IDEM Singapore 2016 the Dental Show in Asia Pacific

IDEM Singapore 2016 is coming up and we’re excited to have the opportunity to exhibit at the most important dental trade show in Asia Pacific.

Tuttnauer will be exhibiting at IDEM Singapore 2016, Floor 4 Booth 4M-15.

The exhibition takes place in Singapore, April 8 - 10, 2016.

You are invited to visit us and learn about the latest sterilization and infection control technologies specifically designed for the dental clinic. You will be able to check out the Elara, a high performing class B autoclave that is in line with the European EN 13060 standard. It is a pre and post vacuum sterilizer that will bring the highest quality sterilization to your dental practice. Besides the Elara we will show additional autoclaves and sterilization technology.

You are invited to schedule a meeting with Tuttnauer at IDEM Singapore 2016 to explore the opportunity to become a Tuttnauer partner.

To schedule a meeting with our regional manager please contact [email protected]

Hope to see you at IDEM 2016 Singapore smiley

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What is an Autoclave?

Third post in series, “Autoclave Sterilization Basics”

Working under pressure is no fun. Deadlines, stress, headaches, a demanding boss. But if you’re an autoclave, you work best under pressure. In fact, you only work under high-pressure conditions. 

In this post we will explore how autoclaves work under the high-pressured conditions of steam and heat to kill microorganisms. We will also look at how the autoclave’s function is similar to a pressure cooker, and what the basic phases of an autoclave cycle are.

Heat Kills All

As we explained in our first post on microbiology, microorganisms need food, the right temperature, and enough moisture to survive and reproduce. So why not just starve them or dry them out? Since microorganisms can survive on tiny amounts of nutrients and moisture, these methods are not effective enough. Moreover, the spore, a kind of bacteria that lives in a quasi-hibernation state, can survive in extremely inhospitable conditions.

So if neither of these methods work, how can we destroy microorganisms? The answer is heat. Heat destroys the proteins inside of the microorganisms, a process called denaturalization. In order to understand how this works, let’s take a look at the two ways we can cook an egg.

  1. If you take an egg, crack it open and drop it into a pot of boiling water, you will cook the egg by poaching it. The white part of the egg starts to stick together and becomes hard, a process called coagulation, which occurs at 52℃. When the egg coagulates, it becomes denaturalized, thus killing all proteins inside the cells of the egg.
  2. Another way to cook an egg is to fry it in a frying pan. At first the egg will coagulate, but if you leave the egg in the pan and let it continue frying, it will all eventually turn black. This burning is called oxidation, and occurs at much higher temperatures than coagulation. Oxidation is a chemical process in which electrons are removed from the atom, and the end result is death of that organism.
An Example of Oxidation - Sterilization Basics - Tuttnauer(L) The poached egg causes the egg to become white and hard, thus coagulating. (R) Here two eggs are burnt in the frying pan, an example of oxidation (image credit here).

Steam sterilization, in the form of an autoclave, uses the first method, coagulation, to kill microorganisms. That means that the autoclave chamber acts similarly to that pot of boiling water that poached the egg. The key ingredient that they both share is the presence of steam, or the gaseous state of water. The steam inside the autoclave is the agent by which the moist heat attacks the microorganisms, thus causing them to coagulate and die. 

In order to understand how autoclaves use the power of steam to kill microorganisms, we will explore how a pressure cooker functions.

A Souped-up Pressure Cooker

The word “autoclave” comes from the Latin “auto” (self) and “clavis” (key), in other words, a self-locking device. The autoclave’s basic functionality is quite similar to that of a pressure cooker, a type of saucepan that is able to cook food 50-70% faster than regular cooking methods.

View of the inside of a pressure cooker - Tuttnauer - Sterilization BasicsView of the inside of a pressure cooker

Take some raw food, for example beans, and place it inside the pressure cooker with water or other liquid, and then seal the vessel with the special locking lid, which includes a round rubber gasket used to seal in the steam. Place on the fire at high heat and wait for the temperature to rise and the steam to start escaping. Inside the sealed chamber the steam will expand and push out the remaining air through the air exhaust valve. 

Lower the flame and let the pressure cooker continue to cook without touching the valve or the lid. Notice that the air exhaust valve allows some of the steam to escape, so that the pressure doesn’t build up too much, thus preventing an explosion. 

This “efficient kitchen delight” literally forces the heat inside of the food by using:

  • High-pressured steam, which is a better conductor of heat than air.
  • High temperature heat (above 100℃), which causes the food to cook faster.

Here Comes the Autoclave

Like the pressure cooker, an autoclave is a machine that uses the combination of high pressure and steam in order to transfer heat to the items placed inside. Invented in 1879 by Charles Chamberland, the first autoclave was essentially a glorified pressure cooker. And just as the pressure cooker has gone through countless design upgrades in the last few centuries, so has the autoclave. From basic, mechanical machines to fully computerized, sophisticated masterpieces of sterilization, autoclaves have come a long way.

Today, hospitals, laboratories and doctors’ offices use autoclaves to sterilize solid and hollow equipment, supplies, fluids, and waste. And in the chemical industries, autoclaves vulcanize rubber, cure coatings, and synthesize crystals -- such as in the growing of synthetic quartz and gems.

Though autoclaves come in a variety of sizes and models, the basic principle remains: harnessing the power of pressure and steam to kill microorganisms.

Bacteria before and after sterilization(L) Before sterilization, the bacteria look healthy and strong. (R) After sterilization, the membranes are cracked and torn from exposure to high temperature steam, thus causing the bacteria to die.

The Autoclave, a Basic Overview

As we discussed above, the pressure cooker forces the moist heat inside of the food in order to cook it. Imagine that instead of food you had a tray of surgical supplies ready to be sterilized for tomorrow’s surgery. Placing them inside the autoclave and running a cycle would force the moist heat into all the possible nooks and crannies on the surfaces of the equipment. 

Here’s the basic overview of an autoclave cycle, which varies, of course, depending on what and how many materials are being autoclaved:

  1. First we heat up water to the boiling temperature to generate steam that enters the autoclave chamber. As the steam enters the chamber, the air is removed from the chamber, and continues to be pushed out as the steam expands. The air must be removed from the chamber either by a vacuum process (as in large autoclaves that use a pump or an ejector) or by a displacement process (as in some smaller tabletop autoclaves).
  2. Now that the air is removed we increase the temperature and pressure by closing the chamber exhaust valve while continuing to add steam to the chamber. The temperature and pressure will rise to the level required for sterilization. The required temperature is usually set to 121℃ or 134℃.
  3. This phase is called sterilization time, or holding time, since now is the time when the actual sterilization takes place. This may take around 3-20 minutes, depending on the size and contents of the load. Goodbye microorganisms!
  4. Now that sterilization is complete, it’s time to reduce the pressure, which we do by opening the exhaust valve and releasing steam. (Remember how pressure cookers have a safety valve for the same reason?)
  5. Finally, we cool down the load, making it safe to handle when we open the autoclave door.
Autoclave Loading - Tuttnauer

Don't Run out of Steam... We're Just Getting Started!

Let’s review: we learned that heat, and specifically, moist heat, is the best way to kill germs. There are two ways to kill using heat, by coagulation or by oxidation. Autoclave sterilization uses coagulation in the form of highly-pressurized steam to denature the proteins inside of the microorganisms. We then compared how a pressure cooker functions to how an autoclave operates. Just as the pressure cooker uses the intense power of steam to force the heat into food, the autoclave also uses steam to “force” steam into the equipment, killing all forms of microbiologic life living on said equipment. And finally we looked at the basic phases of an autoclave cycle, from heating up the water and building pressure, to holding time and cooling down.

We hope you’ve enjoyed this introduction into the world of autoclaves. Just be thankful you are not a little bacteria experiencing it firsthand.

Check out our next post, “Sterilization by Steam,” in which we will explore the science of using steam as a sterilizing agent in the autoclave.

Comments and questions are welcome, as always, in the comment section below.

(Post based on Sterilization of Medical Supplies by Steam by Jan Huys. Images of bacteria before and after sterilization appear with permission from Huys.)


Sterilization and Infection Control News Update - March 2016

Once again, we've collected for you sterilization and infection control news items that we found to be interesting. Enjoy them!


Standard Precautions in Sterile Processing

The SPD Netword – 5 January, 2016

This article describes the standard precautions, also known as universal precautions, as the basic methods of the sterile processing department.

Read More


FDA Report Fults Hospitals, Device Makers, FDA for Deadly "Superbug" Outbreaks

Med Device Online – 14 January, 2016

A report by Democrats on the U.S. Senate’s health committee blames hospitals, medical device companies and the FDA for the deadly outbreaks of so-called “superbug” infections linked to duodenoscopes.

Read More 


FDA: Pick a Sterilization Method, but not Just Any Method

MDDI Online– 21 January, 2016

More than seven years after publishing draft guidance on the topic, FDA is back with final guidance on "Submission and Review of Sterility Information in Premarket Notification (510(k)) Submissions for Devices Labeled as Sterile."

Read More


Autoclaving Alternatives for Effective Sterilisation

Labmate Online – 29 January, 2016

Since Charles Chamberland invented the first autoclave pressure chamber in 1879, the technology has been an almost omnipresent tool to perform sterilisation tasks.

Read More


IoT and Smart Assets Go Hand in Hand for Medtech and Life Sciences

MDDI Online – 6 January, 2016

The rising use of "smart assets" for medical devices makes the Internet of Things particularly valuable to the medical device industry.

Read More 


Single-Use Technologies in Biopharmaceutical Manufacturing - 15 January, 2016

In biopharmaceutical manufacturing, the implementation of single-use technology (SUT) is growing rapidly. Offering improved flexibility and reduced contamination risk, SUTs have more appeal than their expenditure alone.

Read More


You might not know, but Beauty Salons can be a serious threat to your health



Who is to blame for Superbug DeathsNot pretty: Health Violations in Manitoba Nail Salons go Unreported

CBC News – 14 January, 2016

Manitobans looking for a little pampering in some spas or salons may be putting themselves at risk of infection — although if there's a problem, they're unlikely to find out about it.

Read More


Duendoscope ToolTipsy salonbar to Open Boynton Location with Medical Grade autoclave Technology – 15 January, 2016

Tipsy Salonbar, will be opening their newest location on Congress Avenue in the Quantum Town Center in Boynton Beach, Florida with a new state-of-the-art medical grade Autoclave Machine in the middle of the salon. Autoclaves are used to sterilize equipment and supplies by subjecting them to high pressure saturated steam at 121 °C (249°F) for around 15 to 20 minutes depending on the size of the load and the contents.

Read More


5 Things to Look for when You Visit the Salon

Fox25 – 4 February, 2016

A salon is the place for pampering, but safety advocates say there are dirty and potentially dangerous conditions in nail salons across the Bay State.A local woman told FOX25 she believes poor practices at her salon left her with a serious infection.

Read More


Sterilization in Dentistry is always important



Who is to blame for Superbug DeathsColumbia's Dental college Finds RFID Instrumental

RFID Journal – 12 January, 2016

The school's clinic is using passive UHF tags to manage the dental tool kits it loans to students, and to track the instruments during subsequent sterilization.

Read More


Duendoscope ToolDental Clinic of Clay and Associates, DDS, PLC Selected Henry Schein Dental and Primus Dental Design and Construction as Partners for the New Clinic Opening in February

Prweb – 03 February, 2016

Clay and Associates, DDS, PLC selected Henry Schein Dental, the largest dental supply and dental equipment distributor in the world and Primus Dental Design and Construction to partner on the new clinic opening in February. The clinic will also feature Pelton & Crane dental equipment.

Read More


Health-care-associated infections, spore testing, and proper dental sterilization practices

Dentistry IQ – 29 January, 2016

The importance of the proper sterilization of dental instruments, supplies, and equipment used in patient care is a critical aspect of health-care delivery that directly impacts patient safety. Health-care-associated infections (HAIs) impose a significant economic impact on the US health-care system as a leading cause of mortality and morbidity, with annual medical costs from $35.7 billion to $45 billion.

Read More


Disclaimer: The views and opinions expressed in the referenced articles and blog posts are solely those of the original authors and other contributors. These views and opinions do not necessarily represent those of Tuttnauer, the staff, and/or any/all contributors to this site.


Facing the Standards Gap: An Autoclave for the Rest of Us

By Jan Huijs HEART Consultancy, The Netherlands.  [email protected]


The international standards for sterile supply are embedded in Western societies; their implementation requires a strong economy. However due to many socio-economic limitations, transferring these standards - and the resulting advanced technology - to low-income countries is bound to fail. Manufactures are forced to comply with the standards and as a consequence appropriate sterilization equipment and related supplies for this market is hardly available anymore. A major problem is caused by the by the way the requirements for validation of processes have been defined. The current situation related to autoclaves (sterilizers using steam as sterilizing agent) in target health facilities was analyzed; followed by research and development and resulted in prototypes that eventually should mature to an adequate autoclave for the rest of us.

1. Situation analysis of sterilization equipment in target locations

Socio-economic context

Many health facilities have to operate under harsh conditions with poor and/or limited water supply; poor/limited or even no electricity supply; and often long distances over a very poor road network. Well trained staff is extremely scarce and companies available may be very expensive, especially for a remote hospital that may be hundreds to a thousand of kilometers away from the capital, making only the trip of the technician to come to the site already a financial challenge for the hospital.

Mind the gap

The difference between the average spending on health care per person of a population in high income and low income countries is huge. For example in the United States this spending may be approx USD 8200 per person pear year, whereas in Malawi it is as little as approx USD 74 [2]. A difference of a factor 110! It is obvious that technology developed in high income society, assumes the infrastructure of such society: The technology and the resulting products are embedded in their society. And usually requires the infrastructure and related financial resources to keep them operational. The incredible big gap of financial resources and all its implications makes it obvious that advanced equipment developed to be used in the industrialized world is bound to fail when taken to a society where only a fraction of the financial resources are available.

Why do mobile phones thrive and autoclaves die?

Africa is undergoing a communications revolution. Mobile phones have become accessible to major parts of the populations. Mobile phones are very high tech devices; which in spite of that are a huge success in also remote African settings. Whereas advanced autoclaves are found broken down and not used in many places. A major reason here are the economy of scale and the cost per item. Mobile phones are used by the tens of thousands. For such quantities it is economically viable to set up an infrastructure to have the network and the equipment operational. Moreover the price is relatively low and thus are affordable for most individuals. In addition the telephone has a tremendous positive impact on virtually everybody’s life. Autoclaves however are only used in health facilities; thus quantities are very low; while the diversity of makes and models is huge. Of some make/model there may be only a single unit in the country. This makes it for a manufacturer/supplier economically not viable to set up a service network. It simply is too expensive. Thus, there is no or virtually no support for the ever more complex equipment, resulting in many broken down machines. In addition the requirements for utilities such as water and electricity has become more stringent making the equipment even more vulnerable for breakdowns.

Standards and legislation

As for may other fields of industry and services, a wide range of standards related sterile supply have been compiled. Main objectives are to assure safety and health of users and patients, to provide a minimum level of quality and to facilitate international trade. In Europe the standards are issued and managed by CEN (Committée Européenne de Normalisation) whereas ISO (International Standards Organization) compiles standards that are to be worldwide. Compliance with standards is voluntary; however meeting the requirements of standards can be used to demonstrate compliance with the relevant legislation; in the European Union this is the Medical Device Directive. In the context of the Medical Device Directive sterilizers are medical devices and thus sterilizers must comply with the directive.  In order to complement the European legislation, governments may have additional national laws. Due to several (mostly economical) reasons, the target countries in the developing world however are not or cannot be members in these committees. Sub-Saharan Africa has not a single member. Therefore the specific problems related to these countries are not considered in the formulation of the standards. The content of the standards is based on the assumption that they are implemented in the member countries. The standards thus are embedded in the richer, Western societies in which the often totally different conditions of the non-member countries are not considered.

low income countries have no influence on standardsMembership of ISO and CEN. No low income countries are member of the Technical Committees (TC) related to sterilization in the standards organizations and thus have no influence on the standards that are formulated

Validation excludes manual control. Some observations

It is a requirement of the standards on sterilizers that of any autoclave its processes are validated. This implies that there is to be documented evidence that the autoclave renders sterile products and that the process is reproducible. In this context human actions are not considered reproducible and thus also manual control of a machine is not reproducible. In the sequencing of a process, wherever possible, the human factor must be excluded. However, when I, together with many other people board a bus, I put my life in the hands of the bus driver. His actions cannot be validated. We rely on him. The responsibility of the bus driver is not less then a person operating a sterilizer. But still busses are manually driven. And is accepted everywhere. Why then not, at least in locations where advanced technology is not feasible, accepting manual control for sterilizers by well trained operators using reliable autoclaves that result in adequate sterile goods when operated well?

State of the art of sterilization equipment: fully automatic autoclaves. Often a headache for remote hospitals

Based on the concept that human actions are not reproducible and thus that only automatic autoclaves can provide validated processes, it became a requirement that processes for autoclaves are automatic. With the current technology this implies that autoclaves are microprocessor controlled. This results in equipment with a large quantity of high-tech components with a complex control mechanism. An example: In modern standard autoclaves the operation of a valve for steam supply requires a multitude of components: the microprocessor with its software; a relay; an electric valve controlling pressurized air; and the final pneumatic valve that controls the actual supply of steam. Thus there is a chain of multiple components for a single function with each component increasing the machine’s complexity and increasing the risk of breakdowns.

2. Focus on manually operated sterilizers

In many health facilities in developing countries, the use of complex automatic sterilizers as required by the current international standards are not feasible. For many facilities they drain the already very tight hospital budget in many cases hospitals have to resort to very basic, unsafe poor performing manual sterilizers.

Accepting manual controlled sterilizers

For this market, more robust, well performing autoclaves are required, based on manual control and without the need of complex electronic control and related components. By allowing manual control of a sterilizer a drastic reduction of complexity and number of components can be accomplished and resulting in a more reliable essential sterile supply in the target health facilities.

Approval of standards organizations and WHO/health authorities

Allowing manual control in the context of validation would require approval of the authorities related to the publication of the standards. It is therefore is recommended to open a debate on this issue with the relevant organizations such as CEN/ISO, WHO and possible other stakeholders.  Acceptance of manual control by such respected organizations will be crucial for the commercial success of any approved sterilizer suitable for the target market.

Large potential market

The target market for the sterilizer would at least be all low income countries. However large regions of middle income countries, the socio economic situation also does not qualify for a reliable operating of advanced equipment. Thus the market for such sterilizers would include a major part of the worlds’ countries; which are home to a major part of the world population!

Essential requirements for equipment

For any piece of equipment, in the context of this article a sterilizer, to provide its intended function throughout its lifespan, it should meet the following requirements

  1. It should do its job: For an autoclave in our contex this implies that it sterilizes materials as required in the target health facilities e.g. common remote general district hospital or health centre in the developing world.
  2. The equipment meets the local socio-economic setting where it is to be used; in other words, the machine should be able to run during its estimated lifespan against reasonable cost in the target location. This implies that its operation, maintenance and repairs should be compatible with the annual budget for a remote moderate hospital.

Performance requirements specific to sterilizers

For a sterilizer two fundamental performance requirements can be identified

  1. Processed goods must be sterile according to the requirements for an item to be labeled sterile as formulated in the Standard EN556-1. The sterilizer thus must render products sterile inside their packaging.
  2. Processed goods must be dry as specified in standard EN 285

Characteristics of goods to be sterilized in a typical district hospital

In any health facility sterile materials are used; a part of them may be single use/disposable; a large number of items are reusable and must be cleaned, packed and resterilized after each use. In a typical hospital reusable sterile materials are used in the operating theatre, delivery room and treatment rooms. These items are to be reprocessed in the Central sterilization department of the hospital:

  1. Wrapped surgical instruments. They may be in drums or containers. Some surgical instruments may have lumen of limited length such as suction tubes, cannulas. Instruments for MIS (Minimally Invasive Surgery) with long narrow lumen are in general not used. Such instruments require a more advanced autoclave with a pre-vacuum process.
  2. Wrapped textile goods/porous loads, such as gowns, drapes, swabs etc.
  3. A combination of these

Process profile

For a steam sterilizer to render sterile products for use in a hospital environment, the process has the following phases

  1. Air-removal. Air acts as an insulator for heat transfer by steam. Therefore in order for the steam to be in touch with all exposed objects, all air needs to be removed from the chamber and the load
  2. Sterilization. The actual sterilization phase during which all micro-organisms are killed. For saturated steam the standard minimum parameters are: 134ºC for a minimum of 3 minutes; or 121ºC for a minimum of 15 minutes
  3. Drying.  Moisture is a breeding ground for micro-organisms. That is why at the end of a sterilization cycle the load should be dry. This is accomplished by creating a vacuum, causing any residual moisture to evaporate
  4. Air-admission. At the end of the drying cycle, the chamber pressure is below atmospheric, thus the lid cannot be opened. Only after equalizing the pressure in the chamber to atmospheric, the lid can be opened. For preventing recontamination of the load, the air entering the chamber should pass a high quality bacteria filter

Ensuring adequate performance of manually operated sterilizers: research

Given the socio-economic context of the target countries, one of the major requirements would be that it should be possible to use manually-operated sterilizers. Automatic control can be an option, but manual control should remain possible.

It therefore was essential to get scientific evidence that autoclaves that are manually operated can actually result in sterile goods that meet the set standards for sterility and dryness. That is why already in 1999, a research programme was implemented, in collaboration of the medical engineering department of a college on technology (Hogeschool Enschede, (NL) and the Dutch Institute for Public Health and the Environment RIVM [1]. The research took place in one of the laboratories of the RIVM. All procedures regarding the performance testing of the sterilizer were done based on the prescribed performance test methods as formulated in the respective standard for such studies (EN285). During the study two types of manually operated sterilizers, at the time common in district hospitals in developing countries were tested. Its most important conclusions.

  1. Sterilization achieved. The requirements for sterilization of wrapped instrument and porous loads can be met in these sterilizers, provided that adequate air-removal is achieved, by adhering to a process that was the result of the research which includes steam flushing and (3) above-atmospheric steam  pulses.
  2. Dryness achieved. Adequate drying is feasible by using steam condensation. Therefore there is no need of an electric waterring pump, the technology that is widely used in main stream sterilizers. Using a condenser, there is no need of electricity, there no moving parts and only  limited or no water is required.
  3. Waterring pump eliminated. With the performing of the steam penetration by above atmospheric steam pulses and  creating an effective vacuum by a steam condenser, the need for an electric vacuum pump is eliminated. The use of the steam condensor reduces the vulnerability of the autoclave and reduces water consumption of the autoclave tremendously.
  4. Manual control is complex; more simple operation is needed. For a successful sterilization process, the operation of the 4 valves at the correct moment and correct sequence is critical. It makes operating the autoclave rather confusing and prone to operator errors. It was suggested to do further research in order to reduce the complexity for the operator.

Optimizing manual process control

Objective for this part of the research was to drastically reduce operator errors by reducing the number of controls/valves to be operated. In the conventional manually operated autoclaves on the market, each individual valve needs to be operated separately. Valves are at several locations on the machine. It thus requires operating multiple valves; usually 4 valves in the correct sequence and the correct moment. In several situations 2 valves need to be operated simultaneously. This method of operation requires a strict protocol and very much dedication of the staff. It thus is prone for operating mistakes. Therefore a solution was searched for by single-knob mechanical control of all valves. The research was done in collaboration with the Technical University in Eindhoven, The Netherlands in the period of 1999 until 2004. Several mechanisms were tested. However control by a camshaft system with multiple camdisks proved to be the most efficient, flexible, user friendly and cost-effective solution. It is a technology that has been used in autoclaves in the 1960’s and 70’s already but was abandoned when electronic control systems took over.

low income countries have no influence on standardsLeft: Second generation prototype of the autoclave as installed in a district hospital in Eikwe, Ghana.- Right: The camshaft controller with its 4 valves. After a stepping the handle through its distinct 12 positions, the full sterilization cycle is completed. On the right hand side the air-cooled condenser for creating the vacuum for drying

The camshaft controller has a number of advantages:

  1. Very simple operation: a single knob for operating all valves, ensuring the right sequence of operation of valves which is critical for a correct process; thus chances for wrong operation is drastically reduced. Each step in the sterilization process is a distinct step of the control knob. Each disk will put each valve at its correct open or closed position. A full rotation in 12 steps results in a full, validated process for general hospital loads
  2. Valves can be operated mechanically by cams; no need for electric/pneumatic valves; reducing number of components considerably. The control system can work fully independently of electricity.
  3. Very sturdy, robust design; built for a lifetime
  4. Repairs can be done by a well trained plumber
  5. Process profiles can be changed by changing the shape of the disks
  6. The concept can be used for single chamber as well as double-chamber autoclaves
  7. The concept of the system allows automation by adding the required sensing and control components. An upgrade kit could be made available, including sensors, timers and a motor drive for the controller. As it would provide fully automatic control and would open the possibility to have this upgraded model pass the requirements for the current standards. And in case of a breakdown of the electronic control part of the system, it allows to resort to full manual control.

3. Prototyping and scaling up

5 prototypes of several generations were built and field tested in 3 countries in Africa (Ghana, Central African Republic, Zimbabwe). They are jacketed sterilizers, equipped with the camdisk controller and an air-cooled condenser as vacuum system. The first prototype was installed in 2005 has been running for 8 years without repair on the control system.  The next phase is to find manufacturers in order to scale up production and finally come to an adequate commercially available autoclave that the health sector in many countries is waiting for.

4. Discussion

The requirements of current standards have resulted in advanced medical equipment requiring the infrastructure and budget of an industrialized nation. There however is a dire need of equipment that meets the harsh local socio-economic background of many developing countries. A major cause of this situation is the lack of adequate standards and guidelines which all stakeholders involved in health care in the developing world are facing. It is crucial that this huge gap in the quest for quality, that standards organizations are committed themselves to, will be filled in. A gap that now causes sterilizers that meet all standards, and that finally (may) reach their destination in a remote hospital, may never run a single cycle. Through research it has been demonstrated that adequate sterilization can be performed in manually controlled sterilizers. Also by eliminating the electric waterring pump the complexity and water consumption can be reduced tremendously. A manually operated camshaft control system reduces operator errors considerably and thus improves reliability of the process. An add-on kit could make the unit fully automatic, opening the way to meet the requirements of the standards and still have the possibility to resort to manual control. The author is in the process of forming a working group that will address the issue of an adequate sterilizer for the rest of us.

5. Acknowledgements

I herewith thank all those dedicated people involved during the years of research, prototype building and field testing!

6. References

[1] B. Muis, ACP de Bruijn, A.W. Van Drongelen, J.F.M.M. Huijs. “Optimalization of the process for manually operated jacketed steam sterilizers”. Zentral Sterilization/Central Service  2002-10 (6), page 373-384
[2] WHO Department of Health Statistics and Informatics (May 15, 2013) “World Health Statistics 2013”. WHO


First published and presented during the congress on Appropriate Health Technology for Low Resource Settings 2014 - (AHT 2014), London, organized by the Institute of Engineering and Technology, UK.

Jan Huijs is the owner of HEART Consultancy, based in the Netherlands. After working as a medical equipment engineer in Ghana, Africa for 7 years in the 1980's  he started HEART Consultancy, a consulting agency focusing on sterilization of medical supplies and asset management for health facilities, focusing on the health services in the developing world. He presents training for users as well as technicians on sterilization of medical supplies in mainly developing countries since 1997.  He is author of the book “Sterilization of medical supplies by steam”, which  has been translated into 8 languages. He has been doing research on sterilization of medical supplies in remote areas.

Since 2014 Jan is honorary member of SVN; Sterilisatie Vereniging Nederland, (Dutch Sterilization Association).


People and Technology Creating Autoclaves of Excellence

It is important for us that you see beyond the end product and get a glimpse behind the scenes. Tuttnauer is a winning combination of people and technology. We work together as a team globally to provide the best sterilization and autoclaving technology available.

Watch the video to see how it all started and where we are today.

If you enjoyed the video please share it with your friends and colleagues.