FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
PATENTS RULES, 2003
COMPLETE SPECIFICATION (SECTION 10; RULE 13)
1. TITLE OF THE INVENTION: A GESTURE CONTROLLED
WHEELCHAIR
2. APPLICANT:
(a) Name: CHITALU VASH CHETAN
(b) Nationality: INDIAN
(c) Address: A/29, THE ULTRA C.H.S LTD., LT. DILIP GUPTE
MARG, MAHIM, MUMBAI-400016, MAHARASHTRA, INDIA
3. COMPLETE SPECIFICATION: THE FOLLOWING
SPECIFICATION PARTICULSRLY DESCRIBES THE NATURE OF
THE INVENTION AND THE MANNER IN WHICH IT IS TO BE
PERFORMED.

TECHNICAL FIELD:
The present invention relates to a wheelchair controlled by gestures. Particularly, the present invention relates to a wheelchair controlled by certain predefined human
hand gestures.
BACKGROUND OF THE INVENTION:
Commonly available wheelchairs are generally available in two forms - manually operated or operated using a joystick.
Manually operated wheelchairs require severe force to propel them forward. This force is required to be generated by the user by pushing the wheels of the wheelchair. If the patient is not able to push the wheelchair around with his physical force, then an attendant must be present to guide the wheelchair along using his force. This method is energy consuming and tiring for any user.
Electrically operated wheelchairs are generally controlled by a joystick, and are driven by an electric supply which is provided by a battery. This joystick controller involves a manually-engageable control lever which is mounted on the arm of the wheelchair so as to be readily accessible to the user, with the control lever being normally maintained in an upright neutral position by biasing arrangements such as springs. The control lever is then pushed forward/ backward/ leftward/ rightward to energize the drive wheels to carry out the respective forward/ backward/ leftward/

rightward driving/ movement of the wheelchair. For users who can comprehend and understand the functioning and sensitivity of the joystick, this technique is far superior to the former, but for aged users or the mentally incapable users, this kind of a wheelchair becomes bit difficult to handle. Further this type of a wheelchair can be controlled by the user only when the user is seated on it The user cannot summon the wheelchair to it (if it is situated away from the user). Thereby, this wheelchair has to be brought to the user by some attendant or the wheelchair must always be placed close to the user.
Both the aforementioned concepts are effective up to some extent, but are cumbersome to the user as they suffer from the aforesaid drawbacks.
OBJECT OF THE INVENTION:
It is the object of the present invention to improve upon the prior techniques and develop a new design of wheelchairs which overcomes the drawbacks of the existent models of wheelchairs.
SUMMARY OF THE INVENTION:
The present invention relates to a gesture controlled wheelchair comprising of (a) a wheelchair, (b) glove control means located on atleast one of the gloves placed on at least one of the arms of the wheelchair, (c) control means located on the wheelchair to drive the wheelchair, such that signals from the glove control means

are supplied to the control means on the wheelchair to drive the wheelchair; wherein the glove control means comprise of (i) at least one intra red transmitter-receiver pair located on the fingers of the glove, the aforesaid pair connected to a circuit embedded into the glove; and (ii) an accelerometer located on said glove for measuring the tilt of the hand of an user; such that the movement of the fingers of the glove defines the direction of movement of the wheelchair and the tilt of the hand defines the speed of the travel.
DESCRIPTION OF THE INVENTION:
The present invention relates to a gesture controlled wheelchair. These gestures have been specially designed to simplify the control of a wheelchair without human efforts. Using simplistic gestures such as finger directions and hand tilts, this wheelchair can be controlled in the forward as well as reverse directions. The speed of the wheelchair can also be controlled by similar gestures. Further, the gesture controlled wheelchair can be controlled in a wireless manner. Therefore, the gesture controlled wheelchair can be commandeered by the disabled user from a certain distance.
The user operating the wheelchair is required to wear two gloves, one on each hand. Each of these gloves is equipped with two infrared transmitter-receiver pairs. The gloves also consist of a tilt sensor, normally known as an accelerometer that measures Y-directional tilts of the human hand. Initially, the user must give the

wheelchair, a particular direction by pointing with either one or two fingers based upon where the user would like to go. Then keeping the finger gesture intact, the user must tilt the hand with which the gesture was made in either the forward or backward vertical direction. This will initiate motion in the wheelchair in the direction the user wants to travel. Thereby, fingers define the direction and tilt defines the speed of travel. In a preferred embodiment, the right hand is used to control all forward motion and the left hand is used to travel in a reverse direction.
Alternatively, the gestures of the human hand can be interpreted by using 'flex sensor strips', which change their resistance with the amount of flexion they undergo. Connecting these strips to the fingers and developing a circuit to monitor their resistance, we can recognize the differences in the various gestures made by the hand.
Further, the user can detach the gloves from the wheelchair, thereby enabling it to be controlled from a distance. This functionality helps the disabled to summon the wheelchair to themselves when an attendant is not present to do this task.
The present invention is intelligent enough to sense whether the user is seated on the wheelchair or not with the help of a pressure sensor. Accordingly, the speed control of the wheelchair is varied. This functionality has been added to enable the

safety of controlling the wheelchair when the user is not seated on it. Thus when the user is operating the wheelchair from far, the processor situated inside the chair understands that the user is not seated on it, and therefore travels at a slow constant rate, thereby preventing perception errors common in remote controlled crashes. Therefore, the invention is an intelligent wheelchair that understands a variety of common human gestures, and drives itself accordingly.
A preferred embodiment of the present invention will now be described with reference to the figures accompanying the provisional specification wherein:
Fig. 1 shows the block diagram of an embodiment of the present invention.
Fig. 2 shows a flowchart explaining the process in accordance with the present
invention.
Fig. 3 shows the perspective view of an embodiment of the wheelchair.
Fig. 4 shows the back view of an embodiment of the wheelchair.
Fig. 5 shows an exploded perspective view of the controller glove.
Fig. 6 shows an exploded perspective view of the controller glove for controlling
speed in forward motion.
Fig. 7 shows an exploded perspective view of the controller glove for controlling
speed in reverse motion.

Referring to the figures 1 and 2, the present invention primarily comprises of two integers/modules:
1. Wheelchair; and
2. Gloves.
The gloves modules can be operated in two ways - 'Off the dock mode* and 'On the dock mode'. These modules are being explained in detail later. However, the selection of the aforesaid modules are selected when the user sits on the wheelchair or gets up from the wheelchair. This selection is done by a pressure sensing mechanism that is embedded on the seat of the wheelchair. Accordingly, after a person sits on the wheelchair or gets up from the wheelchair, a delay is initiated for about 10 seconds during which the receiver does not listen to any data coming from the gloves. This 10 second delay is used so that the user may adjust himself/herself to the new position and then after 10 seconds, may start controlling the wheelchair by donning the gloves.
GLOVE MODULE:
The user who is seated on the wheelchair inserts his/her hand into the controller gloves (3, 8) that are docked into the wheelchair arms as shown in figures 3 to 5. The user is then capable of controlling the wheelchair using his/her finger gestures and hand tilts. These sensory movements of the hand are recorded at an extremely
high rate by the transmitter motherboard (22) situated on the glove. These values

are then transmitted at an extremely high rate to a receiver module present on the back of the wheelchair as shown in the figure 4. This receiver module decodes the signals transmitted by the gloves and transfers them to the host motherboard situated on the wheelchair base. These values are then interpreted by the host motherboard. The host mother board takes several decisions about the speed and the direction of the wheelchair based on the gestures made using the gloves.
Referring to the figure 5, each glove module (3, 8) consists of two infrared transmitter-receiver pairs implanted on the tip and base (respectively) of the index finger and the little finger. Each of these transmitter receiver pairs are connected to an embedded analog circuit. This circuit is embedded into the fabric of the glove using conductive fabric. Connections are made using conductive thread, which has a minimal resistance of 14 ohms/foot (this may vary depending on the user requirement). An accelerometer (21) is soldered similarly on the top of the glove. The accelerometer gives an exact measurement of the tilt of the hand. An analog to digital converter converts the analog voltage generated by the accelerometer to digital voltage levels. These digital connections, along with finger sensor data are transmitted to the central processing unit located on the receiver side. As a preferred embodiment, a Zigbee based transmitter is used, which is located on the glove transmits the digital tilt value as well as the finger data mat has been given to it by a microcontroller chip.

Further these gloves can be disjointed from the wheelchair, and in this case, the wheelchair can be controlled without being seated on the wheelchair. Based on whether the user is seated on the wheelchair or not, the glove modules are operated in two basic modes:
i. Off the dock mode:
In this mode, the wheelchair understands, that the gloves are not located on the wheelchair but are situated "off the dock", i.e. at an external location. In this mode, the user can control the wheelchair from any location within the maximum range of the receiver. However, in this mode the user is actually not seated on the wheelchair, the user does not have an actual perspective about how much to tilt the hand to control the speed of the wheelchair and therefore may make errors in controlling the wheelchair. Therefore, in this mode, the central processing unit automatically turns off the tilt-speed control of the wheelchair. Thus in this mode, the user can simply control the wheelchair using finger control. The wheelchair moves at a constant rate of say, 2 km/hr in this mode.
ii. On the dock mode:
This is the default mode of the wheelchair. In this mode, the wheelchair understands that the user is actually seated on the wheelchair, and thereby releases the full functionality of the wheelchair. In this mode, the user inserts both his hands into the gloves situated in the left and right docks on the wheelchair. The user can control the direction of motion by pointing a certain selective finger, and the user

can control the speed of motion by the tilt of his/her hand. The speed control has been enabled in this mode since the user has a much better perspective of the speed and direction of the wheelchair.
Use of the right glove for forward motion:
1. When the index and little finger of the right hand are pointed straight with the other three fingers clenched (provided that all the fingers of the left hand are clenched), the wheelchair will move straight-forward when the hand is tilted forwards.
2. When the little finger of the right hand is pointed straight with the other four fingers clenched (provided that all the fingers of the left hand are clenched), the wheelchair will move to the left-forward when the hand is tilted forwards.
3. When the index finger of the right hand is pointed straight with the other four fingers clenched (provided that all the fingers of the left hand are clenched), the wheelchair will move to the left-forward when the hand is tilted forward.
Use of the right glove for reverse motion:
1. When the index and little finger of the left hand are pointed straight with the other three fingers clenched (provided that all the fingers of the right hand are clenched), the wheelchair will move straight-reverse when the hand is tilted backwards.

2. When the little finger of the left hand is pointed straight with the other four fingers clenched (provided that all the fingers of the right hand are clenched), the wheelchair will move to the left-reverse when the hand is tilted backwards.
3. When the index of the left hand is pointed straight with the other four fingers clenched (provided that all the fingers of the right hand are clenched), the wheelchair will move right-reverse when the hand is tilted backwards.
Figure 6 shows the glove position to indicate speed control in a forward motion.
1. The Horizontal Position of the glove indicates that although the finger gestures indicate that the wheelchair is to be moved in forward, the tilt of the hand will cause the reverse motion to happen at a very low speed.
2. The fingers indicate the direction in which the wheelchair is to be moved. In this case, the gesture made by the fingers indicates that the wheelchair is to be moved straight forward.
3. The Horizontal line for reference.
4. The tilt of the hand is now pointing downwards indicating that the forward motion must happen at a faster rate than before.
Figure 7 shows the glove position to indicate speed control in a reverse motion.

1. The Horizontal Position of the glove indicates that although the finger gestures indicate that the wheelchair is to be moved in reverse, the tilt of the hand will cause the reverse motion to happen at a very low speed.
2. The fingers indicate the direction in which the wheelchair is to be moved. In this case, the gesture made by the fingers indicates that the wheelchair is to be moved straight backward.
3. The Horizontal line for reference.
4. The tilt of the hand is now aggravated upwards indicating that the reverse motion must happen at a faster rate than before.
THE WHEELCHAIR MODULE:
The wheelchair module consists of the wheelchair, a wireless receiver, a controlling motherboard, driver boards for the wheelchair motors and battery power for the entire system. The function of this module is to receive (by wireless means), signals from the user's gestures, interpret them in a correct and instantaneous manner, and drive the wheelchair motors accordingly.
The Wheelchair Module comprises of a wheelchair manufactured from several materials like wood, plexiglass, aluminum and HDPE (high density polyethylene). Permanent Magnet DC motors (16,17) have been used to propel the wheelchair and

caster wheels (having the total load bearing capacity of 420 lbs) have been attached to assist the motion of the wheelchair. Situated above the PMDC motors, is a central processing unit and a power station. The power station consists of two 12Volts 20 Ampere hours batteries cascaded together. Similarly, it also consists of a USB charging port that has been brought outside the wheelchair for charging purposes. The Central processing unit consists of a Host Processor, a wireless receiver unit and a motor driver unit.
The Wheelchair Module of the present invention comprises of a receiver module based on a wireless technology, preferably, the Zigbee technology. This receiver is an efficient receiver for any line of sight signals within 30 meters of periphery. The receiver accrues data transmitted by the 'Glove Module' in a wireless manner. This data is then transferred immediately to the host processor. The processor will check the incoming signal for various gestures and interpret these gestures in terms of speed and direction of motion. The host processor then performs an intelligent decision based on the vast database of selective gestures. The basic functions of the host processor are:
i. To determine whether the glove is on the wheelchair or off the wheelchair.
ii. To determine the position of the fingers.
iii. To determine the tilt of the hand wearing the glove module (depending on whether the glove is situated on or off the wheelchair).

iv. To select valid signals from the intensive database of hand and finger gestures of the user and perform the necessary responses.
v. To reject the invalid signals and relinquish control of the wheelchair motors (braking mode) in the case of occurrence of such invalid gestures.
ADVANTAGES OF THE PRESENT INVENTION:
The main advantage of the wheelchair is the ease of operation. Since humans are inherently accustomed to certain gestures, it becomes easier for a user to operate this wheelchair. It is especially essential for users suffering from chronic Alzheimer's disease, or patients who are too feeble to drive manual wheelchairs themselves or use a joystick.
Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. It should be emphasized that the above-described embodiments of the present invention, particularly any "preferred" embodiments, are merely possible examples of the invention of implementations, merely set forth for a clear understanding of the principles of the invention. Accordingly, it is to be understood that the drawings and descriptions herein are

proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

claim:
1. A gesture controlled wheelchair comprising of
a. a wheelchair,
b. glove control means located on atleast one of the gloves placed on at
least one of the arms of said wheelchair,
c. control means located on said wheelchair to drive said wheelchair,
such that signals from said glove control means are supplied to said
control means on said wheelchair to drive said wheelchair;
wherein said glove control means comprise of:
i. at least one infra red transmitter-receiver pair located on the fingers of said glove, said pair connected to a circuit embedded into said glove; and
ii. an accelerometer located on said glove for measuring the tilt of the hand of an user;
such that the movement of the fingers of said glove defines the direction of movement of said wheelchair and said tilt of said hand defines the speed of the travel.
2. A gesture controlled wheelchair as claimed in Claim 1, wherein said accelerometer measures the 'Y' directional tilts of said hand.
3. A gesture controlled wheelchair comprising of

a. a wheelchair,
b. glove control means located on atleast one of the gloves placed on at
least one of the arms of said wheelchair,
c. control means located on said wheelchair to drive said wheelchair,
such that signals from said glove control means are supplied to said
control means on said wheelchair to drive said wheelchair;
wherein said glove control means include flex sensor strips which
change the resistance with varying amount of flexion.
4. A gesture controlled wheelchair as claimed in any of the aforesaid claims, which include two gloves, wherein movement of either of one of said gloves results in the movement of said wheelchair in forward direction and movement of the other glove results in the movement of said wheelchair in a reverse direction.
5. A gesture controlled wheelchair as claimed in Claim 1 including a pressure sensor to sense whether a person is sitting on said wheelchair.
6. A gesture controlled wheelchair comprising of
a. a wheelchair,
b. glove control means located on atleast one of the gloves,
c. control means located on said wheelchair to drive said wheelchair,
such that signals from said glove control means are supplied to said
control means on said wheelchair to drive said wheelchair; and

d. a pressure sensor located on the seat of said chair to sense if a person is sitting on said wheelchair; wherein said glove control means comprise of:
i. at least one infra red transmitter receiver pair on the fingers of said glove connected to a circuit embedded into said glove; ii. an accelerometer located on said glove for measuring the tilt of the hand of an user such that
(i) if said person is sitting on said wheelchair, the movement of the fingers of said person defines the direction where said wheelchair is intended to move and said tilt of said hand defines the speed of the travel; (ii) if no person is sitting on said wheelchair, the accelerometers are deactivated and the movement of the fingers of said person defines the direction where said wheelchair is intended to move at a constant speed.
7, A gesture controlled wheelchair as herein described with reference to the drawings accompanying the specification.