Frequently Asked Questions
What is Personal Bionics?
Personal Bionics™ emulates a specific individual’s muscle and tendon function. People with amputations now have a device that actually powers movement and enhances mobility. By normalizing function, Personal Bionics helps reduce the aches and pains associated with traditional prosthetics, while also relieving stress on the joints that is typically caused by deviations in the gait.
How is Personal Bionics different from prosthetics?
Personal Bionics emulates muscle and tendon function, while traditional prosthetics only replicate bone structure. Although traditional prosthetics have enabled people to stand upright, mobility has always proven to be a greater challenge for these individuals.
What is the BiOM® Ankle System?
The BiOM System is the only commercially-available powered ankle-foot device that restores the biomechanics of ankle-foot function across all walking speeds. Utilizing a comprehensive and robust design, the BiOM System emulates biological muscle-tendons spanning the human ankle joint, and injects more mechanical energy into the amputee’s walking stride than it absorbs. Users are able to move with a natural gait at their chosen speed using the same metabolic energy as a non-amputee.
How does the BiOM Ankle System work?
The BiOM Ankle-Foot System was designed with both passive and actively powered components in order to emulate biological function throughout the gait cycle. The performance is guided by three computers and six sensors that operate biomimetic control firmware. The processors are able to adjust the ankle’s stiffness, spring equilibria, and propulsive torque 500 times a second. An increase in the sensed prosthetic ankle joint torque triggers an increase in the torque generated by the actuator, resulting in the modulation of ankle push-off power with changes in both walking velocity and ground inclination. During personal bionic tuning, the system is adjusted to ensure the walking gait of the patient dynamically emulates the walking gait of a non-amputee across the full range of walking velocities.
What are the clinical benefits of the BiOM Ankle System?
Clinical studies have shown that the BiOM System enables users to:
1. Walk with a more natural gait.
• Ankle biomechanics and step-to-step transition is the same as non-amputees [3-6].
2. Perform activities of daily living with a normal amount of metabolic energy exertion.
• The metabolic energy required is comparable to that of non-amputees [5-10].
3. Walk at a natural speed.
• Enables users to increase their self-selected walking speed an average of 23% [5-6].
4. Stand and move with a greater sense of stability and confidence.
5. Change walking speeds more easily.
• The BiOM System function across different walking speeds .
6. Helps reduce intact leg stress after heel strike to improve comfort and help reduce
long-term joint damage.
• The BiOM System decreases intact leading-leg loading rate by 14% [11-13].
7. Navigate changing surfaces, terrains, hills and stairs with greater ease and stability.
• The BiOM System is the only device [1, 5] that allows people to stand on inclines without
using hand rails.
• While walking on rocky surfaces, BiOM users increased their self-selected walking speed
by 10% compared to a conventional, passive prosthesis .
What is the customer profile for the BiOM Ankle System?
The BiOM System is clinically indicated for transtibial (BK), transfemoral (AK) or bilateral amputees weighing up to 250 pounds.
How is the BiOM Ankle System adjusted during dynamic alignment?
The BiOM Ankle System features Personal Bionic Tuning™ capabilities that adjust the gait cycle to an individual’s preference within normative human performance standards. The process is conducted using an Android application by an iWalk Certified Healthcare Professional.
What does the BiOM Ankle System include?
• BiOM Ankle System • Heel Wedges and Loctite® Kit
• (3) BiOM Batteries • User Manual
• BiOM Charger • Technical Manual
• Foot Module and Cover • Personal Bionic Tuning Device (Optional)
What is the weight of the BiOM Ankle System?
The total weight of the BiOM Ankle System with battery, foot module and foot cover is 5.3 lbs, which is equal to or less than the weight of the anatomical ankle for an individual weighing 190-250 lbs.
What is the build height of the BiOM Ankle System?
The build height to the base of the pyramid is 8 5/8”.
What is the capacity of the BiOM Battery?
The BiOM Ankle System can typically travel approximately 1,500 strides per battery depending on user speed, activity and weight. For an average user, the battery lasts 4-6 hours.
How long does it take to charge a battery?
A BiOM Battery typically fully charges in 1.5 hours after normal usage depletion.
Can the BiOM be used in various environmental conditions?
The BiOM Ankle System and Charger should only be used in the environment conditions specified in the User and Technical Manuals. The BiOM System is not water resistant or waterproof. Limit water exposure to light rain or small puddles. Keep the BiOM System dry and protected from water whenever possible.
What does the warranty cover?
The iWalk limited warranty covers any material defects in the BiOM Ankle System, BiOM Batteries and BiOM Charger for twenty-four (24) months from the original date of purchase.
Is the BiOM Ankle System covered by reimbursement policies?
The BiOM Ankle System is being reimbursed by a number of payer organizations, including the U.S. Department of Defense and the U.S. Department of Veterans Affairs, numerous workers’ compensation programs, as well as a growing list of private insurance policies. Please consult with iWalk for additional reimbursement support.
iWalk, Inc. is the pioneer and leader in personal bionic innovation. With the introduction of BiOM technology, the company enhances mobility and extends potential for people with lower limb loss. In the future, the same underlying technology will also help people whose mobility is limited by stroke, diabetes or other conditions of disease or age.
The company was founded in 2006 by Dr. Hugh Herr, director of the Biomechatronics Group at the MIT Media Lab. Privately held and headquartered in Bedford, Mass, the company has received funding and support from the U.S. Department of Veterans Affairs, the U.S. Army’s Telemedicine and Advanced Technology Research Center (TATRC) and leading venture firms WFD Ventures, General Catalyst Partners, Sigma Partners and Gilde Healthcare Partners.
and Parallel Motor Elasticity. Special Issue of the IEEE Robotics & Automation Society IEEE
Magazine on Adaptable Compliance for Robotic Applications. September 2008; 52-59.
2. D. Gates, J. Aldridge, J. Wilken. “Comparison of powered and unpowered prostheses in
patients with transtibial amputation walking on a rock surface. Department of Orthopaedics
and Rehabilitation, Center for the Intrepid, Brooke Army Medical Center, Ft. Sam Houston, TX,
3. A. Grabowski, S. D’Andrea, H. Herr. “Bionic leg prosthesis emulates biological ankle joint during
walking,” Amer. Society of Biomechanics, 2011.
4. S. Au, J. Weber, E. Martinez-Villapando, H. Herr. “Powered Ankle-Foot Prosthesis for the
Improvement of Amputee Ambulation,” IEEE Engineering in Medicine and Biology International
Conference. Lyon, France, pp. 3020-3026, 2007.
5. Au S., Weber J., Herr H. Powered Ankle-foot Prosthesis Improves Walking Metabolic Economy.
IEEE Transactions on Robotics. 2009; 25 (1): 51-66.
6. H. Herr, A. Grabowski. “Bionic ankle–foot prosthesis normalizes walking gait for persons with leg
amputation,” Proceeding of the Royal society B, 2011.
7. H. Herr, A. Grabowski “Powered ankle-foot prosthesis improves metabolic demand of unilateral
transtibial amputees during walking,” Amer. Society of Biomechanics, 2010.
8. C. Mancinelli, B. Patritti, P. Tropea, R. Greenwald, R. Casler, H. Herr, P. Bonato. “Comparing a
passive-elastic and a powered prosthesis in transtibial amputees,” 33rd Annual International
Conference of the IEEE EMBS, Boston, Massachusetts USA, August 30 - September 3, 2011.
9. A Grabowski & H Herr “Bionic leg prosthesis normalizes the metabolic cost of walking,” Rocky
Mountain Regional Amer. Society of Biomechanics, 2011.
10. C. Mancinelli, B. Patritti, U. Croce, P. Bonato “Metabolic and Biomechanical Characteristics of Gait
in Transtibial Amputees using a Powered vs. a Passive-Elastic Prosthesis,” American Journal of
Physical Medicine and Rehabilitation, (In press) 2013.
11. D. Hill, H. Herr. “Effects of a Powered Ankle Prosthesis on Impact Force and Pressure Distribution
of the Contralateral Limb,” Journal of Rehabilitation Research and Development. (In press) 2013.
12. A. Linberg, J. Shim, E. Wolf. “Use of a Powered Ankle Prosthesis to Decrease Work and Loading of
the Intact Limb in Individuals with Transfemoral Limb Loss,” American Orthotic & Prosthetic
Association (AOPA), Boston 2012.
13. A. Linberg, B. Ritland, B. Hendershot, E. Wolf. “Reduction in Predictors of Secondary Injuries in
Service Members With Unilateral Transfemoral Limb Loss using a Powered Ankle-Foot Prosthesis,
"Journal of Rehabilitation Research and Development. (In press) 2013.
14. D. Morgenroth, M. Orendurff, A. Shakir, A. Segal, J. Shofer, J. Czerniecki. “The Relationship Between
Lumbar Spine Kinematics during Gait and Low-Back Pain in Transfemoral Amputees,” American
Journal of Physical Medicine & Rehabilitation, pp. 635-643, 2010.
15. D. Morgenroth, A. Segal, K. Zelik, J. Czerniecki, G. Klute, P. Adamczyk, M. Orendurff, M. Hahn, S.
Collins, A. Kuo. “The effect of prosthetic foot push-off on mechanical loading associated with knee
osteoarthritis in lower extremity amputees,” Gait & Posture, 34, 502–507, 2011.
16. D. Morgenroth, G. A. Gellhorn, P. Suri. “Osteoarthritis in the Disabled Population: A Mechanical
Perspective,” The American Academy of Physical Medicine and Rehabilitation, Vol. 4, S20-S27, 2012.
BiOM, the BiOM logo, Personal Bionics and Personal Bionic Tuning are trademarks of iWalk, Inc. All other brands
may be trademarks of their respective holders.