IP Library › Granted Patent US 12,447,076
Granted Patent B2
US 12,447,076 · App. 18/506,706 · Granted Oct 21, 2025

Motion-based power assist system for wheelchairs

Inventor: W. Mark Richter (Nashville, TN)
A61G5/04A61G5/045A61G5/047A61G5/048A61G2203/12A61G2203/30A61G2203/36
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Quick Facts
Patent No.
US 12,447,076
App. No.
18/506,706
Granted
Oct 21, 2025
Kind
B2
Abstract

A motion-based push activation power assist system for manual wheelchairs. The system uses motion-based measurements to determine when the user applies a push to the wheelchair handrims and brakes with the handrims. The push recognition activates a drive system that provides an assistive driving force-pulse to the wheelchair to reduce the demand on the user during propulsion. The brake recognition deactivates the power assist. The provided power assist is proportional to the sensed push and can be modulated to different proportional settings.

Claims (37)

1. A power assist system for a wheelchair, comprising:

a drive system including:

a drive linkage that includes an electric drive wheel; and

a mounting assembly connected to the drive linkage,

wherein the mounting assembly is configured to removably attach to a bar connected to the wheelchair, the bar being located between two drive wheels of the wheelchair, the bar being oriented parallel to an axis of rotation of the drive wheels, and

wherein in response to the mounting assembly being attached to the bar, the drive linkage is configured to pivot relative to the bar, the drive linkage extends downward from the mounting assembly so that the drive wheel makes contact with the ground at a position behind the mounting assembly.

2. The power assist system of claim 1 , wherein the electric drive wheel is an electric hub drive wheel.

3. The power assist system of claim 1 , wherein the mounting assembly is configured to attach to the bar between the two drive wheels of the wheelchair.

4. The power assist system of claim 1 , wherein the mounting assembly includes at least one mounting attachment member configured to connect to the bar.

5. The power assist system of claim 1 , further comprising a remote control that is configured to control the motor power of the electric drive wheel.

6. The power assist system of claim 5 , wherein the remote control is configured to removably attach to the wheelchair.

7. The power assist system of claim 5 , wherein the remote control can be clipped to the wheelchair.

8. The power assist system of claim 1 , wherein the drive system is mounted to a wheelchair such that the electric hub drive wheel contacts the ground midway between the wheelchair drive wheels.

9. The power assist system of claim 1 , wherein the bar is an axle of the wheelchair.

10. The power assist system of claim 1 , wherein the mounting assembly is configured to attach to the bar at a location generally midway between the two drive wheels.

11. The power assist system of claim 1 , wherein the linkage contains a battery pack and a printed circuit board.

12. A power assist system for a wheelchair comprising:

a drive system including:

a drive linkage;

an electric drive wheel operably connected to the drive linkage; and

a mounting assembly connected to the drive linkage,

wherein the mounting assembly is configured to removably attach to a bar connected to the wheelchair, the bar being located between a first drive wheel and a second drive wheel of the wheelchair, the bar being oriented parallel to an axis of rotation of the first drive wheel, and the mounting assembly is attached on the bar between the first drive wheel and the second drive wheel,

wherein in response to the mounting assembly being attached to the bar, the drive linkage extends downward from the mounting assembly so that the drive wheel makes contact with the ground at a position behind the mounting assembly.

13. The power assist system of claim 12 , wherein in response to the mounting assembly being attached to the bar, the drive linkage is configured to pivot relative to the bar.

14. The power assist system of claim 12 , wherein the bar is an axle of the wheelchair.

15. The power assist system of claim 12 , wherein the linkage contains a battery pack.

16. The power assist system of claim 12 , wherein the bar is extending between opposing side members of the wheelchair.

17. The power assist system of claim 12 , further comprising a remote control that is configured to control the motor power of the electric drive wheel, the remote control is configured to removably attach to the wheelchair.

18. The power assist system of claim 12 , wherein the mounting assembly is configured to attach to the bar at a position generally midway between the first drive wheel and the second drive wheel.

19. A power assist system for a wheelchair comprising:

a drive system including:

a drive linkage;

an electric hub drive wheel operably connected to the drive linkage; and

a mounting assembly connected to the drive linkage,

wherein the mounting assembly is configured to removably attach to a bar connected to the wheelchair, the bar being connected to the wheelchair by a plurality of connections, the bar located between a first drive wheel and a second drive wheel of the wheelchair, the bar being oriented parallel to an axis of rotation of at least the first drive wheel, and

wherein in response to the mounting assembly being attached to the bar, the drive linkage is configured to pivot relative to the bar, the drive linkage extends downward from the mounting assembly so that the drive wheel makes contact with the ground at a position behind the mounting assembly.

20. The power assist system of claim 19 , wherein the mounting assembly is configured to removably attach to the bar at a position generally midway between the two drive wheels.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 13, 2023
From: RICHTER, W. MARK
To: MAX MOBILITY, LLC
Reel/Frame 065539/0191 →
Continuity (5)
Continuation 17342104 · Jun 8, 2021
Continuation 15218937 · Jul 25, 2016
Continuation 13543598 · Jul 6, 2012
Provisional Application 61504949 · Jul 6, 2011
Related Publication 20240074924A1 · Mar 7, 2024
References Cited (204)
US 2448992A · Love et al. · 1948 [cited by applicant]
US 2495573A · Duke · 1950 [cited by examiner]
US 3905437A · Kaiho · 1975 [cited by examiner]
US 4207959A · Youdin et al. · 1980 [cited by applicant]
US 4260035A · Loveless et al. · 1981 [cited by applicant]
US 4386672A · Coker · 1983 [cited by examiner]
US 4422515A · Loveless · 1983 [cited by applicant]
US 4652026A · Byrge · 1987 [cited by applicant]
US 4728812A · Sheriff et al. · 1988 [cited by applicant]
US 4759418A · Goldenfeld · 1988 [cited by examiner]
US 4767940A · Tuttle · 1988 [cited by applicant]
US 4770431A · Kulik · 1988 [cited by applicant]
US 4823900A · Farnam · 1989 [cited by applicant]
US 4926952A · Farnam · 1990 [cited by applicant]
US 5016720A · Coker · 1991 [cited by examiner]
US 5113959A · Mastov · 1992 [cited by examiner]
US 5135063A · Kropf · 1992 [cited by examiner]
US 5222567A · Broadhead · 1993 [cited by examiner]
US 5234066A · Ahsing · 1993 [cited by examiner]
US 5244051A · Wu · 1993 [cited by examiner]
US 5351774A · Okamoto · 1994 [cited by examiner]
US 5366037A · Richey · 1994 [cited by examiner]
US 5494126A · Meeker · 1996 [cited by examiner]
US 5555949A · Stallard · 1996 [cited by examiner]
US 5651422A · Casali · 1997 [cited by examiner]
US 5818189A · Uchiyama · 1998 [cited by examiner]
US 5826670A · Nan · 1998 [cited by examiner]
US 5878829A · Kanno · 1999 [cited by examiner]
US 5927414A · Kan · 1999 [cited by examiner]
US 6059060A · Kanno · 2000 [cited by examiner]
US 6112837A · Kanno · 2000 [cited by examiner]
US 6230831B1 · Ogata · 2001 [cited by examiner]
US 6290014B1 · MacCready, Jr. · 2001 [cited by examiner]
US 6302226B1 · Kanno · 2001 [cited by examiner]
US 6334497B2 · Odell · 2002 [cited by applicant]
US 6354390B1 · Uchiyama · 2002 [cited by examiner]
US 6360836B1 · Milano, Jr. · 2002 [cited by examiner]
US 6416063B1 · Stillinger et al. · 2002 [cited by applicant]
US 6459962B2 · Ulrich · 2002 [cited by examiner]
US 6481514B2 · Takada · 2002 [cited by examiner]
US 6571892B2 · Kamen et al. · 2003 [cited by applicant]
US 6702051B2 · Chu · 2004 [cited by examiner]
US 6729421B1 · Gluck · 2004 [cited by examiner]
US 6729422B2 · Chu · 2004 [cited by examiner]
US 6807465B2 · Ulrich · 2004 [cited by examiner]
US 6842692B2 · Fehr et al. · 2005 [cited by applicant]
US 6860347B2 · Sinclair · 2005 [cited by examiner]
US 6880661B1 · Oh · 2005 [cited by examiner]
US 7138774B2 · Negoro et al. · 2006 [cited by applicant]
US 7264272B2 · Mulhern et al. · 2007 [cited by applicant]
US 7311160B2 · Lim · 2007 [cited by applicant]
US 7383107B2 · Fehr et al. · 2008 [cited by applicant]
US 7383904B2 · Wu · 2008 [cited by examiner]
US 7404465B2 · Hsieh · 2008 [cited by applicant]
US 7425007B2 · Johannes de Kruijf · 2008 [cited by applicant]
US 7426970B2 · Olsen · 2008 [cited by applicant]
US 7566102B2 · Guile · 2009 [cited by applicant]
US 7581604B2 · Torita · 2009 [cited by applicant]
US 7648156B2 · Johanson · 2010 [cited by applicant]
US 7670263B2 · Ellis et al. · 2010 [cited by applicant]
US 7770674B2 · Miles · 2010 [cited by examiner]
US 7832515B2 · Barthelt · 2010 [cited by examiner]
US 7837210B2 · Kylstra et al. · 2010 [cited by applicant]
US 7886854B2 · Chiu · 2011 [cited by examiner]
US 7976049B2 · Chiu · 2011 [cited by applicant]
US 8038165B2 · Wang · 2011 [cited by applicant]
US 8127875B2 · Mattes et al. · 2012 [cited by applicant]
US 8181992B2 · Mulhern et al. · 2012 [cited by applicant]
US 8186463B2 · Hunziker et al. · 2012 [cited by applicant]
US 8261867B1 · Gainer · 2012 [cited by examiner]
US 8292010B2 · Puskar-Pasewicz et al. · 2012 [cited by applicant]
US 8292678B2 · Burgess, Jr. · 2012 [cited by applicant]
US 8306673B1 · Manning · 2012 [cited by applicant]
US 8413749B2 · Hsu · 2013 [cited by examiner]
US 8430189B2 · Tallino · 2013 [cited by examiner]
US 8556279B2 · McKinnon · 2013 [cited by applicant]
US 8602138B2 · Filkoski · 2013 [cited by examiner]
US 8652009B2 · Ellis et al. · 2014 [cited by applicant]
US 8758191B2 · Takenaka et al. · 2014 [cited by applicant]
US 9144525B2 · Richter · 2015 [cited by examiner]
US 9398990B2 · Richter · 2016 [cited by examiner]
US 9615982B2 · Richter · 2017 [cited by examiner]
US 9795524B2 · Richter · 2017 [cited by examiner]
US 9796401B1 · Ammirati · 2017 [cited by examiner]
US 10167051B1 · Richter · 2019 [cited by examiner]
US 10265228B2 · Richter · 2019 [cited by examiner]
US 10322043B2 · Richter · 2019 [cited by examiner]
US 11576830B2 · Menig · 2023 [cited by examiner]
US 11642256B2 · Menig · 2023 [cited by examiner]
US 12178765B2 · Paltsev · 2024 [cited by examiner]
US 20010022244A1 · Takada · 2001 [cited by examiner]
US 20020019686A1 · Nathan et al. · 2002 [cited by applicant]
US 20020036105A1 · Birmanns et al. · 2002 [cited by applicant]
US 20020171559A1 · Yang · 2002 [cited by applicant]
US 20030089537A1 · Sinclair · 2003 [cited by examiner]
US 20030127261A1 · Borroni-Bird · 2003 [cited by examiner]
US 20030226698A1 · Kamen et al. · 2003 [cited by applicant]
US 20040251649A1 · Wu · 2004 [cited by applicant]
US 20050000742A1 · Mulhern · 2005 [cited by applicant]
US 20050077694A1 · Levi · 2005 [cited by applicant]
US 20050137652A1 · Cauller · 2005 [cited by applicant]
US 20050236208A1 · Runkles · 2005 [cited by applicant]
US 20060244249A1 · Goertzen · 2006 [cited by applicant]
US 20060255581A1 · Goertzen · 2006 [cited by applicant]
US 20070020985A1 · Naitou · 2007 [cited by applicant]
US 20070039766A1 · Jackson · 2007 [cited by applicant]
US 20070095580A1 · Liao · 2007 [cited by applicant]
US 20070095582A1 · Stuijt · 2007 [cited by applicant]
US 20070131730A1 · Mirzale · 2007 [cited by applicant]
US 20070145711A1 · Mulhren · 2007 [cited by applicant]
US 20070152427A1 · Olsen · 2007 [cited by applicant]
US 20070235234A1 · De Kruijf · 2007 [cited by applicant]
US 20070261897A1 · Torita · 2007 [cited by applicant]
US 20070283966A1 · Maples · 2007 [cited by applicant]
US 20080054596A1 · Johanson · 2008 [cited by applicant]
US 20080061627A1 · Spector · 2008 [cited by applicant]
US 20080066974A1 · Pearlman · 2008 [cited by examiner]
US 20080115982A1 · Lin · 2008 [cited by examiner]
US 20080115987A1 · Barthelt · 2008 [cited by examiner]
US 20080300777A1 · Fehr · 2008 [cited by applicant]
US 20090050381A1 · Cheng · 2009 [cited by applicant]
US 20090194974A1 · Smith · 2009 [cited by applicant]
US 20100022908A1 · Cauller · 2010 [cited by applicant]
US 20100036543A1 · Bitzer · 2010 [cited by applicant]
US 20100300777A1 · Tallino · 2010 [cited by applicant]
US 20100301576A1 · Dugas · 2010 [cited by applicant]
US 20110199393A1 · Nurse et al. · 2011 [cited by applicant]
US 20110214929A1 · Filkoski · 2011 [cited by examiner]
US 20110304121A1 · Chiu · 2011 [cited by examiner]
US 20120012416A1 · Mirzaie · 2012 [cited by applicant]
US 20120068435A1 · Birmanns · 2012 [cited by applicant]
US 20120080243A1 · Mulhern · 2012 [cited by examiner]
US 20120138376A1 · Zhou · 2012 [cited by applicant]
US 20120143400A1 · Minkel, III · 2012 [cited by applicant]
US 20120144554A1 · Thellmann · 2012 [cited by applicant]
US 20120217081A1 · Mulhern · 2012 [cited by applicant]
US 20120217713A1 · Mulnar · 2012 [cited by applicant]
US 20130008732A1 · Richter · 2013 [cited by examiner]
US 20130080015A1 · Strothmann · 2013 [cited by applicant]
US 20130205501A1 · Robertson et al. · 2013 [cited by applicant]
US 20130218380A1 · Phillips · 2013 [cited by applicant]
US 20130240271A1 · Tallino · 2013 [cited by examiner]
US 20130253769A1 · Kamo · 2013 [cited by applicant]
US 20140058582A1 · Jaenke · 2014 [cited by applicant]
US 20140262575A1 · Richter · 2014 [cited by examiner]
US 20150298765A1 · Golden, Jr. · 2015 [cited by applicant]
US 20150357948A1 · Goldstein · 2015 [cited by applicant]
US 20160242977A1 · Richter · 2016 [cited by examiner]
US 20170027785A1 · Richter · 2017 [cited by applicant]
US 20170347885A1 · Tan et al. · 2017 [cited by applicant]
US 20200085651A1 · Menig · 2020 [cited by examiner]
US 20210139098A1 · Carrasco Vergara · 2021 [cited by examiner]
US 20210338500A1 · Richter · 2021 [cited by examiner]
US 20230072204A1 · Iacono · 2023 [cited by examiner]
US 20230190546A1 · Emfinger · 2023 [cited by examiner]
US 20230190547A1 · Emfinger · 2023 [cited by examiner]
US 20230190548A1 · Emfinger · 2023 [cited by examiner]
US 20240261161A1 · Togashi · 2024 [cited by examiner]
DE 300247C · 1917 [cited by applicant]
DE 4323937C1 · 1993 [cited by applicant]
DE 19539487A1 · 1997 [cited by applicant]
DE 19748201C1 · 1999 [cited by applicant]
DE 19857786A1 · 1999 [cited by applicant]
DE 29907846U1 · 1999 [cited by applicant]
DE 19848530C1 · 2000 [cited by applicant]
DE 10046963C1 · 2001 [cited by applicant]
DE 102007004704A1 · 2008 [cited by applicant]
EP 1854443A2 · 2007 [cited by applicant]
EP 3260101A1 · 2017 [cited by applicant]
EP 3260101B1 · 2021 [cited by applicant]
GB 2223994A · 1990 [cited by applicant]
GB 2274265A · 1994 [cited by applicant]
GB 2393162A · 2004 [cited by applicant]
JP 06304205A · 1994 [cited by applicant]
JP 09285501A · 1997 [cited by applicant]
JP 2000084007A · 2000 [cited by applicant]
JP 2003052760A · 2003 [cited by applicant]
JP H10314234A · 2003 [cited by applicant]
JP 2006081849A · 2006 [cited by applicant]
JP 2009078044A · 2009 [cited by applicant]
KR 20150089860A · 2015 [cited by applicant]
WO 2005082083A2 · 2005 [cited by applicant]
WO 2013006818A2 · 2013 [cited by applicant]
Int'l Search Report and Written Opinion for PCT/US2018/064935, mailed Mar. 1, 2019 (15 pages). [cited by applicant]
Lutin. Smart Drive Power Assist Wheel DEMO. YouTube. Oct. 23, 2012. Retrieved from internet: <URL:http://www.youtube.com/watch?v=3RbaFns4iXQ>. [cited by applicant]
Sunrise Medical, WheelDrive manual, MD_WheelDrive_EU_DE_RevA_2016_11_17, 12 pages. [cited by applicant]
Sunrise Medical GmbH, GER, Model: Krypton, product sheet for EU Market, 2 pages. [cited by applicant]
Max Mobility, Installation guide for adapter axis, 2 pages. [cited by applicant]
E-Move, Decon product brochure, 10 pages. [cited by applicant]
Alber GmbH, Twion Brochure, 12 pages. [cited by applicant]
Alber GmbH, e-motion brochure, 8 pages. [cited by applicant]
Alber GmbH, e-fix, 8 pages. [cited by applicant]
DPX Systems Drill Powered Wheelchair, https://www.youtube.com/watch?v=eG9q6iHF_bl, 2007, retrieved on Jun. 3, 2021. [cited by applicant]
Sunrise Medical, WheelDrive, Brochure, 8 pages. [cited by applicant]
European Patent Office, Extended European Search Report, Application No. 17162833.2-1651, Dated: Oct. 27, 2017, 6 pages. [cited by applicant]
European Patent Office, Extended European Search Report, Application No. 12807785.6-1651, Dated: Jun. 10, 2015, 5 pages. [cited by applicant]
International Preliminary Report on Patentability , PCT/US2012/045816, Mailed Jan. 7, 2014, 6 pages. [cited by applicant]
Brian D. Mayton, WristQue: A Personal Sensor Wristband for Smart Infrastructure and Control, submitted to the Program in Media Arts and Sciences, School of Architecture and Planning on Oct. 9, 2012, 72 pages. [cited by applicant]
Daniel Petersson, Jonas Johanssen, Ulf Holmberg and Bjorn Astrand, Torque Sensor Free Power Assisted Wheelchair, Proceedings of the 2007 IEEE 10th International Conference on Rehabilitation Robotics, Jun. 12-15, Noordwi… [cited by applicant]
Jonas Johanssen, Daniel Petersson, Torque Sensor Free Power Assisted Wheelchair, Master's Thesis in Electrical Engineering, School of Information Science, Computer and Electrical Engineering, Halmstad University, Techni… [cited by applicant]
Sehoon Oh, Yoichi Hori, Sensor Free Power Assisting Control Based on Velocity Control and Disturbance Observer, IEEE ISIE 2005, Jun. 20-23, 2005, Dubrovnik, Croatia, 6 pages. [cited by applicant]
Takashi Miyazawa, Seiichirou Katsura, Kouhei Ohnishi, A Power-Assisted Wheelchair Taking Running Environment Into Account, Copyright 2003 IEEE, 6 pages. [cited by applicant]
Rick N. Robertson, PhD, Michael L. Boninger, MD, Rory A. Cooper, PhD, Sean D. Shimada, MS, Pushrim Forces and Joint Kinetics During Wheelchair Propulsion, Arch Phys Med Rehabil vol. 77, Sep. 1996, 9 pages. [cited by applicant]
European Patent Office, Extended European Search Report, Application No. 12807785.6-1651, Dated: Jun. 10, 2015, 10 pages. [cited by applicant]