Clinical Need



Rapid detection and assessment of respiratory gas exchange efficiency. Impaired gas exchange may be caused by:
  • COPD
  • Pulmonary fibrosis
  • Pulmonary embolism
  • Pulmonary edema
  • Pneumonia
  • Hypoventilation, etc.

CO2 Waveform


Acute Exacerbations of COPD

COPD is a progressive lung disease caused by structural damage to the alveoli; the tiny air sacs that conduct pulmonary gas exchange within the lungs. This damage causes tissue to be sub-optimal for conducting gas exchange, leading to chronic difficulty in breathing. Impairment of gas exchange can be identified in two ways: as a visual tracing (example shown below) or lower blood oxygen levels.

An acute exacerbation is a sudden worsening of COPD symptoms. It can last for several days, and may be triggered by bacterial or viral infection, or by environmental pollutants. These exacerbations are associated with airway inflammation and narrowed passageways, which reduces airflow and impairs gas exchange.

Diagnosis of Respiratory Distress

When patients experience respiratory distress, clinicians have several tools that aid in the process of diagnosis and treatment to determine the severity of the event and how best to treat it. Pulse oximetry (SpO2) and vitals (blood pressure etc.) are easy to use and provide some immediate indication of oxygenation status. However, neither provide sufficient gas exchange information necessary to make clinical decisions specific to a patient’s need. Imaging methods like chest x-rays can be useful, but the process is time-consuming and expensive. Spirometry can provide airflow and lung capacity measurements, but it requires training and has poor sick patient compliance. Arterial blood gas tests (ABG) provide the most useful gas exchange information, but are cumbersome because they are lab based, highly invasive, and painful as they require drawing blood from the patient from the artery. Clinicians are currently looking for non-invasive alternatives to assessing respiratory status that can guide therapy.

Worldwide Prevalence of COPD

Although estimates vary, it is widely believed that over 200 million individuals suffer from COPD globally. It is the 3rd leading cause of death in the U.S. (CDC, 2016), and a leading cause of death in most developed countries around the globe.

“Chronic obstructive pulmonary disease (COPD) is one of the few major chronic diseases in which mortality has been increasing over the past decade.” (OECD health – 2014)

“Global mortality due to COPD is forecast to more than double over the next 30 years, which would make it the third leading cause of death worldwide by 2020.” (Rowe, et al, Medscape 2011)


Reference Medical Literature

  • Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease – American Journal of Respiratory and Critical Medicine, 187(4), 2013.
  • Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: A systemic analysis for the Global Burden of Disease Study (Lozano R, Naghavi M, Foreman K, et al.) 2010. Lancet 2012; 380(9859): 2095-128.
  • Mechanisms of worsening gas exchange during acute exacerbations of chronic obstructive pulmonary disease (BarberaJA, Roca J, Ferrer A, FelezMA, Diaz O, Roger N, Rodriguez-Roisin R.) Eur Respir J 1997;10:1285–1291
  • How accurate are pulse oximeters in patients with acute exacerbations of chronic obstructive airways disease? (Kelly AM, McAlpine R, Kyle E.) Respir Med 2001;95:336–340.
  • Relationship between arterial blood gases and spirometry in acute exacerbations of chronic obstructive pulmonary disease (Emerman CL, Connors AF, Lukens TW, Effron D, May ME.) Ann Emerg Med 1989;18:523–527.

Respiratory Challenge: Obstructive Sleep Apnea (OSA) and Post Anesthesia Induced Respiratory Depression

OSA is a chronic sleep disorder characterized by complete or partial obstructions of the upper airway during sleep. These obstructions lead to repetitive episodes of shallow or paused breathing, despite the effort to breathe. Often, this is accompanied by a reduction in the blood oxygen saturation (desaturation). OSA is associated with an increased risk of cardiovascular and other long term complications, tying it to three times the normal death rate.

Since the symptoms occur during sleep, OSA remains difficult to diagnose. It is estimated that as many as 80-90% of those who suffer from this disease are unaware of their condition. While approximately 2% to 4% of Americans suffer from severe OSA, it is estimated that nearly 1 in 5 American adults would have at least mild OSA if they underwent diagnosis in a sleep lab.

The dangers of OSA increase for patients after they undergo a surgery, which involves treatment with medications that reduce pain and consequently depress respiratory centers. With many patients, especially those who suffer from OSA, have an increased likelihood of airway obstruction and desaturation. Without proper intervention, this remains a primary concern to caregivers and patients during post-surgical care.

Reference Medical Literature

  • A Rude Awakening — The Perioperative Sleep Apnea Epidemic (Stavros G. Memtsoudis et. el.) The New England Journal of Medicine nengl j med 368;25 June 20, 2013
  • Obstructive Sleep Apnea in the adult obese patients (Benumof), Journal of Clinical Anesthesia13(2): 144-156
  • No Patient Shall Be Harmed By Opioid-Induced Respiratory Depression, Anesthesia Patient Safety Foundation(Fall 2011)
  • Pathophysiology of Sleep Apnea. (Jerome A. Dempsey et. el.) Physiological ReviewsPublished 1 January 2010 Vol. 90 no. 1, 47-112
  • The effects of transcutaneous electrical stimulation during wakefulness and sleep in patients with obstructive sleep apnea. American Review of Respiratory Disease (Edmonds LC, Daniels BK, Stanson AW, Sheedy PF 3rd, Shepard JW Jr.) Am Rev Respir Dis. 1992 Oct;146(4):1030-6
  • Electrical stimulation therapy improves sleep respiratory parameters in obstructive sleep apnea syndrome: A meta-analysis. Journal of HuazhongUniversity of Science and Technology[Medical Sciences] 33, 623-627, Oct
  • Sleep Disordered Breathing and Mortality: Eighteen-Year Follow-up of the Wisconsin Sleep Cohort (Young T, et al) Sleep 2008 Aug 1; 31(8): 1071–1078.
  • Obstructive Sleep Apnea Syndrome. The International Classification of Sleep Disorders American Academy of Sleep Medicine. 2001. pp. 52–8.
  • The Epidemiology of Adult Obstructive Sleep Apnea (Punjabi N. )Proc Am Thorac Soc. 2008 Feb 15; 5(2): 136–143.
  • Obstructive sleep apnea: implications for cardiac and vascular disease (Shamsuzzaman AS, Gersh BJ, Somers VK) JAMA. October 2003.
  • Obstructive sleep apnea syndrome (OSAS). Review of the literature (Azagra-Calero, E; Espinar-Escalona, E; Barrera-Mora, JM; Llamas-Carreras, JM; Solano-Reina, E) Medicina oral, patologia oral y cirugia bucal. Nov 1, 2012.

Global Macro Trend Challenges: Aging Populations, Rising Obesity, Caregiver Shortages

Rate of American Elderly (65+) Population



Elderly population to double in 25 years

US elderly population is projected to rise significantly in coming decades, largely driven by “Baby-Boomer” generation retiring. Chronic conditions associated with aging are increasing rapidly while US and other countries face severe shortages of trained medical professionals.

The elderly are at increased risk of both COPD and OSA.

Trained medical staff in short supply.

US nursing shortfall will reach 36% (~1 million) by 2020 according to an HRSA study (Health Resources and Services Administration). Globally, the World Health Organization (WHO) estimates a shortage of almost 4.3 million doctors and nurses today.

“53% of physicians and 65% of the public cited the shortage of nurses as a leading cause of medical errors.” (New England Journal of Medicine, Dec. 12, ’02 issue)

Hospitals are looking for effective ways to improve patient safety, diagnoses and treatment of COPD, OSA, and opioid induced respiratory depression despite their staffing problems.