Pharmaceutical Controls with Zero Contamination Transfer
How important are intuitive, durable and clean controls for equipment used in your business?
As a practical matter, controls that require operators to actually touch them, wearing gloves or not, can never be really clean, however many protocols or chemicals are employed. Besides, tactile controls with moving parts can fail from use or abuse, leading to expensive replacement and production downtime. And operators who spend shifts pushing buttons or using keypads or keyboards are susceptible to carpal tunnel syndrome or other work-related maladies.
This article explores simple and inexpensive ways to have touchless controls that are cost-effective and reliable, easy to use and tough but free of contamination transfer. Using the most effective technology for controls not only underlines commitment to the newest and best practices but also saves money from equipment repair and replacement, reduces production downtime and limits liability for damages related to contamination transfer and operator repetitive stress claims.
The Initial Spark
A simple test captured our interest. In a busy dentist’s office, where sanitation is supposedly an obsession, a tiny amount of radioactive trace was placed on the handle of the light fixture that shines in your eyes while the hygienist is cleaning your teeth or during the dentist’s more complicated work. Protocol requires that handle to be carefully covered with a sticky plastic tab intended to insure newly gloved hands of the operator remain clean even while periodically adjusting that fixture and to preclude transfer of whatever resides there. Before the arrival of each new patient, office procedure dictates new gloves for each hygienist and dentist, a new paper tray to hold instruments newly cleaned or delivered in sealed bags, a new plastic tab to cover the light fixture’s handle, etc. The office also frequently uses the ubiquitous squirt bottles of disinfectant on counters and surfaces, before and after each patient procedure.
Fast forward: a Geiger counter later reveals trace radiation on the receptionist’s telephone, in file cabinets, in the bathroom, in multiple locations in examination and treatment rooms and even on door handles of patients’ cars outside.
Another time, I was discussing our touchless, holographic HoloTouch® HMI technology with the manager of a soup production plant. Their transfer valves are opened and closed by touching icons on a touch screen. He admitted that occasionally someone operates a touch screen with a screwdriver, destroying the unit and causing expensive repairs and downtime.
What can we learn from these examples about controls which supposedly meet the industry’s demanding standards? Despite best intentions and procedures, busy or inattentive staff cannot insure that tactile control surfaces remain free of contamination transfer. These same limitations apply to the wide variety of tactile controls used in pharmaceutical manufacturing - it’s an inevitable problem with tactile controls, whether keys of keyboards, buttons or more complicated human-machine interfaces that they can never be dependably or reliably cleaned or be free from contamination transfer. Because people must touch them. And carelessness or error can damage or destroy moving parts of tactile controls.
What are viable alternatives to tactile controls and other traditional HMis? Touchless gesture recognition, voice recognition and holographic HMis.
Gesture recognition uses predetermined motions, intuitive to some, tracked by one or more cameras connected to electronics to provide input to them. Common examples range from video games to retail applications for interacting with displays in stores to view different products or order them. Refining this technology to reliably operate specific equipment and comfortably enter data may require detailed programming, adjustment of recognized gestures to suit operational parameters and training operators to use gestures understood by the equipment to complete intended tasks.
Voice recognition employs spoken commands to control electronics. Current common uses include vehicle systems that allow drivers to say a destination and be shown directions on a nearby screen or dictating to a handheld to create a draft e-mail. Anecdotal evidence suggests voice recognition systems can respond differently to voices of different people or even the same people who are very tired or have colds. In addition, ambient sounds such as loud or intermittent machinery noises can interfere with the effectiveness of voice recognition, not to even mention commands spoken by people using different languages or using any language poorly. An important consideration in applying this technology to industrial equipment is that it is insensitive to context; for example, if basic commands such as “on” or “off’ as related to starting or stopping equipment are included in voice recognition vocabulary, someone in range’s saying “move that pallet off the platform” may have unintended results.
More Examples of Touchless Technology
Another touchless way to deliver commands to CNCs or other controls of manufacturing equipment involves merely passing a finger through holographic images of what would otherwise be keys or buttons of those devices, floating freely in the air at a convenient location. This alternative is easily accomplished through tailoring widely patented touchless, holographic HoloTouch® HMI technology to the specific look, feel and function of mission critical electronics. Using this innovative technology, operators control electronics without actually touching any physical surface, an important advantage in areas where control of contamination transfer and durability are paramount. One application of HoloTouch technology, a single-function switch designed to fit into a standard wall box, was successfully tested for more than three (3) years for convenience, durability and freedom from contamination transfer at Yale-New Haven Hospital (an affiliate of Yale University); it replaced tactile “paddle” switches (icon of a wheelchair people hit or punch to open doors) which, in that area, last only six-eight weeks before use incapacitates them.
Human-machine interfaces using HoloTouch technology have only three principal components, contained inside a sealed enclosure:
• a surface relief transmission hologram (akin to what appears on your driver’s license) bearing images of control surfaces selected by the designer;
• a light positioned behind the hologram, causing its reproduced image to float in the air in front of the hologram, coplanar with it; and
• an infrared sensor behind the hologram, focused on the plane of its reproduced image to detect the passage of a finger through particular images and transmit desired commands to connected devices.
Scalable and Customizable
HoloTouch technology is infinitely scalable, whether embodied in a single-function HMI or multi-input controls with the same capabilities as keyboards, keypads or touch screens, dependent only upon how the designer wants the final product to look, feel and function.
HMis using HoloTouch technology are designed around the chosen size, shape and artistic composition of its hologram, selected while recording the hologram. Characteristics such as angle of view of the reproduced image across the horizontal axis and how far in front of the hologram its reproduced image appears to float all provide the operator with bright, easy to understand images, facilitating intuitive and simple operation of connected electronics.
Operator interaction with reproduced holographic images is captured by one simple infrared sensor with a fixed “sweet” spot, in the case of a single-function device, or, in multi-input devices, an infrared sensor which rapidly scans an X-Y plane in the air, coincident with the reproduced holographic image. The latter provides for a wide variety of multiple-input HMis, akin to keyboards and keypads, but without touching any physical surface. All varieties of infrared sensors can be positioned behind the hologram, keeping all parts outside of the reach of operators.
As electronic devices become increasingly sophisticated yet inexpensive, achieving cleanliness and durability objectives with touchless controls of manufacturing equipment is becoming even easier and more cost-effective.