Edward Jones, Marketing Manager, John Evans’ Sons05.23.19
Mechanical components can have a great effect on the quality and safety of a medical device. Counterbalancing mechanisms are revolutionizing patient care, physician usability, and treatment quality, and are currently in place in a number of medical applications, including:
With many counterbalancing options, the ability to move even heavy equipment modules is greatly simplified. Optimally, nurses and other medical personnel can make instant adjustments, using a single hand, while systems remain stationary once fixed. This motor-free, simplified functionality has become the gold standard in many medical environments and is something equipment manufacturers should strive for when creating new devices of any size.
How Counterbalancing Options Have Improved Clinical Conditions
In addition to improved equipment functionality and accuracy, using spring assemblies for counterbalancing provides other effects that increase the core value of equipment in the eyes of facility administrators, doctors, and staff.
Once OEMs see the value of incorporating these automated systems into their designs, the next step is to identify the best materials to achieve the desired results. Fortunately, there are a few spring related components to choose from. The following sections highlight the advantages of each counterbalance spring option available.
Spring Reels
Spring reels, or cable retractors, consist of a cable that is wound around the exterior portion of a metal or plastic spool and kept under constant tension by an inner spring. Its primary purpose is to cause mechanical components to retract, such as doors or adjustable arms. Spring reels are especially valuable for counterbalancing equipment with significant deflection and weight. Cables can easily achieve a deflection beyond 10 feet and can assist with loads of over 50 pounds.
Present Medical Device Applications for Spring Reels
Constant Force Springs
This type of spring consists of a tightly wound coil that offers lateral movement without any inertia to deal with. This provides smooth motion and force requirements that are predictable to the smallest detail. When compared with spring reels, constant force springs provide two significant differences: size and weight. Counterbalancing 10 pounds of equipment weight, for example, may require a constant force spring only 1.16 inches in diameter. This allows OEMs far more flexibility when building unique devices.
Present Medical Device Applications for Constant Force Springs
Spiral Torsion Springs
As the name suggests, spiral torsion springs are formed as a strong spiral with coils that hold their resistance but generally do not touch. The main characteristic of this type of spring is its ability to provide rotational movement in either direction up to a maximum of approximately 360 degrees, though 270 degrees is a preferred maximum. When released, the spring returns to center. This principle is commonly used in the case of self-closing hinges, but the potential applications for medical devices are practically limitless given the range of sizes and thicknesses available.
Present Medical Device Applications for Spiral Torsion Springs
Design Factors to Consider
Creating new medical devices involves artistry in addition to the engineering calculations required. Following are a few aspects of spring composition to consider ahead of the testing phase.
Medical equipment has to meet demanding weight and performance requirements, which may go beyond governmental standards, all while functioning swiftly and easily. This means testing each point of articulation separately and selecting the best counterbalancing options for the desired motion, distance, smoothness and efficiency of travel, and return characteristics.
During the design process, the right spring supplier can make a huge difference if they offer prompt and ongoing assistance. High-quality parts are vital, but so is the company behind them. Expert suggestions and access to custom spring assemblies can shave off significant development time from the R&D schedule and provide unexpected solutions.
Edward Jones is the marketing manager of John Evans’ Sons, an international designer and manufacturer of constant force springs; constant force spring assemblies; and variable force, spiral torsion, and spring reels. Custom design, in-house tooling and precision manufacturing, combined with a wide and varied stock spring selection allows the company to serve a wide variety of applications, including medical device manufacturing.
- X-ray equipment
- Bed adjustment mechanisms
- MRIs
- Machine extensions with multi-axis functionality
- Flexible touchscreens and critical care workstations
- Robotic assisted surgical units, devices, and components
With many counterbalancing options, the ability to move even heavy equipment modules is greatly simplified. Optimally, nurses and other medical personnel can make instant adjustments, using a single hand, while systems remain stationary once fixed. This motor-free, simplified functionality has become the gold standard in many medical environments and is something equipment manufacturers should strive for when creating new devices of any size.
How Counterbalancing Options Have Improved Clinical Conditions
In addition to improved equipment functionality and accuracy, using spring assemblies for counterbalancing provides other effects that increase the core value of equipment in the eyes of facility administrators, doctors, and staff.
- Improved patient comfort: Instead of systems that require an uncomfortable level of weight to deal with, counterbalancing allows patients and patient accessories greater range of motion.
- Superior working conditions: In operating rooms, emergency areas, and other crowded locations, single-handed motion of articulated devices is very desirable to streamline operations and reduce interruptions.
- Reduced workplace hazards: Medical personnel value equipment that accounts for and minimizes the chance of repetitive strain injuries. With counterbalance systems in place, lifting and motion requires far less physical force for medical staff.
- Increased efficiency: Because counterbalancing does not require handling levers or bolts, procedures such as taking X-ray images happen as quickly as possible. This smart use of resources maximizes the amount of patient care provided by each staff member.
Once OEMs see the value of incorporating these automated systems into their designs, the next step is to identify the best materials to achieve the desired results. Fortunately, there are a few spring related components to choose from. The following sections highlight the advantages of each counterbalance spring option available.
Spring Reels
Spring reels, or cable retractors, consist of a cable that is wound around the exterior portion of a metal or plastic spool and kept under constant tension by an inner spring. Its primary purpose is to cause mechanical components to retract, such as doors or adjustable arms. Spring reels are especially valuable for counterbalancing equipment with significant deflection and weight. Cables can easily achieve a deflection beyond 10 feet and can assist with loads of over 50 pounds.
Present Medical Device Applications for Spring Reels
- Cable/Hose Management: Electrical power and signal cable, pneumatic hose, and/or tubing in and around various articulated equipment, preventing tripping hazards as well as insulation chafing, nicking, or other physical damage to cables, etc.
- Full-body X-ray machine: The heavy load of the X-ray machine needs to be responsive to precise movements by the technician, in addition to offering vertical adjustability and cable retraction functions.
- Cabinet drawer: A simple but necessary application is the automatic closure of medical equipment drawers and supply cabinets in clinical environments.
Constant Force Springs
This type of spring consists of a tightly wound coil that offers lateral movement without any inertia to deal with. This provides smooth motion and force requirements that are predictable to the smallest detail. When compared with spring reels, constant force springs provide two significant differences: size and weight. Counterbalancing 10 pounds of equipment weight, for example, may require a constant force spring only 1.16 inches in diameter. This allows OEMs far more flexibility when building unique devices.
Present Medical Device Applications for Constant Force Springs
- Any medical device requiring a nearly flat spring force gradient
- Diagnostic equipment with adjustable touch screens and displays
- Support arms for dental devices
- Articulated mounts for X-ray equipment
- Surgical light fixtures
Spiral Torsion Springs
As the name suggests, spiral torsion springs are formed as a strong spiral with coils that hold their resistance but generally do not touch. The main characteristic of this type of spring is its ability to provide rotational movement in either direction up to a maximum of approximately 360 degrees, though 270 degrees is a preferred maximum. When released, the spring returns to center. This principle is commonly used in the case of self-closing hinges, but the potential applications for medical devices are practically limitless given the range of sizes and thicknesses available.
Present Medical Device Applications for Spiral Torsion Springs
- Small wearable devices and monitors
- Dental X-ray machines
- Swivel arms
- Most devices that rely on a return-to-center function
Design Factors to Consider
Creating new medical devices involves artistry in addition to the engineering calculations required. Following are a few aspects of spring composition to consider ahead of the testing phase.
- Silent operation
- Chemical resistance
- Sterile profile
- Maintenance requirements
- Equipment safety specifications per medical institution standards
Medical equipment has to meet demanding weight and performance requirements, which may go beyond governmental standards, all while functioning swiftly and easily. This means testing each point of articulation separately and selecting the best counterbalancing options for the desired motion, distance, smoothness and efficiency of travel, and return characteristics.
During the design process, the right spring supplier can make a huge difference if they offer prompt and ongoing assistance. High-quality parts are vital, but so is the company behind them. Expert suggestions and access to custom spring assemblies can shave off significant development time from the R&D schedule and provide unexpected solutions.
Edward Jones is the marketing manager of John Evans’ Sons, an international designer and manufacturer of constant force springs; constant force spring assemblies; and variable force, spiral torsion, and spring reels. Custom design, in-house tooling and precision manufacturing, combined with a wide and varied stock spring selection allows the company to serve a wide variety of applications, including medical device manufacturing.