Evidence map›Paper›PMID 41890338›Full record

ArticleThe International journal of robotics research2025

A low-noise low-impedance powered knee prosthesis with direct ball screw drive and torque-sensitive actuation.

Brendon Ortolano, Lukas Gabert, Tommaso Lenzi

Abstract read
In one paragraph

Article in The International journal of robotics research, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Brendon OrtolanoDepartment of Mechanical Engineering, University of Utah, Salt Lake City, UT, USA.ORCID 0009-0003-2248-6734
Lukas GabertDepartment of Mechanical Engineering, University of Utah, Salt Lake City, UT, USA.ORCID 0000-0001-5569-9099
Tommaso LenziDepartment of Mechanical Engineering, University of Utah, Salt Lake City, UT, USA.ORCID 0000-0003-0957-6412

Funding

Lightweight Powered Prosthesis for Above-knee AmputeesR01HD098154 · NICHD · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · PI Tommaso Lenzi · 2019 to 2026
$3.6M
NICHD NIH HHS R01 HD098154
6 · The paper itself

Abstract

The standard of care for individuals with above-knee amputation is the microprocessor-controlled knee prosthesis-a lightweight and quiet device that can actively regulate joint resistance but cannot generate positive power like biological legs during ambulation. Powered prostheses aim to address this limitation with robotic actuators. However, limitations of conventional robotic actuators result in powered prostheses that are either heavy, loud, and have high joint impedance or lack sufficient torque and power to replicate key biomechanical functions of the biological leg. These limitations have limited the clinical success of powered knee prostheses. In this paper, we show that combining quasi-direct drive with a variable transmission in a novel torque-sensitive actuator can overcome the limitations of conventional actuators in robotic knee prostheses. Theoretical analysis shows that this combination of technologies substantially extends the range of torques and speeds of an electromechanical actuator without increasing its output impedance. Mechatronics implementation of the proposed design concept into a robotic knee prosthesis confirms the torque, speed, and output impedance improvements predicted by theoretical modeling. Amputee testing verifies that the proposed knee prosthesis can provide joint torques and speeds up to 145 Nm and 550 deg/s, enabling the user to ambulate on stairs and walk at 2.5 m/s. The prosthesis achieves lower impedance than the biological knee and approximates the weight (1.9 kg) and noise (45-53 dBA) of passive microprocessor-controlled knee prostheses. By enabling lightweight, quiet, and powerful prostheses, the proposed actuation concept has the potential to improve the quality of life in individuals with above-knee amputations.

Indexed as

actuator designmechanism designProstheticsrehabilitation roboticstorque-sensitive actuationvariable transmission

Identifiers

PMID41890338
PMCPMC13015942

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.