prevent diabetes mellitus type 2 .^[8]

Stress monitoring

Bio sensors may provide warnings when stress levels signs are rising before human can notice it and provide alerts and suggestions.^[9]

Serotonin biosensor

Future serotonin biosensors may assist with mood disorders and depression.^[10]

Continuous blood test based nutrition

In the field of evidence-based nutrition, a lab-on-a-chip implant that can run 24/7 blood tests may provide a continuous results and a coumputer can provide nutritaion suggestions or alerts.

Psychiatrist-on-a-chip

In clinical brain sciences drug delivery and in vivo Bio-MEMS based biosensors may assist with preventing and early treatment of mental disorders

Epilepsy monitoring

In epilepsy, next generations of long-term video-EEG monitoring may predict epileptic seizure and prevent them with changes of daily life activity like sleep, stress, nutrition and mood management.^[11]

Toxicity monitoring

Smart biosensors may detect toxic materials such mercury and lead and provide alerts.^[12]

See also

• Nanoelectromechanical system (NEMS)
• Medical research
• Telemedicine
• Functional medicine

References

1. ^ ^{a b c d} Fraser, C. G.; Fogarty, Y. (1989). "Interpreting laboratory results". BMJ (Clinical research ed.) 298 (6689): 1659–1660. PMC 1836738. PMID 2503170. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1836738.  edit
2. ^ "Healthcare 2030: disease-free life with home monitoring nanomedince". Positivefuturist.com. http://positivefuturist.com/archive/345.html. 
3. ^ "Nanosensors for Medical Monitoring.". Technologyreview.com. http://www.technologyreview.com/business/21047/. 
4. ^ "Brain Damage Caused by Neuroleptic Psychiatric Drugs". Mindfreedom.org. http://www.mindfreedom.org/kb/psychiatric-drugs/antipsychotics/neuroleptic-brain-damage. 
5. ^ "Medications That Can Cause Nerve Damage". Livestrong.com. http://www.livestrong.com/article/202044-medications-that-can-cause-nerve-damage/. 
6. ^ ^{a b} Hyman, Mark (December 2008). The UltraMind Solution: Fix Your Broken Brain by Healing Your Body First. Scribner. ISBN 978-1416549710. 
7. ^ "Glaucoma". sensimed.com. http://www.sensimed.com/en/products/glaucoma.html. 
8. ^ "Blood glucose testing and primary prevention of diabetes mellitus type 2 - evaluation of the effect of evidence based patient information.". BMC Public health. http://www.biomedcentral.com/1471-2458/10/15. 
9. ^ ""Stress monitoring using a distributed wireless intelligent sensor system".". IEEE. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1213626. 
10. ^ "Using biosensors to detect the release of serotonin from taste buds during taste stimulation.". Archives Italiennes de Biologie. http://www.architalbiol.org/aib/article/view/347. 
11. ^ Evaluating the use of prolonged video-EEG monitoring to assess future seizure risk and fitness to drive.. PMID 21035403. 
12. ^ "Multiarray Biosensors for Toxicity Monitoring and Bacterial Pathogens". CRC. http://www.crcnetbase.com/doi/abs/10.1201/9781420019506.ch19. 

Further reading

• Monitoring Level of Consciousness During Anesthesia & Sedation , Scott D. Kelley, M.D., ISBN 978-0974069609
• Healthcare Sensor Networks: Challenges Toward Practical Implementation, Daniel Tze Huei Lai (Editor), Marimuthu Palaniswami (Editor), Rezaul Begg (Editor), ISBN 978-1439821817
• Blood Pressure Monitoring in Cardiovascular Medicine and Therapeutics (Contemporary Cardiology), William B. White, ISBN 978-0896038400
• Physiological Monitoring and Instrument Diagnosis in Perinatal and Neonatal Medicine, Yves W. Brans, William W. Hay Jr, ISBN 978-0521419512
• Medical Nanotechnology and Nanomedicine (Perspectives in Nanotechnology), Harry F. Tibbals, ISBN 978-1439808740
• Clean: The Revolutionary Program to Restore the Body's Natural Ability to Heal Itself , Alejandro Junger, ISBN 978-0061735332

External links

• Monitoring medicine intake in the networked home: The iCabiNET solution, IEEE Xplore, Issue Date: Jan. 30 2008-Feb. 1 2008, pp. 116 – 117
• Personal Medical Monitoring Devices, The University of Maryland