Tag Archives: Root Cause Analysis

Patient Wakes While Being Prepped for Organ Harvesting

By ThinkReliability Staff

An extremely rare but tragic case has been recently brought to light.  On October 16, 2009, a patient was brought to a hospital center in Syracuse, New York after suffering a drug overdose.  Over the next several days, the patient was in a deep coma, though she did not meet the requirements for brain death based on scans performed at the hospital.   The family was notified and agreed to donate her organs.  The patient, after being sedated, was prepped for donation after cardiac death (DCD).  The organ harvesting stopped prior to any organs being removed when the patient opened her eyes on the operating table.

The hospital was cited not only for the error, but for the inadequate response and investigation after the error was made by the state Department of Health and the Centers for Medicare & Medicaid Services (CMS).  Specifically, the CMS report states “The hospital’s Quality Assurance Performance Improvement program did not conduct thorough reviews of an adverse occurrence involving a patient who was being considered for withdrawal of life-sustaining treatment when she regained consciousness.”

We can examine the error using a Cause Map, or visual root cause analysis, to determine the issues related to the incident.  This provides a starting point for developing solutions to reduce the risk of such an incident recurring, and improving healthcare reliability at this site.

It’s important to frame the issue with respect to an organization’s goals.  In this case, the patient safety goal was impacted due to the risk of patient death from having organs removed.  The accidental removal of organs can also be considered an impact to the patient services goal.  The compliance goal is impacted because of the sanction and fine (though a minimal $6,000) from the Health Department.  Negative press and public opinion as a result of this incident – which was uncovered and reported to the Health Department by the press – is an impact to the Organizational goal.

Beginning with an impacted goal – in this case the Patient Safety goal – asking “Why” questions allows us to develop the cause-and-effect relationships that led to the issue.  In this case, the risk for patient death was due to risk of removing her organs.  The risk for removing organs is because the organ harvesting process had begun.  (The investigation did find that there were no concerns with the organ donation process itself, indicating that errors were prior to the donation prep process.)  The process began because the family agreed to donate organs after the patient was (incorrectly) determined to have suffered cardiac death.

There were a combination of errors that resulted in the patient being incorrectly declared “dead”.  Because all of these factors acted together to result in the impact to the goals, it is important to capture and fully investigate all of them to be able to improve processes at the organization.  In this case, the patient was injected with a sedative, which was not recorded in the doctor’s notes.  It is unclear who ordered the sedative and why.  (It’s also unclear why you would sedate a dead patient, as another doctor stated “If you have to sedate them . . .they’re not brain dead.”)  The patient had previously been in a deep coma due to the drug overdose.  It is possible the coma went on longer than usual because the patient was not given activated charcoal to inhibit absorption of the drugs by the body after the staff was unable to  unable to place a tube.  There appears to have been no additional effort – another area that should be investigated to ensure that protocol is sufficient for patient safety.

The hospital’s evaluation of the patient’s condition before a diagnosis of cardiac death was insufficient.  Specifically, it has been noted that the staff performed an inadequate number of brain scans, inadequate testing to determine the drug levels remaining in the body, and ignored signs that the patient was regaining consciousness prior to preparing her for organ donation.  Because details of these issues were not thoroughly investigated, it’s impossible to know whether the protocols in place at the organization were inadequate for determining cardiac death or whether the protocols were adequate and weren’t followed by staff.

Determining if changes need to be made to protocols as a result of this tragic (though I do want to emphasize rare – the state was unable to find any similar cases in its records) incident is of utmost importance to reduce the risk of an incident like this happening again.  Hopefully the additional scrutiny from the state and CMS will ensure improved patient safety in the future.

To view the  Timeline, Outline and Cause Map of this issue, please click “Download PDF” above.  Or click here to read more.

Is a Doctor onboard? Management of inflight medical emergencies depends on other passengers

By ThinkReliability Staff

In a recent article, Pierre M. Barker, M.D. describes a terrifying situation – a passenger stops breathing on a plane over the Atlantic Ocean.  Turns out inflight medical emergencies are not that uncommon.  A study published in the New England Journal of Medicine says that about 1 in 600 flights has an inflight medical emergency – for a total of about 44,000 a year, worldwide.  Although the number of people who die as a result of these emergencies is fairly low, the incident that Dr. Barker was involved in indicates there is much room for improvement.

Taking the information from Dr. Barker’s article, we can perform a visual root cause analysis, or Cause Map, of the medical emergency on his flight.  Information gleaned from performing an analysis of one particular incident can provide valuable insight to improving outcomes for similar incidents – in this case, all inflight medical emergencies.

After recording the what, when, and where of the incident (here it’s inflight over the Atlantic Ocean), we capture the incidents to the goals.  Based on Dr. Barker’s description, this situation is aptly described as a “near miss” for patient safety.  What this means is that, had a lot of luck not headed this passenger’s way, he may very well have died on this flight.  We’ll discuss exactly what it is that made it a near miss – and not a fatality – later.   In this situation – and many other inflight emergencies – it seems that the employees are inadequately prepared for medical emergencies.  This is an impact to them – certainly it must be very stressful to have this sort of situation happen on their watch while feeling like there’s not much they can do.   In this case (and occasionally other, similar inflight emergencies), the flight was diverted, an impact to the organization’s goals.  Considering the sick passenger as a “patient” (and this is how I’ll refer to him going forward), the patient services were impacted because the ventilation bag did not connect to the oxygen tank.  Lastly, other passengers were called on to treat the “patient”, which was found to be very typical from the study.  This is an impact to the labor/time goal.

Once we’ve determined which goals were impacted, we can ask “Why” questions to determine which cause-and-effect relationships led to the impacted goals.  In this case there’s a combination of negative impacts and positive impacts – which is how the situation ended up as a “near miss”.  On the negative side, the patient stopped breathing and suffered cardiac arrest.  Because the conditions on a plane are hardly ideal for health, this may contribute to inflight medical emergencies.  There was difficulty in giving the patient oxygen, because the ventilation bag did not connect to the oxygen tank.  Additionally, there was a lack of patient medical history.  The patient was unconscious and there was no health information available which may have aided in his treatment.

The situation described above could have gone very, very badly.  There are some positive causes that contributed as well to make this a near miss.  First, the fact that the patient had stopped breathing was noticed very quickly, because he happened to have Dr. Barker – a pediatric lung specialist – two rows behind him who noticed his difficulty breathing, and then when it stopped altogether.  Because this was not by design but rather a stroke of rather good luck, this is how we get a “near miss”.  After all, you certainly can’t count on a lung specialist tracking the breathing of every person on a plane to stop inflight emergencies.  Not only was the issue noticed quickly it was treated quickly, by Dr. Barker as well as two ER nurses, a surgeon and an infectious disease doctor, as well as a flight attendant who performed a cardiac massage.  This ad-hoc medical team managed to do a heroic job of stabilizing the patient – including use of an AED, which was on the flight, an IV with fluids and glucose, and administration of an aspirin donated by another patient (though according to the study, aspirin should be included in the emergency medical kit on each flight as well).

The flight was diverted – as quickly as possible – to Miami.  This took about two and a half hours, during which time the medical team kept the patient stable until he was transferred off-plane.  This patient was extremely lucky to have these medical personnel aboard.  According to the NEJM study, doctors are present about 50% of time on flights, and the responsibility for treatment of inflight medical emergencies – as well as the decision whether to divert a plane – is generally left up to them.  When an inflight medical emergency occurs and a doctor is not present, the plane is more likely to divert.

As a result of this incident, Dr. Barker has some recommendations on how to make flying safer.  The NEJM study also makes some recommendations.  These solutions are placed directly on the Cause Map, and evaluated for effectiveness.  In this case, creating a standard emergency kit (there is an FAA-mandated emergency medical kit but as seen in this incident, the pieces may or may not work together properly and the kit may be different on different flights) for all flights should be developed.  This kit should ensure that all necessary equipment and medication for the most common and dangerous inflight medical conditions is included and that all flight attendants know where to find and how to put together the necessary pieces of equipment in the kit.  If, as seems to be the case, medical professionals on flights are expected to be responsible for other sick passengers in the case of an emergency, they should be notified as such.  If this occurred, flight attendants would also be aware of where to find these medical professionals.  This could involve a briefing similar to that received by personnel who sit in exit rows.  Where easy diversion is not possible (such as flights over oceans or uninhabited areas), at least one flight attendant should receive EMT training which includes in-depth instruction on how to use the medication and equipment available in the medical kit.  Coordination with onground medical staff should continue, with a focus on trying to make medical history available when possible.

The aviation industry has made flying incredibly safe.  Although inflight medical emergencies are rare and usually non-fatal, the industry now has the opportunity to make experiencing a medical emergency onboard a flight even safer.

To view the Outline, Cause Map, and proposed solutions,  please click “Download PDF” above.  Or click here to read more.

Common Birth Control Pills Have Increased Risk of Blood Clots

By Kim Smiley

Deaths of 24 Canadian women associated with the use of Yaz and Yasmin birth control pills have been making headlines in recent weeks.  South of the border in the US, more than $1 billion has already been paid out to settle thousands of lawsuits over alleged side effects.  Yaz and Yasmin are drospirenone-based birth control pills that are the most widely prescribed birth control pills worldwide so any concerns with the safety of the medication are alarming.

This issue can be analyzed by building a Cause Map, or visual root cause analysis.  A Cause Map lays out the many causes that contribute to an issue in an intuitive way that illustrates the cause-and-effect relationships.  The first step in the Cause Mapping process is to fill in an Outline with basic background information and to determine how the problem is affecting the overall goals of the organization.  In this example, side effects from the pills have been reported to have caused deaths and injuries.    Lawsuits associated with the side effects, specifically blood clots, have cost the drug manufacturer huge amounts of money as well as generated significant negative publicity, neither of which are outcomes a company is hoping for.

The complaints about severe and potentially deadly side effects have been focused on blood clots.  Blood clots are a known potential side effect of using any birth control pills.  It is believed that the estrogen used in birth control pills increases the clotting factors in blood making blood clots more likely.  The reason these specific pills are making headlines is that researchers have found that drospirenone-based birth control pills have a higher risk of blood clots than other birth control pills.  Researchers have estimated that the risk of blood cloths is 1.5 to 3 times higher with drospirenone-containing pills than with some other birth control pills.

For perspective, the FDA has stated that if 10,000 women who are not pregnant and do not use birth control pills are followed for one year, between 1 and 5 of these women will develop a blood clot and for women using birth control pills the range is 3 to 9.  But, and in my opinion this is a pretty big but, it’s worth knowing that the risk of blood clots during pregnancy is estimated to be 5 to 20 out of 10,000 and it’s even higher during first 12 weeks postpartum; estimated to be 40 to 65.

Please talk to your doctor if you have any concerns about blood clots or questions about whether a particular birth control pill is safe for you, especially if you think you may have other risk factors for blood clots.  If you’re curious about the symptoms of a blood clot or about other risk factors you can get more information here.

Please click on “Download PDF” above to see a high level Cause Map of this issue.

Lack of Care After Overdose Led to Patient Death

by ThinkReliability Staff


An inquest into the death of a patient in a Milton Keynes hospital was completed on May 17, 2013 by the local coroner.  The coroner found that the staff failed to take and report appropriate observations and render effective treatment.  Diagramming the cause-and-effect relationships identified in the inquest in a visual root cause analysis, or Cause Map, allows identification of lessons learned and possible solutions to reduce the risk of this type of incident happening again.

We begin with the impacts to the goals.  In this case, the patient safety goal is impacted due to the patient death.   It was suggested that nursing shortages may have been related to the issues that occurred.  If this is the case, the shortages would impact employees.  The inquest that resulted due to the patient death can be considered an impact to the compliance and organization goals.  Last but not least, the insufficient patient treatment is an impact to the patient services goal.

Beginning with these impacted goals, we can ask Why questions to determine the cause-and-effect relationships that resulted in the patient death.  In this case, the patient death was due to respiratory arrest caused by an obstructed airway.  The patient being placed on her back while unconscious (though sources differ on whether the patient was placed on her back or her side) due to a drug overdose.   The patient overdose was due to a self-administered overdose and not being administered the antidote for the drugs on which she had overdosed.

The patient was not given an antidote for the drugs on which she overdosed.  The family of the patient, who had a history of mental illness and frequented the hospital, believes that the staff believed she was faking her symptoms.

Through the patient’s eleven hours within the hospital’s Accident & Emergency (A&E) Department, only 2 formal observations were recorded.  One set of observations was recorded on a glove, which was later lost.  Abnormal results from these observations were not passed along from the healthcare aid who was responsible for the patient, likely due to nursing shortages.

Once all of the causes related to the incident have been recorded within the Cause Map, solutions can be brainstormed and recommended for implementation.  The coroner involved in the case has requested the Secretary of State for Health implement changes that would require seriously ill patients to be observed by nurses rather than healthcare assistants. The hospital has stated that they “have conducted an investigation to ensure lessons are learned” and “will be continuing to improve our service in regard to emergency patients”.  The hospital has commissioned training for their healthcare assistances to improve their skills.

To view the Outline and Cause Map, please click “Download PDF” above.

11 Patients Killed in Nursing Home Fire

by ThinkReliability Staff

A fire broke out in the early morning hours of November 18, 2011 at a residential aged care facility in Sydney, Australia.  At least 11 residents died as a direct result of the fire and nearly 100 were evacuated.    A nurse was been charged with 11 counts of murder as the fire is believed to be a result of arson. The nurse pleaded guilty to all 11 counts on May 27, 2013. (There have been other resident deaths but due to their age and health, it wasn’t clear if the deaths were a direct result of the fire.)

The cause of the fire initiation resulting in the deaths of residents, evacuation and severe damage to the nursing home facility is believed to have been arson.   The reasons for the arson are unclear and may never be fully understood.  However, there is still value in analyzing the event to determine if there are any other solutions that could reduce the risk of patient death in the future, at this facility or at others.

We can perform a root cause analysis in the highly visual, intuitive form of Cause Mapping to understand the issues that led to the tragedy.  We begin the analysis with the “What, When and Where” of the event, captured in a problem outline.  Additionally, we capture the impacts to an organization’s goals.   In this case, the patient safety goal was impacted due to the deaths.  There was an impact to employees, as a nurse at the facility has pleaded guiltily to murder.  Patient services were impacted due to the evacuation of the nearly 100 residents at the facility. The severe damage to the site resulted in the construction of a new facility, which cost $25 million.  (The cost of the new facility cannot all be attributed to the fire, as the new facility is much larger and has been modernized.)  Last but not least, the labor goal was impacted due to the incredibly heroic rescue efforts by the staff, firefighters and other rescue personnel, who were honored for their efforts.

Capturing the  frequency of similar issues can help provide perspective on  the magnitude of nation and world-wide issues.  I was unable to find data on the prevalence of nursing home fires in Australia, but there are more than 2,000 nursing home structure fires in the United States every year.  There have been a number of fatal nursing home fires in Australia over the last several years, so this is obviously a concern for the nation.

Once we have determined the impacts to the goals, we can ask “Why” questions to determine the causes that resulted in those impacts.  In this case, the resident deaths were due to smoke inhalation and complications from smoke inhalation as the result of a fire that spread through the facility.  The fire initiation, as discussed above, is believed to be due to arson.  However, it is believed that staffing levels and lack of an automatic sprinkler system were related to the spread of the fire, speed of the evacuation and the number of deaths.

Studies after the event showed how critical sprinklers can be to slow the spread of a fire.  On January 1, 2013, the government of New South Wales passed a law requiring installation of automatic sprinkler systems in all residential aged care facilities prior to January 1, 2016.  It is hoped that the presence of an automated sprinkler would slow or prevent the spread of a fire, resulting in fewer resident deaths.

To view the root cause analysis investigation of the fatal fire, please click “Download PDF” above.

Concern About a Resurgence of Black Lung Disease

By Kim Smiley 

Did you know that black lung disease has killed 70,000 coal miners since 1970?  Despite regulations designed to protect them, modern coal miners still face very real danger from coal dust.  Changes to the mining industry seem to be exacerbating this long standing issue.

Black lung disease, as coal workers’ pneumoconiosis is colloquially known, is caused by inhalation of coal dust, but there is more to the issue that needs to be understood.  The problem of miners suffering from black lung disease can be analyzed by building a Cause Map, a visual root cause analysis.  Cause Maps lay out the different causes that contribute to an issue visually to illustrate the cause-and-effect relationships.   (To view a high level Cause Map of this issue, click on “Download PDF” above.)

Coal dust is dangerous because it accumulates in the lungs and can cause long-term lung damage and breathing difficulties.  It is irreversible and there is no proven effective treatment.  Death can occur in severe cases.  The only option to fight this disease is prevention.

Black lung disease has a long history and concern about it first came to head in the 1960s.  A strike by 40,000 West Virginia coal miners pushed passage of the Federal Coal Mine Health and Safety Act of 1969.  This legislation limited coal dust exposure to 2 milligrams per cubic meter of air, which was significantly less than most miners were being exposed to at that time.  At first it seemed that the limits were effective in dramatically limiting black lung disease, but some are now worried about a resurgence of the disease.

Some speculate that changes in the mining industry are putting miners at greater risk for black lung disease.  The more dust that miners inhale, the greater the health risk and miners are both working longer hours and using equipment that potentially creates more dust.   The average workweek grew 11 hours since the 1970s which means miners are potentially exposed to dust for hundreds of more hours each year.  Technological advances have resulted in mining technology that is more powerful and can cut through coal faster, which can result in more dust.  The amount of coal produced per hour of work has nearly tripled since the 1970s.  These changes make it more challenging to prevent inhalation of dangerous levels of coal dust.  Increase in demand as well as the rising price of coal has driven these changes because it’s profitable to mine coal as quickly as possible.  Miners are also willing to work in the evolving conditions because mining provides a better living than other jobs available.

One of the most alarming pieces of evidence that cases of black lung may be increasing came from autopsies of the 29 miners killed in the blast at the Upper Big Branch mine in 2010.  The medical examiner was able to test tissue from 24 of the victims’ lungs and he found that 71% of those tested had black lung disease, a truly distressing percentage.  Some of the miners were relatively young and had a limited amount of time on the job.

There is no clear agreement on the best way to prevent black lung disease.  People are still trying to bound the problem and understand how significant the issue is.  But working to understand the problem is always the best first step to trying to solve it.

Mom’s Saliva May Boost Infants’ Immune Systems

By Kim Smiley

A recent study found that “cleaning” a baby’s pacifier by sucking on it may actually have some lasting health benefits.  Researchers determined that babies given pacifiers exposed to their parents’ saliva developed fewer allergies.  It’s still not clear whether the benefits come from the actual oral cleaning of the pacifier or if this was just a marker of parents who had a more laid back approach to cleanliness, but scientists are finding increasing evidence that some exposure to more microbes early in life results in fewer allergies.

A Cause Map, a visual format for performing a root cause analysis, can be used to illustrate this issue.  A Cause Map intuitively shows the causes that contributed to an issue as well as the cause-and-effect relationships between them.  In this example, researchers found that infants whose parents cleaned their pacifiers by sucking on them, rather than by boiling or rinsing with tap water, had lower rates of eczema, fewer signs of asthma and smaller amounts of a type of white blood cell that rises in response to allergies.  The key seems to be that saliva contains traces of the parents’ gut microflora.  The infant’s immune system is stimulated by this exposure to their parents’ microflora and this seems to help prevent allergies, which are caused by the immune system responding to harmless inhaled or ingested proteins.  The study also found that children who are delivered vaginally develop fewer allergies than those who are born via cesarean, which limits exposure to bacteria during birth.

These findings are important because the percentage of the population in industrialized nations suffering from allergies has risen rapidly in the 20th century.  Currently, about a third of the children in affluent countries are affected by allergies.  Studies, such as this one, are being done to try and determine what is causing the increase in allergies but the causes are not definitively known yet.  Circumstantial evidence seems to point to lack of exposure to microbes in early childhood as a risk factor.  This study was relatively small and more research on a larger scale will need to be done, but it is beginning to seem that children who get a little dirty and put a few questionable things in their mouths actually benefit from the exposure.

So if you had a mom who cleaned stuff (and you…) with her spit, you have one more reason to thank her this Mother’s Day.  Or if you were that type of mom you have one less reason to feel guilty.

Check out our previous blog – Amish have few allergies

Successful Emergency Response to Boston Bombing

By ThinkReliability Staff

The successful activation of emergency plans allowed 8 hospitals in the Boston area to treat 144 trauma patients injured in the bombings that occurred April 15, 2013 near the finish line of the Boston Marathon.  Even with that heavy burden, these hospitals ensured the continued safety of patients and staff during a very unsure time, as well as assisting the police and Federal Bureau of Investigation (FBI) with the ongoing investigation.

While details on the bombings themselves are still being determined and disseminated, it’s apparent that emergency planning and preparedness processes within the area Boston hospitals were successful in allowing an ‘unprecedented’ response.  We can view the response to the bombings by the area hospitals in what we like to call a root cause “success” analysis.  After all, lessons can be learned not only from what didn’t go well, but also what did.  Hospitals around the country can learn from the response by the Boston area hospitals to this trauma.

When Massachusetts General asked hospital staff from Israel, who unfortunately see this kind of trauma on a far more regular basis, to give emergency response training they likely did not suspect their hospital to be the site of a horrific mass trauma like that experienced in Boston.  The hospital’s experience with war-style trauma was certainly extremely helpful in dealing with the aftermath of this kind of trauma, rarely seen outside of war zones.  As Dr. Ron Walls, the chairman of the Department of Emergency Medicine at Brigham and Women’s Hospital stated, “For many, many people in emergency medicine who are practicing domestically and not in the military, these are once-in-a-lifetime events.”

For once-in-a-lifetime events, facilities have to hope that the training and education they’ve provided to their staff, and the processes that they’ve developed for dealing with emergencies, can stand up to the tragedy.  In this case, these Boston hospitals (once they have time to take a breath, which may not be for a while), should give themselves a pat on the back for their amazing handling of a tragic event.  Hospitals elsewhere should take note and ensure that their emergency procedures will allow the same sort of successful response.

A pat on the back should also go out to the staff in the medical tent at the finish line, whose quick actions and extensive equipment allowed on-scene stabilization and quick transfer of the severely injured to the area hospitals.  Lastly, the many spectators who kept their cool and assisted on scene should also be commended.

To view the Outline and Cause Map, please click “Download PDF” above.  Or click here to learn more about the emergency procedures at Massachusetts General.

Reuse of Insulin Pens May Have Spread Hepatitis

By ThinkReliability Staff

After a similar incident at a Veterans hospital, a hospital in New York reviewed its insulin injection procedures and discovered that insulin pens may have been used for more than one patient.  Re-use of insulin pens for more than a single patient carries a small risk of cross-contamination, which can result in a patient being infected with a communicable disease, such as hepatitis B, hepatitis C, or HIV.

The hospital notified 1,915 patients who had received injections between November  2009 and January 2013 of the possibility for contamination and recommended testing.  Twelve patients have tested positive for Hepatitis C, and one has tested positive for Hepatitis B, though an investigation is ongoing to determine if this is related to the injections.

The use of insulin pens resulted in 30 outbreaks from syringe or needle reuse over ten years, from 2001-2010. So, although the possibility for cross-contamination is considered low, the risk for the spreading of communicable diseases is unacceptably high.

The potential for spreading communicable diseases is an important impact to the patient safety and environmental goals.  We can examine these impacted goals and the cause-and-effect relationships that led to these impacts, in a Cause Map, or visual root cause analysis.

We begin by defining the impacts to the goals.  In addition to the patient safety goal, the compliance goal is impacted because re-using insulin pens is against recommendations by the FDA and CDC.  The organizational goal is  impacted due to a lawsuit from the patients who have tested positive for Hepatitis B and Hepatitis C.  Patient services are impacted due to the improper reuse of the insulin pens, and the labor and property goals are impacted by the additional follow-up, testing and potential treatment for the almost 2,000 patients affected.  Once we have determined the impacts to an organization’s goals, we can ask “Why” questions, which helps develop cause-and-effect relationships that resulted in these impacts.

Insulin pens are designed for multiple injections, meaning that there is stored insulin within the cartridge after a single injection is given.  Backflow of blood into the pen can result in the remaining insulin being contaminated.  This can result in the spread of communicable disease if the pen is then used on a different patient for subsequent injections.

Because it is known that insulin pens should not be used on multiple patients, it is evident that there was an issue with the procedure or policy regarding use of insulin pens.  It is unclear what the specific issues were relating to this incident, but the hospital involved has reviewed and reinforced policies and procedures related to insulin injection.

Many facilities, including the hospital discussed here, which discovered the potential for re-use during a review after a similar incident at a Veteran’s hospital, have discontinued the use of insulin pens due to the potential for cross-contamination.

To view the Outline and Cause Map, please click “Download PDF” above.  Or click here to read the hospital’s press release.

Click here to visit our previous blog about about hepatitis B and C.

Click here to visit our previous blog about a different contamination issue involving hepatitis C.

 

Helping the Blind See

By ThinkReliability Staff

Retinitis pigmentosa is an eye disease which results in the degeneration of photoreceptor cells in the retina.  Although it is uncommon, it is estimated that 100,000 Americans suffer from it, but a new device may be able to help them.

In normal sight, the light from a signal enters the eye and contacts photoreceptor cells in the retina.  The photoreceptor cells generate electrical impulses, which are sent to the brain by the optic nerve, allowing the vision to be interpreted by the brain.  In retinitis pigmentosa, their photoreceptor cells deteriorate, short-circuiting the vision process, eventually to the point where there is no vision at all.

To assist in our understanding of the normal vision process, and the problems with it resulting from retinitis pigmentosa, we can use a process map, or a visual step by step diagramming of any process that is examined as part of a root cause analysis.  Although in this case the process is a biological one, diagramming any process that is not producing the desired results can provide important information to develop solutions that allow the process to  again provide the desired results.

With advanced retinitis pigmentosa, all vision can be lost.   Although researchers continue to attempt to discover ways to restore as much vision as possible, any improvement can improve quality of life.  A device called the Argus II, which was approved by the FDA for use in the US on February 14, 2013, aims to help those with retinitis pigmentosa – and possibly in the future those who are blind from macular degeneration.  The device was approved in Europe in 2011 for any type of outer retinal degeneration.

The device uses a camera, video process and electrodes which do the processing work normally performed by photoreceptor cells and the optic nerve.  The electrode provides a pixelized light/dark pattern to the brain, which can allow sufferers to  see outlines and differentiate between light and dark.  Again, a process map can help demonstrate how the device works to bypass the normal vision process.

To view a process map of normal vision, and partial vision provided by the Argus II device, please click “Download PDF” above.  Or click here to read more.