French-American rehabilitation technology company REEV has initiated a pivotal clinical study of DREEVEN, its intelligent robotic knee-ankle-foot orthosis designed to support mobility among stroke survivors with chronic gait impairment.
The study will assess how the powered wearable device performs during everyday functional activities, including level walking, movement across uneven surfaces, stair navigation and sit-to-stand transfers.
In addition to supervised clinical testing, participants will be monitored while using the device at home. This will allow the research team to evaluate its safety and performance in real-world conditions rather than limiting the assessment to a controlled rehabilitation environment.
Addressing persistent mobility limitations after stroke
Walking impairment is one of the most common and disabling consequences of stroke.
Many survivors experience some improvement during the early stages of rehabilitation but continue to have difficulty walking independently within their homes and communities. Persistent problems may include reduced knee control, poor foot clearance, gait asymmetry, slow walking speed and difficulty transferring from sitting to standing.
Compensatory movements such as hip hiking and circumduction may help a person advance the affected leg but can increase effort and reduce walking efficiency.
REEV is developing DREEVEN for people who continue to experience these mobility limitations after reaching the chronic stage of stroke recovery.
The company describes the device as an active alternative to passive orthotic systems that stabilise the leg but do not generate powered assistance.
Powered assistance at the knee and ankle
DREEVEN is an electro-hydraulically powered knee-ankle-foot orthosis that uses wearable sensors and control algorithms to respond to the user’s movement.
The system is designed to recognise the individual’s gait pattern and provide an appropriate level of assistance during different phases of walking and functional movement.
According to REEV, its electro-hydraulic actuator technology was adapted from the automotive sector for use within a medical wearable device.
The orthosis is intended to assist activities including:
- Walking indoors and outdoors
- Rising from a seated position
- Navigating stairs
- Moving across uneven surfaces
- Carrying out routine activities at home
- Participating more independently in the community
REEV says the system continuously adapts its support according to the user’s walking pattern rather than applying the same mechanical assistance throughout every movement.
Home monitoring included in pivotal study
A notable feature of the new study is its inclusion of home-based monitoring alongside clinical assessments.
Wearable rehabilitation devices may perform differently in a laboratory than they do in daily life, where users encounter variable flooring, furniture, fatigue, distractions and environmental obstacles.
Collecting data while participants move through their normal routines could provide a more complete understanding of whether DREEVEN supports meaningful independence outside therapy sessions.
The study will examine performance during flat and uneven walking, stair use and sit-to-stand transfers. Safety and device performance will also be assessed as participants use the orthosis within their homes.
Dr Brigid Dwyer said the combination of home monitoring and in-clinic sessions would provide investigators with a broader picture of how the device may support patients during daily activities.
Boston University leads the investigation
The principal investigator is Lou Awad, PT, DPT, PhD, director of the Neuromotor Recovery Laboratory at Boston University.
Clinical sites participating in the study include:
- Encompass Health Rehabilitation Hospital of Braintree, Massachusetts
- Whittier Rehabilitation Hospital in Bradford, Massachusetts
- Boston University’s Neuromotor Recovery Laboratory
These organisations have experience in stroke rehabilitation and the assessment of mobility technologies.
REEV said the study represents a major step towards seeking clearance from the US Food and Drug Administration and preparing DREEVEN for a commercial launch.
New B3 model designed for independent use
The study is using the latest DREEVEN B3 model.
According to the Boston University Neuromotor Recovery Laboratory, the updated version is lighter than earlier prototypes and is designed so participants can put on and remove the device independently using one hand.
Independent donning and doffing is an important consideration for stroke survivors, particularly those with weakness or reduced dexterity on one side of the body.
A mobility device may provide effective assistance while being worn, but its practical value can be limited if the user requires another person to fit or remove it.
The B3 design therefore aims to address both mobility performance and the everyday usability of the orthosis.
Early case series reported changes in gait mechanics
Before beginning the pivotal study, REEV and Boston University evaluated DREEVEN in a small early-stage case series involving five participants.
While using the device, the participants demonstrated:
- A 9.8% improvement in knee torque during walking
- An 83.1% reduction in hip hiking
- A 24.6% improvement in gait symmetry
These findings are preliminary and are based on a very small participant group. They should not be interpreted as evidence of effectiveness across the wider stroke population.
The pivotal study is intended to generate more substantial evidence about the device’s safety, functional performance and potential clinical value.
REEV SENSE supports personalised device control
DREEVEN is being developed alongside REEV SENSE, the company’s wearable gait-analysis system.
SENSE uses inertial measurement units to collect objective information about an individual’s walking pattern. The system is registered with the FDA and is already being used in rehabilitation centres in the United States, according to REEV.
Data generated by SENSE is intended to help configure DREEVEN’s motor control so the orthosis delivers a level of assistance suited to the individual patient.
This could enable the device to respond to differences in gait speed, asymmetry, knee movement and functional ability rather than using a standardised setting for every user.
A 2026 study evaluating REEV SENSE in people following stroke reported high reliability for temporal gait measurements such as step and stride times.
However, the researchers also identified reduced accuracy among people walking at very slow speeds, highlighting the continuing technical challenges of using inertial sensors in populations with highly asymmetric or impaired gait. The study included only 14 post-stroke participants after exclusions, meaning further validation in larger populations remains necessary.
Moving beyond passive stroke orthoses
Conventional ankle-foot orthoses are widely used after stroke to improve foot clearance, control ankle position and provide stability.
Knee-ankle-foot orthoses may be prescribed where the patient also has substantial knee weakness or instability.
These devices can improve safety and compensate for impaired movement, but most remain passive. They control or restrict movement without actively producing the power required to extend the knee, advance the leg or help the user rise from a chair.
DREEVEN is intended to bridge the gap between conventional orthotic bracing and larger rehabilitation exoskeletons.
By integrating powered assistance into a personalised orthosis, REEV hopes the system can be used not only during therapy but also as an everyday mobility device.
This distinction will be central to the pivotal study. The device must demonstrate that it can function safely and reliably across routine activities rather than only during structured gait training.
Orthotic fitting will remain essential
Although DREEVEN incorporates sensors, software and robotic actuation, it remains an orthotic device that must interact closely with the patient’s body.
Clinical success will therefore depend on more than the performance of its motor and control system.
Appropriate assessment and fitting must address:
- Alignment of the hip, knee and ankle
- Skin condition and pressure tolerance
- Muscle tone and joint contractures
- Residual motor control
- Balance and cognitive ability
- Ability to don and remove the device
- Compatibility with footwear
- Fatigue and energy expenditure
- The user’s home and community environment
Orthotists and rehabilitation clinicians will also need to determine which stroke survivors are most likely to benefit from powered assistance and which patients may be better served by a conventional AFO, KAFO, walking aid or other intervention.
Potential relevance across IMEA rehabilitation services
Powered orthoses could have future relevance across the Middle East, Africa and South Asia, where stroke is a major contributor to long-term adult disability.
Many rehabilitation systems in the region have limited capacity to provide prolonged, high-intensity therapy after patients leave hospital.
A wearable device that supports mobility at home could potentially extend rehabilitation beyond scheduled clinical sessions and help selected patients remain active within their communities.
However, adoption across IMEA markets would depend on several factors, including:
- Purchase and maintenance costs
- Regulatory approval
- Availability of trained orthotists and therapists
- Local technical support
- Battery and charging requirements
- Access to replacement components
- Suitability for hot and humid environments
- Reimbursement and insurance coverage
- Evidence from diverse patient populations
Wearable robotics may also need to be adapted for users who live in environments with uneven ground, limited accessibility or frequent stair use.
Evidence must extend beyond laboratory performance
The launch of a pivotal study is an important development, but DREEVEN remains an investigational device and has not yet received FDA clearance.
The forthcoming research will need to establish whether any improvements observed while wearing the orthosis translate into practical benefits for patients.
Important outcomes may include:
- Walking speed and distance
- Ability to rise from a chair
- Stair performance
- Falls and near-falls
- Energy expenditure
- Device wearing time
- Independence in daily activities
- User confidence and satisfaction
- Skin complications or discomfort
- Continued use after the study period
Researchers will also need to determine whether assistance from the device supports longer-term recovery or primarily compensates for persistent impairment while the orthosis is being worn.
REEV’s decision to include home monitoring should help address some of these questions by showing how participants use the system beyond the rehabilitation clinic.
If the study demonstrates acceptable safety and meaningful functional benefit, DREEVEN could contribute to a new category of powered orthotic devices intended for long-term community mobility after stroke.
- Original Business Wire announcement
- REEV DREEVEN
- Boston University Neuromotor Recovery Laboratory study overview
- REEV SENSE gait-analysis research
- American Stroke Association
- World Health Organization stroke information
- International Society for Prosthetics and Orthotics
- World Health Organization rehabilitation resources